Six axle EMD's on light rail?

[deez]

I plan to operate my freelance rr on ex Pacific Electric trackage. I know allot of it was worn out 60-70 lb rail. Would diesels like the SDP35 be too heavy for these rails? I'm pretty sure the SD7's & SD28's I plan to run can be made with smaller fuel tanks etc. to be light on the rails. But I also want to run some ex UP SDP35's & SD40X units also. 70lb or 75lb could be the proposed upgrade but 60lb might have to stick with 4 axles like the GP15T's or GP30's I want to run also. I would like to not stray too far from a prototypical situation and that's why I ask this. 
 I was also moonlighting on the idea of a modern Pacific Electric that is still alive but now dieselized and mostly freight operations. I model the 80's so modern for me would be that time frame. Allot more PE trackage was still around then too. The ex UP SDP35's could be used for passenger service that was the most popular and profitable on certain lines also. Just kickin these ideas around. Let me know what ya think. 

[slowfreight]

I've seen 90lb rail successfully used with 6 axles and coal trains, but 75lb rail will be pushing it because you definitely couldn't do 286k...maybe not even 263k. On the prototype you'd probably be looking at SW-type units at the largest. Truthfully, you'd be in SDL39 territory before you could justify an SDP35.

BUT...if you could justify enough business in your fictional world to need SD's, then you might be able to argue that the rail was upgraded to 90lb or 112lb, using some reasonably-priced relay rail in the late 70s or early 80s...maybe even right after the 1980 recession or something (I know that sounds incompatible with growing business).

[oldrail]

Soo Line had some 85 and 990 lb rail in places on main line in North Dakota in late '70's early '80's. Speed limit was 40 mph for all power (SD40-2) and 263k cars. Weight of rail is only part of the equation. Tie condition, ballast and sub grade all are factors too. Soo Line had very good tie conditions, track was rock ballast tamped and lined and sub graded wasn't all fouled with mud, etc.
On branch lines Soo had 60 and 72 lb rail in places, 263k cars were restricted to 10 mph and only four axle units, the heaviest of which were GP38-2.

If the PE was still around by the '80's they would almost certainly have upgraded to heavier rail because by that time decent 60 thru 90lb rail was no longer available.

Dick haave

[emd16645]

Some roads would remove ballast to lighten an engine for weight restrictions. An example is the Bangor and Aroostook modified two BL-2 locomotives for use on the Greenville branch. The Branch had a trestle that had a weight restriction that caused the modifications. There also were timetable instructions that specified how much fuel was allowed (tank could not be full).

I think by the 80s most of the PE track would have been upgraded if the line was still in operation. It was common to see the main lines upgraded with heavier rail, and the removed rail was often reused on the branches and spurs.

[m a y o r 79]

The Milwaukee Road had a lot of light rail. Typically they would use 4 axle power but they did have some 6 axle RSC's that were light enough. From the EMD side the SD7/9 with a single fuel tank were common light rail power. When the RSC's were worn our they ordered the SDL39 from EMD specifically for light rail branchlines.

[lajmdlr]

The PE was absorbed into SP after 1964. A lot of the tracks were kept for serving industrial customers. But the number of customers have decreased the last 20 years.

[deez]

Thanks guys for the input. I do have a stash of Shinohara code 70 track & switches. Realistically an upgrade on many lines would probably be put in use by the 70's at the latest for PE track. There still is original PE track in use on a branch in Rialto CA by the UP. Idk what lb. it is but I've only seen Geeps on it. I want to keep the jointed rail style mostly too. There is 90lb jointed right? 

[sdp45]

The SP used light weight SD7's and SD9's. Some 6 axle Baldwins also operated on the ex-PE branches. The most common power though were the GP9's and the SW1500's. One thing to keep in mind is the area of the ex PE you are modeling. Some of it was heavier than others and the radius's also varied depending on the line.

An SDP35 is plausible as it is the same length as a SD9 (or close) but I would delete the steam generator detail and shorten the tank to show that it is light on its toes. Same with the SD35. Also I would de-turbo those as well and delete the dynamic brakes as weight saving and performance measures.

[slowfreight]

Mar 15, 2016 1:12:29 GMT -5 sdp45 said:

An SDP35 is plausible as it is the same length as a SD9 (or close) but I would delete the steam generator detail and shorten the tank to show that it is light on its toes. Same with the SD35. Also I would de-turbo those as well and delete the dynamic brakes as weight saving and performance measures.

Like this?

flic.kr/p/gpgTtE

[sdp45]

That works, but i would shorten the tank as well just for fun. I mean you could run it "empty" but what fun is that?

[sdp45]

That works, but i would shorten the tank as well just for fun. I mean you could run it "empty" but what fun is that?

[deez]

It kinda defeats the purpose of aquiring the SDP35's from UP. I wanted half for freight and half would retain their steam equipment for passenger use. I'll figure the situation out. It's perfectly plausible to have lines receive upgraded track as well. Plus not all of the lines acquired would be specifically ex PE.

[milw199]

I've run SD40-2s on 72 lb, and maybe 60 lb rail. End of a branch line, taking headroom. Just go slow. As long as you have good ties,, rails are in gauge, etc., you can run big stuff on spindly rail once in a while. 90 lb stick rail is far more common, represented well by code 70 in HO scale.

Having lightweight engines was more common before 263k cars became essentially standard. These days, the track has to support the heavier cars.

[jmlaboda]

Using an SDP35 may not be all that unreasonable, especially considering that an SD40 was built new to run on such rail...

Really kind of surprised that no one has mentioned it but Seaboard Air Line subsidiary Gainesville Midland had a purpose-built SD40 with a very small fuel tank for use on its spindly light rail branches. Formerly the home of lightweight 2-10-0 Decapods the GM went to using its parent's ALCO RSC2s and RSC3s from the end of steam until around 1966 when GM 10 was delivered and it lasted on those branches up to CSX, even becoming CSX "0010" in patched paint. The engine has been gone for quite a long time now but it was a sight to see on those light rail branches, serving with distinction.

Here are some links to shots of this unique unit. Note that the shots show the unit late in life, still in its original SAL-inspired paint scheme that it was originally painted in, the red trim stripes having vanished years before as the paint gave way to age and weathering. As delivered the unit had the roadname spelled out on the long hood.

rrpicturearchives.net/locoPicture.aspx?id=58248
rr-fallenflags.org/misc-g/gm10jpa.jpg

[brgp302300]

Lehigh Valley had a branch that restricted loco usage.......SW8`s were all that could be used.

[deez]

I guess my real issue is that I don't want to change or "rebuild" these SDP35's. They were basically taken straight out of UP's deadline, given a tune up and thrown into service. My railroad doesn't have the time or money for nice diesels. A paint job that'll probably happen only once in its working life will be about it for any special attention most MB units get lol.