McLaren Engined Locos

 The first diesel locos, 5501 and 5502, were to have been fitted with Helios diesel engines of 18 H.P. made by J. & H. McLaren Ltd. of the Midland Engine Works, Leeds. In fact the Motor Rail records show that the pair were not built due to problems with the engines and the McLaren-Benz 30 H.P. diesel engine was substituted starting with loco 5503, which was delivered in 1929. The loco was available in weights ranging from 4 to 5 Tons. The majority of this type were exported and most were fitted with foot-operated brakes. The cost of a diesel loco at that time was £578.0s.0d, which was around double the cost of the equivalent petrol engined loco. Locos from 5517 to 5520 are known to have been fitted with the MR2 McLaren-Ricardo engine, whereas locos from 5531 were “equipped with latest MDB2 engine”. This latter engine had a bore size of 135-mm and a 200-mm stroke. It incorporated a Benz pre-chamber and had a nominal running speed of 800 R.P.M.

30 H.P. Number Series (built between 1929 and 1936)

5503-5509, 5512, 5514-20, 5522-25, 5531-5533

 10 H.P. Number Series (built 1930)

5513                              3-Ton