what does SD and GP stand for?

Model Railroader General Discussion (Model Railroader)
1

What does SD and GP stand for? thanks

2

SD = Special Duty
GP = General Purpose

SD units were built for use on lines with lower weight limits - they spread the weight of the loco over more axles so the weight per axle is lower. More recently, they have allowed more tractive effort to be exerted. GP’s were intended for normal use in pretty much any job, though to the best of my knowledge there have been no new GP units since the GP60M and GP60Bs built for the Santa Fe’s fast intermodals - I’m guessing the SD’s now offer the best mix of power, weight, fuel capacity, etc.

3

If I remember correctly SD stands for Super Duty or Severe Duty which is the designation for a 6 axle diesel locomostive. GP stands for General Purpose which is a 4 axle locomotive. These designations were used by General Motors Electromotive Division (EMD) I hope this helps

4

[#ditto]
SD stands for super duty, and GP for General Purpose

Greg

5

SD stands for Special Duty, not Super Duty.

6

I knew GP but not SD. Learn something every day (:))

7

I knew that SD stands for SPECIAL DUTY (not super duty or severe duty) before i posted, but didn’t know what “GP” stood for.