Mallard BASIC
It was also optimised for speed it is named after the LNER A4 class 4468 Mallard locomotive, the fastest steam locomotive in the world, once again displaying the company's fondness for railway-oriented nomenclature. (For instance, see the company name itself.) In fact the Locomotive name came from the phrase "To run like a train" and it was this theme that was used to name Mallard BASIC no other Locomotive product was named after anything railway-oriented.
SJ D
When the passenger locomotives were given more powerful motors, they were designated Dk. They had a maximum speed of 100 km/h. This is the last series of locomotives that was built new, all later types have been rebuilt, except the one-off experimental subtype Dr. The last Dk loco was built in 1943 and concluded eighteen years of D production. When the production of Da-locos started in 1953, the Dks were rebuilt to the same engine, and received the designation Du. The last use of Dk was in 1975. In total 117 have had the Dk designation, of which 73 were built as Dk.