D800–802 were produced as a pilot order and differed slightly both mechanically and cosmetically from the others. Aside from the obvious differences of disc versus rollerblind headcodes and the slightly less powerful engines, D800–802 were only equipped with six power controller notches, which was found to be unsatisfactory for smooth acceleration and economical running in operational use. These differences meant D800–802 were effectively a separate sub-class and could not work in multiple with the others (although the "white diamond" code multiple working capability of the Warships was rarely used until the late 1960s, and was removed from many locomotives as a constant source of electrical problems). In 1960, British Railways introduced the Class 43 diesel hydraulic locomotives, with a maximum tractive effort of . These were constructed by North British Locomotives, numbered in the range D833 to D865 and also bore names. Although of a very similar design to the Swindon-built examples, the 43s were equipped with MAN engines and Voith hydraulic transmissions at a similar power rating as the Swindon locomotives. The Maybach engines were a more sophisticated design, with advanced features such as oil-cooled pistons that the MAN design lacked. The German V200 class, upon which the D800 design was based, used Mercedes and Maybach engines – the MAN engines were not fitted in significant numbers to V200 locomotives – coupled to Mekydro and Voith transmissions in roughly equal proportions, with engines and transmissions being completely interchangeable. Thus one locomotive might have one Mercedes engine coupled to a Mekydro transmission and a Maybach coupled to a Voith. This interchangeability of engines and transmissions was theoretically a feature of the BR design as well, but was never exploited. Detail differences in the floor construction after the first few Swindon production locomotives removed the ability to exchange transmissions. Names and liveries Each locomotive bore a name: D825 for example was Intrepid. All except D800 and D812 were named after Royal Navy vessels, thus the "Warship diesel" moniker used to refer to the class. D800 was named Sir Brian Robertson after the Chairman of the British Transport Commission at the time. D812 was planned to carry the name Despatch but was eventually named Royal Naval Reserve 1859–1959. All except these two bore a subtitle "Warship Class" in smaller letters underneath the main name. A notable feature was that throughout the production series examples (including the NBL-built D833–865) the names were allocated