MLW and Alco Locomotive Differences?

Trains Magazine Locomotives
1

Hey y’all! I’m trying to find the differences between MLW and Alco locomotives. The specific models I am looking for info on are the C630’s and M630’s. Thanks to anyone who can help. -Outlaw

2

  1. Different trucks. Alcos used Hi-Ad or Trimount trucks, MLWs used Dofasco trucks.

  2. Aftercooler shape differences and different grill arrangements.

  3. MLWs have hood mounted headlights and cab mounted bells, Alcos have cab mounted headlights and bells mounted under the frame near the front truck.

  4. Radiator arrangement differences.

3

What was the point of the headlight and bell positions being changed?

4

I’m not sure, but it was probably requested by the railroads. GMDs also have the same bell and headlight placement differences from EMDs, though EMDs could be ordered with a hood mounted headlight.

5

It should be noted that C630M units built by MLW indeed had MLW design trucks built by Dofasco but all other features were the same as the Alco units, including the forward mounted intercooler radiator.

However, the M630, at least as built had no separate intercooler radiator, but cooled the intercooler water in the main radiator. In place of the intercooler radiator and grilles was a combined main blower air intake and dynamic brake unit, in which the grids were cooled by the main blower and the hot air exited through three louvred ducts in the centre top of the unit. An interesting feature was that the air intake grilles were a slightly different length on each side.

The radiator arrangements were generally similar, with three horizontal cores.

M636C

6

Thank you, I bow down to your far greater knowledge and experience.

On the radiators, it would probably have been better to say ‘detail differences’. Alcos had an irregular protrusion above the grille, and a rectangular structure at the roofline, where MLWs had this entire side area extended out from the rest of the side with flush grilles, and tapers at the end of the roof grid structure. For reference:

http://www.rrpicturearchives.net/showPicture.aspx?id=2635729

http://www.rrpicturearchives.net/showPicture.aspx?id=206524

Also, some of the SP units had roof mounted bells.

7

In a word “winter”.

It was found that when the healights were placed in the low hood like in a car, during snowstorms headaches caused by having the light reflected off the snowflakes right ahead and above the engineers eyes were reduced.

The bells were moved from near the truck to higher points due to snow flying up from the truck that was packing the bell solid and the clapper couldn’t move. CP made these changes on all brands of locos by about 1960.

Bruce