• Diesels with Pantographs

  • General discussion about locomotives, rolling stock, and equipment
General discussion about locomotives, rolling stock, and equipment

Moderator: John_Perkowski

  by Pensyfan19
So I was wondering on facebook and noticed that this ALCO RS1 had a pantograph. This was likely for a shortline or switching railroad at the time, and I think other diesel locomotives, such as the SW1(?) were equipped with pantographs so that they would work as freight and switching locomotives on interurbans.

https://www.facebook.com/EMDPictures/ph ... 9405556141

With this in mind, could it be possible for either class Is, class IIs or shortlines to electrify spurs near already existing tracks which are under the wire, such as the Northeast Corridor, Metra electric district, South Shore Line and soon to be Caltrain, and use locomotives similar to these for local and switching purposes? Maybe they can even purchase/convert existing engines into dual-mode for this task. :wink:
  by leestepr
That trolley pole was very unlikely to have been used for power, and was intended to engage interurban/trolley line signaling equipment that relied on the trolley pole on the wire. Southern Pacific diesel switchers that operated on the Pacific Electric had similar such poles.
  by Pneudyne
My understanding is that diesel switchers used by Interurbans and similar roads were fitted with trolleys (or pantographs) not to supply power, but to enable them to operate signaling equipment tied into to the overhead power supply. I think that the attached example is illustrative.

Popular Mechanics Railroad Album p.104ex.jpg
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  by Pensyfan19
Ok. Thank you for this information.

In this case, could it be possible to have dual-mode diesel locomotives for easier local freight service along electrified territory?
  by edbear
There is no need for dual mode power in the electrified territory. In the examples cited in original post the owning agency does not operate whatever freight service is provided. It is some other operator. For the NEC east of New Haven there are G&W (P&W) and CSX.
  by Allen Hazen
Don't remember details, but I have seen references (within the past five years or so) to British or European proposals for electric freight locomotives with on-board diesel generators: the Diesel engines wouldn't be powerful enough to pull trains at mainline speeds, but would be used to allow at least slow operation for the "last mile" to non-electrified industrial sidings. A similar idea in principle to the "Bi-power" or "Tri-power" locomotives built for NY Central and DL&W by GE in the early 1930s.
  by Pneudyne
Here is an article on the NYC Three-Power locomotives of the 1930s:
NYC Three-Power DRT 195304.pdf
The British Rail classes 73 and 74 “electrodiesels” of the 1970s conformed to the “electric locomotive with auxiliary diesel power “ description. The class 73, which was very successful, was built as such, as a 1600 hp DC electric with a 600 hp diesel engine. The class 74 was converted from the class 71 2500 hp DC electric with the addition of a 650 hp diesel engine and a new electronic control system. It was not very successful.

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  by CarterB
Illinois Terminal had several battery/diesel/electric locos.
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  by Allen Hazen
Thank you for posting the DRT article on the New York Central tri-power locomotives! Not often that one sees a technical article, in the trade press, on a locomotive almost 20 years old!
As to why the original, 1934, article chose to compare them to an 800 hp diesel... I think the larger I-R Diesel engine was rated at 800 hp when these locomotives were built: it was used in a box-cab switcher that GE built for the Erie about then: technologically (and visually!) comparable. Since the New York Central had ordered a 2-D-2 freight locomotive with the large I-R engine at the same time they ordered the prototype tri-power unit, they were aware of both alternatives.
Mind you, the straight diesel-electric switcher couldn't have its engine turned off for switching inside the butter warehouse! (The West Side freight line was largely abandoned, though Amtrak's access to New York's Penn Station for up-state New York trains uses some of its trackage. The elevated structure that carried it south of Penn Station has been re-cycled as the "High Line" walking path.)
As to the units not being used exclusively for switching, there is a photo of one pulling a short (3 car, I think) commuter train on the non-electrified trackage north of Harmon, NY.