The Historical Museum at Fort Missoula has a set of Russell Wheel and Foundry 10 or 20 ton archbar trucks (wheels cast marked circa 1903). The trucks, which originally were under a logging flatcar, will be placed under a library car (converted logging camp car set up as a branch of the country library system). The car will be on static display.

The wood bolsters and spring planks for the trucks require replacement. I realize this seems a rather obvious question, but what would be the best material for replacement. The Museum has a working sawmill on site, so getting softwood lumber would not be a terrible problem.

I am just trying to figure out what wood would have been used originally. I don't have White's freight car book handy, but can't be sure that would apply to this builder/case.

Michael Seitz
Missoula MT


http://www.fortmissoulamuseum.org/

Appearently there are ways of doing inspection of a sample of the existing wood to determine the kind of wood. This involves looking at the wood with a microscope and comparing the appearance with samples. I have seen a book that an acquaintance has used to do this. But I do not know the name of the book, etc.

You might ask the forestry department of a local insitution of higher education.

The SPCRR at Ardenwood have rebuilt several wood bolstered arch bar trucks. May someone from the group will post something about their projects.

Just from a standpoint of strength and resistance to rot, I would choose white oak if no other determination can be made. This was a wood chosen for many structural car building applications so could be justified.

Bob Kutella

And to add to that --- White Oak is what it is used in most ship timbers as well for the same reasons. Ever wood piece has a life span, but White Oak has both the resistance and the strength your looking for in this case.

TJG

Generally an eastern builder would use oak, probably white oak.

In the west, we also use Douglas Fir (known in the 19th century as Oregon Pine) One problem is that today's Douglas Fir typically has 11 or so grains to the inch, historically it had more like 22 grains per inch. The difference in strength and rot resistance is significant. The Navy preformed tests on Western woods at Mare Island in the 1870's, and qualified old growth Douglas fir as a direct replacement for white oak in wooden war ships.

Since this car will be in static service (and not loaded with 20 or more tons of logs) you can probably use any good local pine or fir.

Anybody else have good luck with Ash?

dave

Ash isn't a local western wood, but the Carter Brothers specified Ash for the vertical posts in passenger car bodies.

Chestnut would also do. It resists rot well and was plentiful in your target time period. Talk to the used barn board people to get pieces big enough to make up your critical timbers.

Steve wrote... “You never forget your first draft gear ...â€

While ash is a look-alike for oak, it is softer, lighter, and not as strong. If this restoration were to be static and housed indoors, it would probably do fine. But unprotected, it is very prone to water damage and rot.

Ash was used in car framing since it was virtually totally protected inside the layers of the car.

And do not be tempted by someone offerring the more common red oak. It is very porous and has little resistance to water born damage. It is a lot more common and cheaper since it has found a market in relatively inexpensive oak funiture, but still looks like oak.

Bob Kutella

In my experience (as a teaching assistant in wood identfication at U.C. Berkeley in the 1960's), it's usually not necessary to use a microscope for wood identification, a sharp knife and a 10x hand lens is usually sufficient to get to the genus.

A standard textbook is Brown, Panshin, and DeZeeuw's "Textbook of Wood Technology" (volume 1). (warning, though, their key will only reliably work for wood from temperate North America, and will give strange answers if a wood is from other regions of the world.)

In addition to your local forestry school, the U.S. Forest Service's Forest Products Lab in Madison, WI also does wood ID.

My vote is they are likely white oak.

White oak should be able to be identified with the naked eye, even if in a very deteriorated state, because of the huge rays this species has. These are the cell structures that go across the annual rings that give quarter sawn oak its characteristic appearance. In a cross section of the timbers in question, they will appear as hard fins running perpendicular to the annual rings.