7-1/4 vs 7-1/2 Gauge

Background
The 7 1/4 versus 7 1/2 Debate

As worldwide communications improved and it became evident that having two standards for 1:8 scale modeling in the U.S. was counterproductive, an attempt was put forth to adopt a true standard for track gauge, wheel profiles and couplers. The organization known as the International Brotherhood of Live Steamers was consulted, with representatives from areas around the world working with riding scale railroads. Via mailings, all known private and club railroads were contacted and asking for input on what the standards should be so a single set could be established. From the replies, it became abundantly apparent there was no easy solution within the U.S. and the I.B.L.S. settled on adopting and recommending standards following those being used in California and sent these out as "proposed standards" to everyone. Since these first included 7-1/2" as the correct gauge for 1:8 scale, they were never officially adopted by everyone and have remained as proposed ever since. However, in the U.S., these proposed standards have been used by most everyone for wheels and couplers and each area has used their local gauge standard. This has allowed for the trains to easily travel to other railroads and interchange equipment fairly easy, except for crossing The 1/4" Demarcation Line in the northeast. Today if you look at most IBLS wheel and coupler charts, you will find gauging standards for both 7-1/4" and 7-1/2" that have become the accepted standards by most. What is really most interesting is the fact that for exact 1/8" scale, the track gauge should be 7 1/16 inches.

Questions and Answers
Question: Someone once told me that the break in gauge between 7 ¼ and 7 ½" gauge started when Carl Purinton wrote a letter to Victor Shattock in the 1950's and accidentally typed 7 ½" as the standard instead of 7 ¼". This seems to be the most plausible story out of all I've heard (including some conspiracy theories) and I wonder: is there any truth to this or is it just another urban legend?

Answer: From Ken Shattock, 23 March 2013

In regards to your question about the 7 1/2 vs. 7 1/4 inch gauge controversy, I don't recall anything about a "letter" between Carl Purinton and my grandfather, Vic Shattock. However, just this evening (March 23rd) while going thru old records of our GGLS club history, I cut out the notation from the GGLS secretary, in the 1956-1957 time period which mentions this gauge problem.


 * By August of 1956 discussion was underway as to whether a planned ground track at Redwood Park should be 7 1/4" gauge or 7 1/2". It was in this month too that Vic Shattock was asked to write a history of the club. A few months later, in November of that same year, Vic celebrated his 50th. wedding anniversary.


 * It is easy to forget that as well as being the oldest live steam club in the country GGLS has other notable attributes to be proud of. The August 1957 issue of the Callboy noted that the club had the longest 2 1/2" gauge track in the world!


 * In September of 1957 it was announced that 7 1/2" gauge had taken hold as the standard gauge on the West Coast and that would be the gauge that the club would use at Redwood Park. That adoption has led to many conflicts over the years. Obviously one cannot travel from coast to coast (or overseas ) with a large scale engine and expect to be able to run on all of the tracks belonging to all live steam clubs. In fact, only for the two smallest, passenger hauling, gauges can one find facilities everywhere on which to run.

Question: According to the stories I've read, the reason that the east has 7 1/4" gauge and the west has 7 1/2" gauge all started with none other than Walt Disney himself.

Answer: No. Walt Disney's Carolwood Pacific Railroad was built in 7-1/4" gauge according. See Carolwood Pacific Railroad - Wikipedia.

Unification
From Richard W. Symmes, Co-Founder (1967) of the North East Live Steamers


 * Some people recently have been having good luck using special frogs on their 7-1/2" gauge pikes which allow the operation of 7-1/4" equipment without further alteration of wheel sets. Nick Edwards in Wimberley, TX is an example that comes to mind. Nick has a marvelous 7-1/2" gauge track, and many have been the visiting locomotives from the northeast that have run successfully on it.  So there is a way to make tracks accept equipment of both gauges.