Milepost 1112

As the caption explains, this is a prototype gauge that was built in a Wheeling & Lake Erie yard to check railroad cars that were routed through an older tunnel on a particular branch. I would think that with some Evergreen Styrene strip stock and perhaps a small shed-type structure, you could knock this out easily in one evening.
When railroads first got started, labor was plentiful and cheap. So digging tunnels was pretty common, especially in some of the areas served by the Wheeling as that was mining country as well. But as time went on, railroad cars and locomotives got bigger and taller... and the cost of labor went up as well. As the larger cars came into service, decisions had to be made as to whether a particular obstruction on a line like a tunnel or even a tight, narrow bridge needed upgraded, eliminated... or whether or not sufficient restrictions could be put into place to allow those parts of the system to remain 'as is." Such was the case with the Robertsville Tunnel. W&LE management decided that traffic through this particular tunnel was not sufficient enough to require its enlarging or "daylighting;" removing the tunnel altogether. Since it remained in place, they had to ensure that traffic going through it would fit so this clearance gauge was built. Its operation was simple; if a car, caboose or even locomotive were to strike any parts of it, that particular piece of equipment was not permitted onto that section of track... period.
As an aside, one of the worst accidents on the NKP occurred when an oversized car struck the top of a tunnel, causing it to fall in. The crew members in the caboose were both killed.
Since Evergreen makes all kinds of strip sizes, this would be an easy project regardless of the scale that you operate in. If you have a tunnel on your layout, I'd simply measure the opening and then pretty much duplicate that with the styrene strips. While there are no particulars given for this particular gauge, I'd guess that 4x8 strip would be used for the outside frame while 2x4 stock would serve for the actual frame & bracing. This one appears to be painted white but I'd think that any bright safety color... white, yellow or orange, would be fine. The picture only shows a portion of a small shed nearby but I'm guessing that was related to the gauge so you might want to add one as well.
Once you are done, the next train to leave your yard can be checked for clearance. What's that you say? You don't have a tunnel on your layout? Well... I suppose you could modify your thinking just a little and allow it to be used for a bridge structure, highway overpass or even close clearances with some buildings. OR... maybe the next division down the line has a tunnel where clearance could be crucial. By all means, don't let practicality get in the way of this fun, interesting project.
dlm