Tractors in tandem
 

In times past it was not uncommon for heavy freight to be hauled by two class 37 locos.

How would two 37s compare to a single class 66 ?

Class 37 power is Maximum: 55,500 lbf (247 kN) with a continuous output of: 35,000 lbf (156 kN) @13.6 mph (22 km/h)


Class 66 power is Maximum: 91,900 lbf (409 kN) at starting with a continuous output of : 58,500 lbf (260 kN) at 15.9 mph (25.6 km/h)


So two class 37's with decent engines and bogies fully maintained will out perform one class 66 on paper

the Class 66 with be more economical on fuel and emissions but the 37's will sound like they are working and look so much more like a real loco should

Thanks Gray, I'd prefer to see a pair of 37s myself.:D

In the same vein, are a pair of 20s better than a single 37 ?

I'd put two 20's on par with a 47 as these two classes were the workhorses here in the Notts coalfields.