Railway Preservation News

A few questions
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Author:  EJ Berry [ Mon Sep 20, 2021 9:34 pm ]
Post subject:  Re: A few questions

Baldwin's production diesels used De La Vergne engines which were heavy and ran at a low speed (625 rpm). They never really acquired a modern diesel prime mover.

Baldwin built the carbodies and running gear for Westinghouse electric locomotives so the Centipede 2-D+D-2 wheel arrangement for each half would not be unusual in an electric in 1945. However, the 3000 HP of each half of a Centipede is very low for that wheel arrangement. By contrast an electric MILW "Little Joe" or CSS&SB "800" has 5000 HP on the same wheel arrangement and era.

Baldwin power plants were not the most reliable and were overweight for their power. They made decent shifters and heavy haul engines. The Centipedes were downrated from 3000 HP to 2500 and put in pusher service at which they did not excel.

Union Pacific returned to the two locomotives on one frame concept with the DD35 through DD40X units from 1963 to 1969. These were successful on UP until EMD's solid state dash-2 controls made MU'd units as reliable as large single units.

One Centipede story. The two halves could not function independently and shared a number. Since both halves were "A" units, one half was, for example, 5823A1 and the other half 5823A2 and they stayed coupled to each other.

They were still in road service when one day a PRR shop had the A1 half of one pair and the A2 half of another pair in the shop. There was a train that had to go, but no motive power. The foreman knew he had a usable A1 and a usable A2 so he made an odd couple and sent them on their way. The two in the shop got repaired and coupled together and they went out as a second odd couple with the same numbers.

Then, one 5823 was coming East with a train and the other 5823 was going West with a different train. A1 was meeting A2. The Block Operator knew this was a future accident and told the dispatcher who told the superintendent. Soon 5823A1, A2 to 5834A1, A2 became 5811A to 5834A.

Phil Mulligan

Author:  djl [ Wed Oct 20, 2021 10:38 am ]
Post subject:  Re: A few questions

But if they had more power, could they had been more succefoul?
A.C. before the solid state rectifiers (did they ever used Selenium rectifiers on locomotives?) was a little bit hard for rail transporation: either you had low frequency current (16 2/3 Hz., 25 Hz.) or using big stuff, like motor - generator or Mercury arc rectefires or ingnitrons. But they where the exception. "New Haven" E5 had ignitrons, but the locomotives where prone to fire because overheating.
In Romania they had the ideea of introducing 3 k.V. D.C. or 15 k.V. 16,7 (16 2/3) Hz. (German system), but the electrification was delayed because of the war and the lack of money and we finally adopted the modern 25-27 k.V. 50 Hz. system.

Among this scale model locomotives is a double electric obiously inspired by American design, but that never existed in real life: https://www.youtube.com/watch?v=68P5AfnhIf8

Author:  EJ Berry [ Wed Oct 20, 2021 8:41 pm ]
Post subject:  Re: A few questions

The Centipedes needed more than better engines.

16 2/3 Hz and 25 Hz allowed the use of commutator motors which gave you better speed control. In the USA residential power was (and is) 60 Hz but a number of industries used 25 Hz and the power companies had separate 25 Hz power systems for them. Safe Harbor dam on the Susquehanna River still has two generators producing 25 Hz power.

The NH EP-5 motors did have cooling problems but the very similar Virginian ELC rectifier motors did not. GE had learned: less horsepower, better cooling. VGN ELC became NH EF-4 and PC/CR E33.

Phil Mulligan

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