I’ve been comparing the stats between New York Central SW1 “Light” (DES-5) switchers and SW1 “Heavy” (DES-6) switchers. Everything (e.g. dimensions, engine size, gear ratio, etc.) are identical between the two - except for the maximum tractive effort:
Was it just a matter of additional weight being added to the chassis or frame to increase tractive effort? If so, where did they generally put it? Or, did they use a heftier frame to accomplish the task?
Thanks for the information ahead of time.
Tom
[Edit: I just noticed that there is some additional piping (between the trucks) in the “heavy” version above. Was this some sort of cooling device?]
It is a matter ‘ballast’ in the frame. All SW1 switchers had a welded frame and a V6-567 power plant producing 600 hp. Those ‘Starting TE’ number at 25% adhesion just means that you can multiple by 4 and get the actual weight of the engine. Extra weight will make it less ‘slippery’. The lower weight means that the engine can be used on ‘light rail’ branches under 50,00 lb axle loading). External difference should be minimal. EMD changed very little during the long product life of the SW1.
Do you have data on the fuel tank capacity of the two engines shown above? At least visually they appear to have rather different sized fuel tanks which in turn would account for some difference in weight when fully fueled.
Not for those specific locomotives, Dave. The specs in my NYC Diesel Locomotive book have the “capacity of fuel oil tank” and the “fuel capacity (in operating hours)” listed at 600 gals. and 90 hours, respectively, for both the Light and Heavy SW1s.
