Passage: Harland and Wolff, the RMS Titanic's builders, opened their private archives to the crew, sharing blueprints that were thought lost. For the ship's interiors, production designer Peter Lamont's team looked for artifacts from the era. The newness of the ship meant every prop had to be made from scratch. Fox acquired 40 acres of waterfront south of Playas de Rosarito in Mexico, and began building a new studio on May 31, 1996. A horizon tank of seventeen million gallons was built for the exterior of the reconstructed ship, providing 270 degrees of ocean view. The ship was built to full scale, but Lamont removed redundant sections on the superstructure and forward well deck for the ship to fit in the tank, with the remaining sections filled with digital models. The lifeboats and funnels were shrunken by ten percent. The boat deck and A-deck were working sets, but the rest of the ship was just steel plating. Within was a fifty-foot lifting platform for the ship to tilt during the sinking sequences. Towering above was a 162-foot-tall (49 m) tower crane on 600 feet (180 m) of rail track, acting as a combined construction, lighting, and camera platform.The sets representing the interior rooms of the Titanic were reproduced exactly as originally built, using photographs and plans from the Titanic's builders. The Grand Staircase, which features prominently in the film, was recreated to a high standard of authenticity, though it was widened 30% compared to the original and reinforced with steel girders. Craftsmen from Mexico and Britain sculpted the ornate paneling and plaster-work based on Titanic's original designs. The carpeting, upholstery, individual pieces of furniture, light fixtures, chairs, cutlery and crockery with the White Star Line crest on each piece were among the objects recreated according to original designs. Cameron additionally hired two Titanic historians, Don Lynch and Ken Marschall, to authenticate the historical detail in the film.

Question: What parts of the ship were not made with steel plating?
boat deck and A-deck