I have an Alco T6 (made by Alco -models-).
I believe that the T stands for Transfer… rather than S or SW for Switcher.
Would someone please tell me what the difference is between a transfer loco and a switcher?
The only other transfers I’m aware of are the huge EJ&E double ended Baldwins. Were there others? T1 -4 or ?
TIA[8D][8D]
SW10 bit comes later… 'cos I received really good answers on the T6 [8D]
According to the Diesel Spotters Guide, the T6 had the ability to make transition, which switchers lacked. It also had a 1000 hp 251 engine. There were no other models in the T series.
Both Baldwin and Lima made 6 axle double ended transfer engines, but neither sold well. Most transfer work is made using conventional switcher or road units.
Dave H.
How about the Baldwin-Lima-Hamilton T2500. That was a BIG transfer locomotive.
Er… what’s “transition” in this case? Did they just mean they rode better for inter-yard work… or? TIA
David,
Transition is changing the wiring of the traction motors from series to parallel as the engine increased in speed(sort of like a manual gear shift). Actually the Alco S6 switcher had ‘transition’, but the T6 used the GE ‘Amplidyne’ excitation system(as did the normal RS series road engines). That and the ‘notch’ number boards were the spotting features of the T6. Back in the 50’s, the GE electrical system in locomotives was considered the ‘best of breed’. Even EMD engineers admitted that(the system was patented). IIRC, the S6 switcher was rated at 900 hp(may 1000 hp later), but the T6 was rated at 1000 hp from the start. The S6 & T6 used a 251 series diesel, and replace the old S2 & S4 that used the inline ‘539’ diesel. The ‘539’ was used in the S1/S2/S3/S4, the RS1, and even the DL109 passenger engine. It was a very early design, and the power/weight ratio was poor compared to the EMD ‘567’ power plant. In spite of that, it soldiered on for many year - a pretty solid design, if not a little overweight.
Jim Bernier
Great help! Thanks [:D]
Any chance of enlightening me on my SW10? This is a UP loco with an enormous hump for fans on the nose. I’ve not found a pic of the real thing… so I can’t tell if this was unique to UP or even to one or two locos. I presume that this one at least did a lot of slow running in a hot environment (Alaska)? [%-)]
Was there a “standard” nosed SW10?
TIA again
Think we’re getting way off base here, as I recall a transfer engine did just that - it transferred cars from one area in a yard to another. Don’t recall the specifics to why they were designated this way, but there must have been something, perhaps geared for low speed service, etc.
Bob Boudreau
I believe UP rebuilt some switchers to SW10s. Not being a UP fan, I do not know what the modification was. If I had to guess, I would say that they are possibly dynamic brakes. They never operated in Alaska (UP does not go there). By the way, I probably does get hotter in the interior of Alaska during summer than most people think it does, however, I doubt it gets as hot as most places in the US. What do you mean by a “hot environment”?
My idea of transistion : when a four axle,four motor switcher starts moving all four traction motors are wired in series to the generator. As speed builds up to overcome the counter EMF the engineer makes a “transistion” which puts the motors into a parallel circuit. This allows the locomotive to reach a higher speed.
Okay, confesion time… I was being lazy. (Don’t know how that got “off base”).
It worked though… as always, as soon as I asked I fell over a heap of really good stuff… on the SW10 at least… anyone is interested try the following link…
http://utahrails.net/webpubs/up-sw10s.php
The site is worth looking around via the home page… Really excellent stuff.
I sit corrected on Alaskan temperatures… should have known… you’re just over the water from Sideria… and that has incredible temperature ranges… and tigers.
By hot temperatures I was really thinking more of steel works and other places where both cooling and filtering might need to be increased. I haven’t read all the article myself so the answer might be in there.
I thought UP went everywhere now? [}:)]
Thanks for help once again everyone.[:D][:D][:D]
Bob,The transfer of cars by a transfer engine-any type of engine will work-could and would include “transfer runs” to other railroads located in the same city.
David,EMD did have a cow/calf set that sold as transfer units.However,these cow/calf sets was also use in heavy switching as well as hump duty.EMD called these sets TR units…
http://www.trainweb.org/chessiephotos/photos/TR4/9624b&o.jpg
SW10s were UP only rebuilds, using components from GP9s. Hence the bulge on the front.
Nick