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:
The AD-60 became known to overseas
enthusiasts, especially those in the United States, as the "Big Boys" Down
Under!'
Specifications
Scale/Gauge: 1/32, Gauge One (45 mm)
Total Weight: 10.83 kg. (23.88 lbs)
(Front Engine 3.04 kg. + Boiler 4.3 kg. +
Rear Engine 3.49 kg.)
Dimensions:
Length: O.B 1,044 mm. (41.1 inches)
Width: 98 mm. (3.8 inches)
Height: 136 mm. (5.35 inches)
Wheel Arrangement: 4 - 8 – 4 + 4 – 8
– 4
(all wheels made of stainless steel)
Driving Wheels: Dia. 43 mm Spoke
Type, Equalized Spring Action.
Pilot Trucks: Dia. 29 mm Disk Type,
Swing Bolster
Trailing Trucks: Dia. 29 mm Disc Type
Engine:
Cylinders: 4 x Cylinders, Bore 12 mm
X Stroke 20 mm
Valve Gears: Walschaert’s Valve Gear
Steam
Port: 1.5 mm, Cut Off
79.3%, Lap 1.25 mm, Travel 5.5 mm.
Boiler Type: Locomotive Type for
Either Coal or Alcohol
(10 x Dia. 9 mm Tubes and 1.x Dia 18 mm
tube)
Water Capacity: 320 cc at 80 full
Pressure: 4 kg/cm2 at Normal Working
Fittings: 3 x Safety Valves, 2 x
Super Heater Tubes, Pressure Gauge, Water Gauge, Blow-Down Valve, Throttle
Valve, Blower Valve, Whistle and Whistle Valve, 2 x Check Valves
Axle Driven Pumps:
Two are mounted on the Trailing Drivers’
Axle on each Front and Rear Engine, 2 x By-Pass Valves
Pump Bore 5 mm x Ram Stroke 6 mm
Lubricators: 2 x Roscoe Displacement
Type
Burner: Convertible to either Coal or
Alcohol
Fire Bed Area: 43.8 CM2
Fuel: Coal or Alcohol
Tenders:
Water Tanks: Capacity 350 cc (front)
+ 250 cc (rear)
Hand Operation Water Pump Mounted in the
Front Tender
Fuel Tank: Capacity 260 cc of alcohol
Head & Rear Lamps: Battery Operation
Minimum Radius: 2 Meters
