I'm pondering upgrades to yer proprietary Brit diesel (any diesel) and keep wondering whether a motor per power bogie is a good idea or not.
Now, I know the best of all worlds is the way the Yanks do it, with a big motor and flywheel in the middle, cardan shafts and a gear train to all axles in both bogies - it gives you true uniform drive. However, it seems easier to put a motor per bogie, driving either one worm gear and a chain of spur gears, or two outer axles with the middle one loose or dummy (as in the Airfix 31 I've just bought, on the one driven bogie, that is).
Wise men tell me this is a no-no, though, as the two motors, however they're wired - series, parallel, DCC controlled - will never run at the same speed and/or "fight" each other so one is always dragging the other so rather than getting twice the power, you're lucky to get even once the power from your lead motor.
Has anyone anecdote or technical reasons as to why this is, if so, and what can overcome it? The only two-motor diesel I've seen in action is the Deltic that roars - and I mean ROARS; in a 100' long shed you have to raise your voice to maintain a conversation as it approaches - round Roy Jackson's Retford, which has two Lima power bogies in one chassis. Is the noise I'm hearing partly the sound of overstressed gears in torment because wheelslip can't release the torque forces (it's well weighted too)? It seems daft to have a big diesel making traction on only six of twelve wheels, to the possible detriment of working a scale-length train, but apparently for ease of use it must be so because some law of physics says so.
Enlightenment please, before I start doing things to myWestern/Warship/31/whatever.
Tony Clarke