• MLW M-636 dimensions and details

  • Discussion of products from the American Locomotive Company. A web site with current Alco 251 information can be found here: Fairbanks-Morse/Alco 251.
Discussion of products from the American Locomotive Company. A web site with current Alco 251 information can be found here: Fairbanks-Morse/Alco 251.

Moderator: Alcoman

  by trainiac
Well, I've added new drawings and information for the units that received M-630 alternators. After pouring over all the photos I could find I've managed to confirm that CP 4202-4206, 4210-4211, 4213-4215, 4220, 4223, 4228, 4234 and 4244 all received new alternators. I've also been able to confirm that most of the remaining units did not get alternator replacements before being scrapped or sold.

The following units are the only ones I haven't confirmed beyond a doubt (with dates indicating the newest photo I could find indicating the original generator, and the date of retirement)
4201 - 1993; ret 1996
4207 - 1994; ret 1996
4208 - 1996; ret 1997
4218 - 1994; ret 1995
4221 - 1992; ret 1996
4224 - 1994; ret 1995
4225 - 1995; ret 1996
4232 - 1993; ret 1995
4246 - 1992; ret 1995
4248 - 1994; ret 1997

Even though the alternator replacements happened very late (early 1990s) I doubt many of these units would have received new alternators, as most of the photos show them very close to retirement.
  by mandealco
Awesome research. I started to do this myself, but now I don't have to. There were reports somewhere that the alternator equipped units were uprated in the horsepower department, but I doubt this was the case, as there was no increase in radiator capacity to match the added horsepower. I believe they retained their 2400hp rating, but had the advantage of reduced maintenance. Anyone else able to contribute to this, as far as why the upgrades were made?

Looking forward to seeing the drawings for these, as I have a couple to make in N-scale, RRPX 4204 in ERS black and 4228 in M&E red.

  by trainiac
And now to resurrect a 2 year-old thread...

I've recently continued researching the modifications CP made to the M-630 and M-636. It appears that some modifications were made rather early, such as the addition of drop steps and triangular handrail sections at the ends, and the replacement of the central door handles with latches. Later modifications included the addition of ditch lights, the relocation of the horn to the rear of the hood, and the addition of extra water tanks ahead of the radiators.

It appears that the last modifications (made around 1990) involved the air intakes, with revisions to the front intake and the addition of intakes under the exhaust stack. Not all units were modified - here's what I've found:

Only a few M-630's received sheets of louvres over the intakes, but over half the M-636's got them:

M-630's 4550, 61-63, 65
M-636's 4702, 03, 05, 06, 08-10, 13-15, 17-21, 23, 24, 30, 36, 38, 42, 43

A few other units received one of several different arrangements of square filters, including cat-repowered 4711:

M-630's 4553, 54
M-636's 4704, 07, 11, 16, 22, 28

Most of the rest appear to have retained the original air intakes with the original bolted panel under the exhaust stack. There are several for which I wasn't able to find photos in the final couple of years before retirement, but they had the original intakes at least up to the following dates:

4509 (1990)
4510 (1990)
4512 (1988)
4558 (1987)
4560 (1991)
4551 (1988)

4700 (1989)
4701 (1990)
4725 (1988)
4732 (1989)
4733 (1990)
4734 (1990)

The remaining units all show the original air intakes up to 1992-1994, so I presume the intakes were never modified.
M-630's 4508, 11, 52, 55-57, 59, 64, 66-73
M-636's 4712, 26, 27, 29, 31, 35, 39-41

I'm in the process of expanding my drawing variations to include the different intake modifications:

http://trainiax.net/mescaleloco-list.ph ... &scale18=1
  by mandealco
Thanks for the update Michael. Great info as usual.
  by trainiac
Well, it would appear that the original subject of this thread is no more. CP M-636 #4723 was cut up for scrap in 2017. As sad as I am to see it go, it was in poor condition, and there's a whole series of similar units in much better condition - two C-424's, an M-420, an M-630, the lone M-640, and a bunch of MLW S- and RS- units - at Exporail, just a stone's throw away from Farnham.

Now for the more exciting news: I've been putting Exporail locomotive measurements to use in more drawings, and have recently finished diagram images for two more models (the M-420 and RS-18). In the process of making the RS-18, I also discovered some significant differences between the RS-10 and RS-18, largely related to the size difference between the 244 and 251 series engines.

Dimensions of the RS-10 and RS-18, along with a (still developing) discussion of the two models, are here:

http://trainiax.net/mephase-mlwrs10-18.php" onclick="window.open(this.href);return false;

I haven't created a detailed history of the M-420 series yet, but the dimensions are here:

http://trainiax.net/medim-mlw-m420.php" onclick="window.open(this.href);return false;

Finally, other M-420, RS-10 and RS-18 drawings (so far representing a few CN ad CP variations) are available in the main Drawings section of my site.
  by Allen Hazen
Thank you for the work you have put into preserving and (web-) publishing these detailed measurements!
Both M-636 and C-636 units were built under license in Australia for Western Australian iron ore railroads. Do you know if they exactly matched North American production or had detail and minor dimensional differences?
  by trainiac
Allan - my knowledge on the Australian units is very limited, but from glancing at photos, the hood door and handrail stanchion spacing appear the same, which would suggest they have the same main dimensions as Canadian units. From what I can see, parts of the radiator, hood and steps were different but built within the same overall size.
  by Allen Hazen
Michael-- Thanks! I think a few of these units have been preserved: someone (not me-- I no longer live in Oz) should visit them with camera, notebook, and measuring tape!
  by mandealco
More valuable research material. Many thanks again for your continued effort to detail these awesome machines.