Madison:
Your Mexican locomotive is a 102 ton "Fairlie" built by Vulcan Foundry in Newton-le-Willows, England in 1911. Scotsman Robert Fairlie designed these double ended locomotives. The principle behind them was to a maximize adhesion and tractive effort by placing all possible weight on two sets of truck or "bogie" mounted drivers in a manner similar to the way in which diesel locomotives evolved. A key element in Mr. Fairlie's desire to increase weight over the drivers was to dispense with the tender and carry all fuel aboard the locomotive making it a tank engine in essence. While single ended Fairlie locomotives exist, the designer, although not the originator of the concept of a double ended steam locomotive, also desired to eliminate the need for turning facilities so most of his locomotives are of double ended construction.
A number of Fairlies are still in existence, several of which can be seen in operation on the narrow gauge Ffestiniog Railway in Wales. I posted a few pictures of these below.
Bob
