They also gave a very smooth ride, being equipped with Commonweath bogies....but the one piece extruded aluminium cab units gave very poor crash protection. The main reason for the poor reliability and constant leakages of the engines, fuel pumps, lube oil pumps, etc. was because the MAN engines built under licence in Glasgow used metric drawings sent over from Nuernberg and all the measurements had to be (not always too accurately) converted for NBL's all-imperial tool settings.
The twenty locos that were rebuilt with Paxman Ventura engines (class 29) were considerably more reliable and powerful than their unconverted class 21 sisters....but were not entirely unaffected by failures. Indeed the final conversion (D6108) was the first to be withdrawn - less than a year later - after incinerating itself on the West Highland Line. At the end of the day, the 29s were still a small non-standard class with a non-standard multiple-working capability, which were expensive to operate and maintain....and with the advent of the National Traction Plan in the early 1970s, which brought about the transfer to Scotland of the remaining LMR class 27s, the writing was on the wall for these charismatic and characterful locomotives which passed my house and school on a daily basis when I was growing up in Scotland. It was a nice touch that the final passenger duty for one of these locos was when 6119 worked the Royal Train from Faslane Junction on the West Highland Line - where she relieved 5382 and 5405 - down the branch to the Clyde Submarine Base on 25th November 1971. Her boiler then kept Princess Anne warm overnight, before the two 27s worked the RT back South in the morning, followed half an hour later by the immaculately repainted 6119 running light back to Eastfield depot....and I had a lump in my throat as I saw her slip quietly doen the bank past my school playground in Craigendoran - the last time I ever saw a 29 on the West Highland Line.
