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Western Railroad Discussion > The Origin of the "A-Frame"

Date: 01/10/19 00:24
The Origin of the "A-Frame"
Author: funnelfan

The Origins of the "A-Frame", a term often incorrectly used to describe any railroad flatcar with a center divider used for shipping lumber such as centerbeams or modified bulkhead flatcars. True "A-Frame" flatcars were developed and sold by K.D.Tomlinson through his Tomco Railway Car Co (KDTX reporting marks). K.D. Tomlinson was the owner of the Tomlinson Lumber Co of Minnesota and frustrated by the amount of time it took to load and unload lumber from rail cars. He also was a lumber broker for other mills and had a intrest in the White Pine Sash Co with mills in Spokane, WA and Missoula, MT. At the time lumber was loaded into boxcars and flatcars one stick at a time by several men. Flatcars further required a wooden framework to be built to hold the loose lumber on the flatcars.
K.D.Tomlinson worked with the Northern Pacific Railway in 1963 to develop the first prototype A-Frame flatcar to hold bundles of lumber that could be secured to the car with cables. Angled risers would pitch the bundles against a center divider consisting a series of "A" frames with linking cross members. Heavy duty forklifts could then easily insert their forks under the lumber bundles and remove the bundles of lumber. NP supplied flatcar NP 67080 for use as a prototype.
While K.D.Thomlinson saw the car as a success, NP saw that the framework reduced the usefulness of the car for return loads from the east. Mr Tomlinson was forced to build his own A-Frames, and thus started the Tomco Railway Car Co. Other major lumber shippers across the west also liked what they saw in the prototype NP car and demanded their own A-Frames. Tomco would buy second-hand flatcars and then construct the A-Frame on top of them. Most did not feature full width bulkheads, just the center divider. Several major lumber companies bought or leased the cars, complete with a large banner on the top of the divider with the company name. While dozens of the cars were sold or leased during the later half of the 1960's,  they unfortunately developed a reputation of being unstable at higher speeds (hard to say if this was true as railroads were deteriorating fast due to the suffocating grip of ICC regulations).
But the cars did prove the concept, and would pave the way for future purpose built lumber cars. It's ironic that Northern Pacific Railway, which facilitated the prototype "A-Frame", and then rejected it, would also buy the first of it's successor, the Centerbeam! In 1969 NP purchased 5 Centerbeams from Thrall Inc. These cars are distinguished from later cars because they feature angular openings in the center divider instead of the iconic oval "opera window" openings on cars built all through the 1970's into the early 1980's. On "Centerbeams" the center beam is an actual structural member of the car allowing higher loading capacities than the A-Frames, which were just a steel frame work, but not integral to the structure of the car. While railroads continued to buy more Bulkhead flatcars than Centerbeams for lumber loading in the 1970's, that took a dramatic change during the 1980's when private operators including upstart reload operations bought their own fleet of centerbeams to ensure a proper supply of the popular cars.
While the centerbeams quickly supplanted the predecessor A-Frames, those earlier cars found new homes on slow speed private operations. Simpson Railway of Shelton, WA used them right up to the end of operations in 2015.

Ted Curphey
Cheney, WA

Edited 3 time(s). Last edit at 01/10/19 08:16 by funnelfan.

Date: 01/10/19 00:33
Re: The Origin of the "A-Frame"
Author: funnelfan

The design of each car using mostly second-hand flatcars varied....A LOT!!!

Ted Curphey
Cheney, WA

Date: 01/10/19 02:20
Re: The Origin of the "A-Frame"
Author: MNNRfan

Very interesting!! Thanks for posting!

Posted from Android

Date: 01/10/19 04:37
Re: The Origin of the "A-Frame"
Author: K3HX

Thanks for the interesting and educational posting.

Be Well,

Tim Colbert  K3HX

Date: 01/10/19 06:22
Re: The Origin of the "A-Frame"
Author: tgcostello

Thanks Ted.

Date: 01/10/19 07:42
Re: The Origin of the "A-Frame"
Author: tomstp

Very interesting.  Thanks.

Date: 01/10/19 09:44
Re: The Origin of the "A-Frame"
Author: highgreengraphics

Bottom photo of Plum Creek flat is mine, posted here on TO, taken 6-72 in Traverse City, MI. I was 14 years old! === === = === JLH

Date: 01/10/19 10:30
Re: The Origin of the "A-Frame"
Author: TCnR

Great info. Interesting to see the private cars at that date. Thanks to everybody taking freight car rosters of these as well.

Date: 01/10/19 11:48
Re: The Origin of the "A-Frame"
Author: Pacific5th

There is a Tomco car used as a bridge in Naples ID. 

Date: 01/10/19 12:13
Re: The Origin of the "A-Frame"
Author: EsPee1229

Thanks, Ted. Very interesting information.  No way to confirm or disprove now, but I wonder if the purported instability was due to the A-frame not being integral to the car.


Date: 01/10/19 13:41
Re: The Origin of the "A-Frame"
Author: fbe

The instability was 2 mty cars meeting on double track with the air being pushed by the open bulkheads running into each other causing one car to twist into the other resulting in both trains derailing. Commonly trains with bulkhead centerbeam cars and other bulkhead cars were restricted to 45 mph to eliminate the derailments.

Date: 01/10/19 15:44
Re: The Origin of the "A-Frame"
Author: mapboy

The Bennett Lumber Products photo reminds me that they were big on using all-door box cars.


Date: 01/10/19 17:46
Re: The Origin of the "A-Frame"
Author: dan

An A frame was comprimised on  I225 today in aurora, looked like granite on it, may have to transload right there.

Date: 01/10/19 17:46
Re: The Origin of the "A-Frame"
Author: dan

An A frame om a semi was comprimised on  I225 today in aurora, looked like granite on it, may have to transload right there.

Date: 01/10/19 23:02
Re: The Origin of the "A-Frame"
Author: aronco

A very interesting posting.  When I worked for the SP in the 60's, we frequently would get trains Eastbound from Bakersfield with 60 to 75 flatcar loads of lumber, about 5000 tons in a train, with 4 SD-9's leading and a three unit helper to Tehachapi.  Riding in the caboose reminded one of the forests of Oregon with the scent of fresh cut lumber.  The loading method was called figure 5-A where a set of cross member and rub rails was placed on the flatcar, then bundles of  lumber were stacked interlocked and banded together.  The intent was that the load would slide somewhat upon impact but the entire unit would remain somewhere on the flatcar.  The develpopment of the A-frame car enabled much larger and heavier loads of lumber and reduced the costs of both loading and unloading.  The new A frames are carrying loads of 180,000 lbs, probably twice that of a 1965 flatcar load.  By becoming more efficient in the shipment of lumber, railroads probably kept a lot of business which might have gone to trucks as they are much easier to load and unload.


Norman Orfall
Helendale, CA
TIOGA PASS, a private railcar

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