7-1/4 and 7-1/2 Dual Gauge

Mike Venezia wrote on Chaski.org:

My track in Jackson, NJ, The Iron Acres Railroad, was a dual gauge railroad. Many visitors came with both gauges (7-1/4 and 7-1/2 inch gauge). It took a bit of experimenting to get it to work but it did. My gauge in the curves was set to a strict 7.562 inch and the straights were about 7.530. We would machine a larger (1/2" wide I think) slot in the switch frog and widen the gap at the points. We then set the Back to Back at exactly 6.875 keeping a very minimal space between the gaurd rail and the stock rail. I would put about a 2.5 to 3" lead on each end of the guard rail to bring the train over smoothly and keep them from wandering. I had a few problema with a couple visiting engines that had wheels that were less than 0.750 inch wide but for the most part once I got it figured out we had lots of fun.

Dual gauge railroads require a lot of close tolerances and a bit more maintanace the a railroad set up to run one gauge. If I do build a railroad at my place in PA it will be 7.5" only to cut down on having to be so finicky.