Randy, when your crew rebuilt that flatcar in Sacramento I think you picked the hottest day of the year. I really felt for the crew.

As for what wood to use on a flat car deck, as I recall the AAR standards there were many woods approved. I think the idea was to use what you could get. My preference would be Douglas fir. Rather than buying new wood, try for some hundred year old wood being salvaged from old buildings. It is a lot of work to use. First you have to go over it with metal detector and find and remove all the old nails. Then belt sand off all the old paint. Next cut a thin strip off each side to get clean straight wood. Then run it through a resaw saw. You will end up with wood as good as what the car was built with.

I left the railroad industry and moved to transit in the late 1980s. At that time there was an AAR approved treatment for flat car decks. It was black and I believe it was a pressure applied treatment. Once the wood was applied to the car it dried out quickly and was not messy like creosote. I just cannot remember what it was. The railroad I worked for bought wood from a broker and we could just order flatcar decking and it came with this treatment applied. Maybe you could call TTX engineering department and see if someone there knows the material. Another thing, when applying the deck boards leave a gap between every board so water does not sit on the deck and so the sides of the boards will dry out.

One doesn't need the strongest wood, but rather the most rot resistant, and that is getting to be hard to come by. The traditional "old growth" timber often grew where growing conditions were less than ideal, adding just a tiny thin growth ring each year. This wood is exceedingly hard and dense, and well steeped in the minerals that accumulate in the heartwood that give decay resistance. Modern lumber is mostly "second growth" or grown on tree farms. It's fast growth with large growth rings and huge pores. It rots away as fast as it grows, no matter what species.

For a flatcar that is going to have to live outside, you should still be able to buy pressure creosoted 3 X 10 from a commercial supplier of pilings and timbers for bridge and dock repair. Oak would be harder than pine, but pine should be sufficient for the use a museum will give the car. While not all railroads used creosoted flatcar decking, some did, making its use not unreasonable.

It is a common misconception that "old-growth" wood (with many growth rings per inch) is always stronger and more decay-resistant than "young-growth" wood -- it depends on the species.

Ring-porous hardwoods (such as oak) produce large pores every spring, and wood with much smaller pores later in the growing season. In a dense stand where growth rings are narrow, oaks produce the larger pores every spring, but very little of the dense "late wood" which gives the wood hardness and strength. Slow-grown oak is very easy to work, but is extremely weak.

Seems to me that we are begging the question here. I don't see how the artifact is any different than your house. They both need periodic (and expensive) maintenance. If the artifact is going to be stuffed and mounted, e.g. stored indoors to be looked at by the admiring public, it really does not matter what wood is used. Authentic is best, but 99.9% of the folks who look at the object will not care one whit. If, however, the artifact will be used as it was intended to be, then the best and strongest materials should be used. We should accept the fact that these materials will have a finite lifetime and will absolutely need to be replaced periodically whether they are worn out from use or rot away before they are worn out.

Not really true. Sitting outside on display is not the same conditions as when the equipment was in service. When it was in service, it ran, at least occasionally, which shook the water out of the structure and blew a steady airflow over it to help dry things out. If we are talking passenger cars or cabooses, they were heated part of the year, which kept them dried out. Also, if they leaked, the defect was turned in, and hopefully the leak was fixed.

Outdoor display is a set and forget kind of deal, leaving the mushrooms undisturbed for years. Conversally, operational equipment that is stored indoors only sees the weather for a small portion of its life, and being operational, my comments above apply. It gets to dry out.

The specific example was a disconnect truck which hadn't moved since it was restored. CCA treated wood certainly would have been a good idea.

The other question was about a flatcar deck for a work car. Not sure this qualifies as a historic restoration or not, but since CCA is no longer available (possibly commercially) and the current lumber yard pressure treated lumber is basically eyewash, creosote would seem to be the way to go... not brushed on, but pressure treated like railroad ties are done, with any cut ends swabbed with creosote after cutting.

Or, they can just pay to renew the deck two or three times as often.

I should qualify the flat car project..... It's not a historic restoration per se, more of a return to service that will look good in an earlier original paint scheme but period appropriate. Partly historical but mostly functional as it will be used as originally intended with the X-216 either doing work or in demonstrations.

We'd like to put the best deck on it that we can afford which isn't going to be an exotic Brazilian hardwood. Wooden flat car decks were usually projected to get 6 - 8 years of life including physical damage repairs so if we can close to double that with light use, I'd be extremely happy.

Seems to be some good info here:

http://www.afoa.org/PDF/n150115a.pdf

When I worked for the transit authority, we were using creosoted 2x6 for platform decking; this was pressure treated, but in a light oil base, so the boards didn't have the typical tar on the outside. I believe at the time they were figuring a service life of 30-35 years. Since I left (about thirty years ago) it appears they've gone to CCA treated lumber. I have no idea what the service life might be, I'm sure the change was done for political reasons, not service (the boards are green, so they must be "green", right?)

John T:
Was the wood used in the original log car restoration allowed to season many years until dry, before painting?

I know of an example of a wood flatcar that was restored around 2001, and then so fully rotten in parts of the framing that it needed to be re-restored within the last few years, replacing the new wood. I believe the problem lied not in the wood, and while dry storage or more sunlight in storage may have helped, that probably was not the problem. Fresh wood that was used in the project was carefully and appropriately painted, with modern primer sealants and high quality finish. This effectively prevented moisture from moving through the paint. However, the problem was that all the moisture in the wood was not allowed to escape!

While we think we know better with our improvements, to me it is no surprise when it failed. While we may think that the painters were being lazy in not painting all the surfaces of a wooden railcar, they may have inadvertently allowed the car to survive much longer by letting wood dry initially, and later out after getting wet.

If I were to reside a railcar, I would not pre-paint all the surfaces, and just apply paint after construction was completed to keep the outside moisture out. The back of the wood could release small amounts of moisture to the cavities in the wall, which should vent. Likewise for a center sill, I would paint the visible/exposed surfaces, leaving at least the bottom of the wood unpainted.

My 2 cents on this subject, which comes up from time to time.

With this question, we should really be asking our friends at the Seaport/Marine Museums. Their Ships, Wharves and Docks see worse environmental conditions than we normally do.

Back in the early 90's , at the Connecticut Eastern RR Museum in Willimantic, Ct, we restored our 1914 built Central Vermont Railway 4287 flatcar. The decking we used were salvaged from the Dry-dock at Mystic Seaport Museum (Mystic, Ct). They were servicing/restoring the Dry-dock and replacing the wood decking and had a bunch of salvageable boards (~2.5" thick) Since then we have only replaced 2 or 3 boards, due more to mechanical failure (grain failure) than rot, she is left outside year round and is used for rides during events.

The wood looks to be a softwood, not sure of the species and not sure of any treatment it might have received, other than being sprayed with brackish water (brackish water is where ocean salt water meets fresh river water). The old wood hasn't seen any treatments since we got them and the new boards get a coating of Thompson or Cabot water sealer every few years.

Rich C.