Alco T6 Drawings/Diagrams

Discussion of products from the American Locomotive Company. A web site with current Alco 251 information can be found here: Fairbanks-Morse/Alco 251.

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Luther Brefo
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Alco T6 Drawings/Diagrams

Post by Luther Brefo »

Has anyone got drawings, diagrams, or any artwork feature the last Alco end cab design, the T6?

I would prefer something with dimensions but for now anything is better than nothing.
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GOLDEN-ARM
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Post by GOLDEN-ARM »

Like this?
Image

txbritt
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Post by txbritt »

Aren't they just S-2's with type A's and 251's? That was my impression when I worked on them up on the A&M. Different nose too, the T-6 has the notched corners.

Britt

Luther Brefo
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Post by Luther Brefo »

GOLDEN-ARM wrote:Like this?
Image
Just like that. Have you got any more? Perhaps one from the rear of the cab, and any overheads? Also would this be the artwork for a normal version or an NW version? I am guessing this is for the normal version as the NW louvers were staggered diffrently.
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truman

Post by truman »

Got my first cab ride in one of these.
I seen to recall something about the controls being different too, something about being able to make transition like a road engine?

Allen Hazen
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Post by Allen Hazen »

Luther Brefo--
Non-N&W. The drawing Golden-Arm posted is from the Pennsylvania Railroad's diagram book; it and many (but by no means all) others are available on-line at George Elwood's "Fallen Flags" rail picture site.

txbritt--
Alco didn't change the basic configuration for their switchers much over the years-- seen from behind, a T-6 looks very much like an HH-600! So, yes, the T-6 is the basic Alco 1,000 hp switcher (which went to "Type-A" trucks with the S-4 of 1950) with modernized components: Alco 251 engine, appropriate newer GE generator model, and-- this makes a real difference in lugging ability-- 752 traction motors. Compare the continuous tractive effort figures with those for an S-2!

Truman--
That's the story, anyway: T-6 had transition, fitting it for higher speed service than the earlier switchers. "T" instead of "S" in the model designation because Alco billed it as a "transfer" locomotive.

EDM5970
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Transition

Post by EDM5970 »

I keep reading about Alco switchers being equipped with transition, here and even in Kirkland, and have to comment. All of the 539 and 251 switchers (and the RS-1) were equipped with transition, automatic as the speed increased.

They all started in series, went to series-parallel, and then had a stage of reduced field. The maximum speed of 60 MPH usually listed for Alco switchers was based on gear ratio and maximum TM speed. I'm not sure I would want to go 60 on just about any switcher, unelss it was on Metroliner track. (BTW, the 74/18 gear ratio listed with the drawing is good for 65 on an RS-xx, 70 on a Century-)

Now, the EMD SW-1 didn't always have transition, it was at one time an option. I'm used to run one that was said to be capable of going 19 MPH downhill, and with a tailwind. The back EMF just held it there.

Perhaps some of the old timers comparing SW-1s with Alcos gave rise to this story about transition.

Allen Hazen
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Post by Allen Hazen »

EDM5970--
Sorry, I goofed! I was just going along with the statements in the railfan literature about transition being something special with the T-6, and repeating what is in the railfan literature is NOT ... well, not good scholarship. (In my defense, though, even Kirkland says it [as you note]!)
Maybe Alco -- seeing that there wasn't all that much demand for 1000hp switchers in 1958 (when the T-6 was introduced) just decided to highlight, in sales literature and model number, a feature that had been there all along?
--
About the top speed of Alco switchers: The New York Central's diagram pages (of which there are some at George Elwood's site, though not for as many models as one would wish!) list 60mph as the top speed for Alco switchers on the line where top speeds are given, but adds a footnote: the 60mph is calculated from the gear ratio, but the locomotive itself is limited to 40mph.

EDM5970
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Switcher comparisons

Post by EDM5970 »

Allen-

Interesting speculation, in regard to Alco pointing out a feature that had always been there. Even more interesting is the fact that John Kirkland, a life long Baldwin employee, only mentions transition (as an option) in respect to the RS-23, which (along with the S-13) was offered with either 731 or 752 motors. (At least this is what I picked up from a real quick review, just now-)

Going back to Kirkland being a BLW man, Baldwins never made transition. Period. They were always connected in series-parallel, and had one or more stages of field shunting as speed increased. Perhaps Kirkland saw some Alco/GE sales literature, from around 1960, and this feature stuck in his mind: BLWs didn't transition, Alcos can.

Switcher trucks don't ride well as speed, your NYC information is quite correct. The rigid bolster truck rides better than the Blunt truck that it replaced, but not as well as the swing bolster truck; I've been over part of the NYC main at 60 on an RS-1, and run the same unit down part of the West Shore at 50.

Another comparison has to be made between the SW-1 and its rival S-1 or later S-3. Aside from having a few more horsepower and transition as a standard feature, the Alcos had a feature that the SW-1 never had: traction motor blowers. You had to go to the NW-2 to get TM blowers, although tne NW-2 had transition and as an option could be built with field shunting.

Alcoman
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Post by Alcoman »

Off the top of my head, I think the difference between the T-6 and other Alco switchers was not just the transition feature, but AUTOMATIC transition vs manual transition. I have to dig out my T-6 specifications and manuals to be sure.

Correct me if I am wrong, but I seemed to recall that when transition was made with some locomotives, you had to shut off the throttle and then advance the field using another handle each time you wanted to go up or down with the fields to gain or slow the speed.

With a T-6, this was done with electrical circuits.

txbritt
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Post by txbritt »

Alcoman wrote:Off the top of my head, I think the difference between the T-6 and other Alco switchers was not just the transition feature, but AUTOMATIC transition vs manual transition. I have to dig out my T-6 specifications and manuals to be sure.

Correct me if I am wrong, but I seemed to recall that when transition was made with some locomotives, you had to shut off the throttle and then advance the field using another handle each time you wanted to go up or down with the fields to gain or slow the speed.

With a T-6, this was done with electrical circuits.

on the S-2 it was done with the reverser. If I'm not mistaken, the reverser has 7 positions?

Britt

EDM5970
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Post by EDM5970 »

Forward transition on the 539s was automatic but to make backwards transition you had to close and reopen the throttle. You didn't have to move the handle for backwards transition, unless you wanted to keep the unit in a particular connection, I.E going up a stiff grade and you wanted to hold in series. Personal experience, and also in TP-105 and TP-107.

Britt is correct, the single unit (non-MU) locomotives had a seven position reverser. Off was in the center, one position forward (or reverse) gave you series, the middle position forward (or aft) set the unit up for series-parallel, the third, full forward (or reverse) position allowed reduced field operation.

A good analogy would be a three speed automatic transmission in a car: P-R-N-D-2-L. Almost all of the time we go right to Drive, and the transmission automatically shifts up through L and 2 to the third gear, D. But on a hill, or with a trailer, we may want to stay in 2 or even L. The transmission goes to that gear and won't advance to the next one.

Kicking cars, as mentioned in the Alco TPs, (and also in EMD manuals), is when you want to stay with the series connection, and "forstall" (again, borrowing the term from EMD) transition. But for road operation, crank the thing all the way to the end and open the throttle.

The MU units had a three position reverse handle: F-Off-R. A seperate push-pull switch on the control stand was used for "series hold", which kept the unit or entire consist in series. There was no way to allow series-parallel operation, but to disable reduced field.

If anyone comes up with any more on this transition myth, please post it here. But every 539 I've seen, and every manual or schematic I've collected and studied show that transition was automatic forward, and manual backwards.

txbritt
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Post by txbritt »

Answer me this then!

The 2350 ( Alco S-2, ex santa fe, 1945 ) has the old EMD drum stand with a transition lever. I believe its 4 position ( off-1-2-3 ) How do you think Santa Fe figured this out? Are the Alco transition circuits, and EMD controllers that similar?

The contactors in the elec. locker look origional.

Britt

EDM5970
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Wires is Wires-

Post by EDM5970 »

--- well, not quite---

Alco, or in this case GE, used one handle to control two functions. The direction and motor connection controls are combined in that 7 position controller.

EMD, with the "can" controller, had 2 levers, one for direction, the other for selecting motor connections. I suspect 2350 is wired off/series/series-parallel/reduced field. (One quick way to find out would be to ring out that last finger and see if it goes to the M contactor coils.)

So yes, its the same thing, but with wires running to different places on different numbers and types of switches. And remember that EMC/EMD used electrical equipment from GE (usually) until they started building their own, so there would be similarities, at least on older equipment.

Compare an NW-2 and S-2 schematic sometime; the biggest differences are in excitation and load regulation. The rest is very similar.

In later units, like with the RS-2 and up, the selector lever would set up transition, and would also modulate your dynamic braking through a rheostat in the control stand. Those units had a seperate reverse handle, though.

I believe current standards (AAR recommendation?) call for three handles on a control stand: throttle, direction and (optional) DB. Manual transition is a thing of the past, and there is no transition handle or assigned trainline wires, which used to be 18 and 19.

txbritt
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Post by txbritt »

You need to write a book before your head explodes! I mean that as a complement. Maybe a book on the history of locomotive electrical theory?

I was supposed to have called you this evening, but I got home too late to do so - you're an hour ahead of me, and I don't want to call too late.

Britt

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