Looking for a little advice. Before I start on my electric railway I’m thinking I’m going to put up a big loop in a pine grove on the back of my property for my live steam engines. I have a lot of old weathered LGB track that I’ll be using. I want to put posts in the ground and put a “T” at the top to set the track support on. My idea is to use two pieces of 1/8" steel 2" wide set on edge with some 2.5" pieces mig welded in between the two making curves easily and the 2" on edge should be plenty strong and straight between posts. I will probably make a double track but will start with one at first. I am using a laser level so everything will be 0 grade around the loop. My question is how far between posts would you think will be good. I realize the straight sections can be a bigger span than the curved sections that need more support through the curve. The 2" ladder type framework should stay fairly rigid but I realize live steam engines can be fairly heavy and if I invite others over who have large engines I want the rail bed strong. It will be at waist height for convenience and the curves will be as large as I can make them. The area is around 40’ x 70’ so it should be nice and gentle. Thinking of a sort of kidney shape just for aesthetics but was curious would be best for steam.
Ted, your design concept is quite robust. Flat bar on edge is quite strong if you control the twisting, which you will be doing with the 2.5" spacers. I would suggest the spacers between 12 and 24 inches apart. The spacer plates do not need to be full welded on either end, 3/8 to 1/2 inch top and bottom will be plenty. I would suggest adding a foot or so of plate/flat bar horizontally across the bottom of the stringers welded in place to account for lateral movement between posts. Support posts can be in the 6 to 8 foot range. I would not be too concerned in the corners as I am reading into this that you will be using large sweeping curves so the deviation from straight will not be sufficient to significantly affect post spacing. Also consider that a piece of paper on edge has no strength, but if you put a curl or make it a tube the strength increases significantly, as it will do with the steel. Part of the stability will depend on how deep you sink the posts in the ground, and in your case I would suggest making certain the bottom of the post is at least 6 inches below the local frost line. Also do not put a point on the bottom of the post, it will act like a wedge and work the post upward faster than a squared off bottom.
I agree with Bob’s observations about the track. Another option is 4" plastic pipe placed in concrete ‘deck supports’ with a pipe over that for adjustments and a flange at the top under the flat table…
Thinking of a sort of kidney shape just for aesthetics but was curious would be best for steam.
I absolutely would suggest a kidney shape. Tradewinds & Atlantic RR put in a shallow reverse curve on one side and it adds lots of visual interest.
P.S. The “Old FS” files are now unreachable. Ask me how I know.
Thanks for the advice guys and that’s exactly the info I was looking for. I have a 9” auger 3 pt post hole digger for my kubota so I’ll be getting down deep enough. There is a local guy selling 2” heavy wall fiberglass pipe that would probably make great, rot free posts so I’m going to give him a call.