The history of the Garratt locomotive goes back to 1907 when William Garratt
patented his articulated locomotive design. After returning to England from
working on railways located in Cuba, Peru and Australia, he devised a scheme for
mounting heavy artillery on railway bogies. He discussed his idea with
Beyer-Peacock & Company and this subsequently led to the development of the type
of locomotive which now bears his name.
The first Garratt, called the K1 Class, was built in 1907 for operation on the 2
foot (600 mm) gauge N.E. Dundas Railway in Tasmania. It was a tiny 0-4-0 +
0-4-0 compound which weighed 33 tons, and one of the two locomotives is
currently running on the Welsh Highland Railway in UK. Garratts were destined
to expand in gauge, weight and power eventually culminating in a Russian 5 foot
(1500 mm) gauge monster built in 1932, and the most powerful, a South African 3
foot 6 inch gauge (1067 mm) GL class 4-8-2 + 2-8-4 which developed 78650 lb
tractive effort.
Over the years, more than 2000 Garratts of all types were built. The merit of
the Beyer-Garratt design was in their free-steaming capability which was
achieved by optimizing a boiler design which was uncompromised by the need to
have driving wheels or trailing trucks beneath the boiler, firebox and ash pan.
The concept of two identical chassis, one positioned forward and one reversed
with the boiler assembly slung between them, resulted in excellent riding
characteristics and great stability on curves and uneven track. The 'flexible'
Beyer-Garratt locomotive rode inside curves, with its boiler within the radius,
unlike a conventional locomotive, whose boiler projected outside the curve.
Beyer-Garretts proved to be splendid locomotives and, given the early
association with Australia, the standard gauge AD-60 is perhaps the most
significant of these locomotives to have operated in the Far East and
Australasia. These 4-8-4 + 4-8-4s were built in 1952 and had a tractive effort
of 63600 lb. They weighed 262 tons and were thoroughly modern, incorporating
the latest state-of-the-art in locomotive design. Aster selected the AD-60 to
serve as the Beyer-Garratt prototype to model. The AD-60 Garratts still in
existence are:
