PVC Portable Steamup Track Experiment

Back in early November or late October of last year (2009), Marc Horovitz sent out an appeal for live steamers willing to run some trains at a train show in Denver. At the time, Marc indicated that since no one had a raise, portable steam up track, the "running" would likely be done on the floor. At least one person responded that running on a ground level track would not work for them because of physical issues. I tend to agree that running a live steam engine on a ground level track is something that my knees are not interested in. I own a pair of knee pads for just such an occasion, but even then, it is still a pain.

So, I got to thinking about what it would take to make a portable steamup track. Being a typical engineer (not the railroad kind in this case), I got to thinking about the requirements for such a track and came up with the following:

  1. Cheap ...
  2. Must be light weight and easily portable, easy to put up with a single person.
  3. Must be strong enough to hold two tracks, with typical engines and cars, etc.
  4. Could be set up and left outside without weather damage.
  5. Broad enough curves to run most engines, but small enough that space would not be an issue at a train show.
With this list of requirements, I started to think about what materials I could use for the "benchwork". So, the obvious candidate would be wood. In my experience of tearing down the wood tracks at the Diamondhead steamup in 2008, they were heavy, the sections were all screwed together, and it was not really possible to handle them with one person. Wood would also not be my first choice for leaving outside in the weather unless it were properly treated. A second option would be metal. I happen to have an ample supply of 1" steel C-channel that could possibly be welded into a framework for a track, but it would probably be on the heavy side and given how rusty it is, messy to handle. Which pushed me to a third option ... using inexpensive PVC pipe.

A quick check at the local hardware store showed that a 3/4" PVC pipe 10' long was only $2.21. A bag of 10 Tee connectors was only $xxx. I already own the PVC pipe cleaner and clue. So it seemed that I could experiment with PVC without shelling out a bunch of $$$.

The first obstacle is the question of how to make the curved sections of the benchwork. I have seen PVC pipe based furniture that is made from bend pieces of PVC pipe, so I knew it was possible to do. A quick bit of searching on Google revealed several options:

  1. Use angled elbow fittings to make a roughly curved section. This would look like a low resolution rendering of a circle make up of a bunch of short straight sections joined by small angle elbows. The problem with this idea is that the "cheap" elbows are only 45 degrees or 90 degrees. There are 22.5 degree and 11.25 degree elbows, but they tend to bea bit more expensive and seem to be available only in larger sizes.
  2. Fill the PVC pipe with sand and use a heat gun to soften the pipe to make the bends. The sand serves to keep the pipe from collapsing when bending. The bends could either be done as a broad curve or as sharper incremental segments. (Think of the latter as 11.25 degree bends instead of using elbow fittings.)
  3. Fill the pipe with boiling water or "soak" in boiling water until soft, then carefully bend. This is only suited to making broad curves because the pipe would likely collapse when attempting to bend it sharply.
Given the inexpensive nature of 3/4" PVC pipe and hardware store fittings, I purchased 4 sections of pipe and a  10 count bag of tee fittings. The total bill was ~$10. I later purchased two end caps and a bag of sand for another $4.

I solicited the opinions of some local live steamers on minimim radius and track spacing. In the end, I decided on the outer track being ~8 foot radius and the inner one at 7 1/5 feet. So, a center to center track spacing of 6 inches. I added a couple of inches to the outside and inside to define the edge of the benchwork. With this in mind, I used some chalk and drew a set of lines on the driveway to define a 1/4 circle of the curved benchwork to serve as the plan. (I call this eyeball engineering.) I divided the 1/4 section in half to because I really don't want to handle really long pieces. So a full circle will be 8 segments. The chalk outline looks like this:


Yes, this is a real high tech operation!!!

To experiment with the idea of using elbow fittings, I picked up two 45 elbows @ ~$0.80 a piece to see if that would work for making the curved sections. I laid the pipes and fittings out on the chalk lines to gauge how it would work. The following two photos show that for 45 degree elbows, it is not reasonable.


Outside, is not too unreasonable.


The inside part would leave a lot of space in the inside of the benchwork.

My general conclusion is that I would need access to 22.5 or 11.25 degree elbows to make this work well enough. I haven't been able to find these locally, so if I decided to go that route, I will have to order the parts on-line.

The next experiment was to try bending the PVC pipe using the sand and heat gun approach. I did not own a heat gun, but it was a great excuse to buy one. I used a 20% off coupon from the Sunday paper and a sale at Harbor Freight to get a really cheap one for $7.99. (As a side note, the sales guy offered to sell me an extended warrenty for $4 ... ha ha ha ha!)

The procedure is simple:

  1. Cap one end of the pipe.
  2. Prop the pipe up with the open end at the top.
  3. Fill with sand.
  4. Tamp it down by tapping the pipe on the capped end to settle the sand.
  5. Repeat #3 & #4 until the sand will not compress any more an the pipe is full.
  6. Cap the open end.
  7. Lay the pipe on the chalk lines so that it starts tangential to the curve such that the pipe would lie on the straight line leading to the curve.
  8. Put on some work gloves to handle the heated and softened pipe.
  9. Start heating the pipe over a 1 foot section moving the heat gun slowly over the pipe. I held the gun about 1 inch from the pipe and used the hottest heat setting.
  10. Periodically test the pipe to see if it is soft enough to bend. I found that it remained quite stiff up to the point that it became soft.
  11. Carefully bend the pipe using your thumb as a brace. Go slow and leave it on the ground to be sure that you don't introduce any twisting.
  12. Move to the next section and repeat 9-11 until you have fully curved the 1/8th section.
I did this for both an inside piece and an outside piece. The following pictures show the result:





These are not smooth, perfect curves, but they will work for my needs. The next step was to tie the two sides together with cross pieces. Again, in the tradition of eyeball engineering. I did not measure anything, but just laid the parts out and marked things off from there. Here is the resulting section completed:



At this point, I still need to make accommodations for the legs and glue everything together. After that, I will make some tests of the strength to see if the 3/4" pipe is strong enough to support the track and trains.