How do folks address platforms sagging on wooden passenger cars.

We are dealing with both Miller (most with Janney heads) and Janney coupler systems. and with Miller (trussed) platforms and simpler untrusted designs.

Has anyone developed a way to reinforce the traditional designs?

Randy

What we have seen on the open platforms, where there is no protection from the weather for the structure, that the iron and steel rods and fasteners are rusted to almost nothing inside the timbers. Without this support for many years, the timbers sag and take a set that is nearly impossible to get out. Replacement of the timbers and steel supporting rods and fasteners may be the only answer. The car that comes to mind is Key 1201, the Carter Brothers built car at WRM.

The cars I am working on (at two sites) are classic open platform... four are "miller style" with truss rods running from the bolster, over the end beam then under the platfom, the other without the truss.

On the one miller car that I have rehabilitated, the truss and tenson rods were in good shape but all wood was replaced... it is holding up well 16 years later. It was stored outside until recently (but is now inside)

A second has an untrussed platform. It was restored in 1970, then stored inside. Its platform had sagged, but was solid. We have tightened all the bolts (which required removing the floor, we added nut locks so we will not have to remove the floor again.) Even when tight and in good repair it sags a bit (about 1/2")

Both of these cars see limited operation and are stored inside.

The next three are about to undergo rehabilitation, and will be used more often in more demanding service. These cars all have miller trussed platforms, and miller draft gear with knuckle couplers. These platforms will be rebuilt with the exisiting truss and tension rods and likely new bolts (all are present and all seem to be ok, but I have seen bolts come out of oak timbers looking somewhat eroded)

We have been told that a similar operation has to rebuild their platforms every 4 years.

We will be installing some form of nut lock so the bolts through the platform timbers and sills so they may be tightened without pulling the floor.

We are looking for other statagies to reinforce the system. The historic railroad system we have found only deals with the draft gear attachemet, and not sag...

Again... Thoughts...

Randy

I'd expect to see cars made as cars were made need the same intensive amount of maintenance they needed way back when there were thousands of carmen at work if they are also in intensive use. Every 4 years isn't out of the question, especially as the joints will open up every time they get loose and are tightened again.

Many platforms as designed had a subtle slope away from the carbody - let's make sure that one with the half inch of droop isn't actually not drooping at all.

I'd be working on a steel truss system under and inside the wooden frame, bolted through the end sill with the bolts available for tightening as necessary from underneath the car if I wanted to use this type of car in service.

dave

I'm not so sure nut locks are going to do what you want. Bolts through wood members loosen up because the wood goes through seasonal change, whether stored indoors or not. If the bolts are tightened when the humidity is high, they will be loose during the low humidity season. If they are re-tightened when the humidity is low, the next time the wood swells, it will exceed its limit of plastic deformation (take a permanent set) and the bolts will be loose yet again next time the humidity drops. It's just the nature of the beast.

I think a better strategy to keep from having to pull the floor is to orient the bolts so the nuts are accessible from below, and use some sort of head lock so the upper end won't turn when it is buried under the floor. These can be as simple as a square washer with lugs that engage the head let into a pocket in the upper timber, or even a length of bar stock welded to the head let into the sub-flooring laid over the bolt. I seem to recall seeing antique oval shaped cast washers that had square pockets cast into their top surface, I imagine this is the historically correct solution.

Then you just have to periodically tighten the nuts under the platform.

On the street railway equipment it is important that the platforms stay level and square with the car. They is so the folding doors will stay in the upper track. To facilitate this the platform sill (platform Knee) is made with a slight upward angle in it. There are about 3/4" of steel shims placed on top of the knee where it goes under the body end sill. If the platform starts to sag, the knee is loosened and a shim is removed. This brings the knee back up level. To make this loosening and shim removal easy, the bolts that support the knee at the platform end sill are some sort of a u bolt arrangement. There is a steel plate under the knee with bolts going up each side. Depending on the design of the car, there can be attached to the side of the platform end sill, or go up beside an intermediate stringer with a second plate over the top.

A tool that would make this whole process easier would be a Snap On stud driver. This is a threaded collet which can be threaded onto the end of the bolt and then a sleeve locks the split collet. This allows you to hold a bolt from the threaded end while loosing or tightening the nuts. This tool is normally used to insert or remove studs from engine blocks, but it can be used in many other applications. Not cheap though.