Page "British Rail Class 43 (Warship Class)" Paragraph 4

No further examples of this design were ordered but NBL then received an order for 33 locomotives to a more advanced design, the D800 design drawn up by Swindon Works in turn derived from the original German Krauss-Maffei V200 design.

The prime mechanical components of these were two MAN L12V18 / 21B diesel engines, each rated at at 1530 rpm and coupled to a Voith LT306r hydraulic transmission ; each engine / transmission combination drove one bogie.

Unlike the Mekydro four-speed transmissions in the Swindon-built locomotives, the Voith was only a three-speed design but was chosen because it kept compatibility with D600-4 and because NBL already had a licence to manufacture it.

Whereas the Swindon-built locomotives had all their engines and transmissions supplied by the German manufacturers ( albeit with ten engines and three transmissions supplied as kits of parts for the British licensee to re-assemble ) the engines and transmissions required for D833-65 were all built by NBL.