House (TV series)

House (also called House, M.D.) is an American medical drama television series that originally ran on the Fox network for eight seasons, from November 16, 2004, to May 21, 2012. The series' main character is Dr. Gregory House (Hugh Laurie), an unconventional, misanthropic medical genius who, despite his dependence on pain medication, leads a team of diagnosticians at the fictional Princeton–Plainsboro Teaching Hospital (PPTH) in New Jersey. The series' premise originated with Paul Attanasio, while David Shore, who is credited as creator, was primarily responsible for the conception of the title character.

The series' executive producers included Shore, Attanasio, Attanasio's business partner Katie Jacobs, and film director Bryan Singer. It was filmed largely in a neighborhood and business district in Los Angeles County's Westside called Century City. The show received high critical acclaim, and was consistently one of the highest rated series in the United States.

House often clashes with his fellow physicians, including his own diagnostic team, because many of his hypotheses about patients' illnesses are based on subtle or controversial insights. His flouting of hospital rules and procedures frequently leads him into conflict with his boss, hospital administrator and Dean of Medicine Dr. Lisa Cuddy (Lisa Edelstein). House's only true friend is Dr. James Wilson (Robert Sean Leonard), head of the Department of Oncology.

During the first three seasons, House's diagnostic team consists of Dr. Robert Chase (Jesse Spencer), Dr. Allison Cameron (Jennifer Morrison) and Dr. Eric Foreman (Omar Epps). At the end of the third season, this team disbands. Rejoined by Foreman, House gradually selects three new team members: Dr. Remy "Thirteen" Hadley (Olivia Wilde), Dr. Chris Taub (Peter Jacobson) and Dr. Lawrence Kutner (Kal Penn). Chase and Cameron continue to appear occasionally in different roles at the hospital. Kutner dies late in season five; early in season six, Cameron departs the hospital, and Chase returns to the diagnostic team. Thirteen takes a leave of absence for most of season seven, and her position is filled by medical student Martha M. Masters (Amber Tamblyn). Cuddy and Masters depart before season eight; Foreman becomes the new Dean of Medicine, while Dr. Jessica Adams (Odette Annable) and Dr. Chi Park (Charlyne Yi) join House's team.

House was among the top 10 series in the United States from its second season through the fourth season. Distributed to 66 countries, House was the most-watched television program in the world in 2008. The show received numerous awards, including five Primetime Emmy Awards, two Golden Globe Awards, a Peabody Award, and nine People's Choice Awards. On February 8, 2012, Fox announced that the eighth season, then in progress, would be its last. The series finale aired on May 21, 2012, following an hour-long retrospective.

## Production

### Conception

In 2004, David Shore and Paul Attanasio, along with Attanasio's business partner Katie Jacobs, pitched the series (untitled at the time) to Fox as a CSI-style medical detective program, a hospital whodunit in which the doctors investigated symptoms and their causes. Attanasio was inspired to develop a medical procedural drama by The New York Times Magazine column "Diagnosis", written by physician Lisa Sanders, who is an attending physician at Yale–New Haven Hospital (YNHH); the fictitious Princeton–Plainsboro Teaching Hospital (PPTH, not to be confused with the University Medical Center of Princeton at Plainsboro) is modeled after this teaching institution. Fox bought the series, though the network's then-president, Gail Berman, told the creative team, "I want a medical show, but I don't want to see white coats going down the hallway". Jacobs has said that this stipulation was one of the many influences that led to the show's ultimate form.

After Fox picked up the show, it acquired the working title Chasing Zebras, Circling the Drain ("zebra" is medical slang for an unusual or obscure diagnosis, while "circling the drain" refers to terminal cases, patients in an irreversible decline). The original premise of the show was of a team of doctors working together trying to "diagnose the undiagnosable". Shore felt it was important to have an interesting central character, one who could examine patients' personal characteristics and diagnose their ailments by figuring out their secrets and lies. As Shore and the rest of the creative team explored the character's possibilities, the program concept became less of procedure and more focused upon the lead role. The character was named "House", which was adopted as the show's title, as well. Shore developed the characters further and wrote the script for the pilot episode. Bryan Singer, who directed the pilot episode and had a major role in casting the primary roles, has said that the "title of the pilot was 'Everybody Lies', and that's the premise of the show". Shore has said that the central storylines of several early episodes were based on the work of Berton Roueché, a staff writer for The New Yorker between 1944 and 1994, who specialized in features about unusual medical cases.

Shore traced the concept for the title character to his experience as a patient at a teaching hospital. He recalled: "I knew, as soon as I left the room, they would be mocking me relentlessly [for my cluelessness] and I thought that it would be interesting to see a character who actually did that before they left the room." A central part of the show's premise was that the main character would be disabled in some way. The original idea was for House to use a wheelchair, but Fox rejected this. Jacobs later expressed her gratitude for the network's insistence that the character be reimagined—putting him on his feet added a crucial physical dimension. The writers ultimately chose to give House a damaged leg arising from an incorrect diagnosis, which requires him to use a cane and causes him pain that leads to a narcotic dependency.

#### References to Sherlock Holmes

References to fictional detective Sherlock Holmes appear throughout the series. Shore explained that he was always a Holmes fan and found the character's indifference to his clients unique. The resemblance is evident in House's reliance on inductive reasoning and psychology, even where it might not seem obviously applicable, and his reluctance to accept cases he finds uninteresting. House's investigatory method is to eliminate diagnoses logically as they are proved impossible; Holmes uses a similar method. Both characters play instruments (House plays the piano, the guitar, and the harmonica; Holmes, the violin) and take drugs (House is dependent on Vicodin; Holmes uses cocaine recreationally). House's relationship with Dr. James Wilson echoes that between Holmes and his confidant, Dr. John Watson. Robert Sean Leonard, who portrays Wilson, said that House and his character were originally intended to work together much as Holmes and Watson do; in his view, House's diagnostic team has assumed that aspect of the Watson role. Shore said that House's name itself is meant as "a subtle homage" to Holmes. House's address is 221B Baker Street, a direct reference to Holmes's street address. Wilson's address is also 221B.

Individual episodes of the series contain additional references to the Sherlock Holmes tales. The main patient in the pilot episode is named Rebecca Adler after Irene Adler, a character in the first Holmes short story, "A Scandal in Bohemia". In the season two finale, House is shot by a crazed gunman credited as "Moriarty", the name of Holmes's nemesis. In the season four episode "It's a Wonderful Lie", House receives a "second-edition Conan Doyle" as a Christmas gift. In the season five episode "The Itch", House is seen picking up his keys and Vicodin from the top of a copy of Conan Doyle's The Memoirs of Sherlock Holmes. In another season five episode, "Joy to the World", House, in an attempt to fool his team, uses a book by Joseph Bell, Conan Doyle's inspiration for Sherlock Holmes. The volume had been given to him the previous Christmas by Wilson, who included the message "Greg, made me think of you." Before acknowledging that he gave the book to House, Wilson tells two of the team members that its source was a patient, Irene Adler. Season 7 episode 3 includes a young adult boyhood detective book series written by the patient, whose final unpublished volume ends in an ambiguous end to the main character reminiscent of "The Final Problem". The series finale also pays homage to Holmes's apparent death in "The Final Problem", the 1893 story with which Conan Doyle originally intended to conclude the Holmes chronicles.

### Production team

House was a co-production of Heel and Toe Films, Shore Z Productions, and Bad Hat Harry Productions in association with Universal Network Television for Fox. Paul Attanasio and Katie Jacobs, the heads of Heel and Toe Films; David Shore, the head of Shore Z Productions; and Bryan Singer, the head of Bad Hat Harry Productions, were executive producers of the program for its entirety. Lawrence Kaplow, Peter Blake, and Thomas L. Moran joined the staff as writers at the beginning of the first season after the making of the pilot episode. Writers Doris Egan, Sara Hess, Russel Friend, and Garrett Lerner joined the team at the start of season two. Friend and Lerner, who are business partners, had been offered positions when the series launched, but turned the opportunity down. After observing the show's success, they accepted when Jacobs offered them jobs again the following year. Writers Eli Attie and Sean Whitesell joined the show at the start of season four; Attie would stay on the show's writing staff through the series finale, which he co-wrote. From the beginning of season four, Moran, Friend, and Lerner were credited as executive producers on the series, joining Attanasio, Jacobs, Shore, and Singer. Hugh Laurie was credited as an executive producer for the second and third episodes of season five.

Shore was House's showrunner. Through the end of the sixth season, more than two dozen writers had contributed to the program. The most prolific were Kaplow (18 episodes), Blake (17), Shore (16), Friend (16), Lerner (16), Moran (14), and Egan (13). The show's most prolific directors through its first six seasons were Deran Sarafian (22 episodes), who was not involved in season six, and Greg Yaitanes (17). Of the more than three dozen other directors who have worked on the series, only David Straiton directed as many as 10 episodes through the sixth season. Hugh Laurie directed the 17th episode of season six, "Lockdown". Elan Soltes was the visual effects supervisor since the show began. Lisa Sanders, an assistant clinical professor of medicine at the Yale School of Medicine, was a technical advisor to the series. She writes the "Diagnosis" column that inspired House's premise. According to Shore, "[T]hree different doctors ... check everything we do". Bobbin Bergstrom, a registered nurse, was the program's on-set medical adviser.

### Casting

At first, the producers were looking for a "quintessentially American person" to play the role of House. Bryan Singer in particular felt there was no way he was going to hire a non-American actor for the role. At the time of the casting session, actor Hugh Laurie was in Namibia filming the movie Flight of the Phoenix. He assembled an audition tape in a hotel bathroom, the only place with enough light, and apologized for its appearance (which Singer compared to a "bin Laden video"). Laurie improvised, using an umbrella for a cane. Singer was very impressed by his performance and commented on how well the "American actor" was able to grasp the character. Singer was not aware that Laurie was English, due to his American accent. Laurie credits the accent to "a misspent youth [watching] too much TV and too many movies". Although locally better-known actors such as Denis Leary, David Cross, Rob Morrow, and Patrick Dempsey were considered for the part, Shore, Jacobs, and Attanasio were as impressed as Singer and cast Laurie as House.

Laurie later revealed that he initially thought the show's central character was Dr. James Wilson. He assumed that House was a supporting part, due to the nature of the character, until he received the full script of the pilot episode. Laurie, the son of medical doctor Ran Laurie, said he felt guilty for "being paid more to become a fake version of [his] own father". From the start of season three, he was being paid \$275,000 to \$300,000 per episode, as much as three times what he had previously been making on the series. Laurie was earning around \$400,000 per episode by the fifth season, and \$700,000 per episode for the final season, making him one of the highest-paid actors on network television.

Robert Sean Leonard had received the script for the CBS show Numb3rs as well as that for House. Leonard thought the Numb3rs script was "kind of cool" and planned to audition for the show. However, he decided that the character he was up for, Charlie Eppes, was in too many scenes; he later observed, "The less I work, the happier I am". He believed that his House audition was not particularly good, but that his lengthy friendship with Singer helped win him the part of Dr. Wilson. Singer had enjoyed Lisa Edelstein's portrayal of a prostitute on The West Wing, and sent her a copy of the pilot script. Edelstein was attracted to the quality of the writing and her character's "snappy dialogue" with House, and was cast as Dr. Lisa Cuddy.

Australian actor Jesse Spencer's agent suggested that he audition for the role of Dr. Robert Chase. Spencer believed the program would be similar in style to General Hospital but changed his mind after reading the scripts. After he was cast, he persuaded the producers to turn the character into an Australian. Patrick Dempsey also auditioned for the part of Chase; he later became known for his portrayal of Dr. Derek Shepherd on Grey's Anatomy. Omar Epps, who plays Dr. Eric Foreman, was inspired by his earlier portrayal of a troubled intern on the NBC medical drama ER; his character was given the name "Eric Foreman" despite the fact that Fox was still airing That 70's Show when House premiered and had the similarly named Eric Forman as that series' main protagonist. (The two series overlapped on Fox's schedule for two seasons, though Topher Grace left That 70's Show at the end of its 7th season and House's first, only returning for that show's series finale.) Jennifer Morrison felt that her audition for the part of Dr. Allison Cameron was a complete disaster. However, before her audition, Singer had watched some of her performances, including on Dawson's Creek, and already wanted to cast her in the role. Morrison left the show when her character was written out in the middle of season six.

At the end of season three, House dismisses Chase, while Foreman and Cameron resign. After an episode in which he "borrows" a janitor whom he calls "Dr. Buffer" to assist in a diagnosis, House must then recruit a new diagnostic team, for which he identifies seven finalists. The producers originally planned to recruit two new full-time actors, with Foreman, who returns in season four's fifth episode, bringing the team back up to three members; ultimately, the decision was made to add three new regular cast members. (Along with Epps, actors Morrison and Spencer remained in the cast, as their characters moved on to new assignments.) During production, the show's writers dismissed a single candidate per episode; as a result, said Jacobs, neither the producers nor the cast knew who was going to be hired until the last minute. In the season's ninth episode, House's new team is revealed: Foreman is joined by doctors Lawrence Kutner (Kal Penn), Chris Taub (Peter Jacobson), and Remy "Thirteen" Hadley (Olivia Wilde). The candidates rejected by House did not return to the show, with the exception of the last one cut: Amber "Cutthroat Bitch" Volakis (Anne Dudek), who appeared for the rest of season four as Wilson's girlfriend, and in seasons five and eight as a hallucination of House's. While Penn and Wilde had higher profiles than the actors who played the other finalists, Jacobs said they went through an identical audition process and stayed with the show based on the writers' interest in their characters. Kutner was written out of the series in episode 20 of season 5 after Penn took a position in the Obama White House Office of Public Engagement and Intergovernmental Affairs.

The contracts of Edelstein, Epps, and Leonard expired at the end of season seven. As a cost-cutting measure, the three actors were asked to accept reduced salaries. Epps and Leonard came to terms with the producers, but Edelstein did not, and in May 2011, it was announced that she would not be returning for the show's eighth season.

### Filming style and locations

House is often filmed using the "walk and talk" filming technique, popularized on television by series such as St. Elsewhere, ER, Sports Night, and The West Wing. The technique involves the use of tracking shots, showing two or more characters walking between locations while talking. Executive producer Katie Jacobs said that the show frequently uses the technique because "when you put a scene on the move, it's a ... way of creating an urgency and an intensity". She noted the significance of "the fact that Hugh Laurie spans 6'2" and is taller than everybody else because it certainly makes those walk-and-talks pop". Nancy Franklin of The New Yorker described the show's "cool, Fantastic Voyage–like special effects of patients' innards. I'll bet you didn't know that when your kidneys shut down they sound like bubble wrap popping." "Cameras and special effects travel not only down the throat" of one patient, another critic observed, "but up her nose and inside her brain and leg". Instead of relying primarily on computer-generated imagery, the interior body shots tend to involve miniature effects and motion control photography. Many of the sets are dressed with a variety of unscripted props that allow Laurie to physically improvise, revealing aspects of his character and the story.

The pilot episode was filmed in Vancouver; primary photography for all subsequent episodes took place on the Fox lot in Century City, Los Angeles. Bryan Singer chose the hospital near his hometown, West Windsor, New Jersey, as the show's fictional setting. Princeton University's Frist Campus Center is the source of the aerial views of Princeton–Plainsboro Teaching Hospital seen in the series. Some filming took place at the University of Southern California for the season-three episode "Half-Wit", which guest-starred Dave Matthews and Kurtwood Smith. Part of House's sixth season was filmed at the abandoned Greystone Park Psychiatric Hospital, in Parsippany-Troy Hills, New Jersey, as the fictional Mayfield Psychiatric Hospital.

### Opening sequence

The opening sequence begins with an MRI of a head with an image of the boxed "H" from the logo (the international symbol for hospital) in the foreground. This is then overlaid with an image of Dr. House's face taken from the pilot episode with the show's full title appearing across his face. House's head then fades and the show's title is underlined and has the "M.D." appear next to it, producing the entire logo of the show. This was the full extent of the title sequence in the pilot episode. All subsequent episodes contain a longer sequence including the names of the six featured cast members and creator David Shore. Laurie's name appears first, followed by the names of the five other featured cast members in alphabetical order (Edelstein, Epps, Leonard, Morrison, and Spencer), then Shore.

After the show's title fades, an aerial view of PPTH (actually various Princeton University buildings, primarily Frist Campus Center) is followed by a series of images accompanying each member's name; most are shown next to, or superimposed upon, illustrations of human anatomy. Laurie's name appears next to a model of a human head with the brain exposed; Edelstein's name appears next to a visual effects–produced graphic of an angiogram of the heart. Epps's name is superimposed upon a rib cage X-ray; Leonard's name appears on a drawing of the two hemispheres of the brain. The producers originally wanted to include an image of a cane and an image of a Vicodin bottle, but Fox objected. Morrison's title card was thus lacking an image; an aerial shot of rowers on Princeton University's Lake Carnegie was finally agreed upon to accompany her name. Spencer's name appears next to an old-fashioned anatomical drawing of a spine. Between the presentations of Spencer and Shore's names is a scene of House and his three original team members walking down one of the hospital's hallways. Jacobs said that most of the backgrounds have no specific meaning; however, the final image—the text "created by David Shore" superimposed upon a human neck—connotes that Shore is "the brain of the show". The sequence was nominated for a Primetime Emmy Award for Outstanding Main Title Design in 2005. The title sequence continued to credit Spencer and Morrison, even when their characters were reduced to background roles during seasons four and five, and Morrison even after hers was written out. A new opening sequence was introduced in season seven to accommodate the changes in the cast, removing Morrison's name and including Jacobson's and Wilde's. It was updated in season eight, removing Edelstein's and Wilde's names and adding Annable's and Yi's.

The series' original opening theme, as heard in the United States, comprises instrumental portions of "Teardrop" by Massive Attack. The piece was used in part because of the distinct tempo which roughly mimics the sound of a beating human heart. An acoustic version of "Teardrop", with guitar and vocals by José González, is heard as background music during the season-four finale.

## Series overview

Gregory House, M.D., often construed as a misanthropic medical genius, heads a team of diagnosticians at the Princeton–Plainsboro Teaching Hospital in New Jersey. The series is structured around a central plot with some supporting secondary stories and narratives that cross over seasons. Most episodes revolve around the diagnosis of a primary patient and start with a cold open set outside the hospital, showing events ending with the onset of the patient's symptoms. The typical episode follows the team in their attempts to diagnose and treat the patient's illness, which often fail until the patient's condition is critical. They usually treat only patients whom other doctors have not accurately diagnosed, and House routinely rejects cases he does not find interesting.

Typically, the patient is misdiagnosed at least once which usually causes further complications, but the nature of the complications often provides new evidence which helps them diagnose the patient correctly. House often tends to arrive at the correct diagnosis seemingly out of the blue, often inspired by a passing remark made by another character. Diagnoses range from relatively common to very rare diseases.

The team faces many diagnostic difficulties from patients' concealment of symptoms, circumstances, or personal histories, so House frequently proclaims during the team's deliberations, "The patient is lying", or mutters "Everybody lies"; such an assumption guides House's decisions and diagnoses and makes the countermeasure of housebreaking a routine procedure. Because many of his hypotheses are based on epiphanies or controversial insights, he often has trouble obtaining permission for medical procedures he considers necessary from his superior, who in all but the final season is hospital administrator Dr. Lisa Cuddy. This is especially the case when the proposed procedures involve a high degree of risk or are ethically questionable. Frequent disagreements occur between House and his team, especially Dr. Allison Cameron, whose standards of medical ethics are more conservative than those of the other characters.

Like all of the hospital's doctors, House is required to treat patients in the facility's walk-in clinic. His grudging fulfillment of this duty, or his creative methods of avoiding it, constitute a recurring subplot, which often serves as the series' comic relief. During clinic duty, House confounds patients with unwelcome observations into their personal lives, eccentric prescriptions, and unorthodox treatments. However, after seeming to be inattentive to their complaints, he regularly impresses them with rapid and accurate diagnoses. Analogies with some of the simple cases in the clinic occasionally inspire insights that help solve the team's case.

A significant plot element is House's use of Vicodin to manage pain, caused by an infarction in the quadriceps muscle of his right leg five years before the show's first season, which also forces him to use a cane. In the first-season 11th episode "Detox", House admits he is addicted to Vicodin but says he does not have a problem because the pills "let me do my job, and they take away my pain". His addiction has led his colleagues Cuddy and Dr. James Wilson to encourage him to go to drug rehabilitation several times. When he has no access to Vicodin or experiences unusually intense pain, he occasionally self-medicates with other narcotic analgesics such as morphine, oxycodone, and methadone. House also frequently drinks liquor when he is not on medical duty and classifies himself as a "big drinker". Toward the end of season five, House begins to hallucinate; after eliminating other possible diagnoses, Wilson and he determine that his Vicodin addiction is the most likely cause. House goes into denial about this for a brief time, but at the close of the season finale, he commits himself to Mayfield Psychiatric Hospital. In the following season's debut episode, House leaves Mayfield with his addiction under control. However, about a year and a half later, in season seven's 15th episode, "Bombshells", House reacts to the news that Cuddy possibly has kidney cancer by taking Vicodin, and he returns to his addiction.

## Cast and characters

### Main characters

Throughout House's run, six of the main actors have received star billing. All of them play doctors who work at the fictional Princeton–Plainsboro Teaching Hospital in New Jersey. Dr. Gregory House (Hugh Laurie), the title character, was educated at Johns Hopkins University and heads the Department of Diagnostic Medicine. House describes himself as "a board-certified diagnostician with a double specialty of infectious disease and nephrology". Dr. James Wilson (Robert Sean Leonard), House's one true friend, is the head of the Department of Oncology. Dr. Lisa Cuddy (Lisa Edelstein), an endocrinologist, is House's boss, as she is the hospital's dean of medicine and chief administrator. House has a complex relationship with Cuddy, and their interactions often involve a high degree of innuendo and sexual tension. In the sixth episode of season five, "Joy", they kiss for the first time. Their physical relationship does not progress any further during the fifth season; in the season- five finale, House believes he and Cuddy had sex, but this is a hallucination brought on by House's Vicodin addiction. In the finale of season six, Cuddy tells House she loves him. They kiss and agree to try being a couple. Throughout season seven, House and Cuddy try to make their relationship work, but Cuddy eventually breaks it off because of House's addiction. House struggles to deal with this and, in the season-seven finale, drives his car into Cuddy's living room in anger. As Lisa Edelstein left the show before season eight, after this incident Cuddy leaves the hospital and House never sees her again.

House's original team of diagnosticians consists of Dr. Eric Foreman (Omar Epps), a neurologist; Dr. Robert Chase (Jesse Spencer), an intensivist; and Dr. Allison Cameron (Jennifer Morrison), an immunologist. In the season-three episode "Family", Foreman announces his resignation, telling House, "I don't want to turn into you". During the season finale, House tells Chase that he has either learned everything he can, or nothing at all, and dismisses him from the team. Cameron, who has developed an affection for Chase, soon resigns. This leaves House without a team for the season-four premiere.

Under orders from Cuddy to recruit a new team, House considers 40 doctors. Season four's early episodes focus on his selection process, structured as a reality TV–style elimination contest (Jacobs referred to it as a "version of Survivor"). House assigns each applicant a number between one and 40, and pares them down to seven finalists. He assesses their performance in diagnostic cases, assisted by Foreman, who returns to the department after his dismissal from another hospital for House-like behavior. While Foreman's return means only two slots are open, House tricks Cuddy into allowing him to hire three new assistants. He ultimately selects Dr. Chris Taub (Peter Jacobson), a former plastic surgeon; Dr. Lawrence Kutner (Kal Penn), a sports medicine specialist; and Dr. Remy "Thirteen" Hadley (Olivia Wilde), an internist (nicknamed for her number in the elimination contest). In the season finale, Thirteen discovers she has, as she had long dreaded, inherited Huntington's disease, which is incurable, from her mother.

In the 11th episode of season five, "Joy to the World", Foreman and Thirteen engage in a passionate kiss. Thirteen is at first reluctant to start a relationship with Foreman, but the two eventually begin dating and are still together at the end of the season. They break up early in season six. In the 20th episode of season five, "Simple Explanation", Kutner is found dead in his apartment with a gunshot wound to the head. Because Kutner left no note, House suspects foul play, though the death is accepted by the other characters as a suicide.

In the seventh episode of season two, "Hunting", Cameron and Chase have a one-night stand. In the middle of season three, they initiate a sexual relationship that Cameron insists be casual; when Chase declares that he "wants more", Cameron ends the affair. By the end of the season, however, Cameron recognizes that she has romantic feelings for Chase and they begin a serious relationship. After leaving the diagnostic team, they assume different roles at the PPTH, Cameron as a senior attending physician in the emergency room and Chase as a surgeon. They become engaged in the season-five episode "Saviors" (the episode immediately following Kutner's suicide) and are married in the season finale. When Chase rejoins House's team in season six, Cameron leaves her husband and the hospital in "Teamwork", the season's eighth episode. She returns as a guest character in "Lockdown", nine episodes later.

Early in season seven, Thirteen takes an unexplained leave of absence. Cuddy orders House to fill her position with another woman, but eventually makes the choice for him: medical student Dr. Martha M. Masters (Amber Tamblyn), who makes her first appearance in the season's sixth episode. Thirteen returns in "The Dig"—the season's 18th episode and the show's 150th—in which the reason for her absence is revealed: she was in prison for six months for having helped euthanize her brother, who was suffering from advanced Huntington's. While Jacobson and Wilde play central characters (as did Penn), they did not receive star billing until season seven. They were credited as "Also Starring", with their names appearing after the opening sequence. In season seven, Jacobson and Wilde received star billing; new regular cast member Tamblyn did not.

### Recurring characters

The first six seasons of House each included one or more recurring featured characters, who appear in multiple-episode story arcs. In season one, Edward Vogler (Chi McBride), the billionaire owner of a pharmaceutical company, appears in five episodes. He donates \$100 million to the PPTH in return for chairing its board. Vogler represented an attempt to introduce a villain, a move urged by Fox. By the time the Vogler episodes began to air, the show had become a hit and the character was soon dropped. Shore said the concept of a villainous boss was not really viable for the series: "It's called House. The audience knows he'll never get fired."

Stacy Warner (Sela Ward), House's ex-girlfriend, appears in the final two episodes of the first season, and seven episodes of season two. She wants House to treat her husband, Mark Warner (Currie Graham), whom House diagnoses with acute intermittent porphyria in the season-one finale. Stacy and House grow close again, but House eventually tells Stacy to go back to Mark, which devastates her.

Michael Tritter (David Morse), a police detective, appears in several season-three episodes. He tries to extract an apology from House, who left Tritter in an examination room with a thermometer in his rectum. After House refuses to apologize, Tritter brings him up on charges of unprescribed narcotics possession and forces him to attend rehabilitation. When the case reaches court, Cuddy perjures herself for House and the case is dismissed. The judge reprimands Tritter for pursuing House to excess, and tells House that she thinks he "has better friends than he deserves", referring to Cuddy's 11th-hour testimony on his behalf. House is sentenced to one night in jail for contempt of court and finishes his rehabilitation under the influence of Vicodin.

The candidates for House's new diagnostics team are season four's primary recurring characters. In addition to the three who are chosen, the other four finalists are Jeffrey Cole (Edi Gathegi), a medical geneticist; Travis Brennan (Andy Comeau), an epidemiologist; Henry Dobson (Carmen Argenziano), a former medical school admissions officer; and Amber Volakis (Anne Dudek), an interventional radiologist. Each of the four departs the show after elimination, except for Volakis, who appears throughout the season, having started a relationship with Wilson. In the two-part season finale, Volakis attempts to shepherd a drunken House home when Wilson is unavailable. They are involved in a bus crash, which leads to her death. She reappears late in season five and again in the series finale as hallucinations by House.

Private investigator Lucas Douglas (Michael Weston), a character inspired in part by Shore's love of The Rockford Files, appears in three episodes of season five. House initially hires Douglas to spy on Wilson, who has ended their friendship after Volakis's death (the friendship is subsequently rekindled). House later pays Douglas to look into the private lives of his team members and Cuddy. If the character had been accepted by the audience, plans existed to feature him as the lead in a spin-off show. In September 2008, Shore spoke to Entertainment Weekly about his vision for the character: "I don't want to do just another medical show. What does excite me in terms of writing is the choices people make and the nature of right and wrong... and a private investigator can approach that question much more readily than a doctor can." There was no show featuring Douglas on the fall 2009 network television schedule. He returns to House in season six as Cuddy's boyfriend. They are briefly engaged until Cuddy breaks it off, realizing that she is in love with House.

## Episodes

## Reception

### Critical reception

House received largely positive reviews on its debut; the series was considered a bright spot amid Fox's schedule, which at the time was largely filled with reality shows. Season one holds a Metacritic score of 75 out of 100, based on 30 reviews, indicating "generally favorable" reviews. Matt Roush of TV Guide said that the program was an "uncommon cure for the common medical drama". New York Daily News critic David Bianculli applauded the "high caliber of acting and script". The Onion's "A.V. Club" approvingly described it as the "nastiest" black comedy from FOX since 1996's short-lived Profit. New York's John Leonard called the series "medical TV at its most satisfying and basic", while The Boston Globe's Matthew Gilbert appreciated that the show did not attempt to hide the flaws of the characters to assuage viewers' fears about "HMO factories". Variety's Brian Lowry, less impressed, wrote that the show relied on "by-the-numbers storytelling, albeit in a glossy package". Tim Goodman of the San Francisco Chronicle described it as "mediocre" and unoriginal. Mikhail Varshavski, a Russian-American Osteopathic Doctor, reviewed the medical content of House on his YouTube channel. According to Varshavski, the medical information presented on the show was usually fundamentally accurate though often highly exaggerated for dramatic effect, but he described Gregory House's tendency to quickly use invasive tests and procedures as outside the medical mainstream.

General critical reaction to the character of Gregory House was particularly positive. Tom Shales of The Washington Post called him "the most electrifying new main character to hit television in years". The Pittsburgh Post-Gazette's Rob Owen found him "fascinatingly unsympathetic". Critics have compared House to fictional detectives Nero Wolfe, Hercule Poirot, and Adrian Monk, and to Perry Cox, a cantankerous doctor on the television show Scrubs. One book-length study of the series finds a powerful kinship between House and another famous TV doctor, Hawkeye Pierce of M\*A\*S\*H. Laurie's performance in the role has been widely praised. The San Francisco Chronicle's Goodman called him "a wonder to behold" and "about the only reason to watch House".

Critics have also reacted positively to the show's original supporting cast, which the Post's Shales called a "first-rate ensemble". Leonard's portrayal of Dr. Wilson has been considered Emmy Award worthy by critics with TV Guide, Entertainment Weekly, and USA Today. Bianculli of the Daily News was happy to see Edelstein "was finally given a deservedly meaty co-starring role". Freelance critic Daniel Fienberg was disappointed that Leonard and Edelstein have not received more recognition for their performances.

Reaction to the major shifts of season four was mixed. "With the new crew in place House takes on a slightly more energized feel", wrote Todd Douglass Jr. of DVD Talk. "And the set up [sic] for the fifth season is quite brilliant." The Star-Ledger's Alan Sepinwall wrote, "The extended, enormous job audition gave the writers a chance to reinvigorate the show and fully embrace Laurie's comic genius". Mary McNamara of the Los Angeles Times, on the other hand, took issue with the developments: "the cast just kept getting bigger, the stories more scattered and uneven until you had a bunch of great actors forced to stand around watching Hugh Laurie hold the show together by the sheer force of his will". USA Today's Robert Bianco cheered the season finale: "Talk about saving the best for last. With two fabulous, heartbreaking hours ... the writers rescued a season that had seemed diffuse, overcrowded and perhaps too ambitious for its own good."

Season five of House was met with a more positive response in comparison to the previous season. It holds a Metacritic score of 77 out of 100, based on ten reviews, indicating "generally favorable reviews". It also holds a 100% approval rating on aggregate review website Rotten Tomatoes, with an average score of 8.1 based on nine collected reviews. USA Today praised Laurie's performance and the repercussions of the season-four finale, stating "a carry-over from last season's brilliant finale, House is firmly in the forefront. And when you have an actor of Hugh Laurie's range, depth and charisma, putting him center-stage makes perfect sense, particularly when you've written a story that explores the character and his primary relationships in a way that seems integral to the series". The New York Daily News noted that "The show pays more attention to relationships we care about, hints at a sensible number of new ones that show some promise, and thus doesn't rely on obscure medical mysteries to carry the whole dramatic burden", and noted that "the prognosis for this season could be better than last season seemed to foreshadow". Mary McNamara of the Los Angeles Times highlighted the performances of the cast, especially Michael Weston as detective Lucas Douglas, calling him a "delightful addition". She concluded, "So different is the premiere that the savvy House (and Fox) viewer may expect the revelation that it was all a fever dream. That does not seem to be the case, and one assumes that Laurie and the writers will be bringing a different version of their now-iconic character back to Princeton. Not too different, of course, but different enough." Conversely, The Chicago Tribune's Maureen Ryan disliked Weston's character, calling him "An unwelcome distraction ... an irritating pipsqueak". She continued saying "House used to be one of the best shows on TV, but it's gone seriously off the rails". The Sunday Times felt that the show had "lost its sense of humour". The focus on Thirteen and her eventual involvement with Foreman also came under particular criticism.

At the end of the show's run, Steven Tong of Entertainment Weekly wrote that "House had, in its final seasons, become a rather sentimental show". In New York Magazine'''s blog 'Vulture', Margaret Lyons wrote, "More than a hospital drama or a character piece or anything else, House is a complex meditation on misery." But, continued Lyons, there is a line between "enlightened cynicism" and "misery-entropy", and "as the show wore on, its dramatic flare dimmed while its agony flare burned ever brighter." Alan Sepinwall wrote, "The repetition and muck of [the] middle seasons ultimately severed whatever emotional connection I had to House's personal struggles."

In 2007, House placed \#62 on Entertainment Weekly's "New TV Classics" list. The show was declared the second-highest-rated show for the first ten years of IMDb.com Pro (2002–2012). The show was ranked the 74th best-written television series in a 2013 survey of Writers Guild of America West members.

#### Critics' top ten lists

After its first five seasons, House was included in various critics' top-ten lists; these are listed below in order of rank.

### U.S. television ratings

In its first season, House ranked twenty-fourth among all television series and was the ninth-most popular primetime program among women. Aided by a lead-in from the widely popular American Idol, the following three seasons of the program each ranked in the top ten among all viewers. House reached its peak Nielsen ratings in its third season, attracting an average of 19.4 million viewers per episode. According to Jacobs, the production team was surprised that the show garnered such a large audience. In its fifth season, the show attracted 12.0 million viewers per episode and slipped to nineteenth place overall. It remained Fox's most popular show other than American Idol.

The most-watched episode of House is the season four episode "Frozen", which aired after Super Bowl XLII. It attracted slightly more than 29 million viewers. House ranked third for the week, equaling the rating of American Idol and being surpassed only by the Super Bowl itself and the post-game show. Below is a table of House's seasonal rankings in the U.S. television market, based on average total viewers per episode. Each U.S. network television season starts in September and ends in late May, which coincides with the completion of May sweeps.

### Awards and honors

House has received many awards and award nominations. In 2005, 2007, 2008, 2009, 2010 and 2011 Laurie was nominated for an Emmy Award for Outstanding Lead Actor in a Drama Series. The Emmy board also nominated House for Outstanding Drama Series in 2006, 2007, 2008, and 2009, but the show never won the award. For the season one episode "Three Stories", David Shore won a writing Emmy in 2005 and the Humanitas Prize in 2006. Director Greg Yaitanes received the 2008 Primetime Emmy Award for Outstanding Directing for a Drama Series, for directing "House's Head", the first part of season four's two-episode finale.

The show has been nominated for six Golden Globe Awards and received two. Hugh Laurie has been nominated six times for the Golden Globe Award for Best Actor – Television Series Drama; he won in 2006 and again in 2007. In 2008 the series received its first nomination for the Golden Globe Award for Best Television Series – Drama. House was nominated for best dramatic series again the following year, but did not win in the category.

The show received a 2005 Peabody Award for what the Peabody board called an "unorthodox lead character—a misanthropic diagnostician" and for "cases fit for a medical Sherlock Holmes", which helped make House "the most distinctive new doctor drama in a decade". The American Film Institute (AFI) included House in its 2005 list of 10 Television Programs of the Year.

In 2011, House won four People's Choice Awards: favorite TV drama; favorite dramatic actor and actress for Laurie and Edelstein; and favorite TV doctor.

Laurie won the Screen Actors Guild's award for Outstanding Performance by a Male Actor in a Drama Series in both 2007 and 2009. Writer Lawrence Kaplow won a Writers Guild of America Award in 2006 for the season two episode "Autopsy". In 2007, the show won a Creative Arts Emmy Award for prosthetic makeup.

In 2005, Laurie appeared on the cover of TV Guide as "TV's Sexiest Man". In 2008, Gregory House was voted second-sexiest television doctor ever, behind ER's Doug Ross (George Clooney).

## Distribution

In 2008, House was distributed in a total of 66 countries. With an audience of over 81.8 million worldwide, it was the most-watched television show on the globe and far surpassed the viewership figures of the leading TV dramas the previous two years (CSI and CSI: Miami). The following year, it placed second in the world after CSI.

House episodes premiered on FOX in the United States and Global in Canada, which have identical schedules. The show was the third-most popular on Canadian television in 2008. That same year, House was the top-rated television program in Germany, the number 2 show in Italy, and number 3 in the Czech Republic. The series is also very popular in France, Spain, Sweden, and the Netherlands. In the United Kingdom, the first four seasons were broadcast on Five. Sky1 acquired first-run rights beginning with season five. The original, English-language version of the show aired in Australia on Network Ten, in New Zealand on TV3, and in Ireland on 3e, TV3's cable channel.

Episodes of the show are also available online for download: Amazon Video on Demand, iTunes Store and the Zune Marketplace offer episodes from all of seasons 1 through 8. In 2007, NBCUniversal (the show's distributor) and Apple Inc. (iTunes' owner) had a disagreement that temporarily kept the fourth season off iTunes. In a statement to the press, Apple claimed that NBCUniversal wanted to drive up the per-episode price to \$4.99. In September 2008, it was reported that the issue between Apple and NBC had been resolved. Some episodes are available in streaming video on Fox's official House webpage and all eight seasons were available on Netflix until April 2017.

Seasons of the show and box sets were released on DVD encoded for regions 1, 2 and 4. Special features, such as anamorphic widescreen (the original release is letterboxed), depend on region.

### DVD and Blu-ray releases

## Merchandise

For a charity auction, T-shirts bearing the phrase "Everybody Lies" were sold for a limited time starting on April 23, 2007, on Housecharitytees.com. Proceeds from sales of those shirts and others with the phrase "Normal's Overrated" went to the National Alliance on Mental Illness (NAMI). House cast and crew members also regularly attended fundraisers for NAMI and have featured in ads for the organization that appeared in Seventeen and Rolling Stone. The show's efforts raised hundreds of thousands of dollars for the charity. Jacobs said that through their association with NAMI, they hoped to take "some of the stigma off that illness".

Nettwerk released the House M.D. Original Television Soundtrack album on September 18, 2007. The soundtrack includes full length versions of songs featured in House and previously unreleased songs especially recorded for the series. In 2008, the Spanish game company Exelweiss designed a cellphone game for the show, which was released in both Spanish and English versions.

In June 2009, Legacy Interactive announced a licensing agreement with Universal Pictures Digital Platforms Group (UPDPG) to develop a video game based on the series, in which players step into the roles of House's diagnostic team to deal with five unusual medical cases. The game, released in May 2010, included a minigame calling upon the player to "navigate a restaurant-placemat-style maze, in which a giant sandwich must avoid hungry physicians on its way to Dr. House's office." It received an F from The A.V. Club''; however, Legacy updated the game by August 2010.

American television medical drama

2000s American medical television series

2000s American mystery television series

2000s American workplace drama television series

2010s American medical television series

2010s American mystery television series

2010s American workplace drama television series

Fox Broadcasting Company original programming

Peabody Award-winning television programs

Primetime Emmy Award-winning television series

Television series by Bad Hat Harry Productions

Television series by Universal Television


M113 armoured personnel carriers in Australian service

The Australian Army has operated M113 armoured personnel carriers since 1964. An initial pair of M113s was purchased for trials purposes in 1962. Either 817 or 840 were acquired by 1979, comprising nine different variants. A long-running modernisation program that commenced in the 1990s resulted in 431 M113s being upgraded between 2007 and 2012. All of the upgraded M113s remain in service as of 2020.

In Australian service, the M113 has equipped armoured transport and reconnaissance units as well as mechanised infantry formations. It has also been used as a support vehicle by many other units. The type played an important role in Australia's commitment to the Vietnam War between 1965 and 1972. Some M113s were deployed as part of peacekeeping missions in Somalia during 1993 and Rwanda between 1994 and 1995. Larger numbers of M113s operated in East Timor from 1999 to 2002 and 2006 to 2008.

Despite the upgrade program, the Australian Army's M113s are now obsolete and they have not been included in recent deployments due to their vulnerability to attack. A project to replace the M113s with infantry fighting vehicles is underway, with a decision on the type to be procured scheduled for 2023. It is planned that the replacement vehicles will begin to enter service from 2025 and the M113s will be retired when this process is complete.

## Acquisition

### Trials

In 1958, the Chief of the Australian Army's General Staff, Lieutenant-General Ragnar Garrett, initiated a program to modernise the Army's organisation and equipment so that it was compatible with those of Australia's allies, particularly the United States Army. This program included the acquisition of armoured personnel carriers (APCs), as well as FN FAL rifles, M60 machine guns, M2A2 howitzers, M40 recoilless rifles, L16 81mm mortars and radios.

The adoption of the pentropic organisation in 1960 led to a requirement for APCs to equip the Army's armoured units within the Royal Australian Armoured Corps (RAAC). This organisation included two APC regiments, the 12th/16th Hunter River Lancers and the 8th/13th Victorian Mounted Rifles; both were reserve Citizen Military Forces (CMF) units. Each regiment was authorised 119 APCs. A further two APCs were planned to be issued to each of the Army's two armoured regiments and nine were to form part of the equipment of the two divisional reconnaissance squadrons. The reconnaissance regiment in the pentropic divisions' combat support group was to have 25 APCs. The pentropic structure was abandoned in 1965, before M113s had been delivered in significant numbers.

A formal Weapons and Equipment Policy Statement specifying the Army's requirements for tracked APCs was issued on 26 June 1960. This document was very similar to a British War Office Policy Statement issued in the late 1950s. It called for the Army to acquire tracked APCs that were amphibious and could be carried by aircraft. These vehicles were to replace the Army's wheeled scout cars and APCs which had been purchased in the 1950s, as well as obsolete armoured fighting vehicles (AFVs) dating from the Second World War. It was believed that the wheeled armoured vehicles were no longer suitable, as the Australian Army expected that it would need to fight in tropical conditions in South East Asia. Tracked vehicles were preferred for these conditions as they had superior off-road performance, including in jungle terrain. The statement specified that the new vehicles would be used to equip the Army's APC, armoured and reconnaissance units. At this time the Army did not include any mechanised infantry units which were permanently issued APCs, and separate APC-equipped units were used to provide protected transport for light infantry.

The Weapons and Equipment Policy Statement included a requirement that potentially suitable designs be subjected to extensive trials in tropical conditions before an order was placed. The American M113, the British FV432 and the Canadian Bobcat were considered. The Bobcat was the least advanced and no prototype had been completed, so it was rejected before trials were conducted. After negotiations between the Australian and British governments between 1960 and 1962, the British Ministry of Defence (MOD) requested that Australia conduct a trial of the FV432 in tropical conditions. The Australian Army rapidly agreed to this request, and two FV432s were shipped to Australia, arriving in September 1962. These were prototypes, as the FV432 was yet to enter production. It proved simpler to acquire M113s for trial as the type had been in mass production since 1960. Two were ordered in 1961, and they arrived in Australia on 9 October 1962.

From November 1962 to April 1963, the two FV432s and two M113s were subjected to trials at several locations with different climatic conditions in the state of Queensland. The trials began with crew familiarisation and driver training on both types in the Innisfail area. Once this was complete, the four vehicles were driven 1,100 kilometres (680 mi) to Mount Isa to conduct trials in hot and dry conditions. These included automotive and physiological tests, the latter of particular interest to the MOD. Testing in extreme heat during this phase found the M113's poor ventilation took a heavy toll on crew and passengers; one driver lost 5 kilograms (11 lb) in two hours. The FV432's forced air ventilation system proved superior. At the conclusion of this stage of the trials, the vehicles were driven a further 1,200 kilometres (750 mi) back to Innisfail for hot and wet trials at nearby Mourilyan. This phase included extensive driving through jungles and on sandy beaches, amphibious testing and being left unattended for 14 days. The M113 outperformed the FV432 in almost every aspect; its smooth sides and roof stowage proved far superior when driving through overgrown jungle, the lower track pressure and better track design proved superior on sand and it was significantly more waterproof. It was also found that the M113 required significantly less time to prepare for amphibious operations, though it was slightly slower than the FV432 in the water. The FV432's amphibious preparations included the removal of every inspection plate and the erection of a large rubber flotation screen; the latter was seen as a major drawback as it completely blocked the driver's vision and the rubber screen was easily punctured by debris or vegetation.

At the conclusion of the trials, the FV432s were shipped back to the United Kingdom. One was later used by the British Army for trials purposes during the development of the FV438 Swingfire. The M113s were retained by the Australian Army, which used them to trial several modifications to the type. Both were eventually transferred to the Royal Australian Armoured Corps Memorial and Army Tank Museum.

### Purchase and deliveries

The trials demonstrated that the M113 was much better suited to the Army's requirements than the FV432, and accordingly the M113 was selected. Several improvements to the type were recommended before final acceptance. These modifications included the installation of a ventilation system and, in coordination with engineers from the vehicle's manufacturer FMC, a ventilation system unique to Australian vehicles was developed. Orders were placed during the 1963–1964 financial year. At this time, it was planned to retain the M113 in service until 1995.

The M113A1 variant was ordered for the Army, the first deliveries being scheduled for 1964. This vehicle had a crew of two and could carry up to eleven passengers. Its armour provided protection against small arms and shrapnel. While the original US Army M113s were powered by a petrol engine, the Australian Army selected the M113A1 variant that used the General Motors 6V-53 Detroit Diesel engine. This is a V-6 displacing 5.2 liters (318 cubic inches), developing up to 300 bhp (220 kW) @2,800 rpm and 666 lb⋅ft (903 N⋅m) of torque @1,400 rpm. This was chosen because the variant had greater range and the diesel fuel it used was less likely to combust if the APC was damaged in combat. As the same engine was used to power buses in Australia, spare parts were also readily available. The Australian M113A1s were initially armed with a single pintle-mounted 0.5 inch calibre M2 Browning heavy machine gun.

In 1962 the Army decided that cavalry regiments equipped with lightly armoured vehicles would be its main armoured units. It was believed at the time that tanks were unsuited for the tropical environments the Army expected to fight in, and that lightly armoured vehicles would provide adequate support for the infantry. The structure of the cavalry regiments was established in 1964, the same year as the decision to abandon the Pentropic structure was made. They were to include three fighting squadrons, each with three troops equipped with APCs, a fire support troop and an anti-tank and surveillance troop. At the time the Army did not have any fire support vehicles; the M113A1 Fire Support Vehicle (FSV) later filled this role. In 1965 it was decided to structure the RAAC as armoured (tank), cavalry and APC regiments. The M113s were to be operated by RAAC personnel, and be treated as fighting vehicles rather than only armoured troop transports. The CMF armoured units were to be equipped with M113s for training purposes. In his history of the RAAC, Major General Ronald Hopkins judged that the cavalry regiment structure produced "handy" units with considerable mobility and firepower, but their effectiveness "rested on not being opposed by medium tanks or heavy anti-tank weapons".

Deliveries of the M113 began in 1964 but proved slow, the first bulk shipment of the type arriving in early 1965. The first vehicles to be delivered included specialist variants, including fitters vehicles (which carried maintenance personnel) and mortar carriers. M113s were initially issued to the Armoured Centre at Puckapunyal for crew training, which was conducted by US Army personnel at first. The type began to be issued to RAAC units on 19 March 1965. Priority was given to the Australian Regular Army's APC units, where the M113s initially replaced Alvis Saracen wheeled APCs. CMF units were accorded a low priority for M113s due to the need to allocate them to units involved in the Vietnam War, and some did not receive any until the late 1960s. Deliveries of the M113s were completed in 1979.

The planned cavalry and APC regiments were established in 1966. The 1st Cavalry Regiment was formed in January, and renamed the 2nd Cavalry Regiment later that year. The APC regiment was established as the 3rd Cavalry Regiment. The CMF 4th/19th Prince of Wales's Light Horse, 10th Light Horse Regiment, 2nd/14th Light Horse Regiment and 3rd/9th Light Horse (South Australian Mounted Rifles) were also converted to the cavalry regiment structure during 1966. The 4th Cavalry Regiment, a cavalry formation, was established in 1971.

## M113A1 variants and modifications

### M113A1 variants

The original orders of M113s included several variants in addition to the M113A1 APC:

- M125A1: These vehicles were based on the M113A1 and fitted with a single 81 mm mortar. The mortar was mounted inside the rear hull on a turntable, and racking was fitted inside the vehicle to carry mortar ammunition. The variant had a large hatch on the roof of its hull which the mortar was fired through. The M125A1 was armed with a M2 Browning for self-protection.
- M113A1 Fitters: These vehicles were also based on the M113A1 and were used to repair equipment in combat areas. They were fitted with a hydraulic crane on their roof capable of lifting an engine and transmission pack. The vehicles also carried tools, spare parts and technicians. They were armed with a M2 Browning.
- M113 Armoured Recovery Vehicle Light (ARVL): This variant was used to recover other vehicles from the field.
- M577A1 Armoured Command Vehicle (ACV): This variant had a raised rear hull to accommodate working spaces for headquarters staff. The working space could be extended by erecting a canvas tent which was attached to the hull. The M577A1 was originally armed with a 0.3 inch M1919 Browning machine gun, though a M60 machine gun was sometimes fitted instead.
- M548 Tracked Load Carrier (TLC): The M548 was an unarmoured logistics variant of the M113. The type was acquired in the early 1970s to replace wheeled logistics carriers within armoured units.

### Vietnam War-era modifications

In common with almost all the other countries that have operated M113s, a number of Australia-specific variants of the type were developed. Operational experience in South Vietnam rapidly demonstrated a need to provide armour protection for the M113's machine gun, as the crew commander who operated the machine gun was highly vulnerable when using the weapon. From August 1965, M113A1s began to be fitted with armoured shields that comprised a front plate and angled wings on each side. They were built by Army workshops in South Vietnam to varying designs, and were similar to shields fitted to the Army of the Republic of Vietnam's M113s. While the shields provided some protection, the gun position remained unprotected from the sides and rear.

As an interim measure to improve protection, 19 M113A1s in Vietnam and one in Australia were fitted with Model 74C turrets between September and November 1966. These provided all-round protection, and were armed with two M1919A4 Browning machine guns. The turret was very cramped, and its traverse mechanisms rapidly wore out. All of the Model 74C turrets were withdrawn by December 1968.

The T50 turret was selected as the standard turret for Australian M113s. The US Army had fitted one of these turrets to an M113 on an experimental basis in 1964. The Australian Army was aware of this experiment, and began its own trials of the turret in April 1966. The trials team delivered a favourable report, and the turret was approved for service in late 1966. M113A1s fitted with T50 turrets began to arrive in South Vietnam in August 1968. Almost all of the Australian Army's M113A1s were eventually fitted with these turrets. The turret was initially armed with two L3A3 machine guns (an improved version of the M1919A4), but some were later fitted with a M2 Browning and a M1919A3. The turret was regarded as unsatisfactory by soldiers, as it was cramped and it proved difficult to keep the guns aimed when the vehicle was moving. The turret was also very slow to rotate, which led to delays in engaging targets. To free up space, the right-hand side L3A3 machine gun was removed from all the T50 turrets in South Vietnam by early 1970; these guns were instead fitted to the roof of the turret using a pintle mount. Fitting the machine gun on the turret roof also allowed it to be quickly brought to bear on targets, though the commander lacked armoured protection while using the weapon. The Australian Army is one of only two M113 operators to have fitted turrets to the type.

Combat experience also led to improved protection against land mines. From July 1969, an armoured plate was welded to the sponson above the first three road wheels on each side of vehicles. This modification was eventually fitted to all Australian M113s. From May 1970, all of the Army's M113s were also fitted with a shock-absorbing footrest for the driver. Finally, a 38-millimetre (1.5 in) thick aluminium armoured plate was installed on the underside of all M113s starting from August 1970. While the plate added an extra 680 kilograms (1,500 lb) in weight, this was considered acceptable given the improvement to crew protection. The addition of the armoured plate led to a large reduction in casualties from mine explosions. The armoured plates were removed from the underside of the M113s following the Australian Army's withdrawal from South Vietnam as they slightly hindered the type's mobility and it was not considered necessary to retain them in peacetime. The plates were placed in storage.

During 1967 a M113A1 in South Vietnam was fitted with a 7.62 mm GAU-2B/A Minigun on an experimental basis. The gun was mounted on the commander's cupola. This was undertaken to improve the vehicle's firepower. The gun proved unsatisfactory, as it was very difficult to accurately aim and keep supplied with ammunition. The problems with aiming the gun meant that it could not be safely used to support infantry. It was also judged that few targets the Australian Army was likely to encounter required this much firepower. As a result, the project was abandoned.

In 1969 three M113A1s were modified in South Vietnam to dedicated mine clearance vehicles. These M113A1s were fitted with a boom of truck tyres on each side of their hull, which were used to detonate mines. They were also later modified to be driven from the turret. These APCs were operated by the 1st Field Squadron, which nicknamed them Her Majesty's APC (HMAPC) Flint, HMAPC Steele and HMAPC George. These vehicles proved successful in helping to clear a large barrier minefield that had originally been laid by Australian forces but was being used as a source of mines by the Communist forces they were fighting.

### Fire support vehicles

Experience in South Vietnam led to the development of fire support variants of the M113 armed with medium-calibre guns. These variants were unique to Australia.

The initial M113A1 FSVs were fitted with a turret taken from the Army's Alvis Saladin armoured cars. This was intended to be an interim design, used until an air-portable armoured fighting vehicle was procured. The turret was armed with a 76 mm L5A1 gun which could fire high explosive, canister and smoke rounds. One .30 calibre machine gun was mounted coaxially with the 76 mm gun, and another was installed on the roof of the turret.

Trials of the M113A1 FSV began in 1967, and continued for almost three years. Two M551 Sheridan light tanks were also trialled in Australia during early 1968 to determine if this type could meet the requirement for an air-portable armoured fighting vehicle. This included comparative trials against a M113A1. The trials found that the Sheridan was unsuitable, which led to a decision to accelerate the M113A1 FSV project. Production of M113A1 FSVs commenced during 1970, and involved fitting newly acquired M113A1s with Saladin turrets. The work was undertaken by 4 Base Workshop Royal Australian Electrical and Mechanical Engineers (RAEME) at Bandiana, Victoria. A total of 15 were produced, using the turrets of all the Australian Army's Saladins.

The development of a second tranche of FSVs began in 1972, when a requirement for further such AFVs was issued. It was decided that the new AFV would use the turret of a FV101 Scorpion fitted to the chassis of a M113A1 APC. This turret was armed with a 76 mm L23A1 gun. Buoyancy aids were also installed on the sides and front of the hull so that the vehicles remained amphibious. The prototype vehicles began to be constructed by the Ordnance Factory in Maribyrnong, Victoria, during 1974; three were completed in mid-1975. The design was approved for production in 1978, and another 45 FSVs were eventually completed by converting newly acquired M113A1s. The type was later designated the Medium Reconnaissance Vehicle (MRV).

### Post-Vietnam modifications

Despite the T50 turret's shortcomings, it remained in service with all of the M113A1 APCs for over 30 years. Minor modifications were made to improve the turret's performance, but it was never considered genuinely satisfactory. For instance, the turret lacked predictive gun sights and had no integral night vision capabilities. An improved variant of the turret was developed during 1990 and early 1991; this design sought to address problems with the weapons mounting, gun sight and ammunition feed system. The variant also had improved elevation and transverse systems.

In the late 1980s, several M113A1s were modified to carry RASIT ground surveillance radars and AN/TAS 6A Thermal Imaging Units. These vehicles were assigned to the 2nd Cavalry Regiment's Surveillance Troop.

### Other variants

Between February and May 1965 a M113 command and reconnaissance vehicle on loan from the US Army was trialled near Innisfail. Two command and reconnaissance variants of the M114 armoured fighting vehicle had been trialled in early 1964. These trials produced mixed results, and it was decided to not purchase either AFV.

In late 1971 a mine-damaged M113A1 was converted to a mechanical training aid. This comprised the forward section of the vehicle that was mounted on a stand so that instructors and students could easily observe its mechanical layout.

### Numbers

The total numbers of M113s acquired by the Australian Army differ between sources:

## M113AS4 variants

### M113 upgrade program

A project to replace the M113s began in the 1980s, but was abandoned in favour of upgrading the type. In October 1980 the Army initiated Project Waler which aimed to replace the M113s with new armoured vehicles by the mid-1990s. Between 500 and 1,000 AFVs were to be procured, the Army considering both wheeled and tracked armoured vehicles. A total of 14 companies submitted proposals to initial phase of the project, that closed in February 1982. Three proposals were selected for further consideration in July that year; each comprised four different wheeled and tracked options. Project Waler was cancelled in July 1985, the government deciding to upgrade the M113 fleet instead. Minister for Defence Kim Beazley stated that while the designs under consideration for Project Waler would have been superior to the M113, they would be very costly to procure. The Canberra Times reported that it had also proven difficult to tailor the designs to Australian conditions, and that the government regarded them as unsuited to Australia's needs.

Work on the upgrade project began in the early 1990s. The 1992 Defence Review found that the M113 fleet could remain viable until 2010 if the vehicles were upgraded. This finding was generally supported within the Army, though there were concerns over whether it would be economical to retain the M113s until 2010. The Department of Defence agreed to a limited upgrade of 537 M113A1s in October 1992, and the government approved the project in November the next year.

In 1994 the Army decided to split the project into two phases. Under Phase 1, the vehicles' suspension and engine cooling systems would be upgraded to M113A2 standard and they would be fitted with a new turret, spall liners and a cooled drinking water system. Night-vision goggles would also be acquired for M113 drivers and commanders. As part of Phase 2, the vehicles would be upgraded further to M113A3 standard, which would involve fitting them with a new engine, a new transmission system, appliqué armour and a climate control system. Tenix Defence was selected as the prime contractor for Phase 1, the contract being signed in May 1997. Tenix delivered four M113A2s in 1998, and they were used for trials by the School of Armour and B Squadron, 3rd/4th Cavalry Regiment between August and October that year.

In November 1997 Tenix proposed combining both phases of the upgrade program. The Department of Defence accepted this proposal in November 1998, but further design and developmental work demonstrated that the intended savings from combining the phases would not eventuate. As a result, the Department of Defence cancelled all further work on this approach to the upgrade program in October 2000. The Army and Department of Defence remained committed to upgrading the M113s, however.

The 2000 Defence White Paper included a commitment to upgrade 350 M113s to improve their capabilities and retain the type in service until around 2020. As part of the development of a business case for the upgrade, consideration was given to replacing the M113s with infantry fighting vehicles (IFVs) such as the American M2 Bradley. It was decided to not procure IFVs on the grounds that they would be too expensive and difficult to deploy by air given their weight. The Cabinet approved the M113 Major Upgrade Project in June 2002, and a contract was signed with Tenix the next month. While it was intended that the upgraded M113s would begin to enter service in the second half of 2006, technical problems with the prototype vehicles led to delays. These delays were in addition to those caused by the mismanagement of the upgrade project, which was extensively criticised by the Australian National Audit Office (ANAO) in 2005. In particular, the ANAO noted that the project had suffered "extensive scope changes and chronic schedule delays since its inception", the Department of Defence doing a poor job of managing the project until the Major Upgrade Project contract was signed in 2002. In 2008 the government approved the upgrade of a further 81 M113s, taking the total to 431.

The M113s were upgraded at Tenix's facilities in Bandiana. The work on the vehicles included stripping them back to bare hulls and then installing new engines (MTU 6V 199 TE20, 11.9 litre diesel, 350 bhp (260 kW) @2100 rpm), armour and a range of other modifications. The Department of Defence accepted the first upgraded M113s in November 2007. The next year the Parliamentary Secretary for Defence Procurement announced that the technical problems affecting the vehicles had been resolved, and the upgrade project had been removed from the Defence Projects of Concern List. The last upgraded M113 was accepted in September 2012.

By the time the M113 upgrade project was complete, the operational environment had changed with a new threat improvised explosive devices (IEDs) that made the vehicles unsuitable for combat. Although the hull had been reinforced during the upgrade to "improve mine blast protection" it did not provide protection against large IEDs. The vehicles also did not provide adequate protection against most forms of modern anti-tank missiles and anti-tank mines. The shortcomings of the upgraded M113s left the Army with a significant capability gap, requiring a replacement project to be launched.

The M113s that were not upgraded were disposed of. In 2000 a M113A1 that had been deployed to South Vietnam, Rwanda and East Timor was transferred to the Australian War Memorial. The Memorial later received a M577A1. As of 2016, a further 201 M113s were to be scrapped and 31 preserved for heritage purposes.

### Variants

The upgrade program involved seven variants:

All of the variants other than the M806AS4 ARVL were built on extensively upgraded M113A1 APC hulls. M806A1 ARVLs were converted to M806AS4s. All AS4 variants have lengthened hulls, with the number of road wheels being increased from five to six, unlike the AS3 variants which have remained the same in length. Common upgrades to all variants include new suspension, a new power pack and engine, the addition of spall liners and appliqué armour, increased external stowage and the fuel tanks being moved from inside to outside the hull. All upgraded vehicles have been fitted with new T150F tracks and sprockets. The height and width of the AFVs was also increased. These modifications added 2.5 tonnes (2.8 short tons) of weight for the AS3 variants and up to 5.5 tonnes (6.1 short tons) for the AS4 variants. As a result of their larger dimensions, the upgraded M113s cannot be transported by air or road without some elements being disassembled and fewer can be embarked on each transport ship. They also lost their amphibious capabilities.

In 2019 two M113AS4 APCs were converted to optionally crewed combat vehicles by BAE Systems Australia. These vehicles were used by the Army for trials to improve its understanding of how uncrewed vehicles could be used, the head of the project stating that "we are using M113s because we have them in service and we understand them really well." By 2022 the Army had a force of 20 optionally crewed M113AS4 which were being used for further trials.

## Operational history

### Vietnam War

#### Numbers deployed

M113s were extensively used by the Australian Army during the Vietnam War. M113A1, M113A1 Fitters vehicle, M577A1, M125A1 and M113A1 FSVs were deployed to South Vietnam, where they were employed in a wide range of roles.

A troop of eight M113A1s from the 4th/19th Prince of Wales's Light Horse was assigned to the first Australian combat unit to deploy to South Vietnam, the 1st Battalion, Royal Australian Regiment (1 RAR), and left Australia in May 1965. Two other M113A1s were allocated to this force as a reserve. The troop had replaced its wheeled APCs with M113A1s only shortly before departing for South Vietnam, and had conducted little training with the type. Further M113A1s and two M125A1 mortar carriers were dispatched in September that year.

The APC force in South Vietnam was expanded to a squadron in 1966; this force was initially designated the 1st Armoured Personnel Carrier Squadron and was renamed A Squadron, 3rd Cavalry Regiment in September 1967. At the time the 1st Armoured Personnel Carrier Squadron was established, the M113 fleet in South Vietnam was increased, with M113A1 Fitters variants and M577A1 ACVs joining the force. The squadron was redesignated B Squadron, 3rd Cavalry Regiment in mid-1969 and A Squadron, 3rd Cavalry Regiment in April 1971. While infantry units rotated in and out of South Vietnam as formed bodies, RAAC personnel were posted individually.

The cavalry squadron usually comprised a squadron headquarters, three cavalry troops, a support troop and a light aid detachment. Each of the cavalry troops was equipped with thirteen M113A1s, and was organised into a headquarters with four APCs and three sections each with three APCs. The tank squadron which also formed part of the 1st Australian Task Force (1 ATF) between February 1968 and August 1971 was allocated two M113A1 APCs, three M113A1 Fitters vehicles and a M577A1 ACV to support the Centurion tanks. During the final stage of the withdrawal of Australian forces from South Vietnam, the cavalry squadron was reduced to a single troop equipped with 12 M113A1s, 6 Fire Support Vehicles, 2 M125s and a M577 from December 1971. The role of this troop was to protect the Australian logistics base at Vung Tau. The last Australian M113s left South Vietnam in May 1972.

Overall, 200 M113s were deployed to South Vietnam. This made the type the most numerous armoured fighting vehicle used by the Australian Army during the war. The M113s were returned to Australia to be rebuilt after reaching a set mileage; only three were deployed twice.

#### Employment

The M113A1s were mainly used as armoured personnel carriers, and transported troops in and out of battle. In this role they were able to carry an infantry section with all of its combat equipment. The Battle of Long Tan on 18 August 1966 was the first major engagement involving Australian M113A1s. During this battle a troop of APCs carrying a company of infantry played a key role in preventing another Australian infantry company from being overrun.

M113A1s operated in other roles. These included escorting convoys, conducting independent patrols and carrying supplies. They were also employed in ambushes and cordon and search operations. The M113A1s supported artillery units by transporting L5 Pack Howitzers internally and towing the larger M2A2 howitzers. During the later years of the Australian deployment to South Vietnam, when 1 ATF's area of operations was largely secure, groups of M113A1s frequently operated without infantry in a reconnaissance role. M113A1s proved to be highly effective, as they provided mobility, protection and firepower to support infantry operations, but their thin armour left them vulnerable to mines and other anti-tank weapons. Operations were at times hindered by infantry units not being sufficiently trained to make the best use of M113s' capabilities.

M125A1 mortar carriers were usually used to provide fire support for the infantry with their 81mm mortar. They were also often employed as armoured personnel carriers with their mortar removed.

The M113A1 Fitters variants were assigned to the light aid detachments that formed part of cavalry and tank squadrons. They were operated by RAEME personnel, and were heavily employed at both Australian Army bases and in the field during operations. The variant's crane proved particularly useful. Australia was the only country to use this M113 variant in the Vietnam War.

Each cavalry and tank squadron headquarters was assigned a single M577A1, and a further five were allocated to the headquarters of 1 ATF. 547 Signal Troop, 1 ATF's signals intelligence element, was assigned an M577A1 from late 1968 and used it to support large-scale operations. The radio fit outs differed between M577A1s depending on their assigned role. The M577A1s were often stationed at fire support bases, and were rarely used in patrols and convoy escort tasks.

The first M113A1 FSVs arrived in Vietnam during July and August 1971, and were initially used to establish a fire support troop in A Squadron, 3rd Cavalry Regiment. Six were allocated to the squadron, and two others were held in reserve. After the Centurion tanks were withdrawn, the FSVs were assigned to support infantry units. They were used for patrols, protecting foliage-clearing teams and defending fixed positions, and typically operated with M113A1s. The FSVs proved unsatisfactory replacements for the Centurions, as they were too lightly armoured. The vehicles were also prone to throwing tracks, became bogged more easily than standard M113s and lacked gun sights for their main armament during the first months of their deployment. 1 ATF soon concluded that the FSVs were almost useless, and they never saw combat. The vehicles were withdrawn from South Vietnam in February 1972.

Many of the M113s deployed to South Vietnam were damaged, most frequently by mines. In many cases the damage could be repaired in theatre, but 23 M113A1s and a M125A1 were written off. Most of these vehicles' hulls were shipped back to Australia for disposal. A further 28 M113s were returned to Australia for repair after incurring damage which was beyond the capabilities of the Army workshops in South Vietnam to handle. Of these M113s, 15 had sustained such serious damage that they needed to be rebuilt using newly purchased hulls. The cavalry squadron incurred significant casualties, 20 of its members being killed (including 17 in action) and 110 being seriously wounded in action; this represented approximately one in seven of the officers and men that served in it between 1966 and 1972. Many others suffered minor injuries. A M113A1 that was damaged in combat in South Vietnam was donated by the Army to the Australian War Memorial on 19 April 1972. The APC was later removed from the Memorial due to health and safety concerns and transferred to the Royal Australian Armoured Corps Memorial and Army Tank Museum.

Extensive training was undertaken in Australia to prepare soldiers and units for service in South Vietnam. During 1969 alone M113s in Australia were driven for 530,000 miles (850,000 km) during training. Soldiers were trained by the squadron of the 3rd Cavalry Regiment which was stationed in Australia at the time immediately before being posted to the squadron in South Vietnam.

### After Vietnam

In mid-1970 the M113A1 fitted with a T50 turret was selected as the standard vehicle for all RAAC units other than the armoured regiments, which primarily used tanks. The CMF RAAC units were each authorised eight M113A1s to replace their obsolete armoured cars, as well as a single M577A1 ACV. Deliveries of these M113s were completed in 1972. By this time, all the CMF RAAC units had been organised as cavalry or APC formations. The M113A1 FSVs were used by regular cavalry regiments and the Armoured Centre until 1979, when they were transferred to Army Reserve units.

The Australian Army began to develop a mechanised infantry capability during the late 1970s. The 5th/7th Battalion, Royal Australian Regiment (5/7 RAR) began trialling mechanised tactics beginning in 1976. This reform aimed to improve the unit's mobility, and make better use of the capabilities of the APCs. The battalion was fully mechanised by mid-1977; in this role it was equipped with 72 M113s. Following the Sydney Hilton Hotel bombing in February 1978, 50 of 5/7 RAR's M113s were stationed along the Hume Highway to protect national leaders as they travelled from Sydney to Bowral for the Commonwealth Heads of Government Regional Meeting. There was scepticism within Army Headquarters over the cost-effectiveness of mechanisation and the viability of maintaining a single mechanised battalion. At the conclusion of the mechanisation trial in mid-1978, only one company of 5/7 RAR was retained as a mechanised unit with the others reverting to light infantry.

In early 1983 a decision was made to permanently convert 5/7 RAR to a fully mechanised unit. The battalion transitioned to this role between July 1983 and 1984. Some supporting elements of the 1st Brigade were also mechanised. 5/7 RAR had completed its transformation to a mechanised battalion by 1986; as of early that year, it was equipped with 56 M113A1 APCs, 4 M125A1s, 4 M113A1 Fitters vehicles, 3 M577A1s, 1 M113 ARVL and 7 TLCs. The battalion cooperated closely with the 1st Armoured Regiment and a troop of mechanised engineers that was established within the 1st Field Squadron.

The M113 fleet saw some changes over the 1980s and 1990s. All of the Army's M113A1s were "grounded" between September 1982 and July 1983 due to serious problems affecting their control differential. This greatly disrupted training activities. An audit undertaken by the Australian National Audit Office in 1985 found serious problems with how the M113 fleet was being managed. This had led to only 488 of the Army's 790 M113s being serviceable. The M113A1 FSVs were retired in 1986, and six of the vehicles were sold to the New Zealand Army after being converted back to standard M113A1s. The 1987 Defence White Paper called for the number of M113s to be reduced to below 600, with some of the remaining vehicles being upgraded. The White Paper also recommended that the 2nd Cavalry Regiment's M113s be replaced with wheeled vehicles. The ASLAV was selected for this role in 1992. The 2nd Cavalry Regiment was converted to ASLAVs during 1995 and 1996. The M113A1 MRVs were withdrawn from service in late 1996 due to shortages of spare parts for their turrets and concerns that the fumes ejected when their main gun was fired were toxic.

In April 1993 a civilian stole a M113 from an Army facility in Perth, and rampaged through the city for two hours. The APC was used to damage the city's police headquarters, a police station, at least eight police cars and the Central Law Courts before the civilian was arrested by the Tactical Response Group. The man, who had been diagnosed with paranoid schizophrenia, was sentenced to four and half year's jail in December 1993.

### Peacekeeping deployments

Between January and May 1993, B Squadron, 3rd/4th Cavalry Regiment was deployed to Somalia to support 1 RAR during the Operation Solace peacekeeping operation. The unit was equipped with 36 M113A1 variants, including 28 APCs and two M125A1 mortar carriers. This deployment proved successful, the vehicles being used in similar roles to those they had undertaken during the Vietnam War. Australian soldiers found that mechanised infantry tactics using the M113s were highly effective in what proved to be a low-intensity conflict. The M113s were obsolete in comparison to the armoured vehicles other western militaries deployed to Somalia. B Squadron had difficulty maintaining the M113s, due in particular to a shortage of links for their caterpillar tracks. It also experienced shortages of other spare parts. After the withdrawal of 1 RAR, a ten-man team from the Special Air Service Regiment that was deployed to Somalia in 1994 used two United Nations' M113s.

Three M113A1 APCs and a M113A1 Fitters vehicle were deployed to Rwanda between 1994 and 1995. These vehicles were used to protect Australian Army medical teams that had been assigned to the United Nations Assistance Mission for Rwanda following the Rwandan genocide. The M113s were initially operated by B Squadron, 3rd/4th Cavalry Regiment, from August 1994 to March 1995, and 5/7 RAR subsequently. They were only occasionally used, as the Australian contingents did not face threats which required armoured support. Some of the Australian M113 crew members served as driving and gunnery instructors for a Ghana Army unit in Rwanda which had recently received 50 M113A1s donated by Germany and had not trained with the type before starting their deployment.

In September 1999, B Squadron, 3rd/4th Cavalry Regiment was deployed to East Timor as part of the INTERFET peacekeeping mission. The unit supported light infantry units, and its M113s proved better suited to East Timor's rugged terrain and tropical climate than the 2nd Cavalry Regiment's ASLAVs, which at times were unable to operate off road due to muddy conditions. 5/7 RAR was subsequently deployed to East Timor and proved highly effective. It was found that the mechanised battalion could cover an area which had previously needed to be patrolled by several light infantry battalions. Australian M113s remained in East Timor until 2002 to support the infantry battalions deployed there. While the deployment of M113s to East Timor was considered successful, the age of the vehicles and their obsolescent communications and navigation systems proved to be a limitation; this included the absence of Global Positioning System equipment to aid navigation. There were also concerns regarding the lack of stabilisation and night sights for the vehicles' armament, and the driver being unable to use a night driving system which had a wide field of view. The M113s also proved less mechanically reliable than the newer ASLAVs, which were also better armed. The experiences gained from operating M113s in East Timor helped to validate and improve the Army's mechanised doctrine, and influenced the requirements which were set for the M113 upgrade project.

### Plan Beersheba

The number of mechanised infantry units was increased in 2007 when 5/7 RAR was de-linked to form the 5th Battalion, Royal Australian Regiment (5 RAR) and 7th Battalion, Royal Australian Regiment (7 RAR). 7 RAR was the first combat unit to receive M113AS4s, with enough of the type to transport an infantry company being delivered in December 2007. Both battalions operated in the mechanised role until 2013, when they were converted to light infantry as part of the Plan Beersheba restructure. As part of this restructure, each of the Army's three brigades included two light infantry battalions that could access a squadron of M113s in the brigade's armoured cavalry regiment. This structure proved short-lived, and the 3rd Battalion, Royal Australian Regiment, 6th Battalion, Royal Australian Regiment and 7 RAR began converting to mechanised infantry units in 2018. This change was an interim measure to prepare infantry units to operate IFVs ahead of these vehicles being ordered and delivered.

The Army Reserve RAAC units were not issued with upgraded M113s, and their M113A1s were progressively withdrawn from service during the mid-2000s. Most of these units were converted to a light cavalry role, and initially re-equipped with unarmoured Land Rovers. As part of Plan Beersheba, all of the Army Reserve RAAC units received Bushmaster Protected Mobility Vehicles from 2011. These vehicles are used in both reconnaissance and armoured transport roles.

B Squadron, 3rd/4th Cavalry Regiment deployed 33 M113s and supporting vehicles again to East Timor in June 2006 as part of Operation Astute. M113s supported subsequent rotations of the ANZAC Battle Group until 2008, with 7 RAR providing mechanised infantry platoons during 2007 and 2008.

No M113s have been deployed to Afghanistan during the long-running Australian operations there as the Army considered them to be too vulnerable to improvised explosive devices and other threats. The type was also not included in the deployments of Australian Army units to Iraq between 2003 and 2008. In 2010 the Department of Defence advised a parliamentary committee that the upgraded M113s would require additional protection to be able to serve in Afghanistan, and that ASLAVs and Bushmasters were best suited to conditions there. The department also noted that it was unlikely that the M113s would ever be deployed to "a place where there is sustained close combat expected on a daily basis". In 2015, Australian Strategic Policy Institute analyst Andrew Davies described the M113s as "essentially obsolete" and "no longer fit for purpose in anything but a benign operational environment". All 431 upgraded M113s remained in service as of 2020.

On 19 May 2022, Defence Minister Peter Dutton announced that the government would gift 14 M113AS4s to Ukraine as part of Australia's assistance for the country following its invasion by Russia. The government had also committed to gift Bushmasters to Ukraine. On 4 July 2022, Defence Minister Richard Marles announced that the government had increased the number of M113AS4s to be gifted to 28. On 26 June 2023, the government announced that a further 28 M113s would be gifted to Ukraine.

## Replacement

As part of the LAND 400 project, the Australian Government is currently aiming to procure IFVs to replace the M113s from 2025. The Army believes that the M113s are "not expected to be deployable for anything other than low intensity/low risk missions beyond 2025", and will reach the end of their service life in 2030. The introduction of IFVs will give the Australian Army a new capability, and better enable it to take part in high intensity warfare.

A request for tender for IFVs was issued in mid-2018. At this time, it was intended to acquire up to 450 IFVs as well as 17 manoeuvre support vehicles. In September 2019, Hanwha Defense Australia's AS21 Redback and Rheinmetall Defence Australia's Lynx IFVs were selected for further evaluation. The number of vehicles to be acquired was reduced to 300 in mid-2022. A decision on the type of IFV to be purchased was originally scheduled for 2022, but was delayed until 2023 to align with completion of a Defence Strategic Review in March that year. The ABC reported in October 2022 that there was speculation that the project may be cancelled due to its cost. In April 2023 the number of IFVs to be acquired was reduced to 129 to free up funding for other defence priorities. This will be sufficient to equip a single mechanised battalion. It was announced in July 2023 that the AS21 Redback had been selected, with deliveries to begin in 2027. M113s will remain in service with the Army's combat units until they are replaced by the new IFVs.

Australian Army armoured fighting vehicle

Armoured personnel carriers of the post–Cold War period