I don't follow this thread regularly so apologies if this has come up before but can any traction engineers explain why diesel electrics (say) above 2000hp are often co-co's, especially freight locos, whereas electric locos are often bo-bo's even though the power can often be well over double this amount. I have just seen a mock up of the new Stadler class 93 freight bi mode which is well over 5000hp but still a bo-bo. I have always assumed that although the method of creating the power differs between them, the actual traction motors in the bogies are basically the same, so the more wheels, the more motors and the more motors the more power at the railhead?