I specialize in modeling diesels in HO for D&RGW, and some for CB&Q, so I
have done quite a lot of research on them, especially the F units. My
sources have been Diesel Era's *The Revolutionary Diesel - EMC's FT *(1994),
Daniel Mulhearn/John Taibi *General Motors' F Units *(1982), Jeff Wilson's *F
Units - The Diesels That Did It *(2000), plus numerous articles from *Trains,
Model Railroader, *and other rail magazines.
When GM introduced the FT in 1939 with the test run of #103 across the
nation's railroads and when production FTs were first delivered in 1941,
most were drawbar-connected A-B units. The original EMC thinking was that
the FTs would be operated as 2 or 4-unit sets and that an A-B set would
always be operated together. The A-B set would be semi-permanently coupled
together with a drawbar. Most railroads bought A-B-B-A sets, usually
numbered with the same number for the entire set with each A or B unit
numbered with an A, B, C, or D. This varied for several roads, and the
D&RGW even numbered units at one point early in their careers with a very
confusing 540 1/4, 540 2/4, etc. system. The connection and numbering of FT
units depended on the individual road. Some roads, such as AT&SF, ordered
the original FTs with couplers on each unit. Most roads dropped the
drawbars not long after delivery and installed couplers to provide more
flexibility. If a B unit needed major maintenance, you would not lose use
of an A unit simply because it was connected to the B unit. This thinking
soon became prevalent with the FTs and other F series, so that the drawbar
was changed to couplers to provide more flexibility. Roads also found that
keeping F units in A-B or A-B-B-A consists was impractical, as it was easier
to couple an F unit into what other diesel units were available. In the
1950s, F units were being run with other F unit series and GPs and SDs.
Keeping a full A-B-B-A set as one unit looked nice, but it impacted on the
flexibility needed to utilize the MU concept of the diesel that made it so
much more efficient than the steam locomotive.
With the original order for FTs, the Q asked for them to be all equipped
with couplers. EMD's Dick Dilworth and D.H. Queeny argued that the A-B
units should be equipped with drawbars because couplers caused poor riding,
abnormal wheel and diaphragm wear, and reduced the amount of water carried
for the steam generator system. When the AT&SF ordered all their FTs with
couplers, EMD had to do some reengineering to make a coupler that would fit
between A and B units with the short clearance between the traction motors
of adjacent units. FTs were designed with truck wheelbases of 27'6" for
the A unit and 26'6" for the B unit. The B unit had a long overhang behind
the rear truck, but the front truck next to the A unit was right at the end
of the unit. Later F units, beginning with the F2, had 30'0" truck
wheelbases with the trucks well inside the body to allow couplers to be
mounted. Drawbars were not standard for any series after the FT. The Q
bought these initial arguments but soon made the decision during
construction to delete the steam generators and use the FTs only for freight
service. By late 1951, only 11 four-unit sets of the original FT remained
together, as 10 A-B sets had been coupled to F2As. The Q then began
equipping them with couplers over a long period of time. D&RGW did the same
thing over the 1950s, and even #5481, an FT which was badly damaged in a
wreck in 1950, was rebuilt with an F7 carbody, but it still had a drawbar to
connect to its B unit.
With the exception of the AT&SF and a few other customers, FT A-B sets came
with drawbars when delivered, as they were designed and built that way.
Each road gradually changed to couplers, and most FTs were scrapped or
traded in for second generation diesels in the 1960s, having all couplers by
that time. I am not aware of any FTs surviving to the 1960s with drawbars,
although there may have been some exceptions, as changing the drawbars for
couplers was quite an effort and expense.
By the time the F2 and F3 were introduced after the war, EMD had learned
that drawbars were a handicap and had lengthened the carbodies, allowing an
overhang for couplers to be mounted in draft gear to the frame and other
improved technology. EMD had quickly learned that operation in two and
four unit sets of F diesels was not a reasonable option for most railroads.
Best way to determine if drawbars continued on an FT is to look at a photo,
preferably a side view showing the connection between A and B units. You
may also be able to see by the close connection between A and B in a photo,
but that is not the best way to tell. The easiest way to tell is to see FT
units coupled to other types of units - F or GP/SD - as the D&RGW frequently
did into the 1950s and later.
- John Manion
On Sat, Oct 23, 2010 at 2:58 PM, Supplement Less
<supplementless@yahoo.com>wrote:
>
>
> Were the FT's ever broken down into single units or just AB sets? I know
> they started out with drawbars and there were some sets broken up and
> matched with F2's.
>
>
>
[Non-text portions of this message have been removed]
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