I doubt the CB&Q caboose underframes had anything to do with the cars sagging; same as the Soo Line retrofits, they were done because the ICC required all cabooses to have steel underframes after a certain date in the twenties.

As for adding new steel to a historic artifact, I'm of the opinion that if it made it through the first hundred years, it will likely be OK through the second. More important is to pay attention to the details of the original construction.

One of the chronic problems with carbodies that have been adapted to use as buildings is doors cut in the sides. These inevitably cause a section of the "overhang truss" to be cut out. When I've asked about the details of the repair on a couple of different restorations, the reply has been, "What's an overhang truss?" This doesn't bode well for the longevity of those restorations if they ever see any sort of service, and the mechanical department is going to wonder why the platforms and ends past the bolsters are drooping and can't be pulled up.

Repairs to this item are problematic. It's typically in close proximity to the belt rail, which means welding in place is difficult, if it's even possible, since these are likely wrought iron on all but the latest built wood cars. It's difficult to remove, so forge welding is not an easy option. There is not a lot of room for splice plates, so a bolted connection is not easily obtainable. Yet it's an important part of the structure, and needs to be intact. Adding plywood under the siding isn't an adequate substitute.

As to adding steel to the underframe, one has to keep in mind that wood frames do not rely on bolts to transmit forces, but rather shoulders of gains cut in the wood, working against "key blocks" often made of cast iron. These are typically used between the side planks of wood gondolas to unify the planking into one structural member, and between the draft sills and center sills. If I were to add steel to reinforce splices in the wood center sills, I'd want steel blocks welded to the mating edge, fitted into notches cut into the sills. The bolts hold the steel on, but the shoulders of the blocks transmit the forces.

Dennis,

I have found a variety of wall framing, bracing, trussing styles. I am not familiar with the term "overhang truss" but suspect I understand the term.

I agree, if properly restoring a car, you would need to address any structural system, including damaged or cut wall trusses.

I suspect this is the strength of the Strasburg plywood "unibody" system... They clean out the rotten trussing and blocking, then replace the structure with a rigid stressed skin. They use high grade marine plywood, less likely to rot if water gets in occasionally.

It may be because I work in the west, mostly on western built equipment. Alternately work on earlier rolling stock, but in my experience, most cars don' have a full wall truss, and therefore the west we generally don't have iron truss rod running through the length of the wall to be disturbed (or repaired).

In the place of the wall truss we find a brace and brace rod in each window pocket below the window. This is a system much easier to repair or replace. I have seen this system in various car builders dictionaries, used by eastern roads (N&W?) so it is not unique to the west... I have also found a couple of cars with the brace system, with a king post truss in the wall over each bolster, but no general truss the length of car body.

More on my experience (and research) on tightening tension rods later...

Randy

Disclaimer: Most everything I know about wooden passenger cars I learned from Randy Hees.

The Hawaiian Railway Society is currently restoring, rebuilding, replicating (take your pick) Oahu Railway and Land Co. commuter (2nd class) coach No. 57 which was built in the OR&L shops in 1920. Our restoration plan calls for using construction techniques "as found". No additional steel, laminated material or plastic wood. We are using West System epoxy to consolidate existing wood parts for reuse. The sidewall construction mentioned by Randy may be illustrated by what we found on No. 57.





No. 57 is the newest of our three passenger cars coach 2 having been built in 1910 and parlor/observation No. 64 built in 1900. No. 2 has more steel in its construction than No. 57 and has both a wood truss and steel truss within the side walls. No. 64 is of unique construction with one-third of her length an observation platform. No. 64 appears to have a combination wood and steel system within the side walls but we don't know for certain.

Jeff Livingston
Historian
Hawaiian Railway Society

The structure of a wood car is critical. If wood is rotted or damaged, replace it with similar salvaged or new wood, replicating the original joinery. If desired, many modelers’ can tell you how to antique the salvaged or new wood. The original pieces can be bagged, tagged and stored for future reference.

Wood fillers and epoxy alone are no fix for structural parts. Epoxy is brittle. Even properly prepared joints can fail due to extreme humidity changes. Many epoxies are thin enough to penetrate deep into the wood however; the challenge is keeping sufficient epoxy in the joint during the 24 hours it takes to cure. Plastic shrink wrap certainly helps. I use West System epoxies on a regular basis. PL Premium construction adhesive is more flexible and sometimes a better option.

For mortise and tenon joints, I seal or prime first and during assembly, apply 3M 4200 adhesive sealant to caulk and seal the joint. It remains flexible and it’s removable.

Some scarf joints are okay but usually only on cosmetic stuff. I’ve seen many restoration projects that are loaded with scarf joints. If the original wood is that precious then put it in storage, putting it back in service isn’t really helping to preserve it.

The original cab for my Porter locomotive cab was intact but not structurally sound so the simplest solution was to replicate it. The original cab now sits on a storage shelf.

Just another opinion…

Dave

I don't know about antiquing the replaced wood.

At one of the CSRM railroad preservation symposiums that were held some years ago there was a presenter from the Smithsonian Air and Space Museum restoration team. We were told that when rebuilding airplanes the replaced parts were clearly marked (at locations not seen from the outside) as being replacements and the year of the replacement. This being done to document what they had done for researchers or restorers who will look at the artifact years later.

What method(s) did the Smithsonian preservation specialist recommend for marking replica replacement parts?

Thought some of you might like to see this builders photo and how the car met it's demise. This was the Morristown & Cumberland Gap RR that ran between Morristown and Corryton,Tn via Bean Station.Taken over by Southern Ry in 1903 and abandoned in 1928. http://cdm15323.contentdm.oclc.org/cdm/ ... l6/id/2919 http://i110.photobucket.com/albums/n83/ ... ngs003.jpg

That, right there.

I had heard the term "over truss" before, searched through one of the Car Builder's Dictionaries available on-line, and found "overhang truss" in the List of Part Names illustration, and decided it was the more descriptive term. I am more familiar with the form that runs along the belt rail from one end of the car to the other, rather than bringing the inner end back down to the sill, using the weight of the middle of the car to counterbalance the weight of the end, but either style needs to be reconnected if cut. This looks like the easier style to fix.

The problem with the style that runs in a groove in the belt rail is it's easy to miss if the restorer is only trying to patch the hole in the side and hasn't opened up all the framing the whole length of the car to view.The cut ends just look like a 1/2" x 2" steel bracket of some sort; it's not readily apparent that this is a truss rod, and is just as important as the truss rods under the car.

A quick look at the framing drawings in the 1906 Car Builder's Dictionary shows that both Pullman and Barney & Smith seemed to like the style that ran the length of the car, but of course they may may well have done different length cars differently. The illustrations that show the car length style tend to be big cars with six wheel trucks and long overhangs past the bolster.

Gee, that was a long, long, long time ago. She talked about wood framed biplanes and also metal skinned aircraft.

It seems that they preferred to replace material in-kind.

Suppose its time to chime in as well, my Pullman at 56ft has the long iron truss thru the belt rail, so did the C&S 529 65ft built by St Charles in 1900, also interestingly it looks like 'Omaha' the 1866 Wagner sleeper / C&S car 54ft has that pattern too.

Picture of our framing here
http://car57.zenfolio.com/p331500692/h1 ... #h123b6657

Mike Pannell

West-System appear to be able to make sawdust perform like new wood, and they are great at making old wood last and last. Great choice.

The multi-lam Luan and Mohagany marine plywoods are said to be able to withstand being burried in a grarden for 20+ years without showing any delamination. Its still wood, just sealed better and put togehter better. Its not cheap, but it might be cheaper than a big barn and frequent linsead repainting, if its mass use is acceptable to you and your aims.

Read a copy of "Wooden Boatbuilding" magazine to learn about that.