CPR S4 switchers

[Dayliner]

Well, I was pleased as punch when a friend told me that Atlas was bringing out an N scale S4 in CP Rail Action Red.  A little research confirmed that even the numbers were correct for the era and locale of my layout.  Woo-hoo!  It doesn't get any better than that in model train land.

Then reality struck, as it so often does.  The numbers may be accurate, but the models are not.  The CP ordered two lots of S4s, of ten locomotives each.  The Atlas model is indeed an accurate rendition of the first batch, built in 1949 for yard service.  The second batch were built in 1952-53 for yard, work, and plow train service on the main line between Calgary and Revelstoke and on the Kootenay-Kettle Valley lines.  These latter units have a raised walkway on both sides of the unit in front of the cab.  On both sides, the space under the walkway is enclosed, except for a short space immediately in front of the cab.

The easiest solution would be simply to renumber the model, but as I want the factory number, I'm going to have to modify the model--and that task will be a bit easier if I have some idea what it is I am trying to represent.

Any guesses, anyone?  I see pipes running through the open space in front of the cab--is it something to do with the fuel filter and supply system?  Is it something to do with the engines' orginally-intended main line service?  Any tips will be gladly received.

I do have a couple of photos, and if I can figure out how to post them, I will put one up.

Many thanks.

[MARTIN STATION]

 You might try contacting Atlas with the information you have listed in your post. At this early stage, it's possible that changes can still be made for the CP S4s. I know where this has happened before. It really doesn't hurt to try, especially if you have photos and suggestions that you can send them. 

Ralph

[cv_acr]

MARTIN STATION

 You might try contacting Atlas with the information you have listed in your post. At this early stage, it's possible that changes can still be made for the CP S4s. I know where this has happened before. It really doesn't hurt to try, especially if you have photos and suggestions that you can send them. 

Ralph

 

Atlas doesn't do major road-specific body variations like that, so you will definitely not see them tool those boxes, but they could possibly change road numbers to the lower group 7100-7108.

Also those boxes (I think they are expanded fuel tanks) on the walkway seems to have been in-service modications added by CP. Have seen an early photo of 7113 in the older maroon and grey with block lettering without them, and several later shots of the same unit with the boxes added.

[cv_acr]

Dayliner

Is it something to do with the engines' orginally-intended main line service?

I'm not sure what you mean by "intended for main line service".

The units didn't have m/u capability, so could only run as a single unit, and clearly intended for yard work.

[MARTIN STATION]

Sorry, Chris is right, I really ment to suggest a change in road numbers to one that would be more correct for the Atlas style of locomotive.

Ralph

[cx500]

cv_acr

 I'm not sure what you mean by "intended for main line service".

The units didn't have m/u capability, so could only run as a single unit, and clearly intended for yard work.

 

 

Main line service does not mean only hauling heavy long distance trains.  Various branches were also operationally "main lines" and used the same rules.  Often traffic was light and could easily be handled by one unit, so no m/u capability was required.  Speeds on the branch "main lines" were usually slow so horsepower was not a concern, and switchers generally had more than enough tractive effort.  Being smaller they were usually lighter, an important consideration where fragile bridges existed.

 

And out on the important main lines there was still a need to service local industries with a wayfreight and provide work trains for the maintenance of way personnel that did not need big power.  A cheaper locomotive seemed an obvious choice.

 

These S-4s were versatile units that were intended to be used in the yard and out on the road as required.  They were in most respects standard production, with the addition of class lights being the significant modification.

[Dayliner]

Thank you, gentlemen.  Chris' guess that these were additional fuel tanks seems a likely one to me; the location and the piping make sense from what I know of the innards of the 539-equipped S-series switchers.  I am sure that this was indeed an after-market modification; but of the 10 engines in the series the only one I have seen not so equipped was 7110, which had the "watchman" heater installed.

The S4s were indeed orginally intended for "main line" service, particularly on the Kootenay and Kettle Valley divisions, although they didn't last long in that role and five of the later batch were soon sent to Vancouver for transfer service.  I know that at least some of the original batch (7099-7108) were equipped with MU controls, and possibly some of the later batch as well, although this too would have been an in-service modification.

Ralph, I am sorely tempted to go the easy route and just re-number (or get Atlas to do it for me, as you suggest!), but I have this "thing" that I want to run locomotives that actually ran on my prototype, more or less consistent with the era I am modelling.  I have some friends who have set the bar pretty high in this respect, and I don't want to be seen to be letting the side down! (I know--that's my problem, and mine alone.)

Thanks again for your guidance.