Queensland Abt Tank Engines

When gold was discovered in the Dawson Valley, west of Rockhampton, it wasn’t long before a railway line was built into the valley to supply the mines and the town of Mt Morgan that had sprung up to serve the goldfields.

Unfortunately the surveyors struggled to find a route over the steep Razorback Range that separated Mt Morgan from the coast and when the line did open it included over a mile of 1 in 16 track just east of the town.

In 1898 two 0-4-2T locos fitted with the Abt System arrived from Dubs & Co of Glasgow, Scotland to assist trains over that 1 in 16 section.

The Abt System was invented by a Swiss engineer and was first used in Europe in 1885. The system consisted of one, two or three steel bars topped with teeth that were placed between the rails.

Locomotives that could use this system were fitted with a steam powered set of wheels mounted between the frames that also had teeth and could engage with the teeth on the steel bars.

ABT rack locomotive at Mount Morgan Queensland ca.18901900

No 339 was the first Queensland Abt tank engine to be written off in 1916. The handwritten information refers to the load that the two classes of standard locos could haul over the rack section when assisted by the two Abt locos in this class.

The system was first used in Australia on the Mt Lyell Mining and Railway Company’s line between Queenstown and Regatta Point on the west coast of Tasmania and Queensland’s first two locos were very similar to the locos used in Tasmania.

When the Queensland Abt tank engines arrived they were classified as the 4D11½ Abt Class and went to work assisting trains up and down the 1 in 16 section. Trains heading up the grade were banked in the rear while trains heading down the grade had the Abt tank engine attached to the front.

To assist with braking these locomotives were fitted with both Westinghouse and Le Chatelier counter pressure brakes.

These two engines and the six 0-6-0 Abt tank engines that began arriving in 1900 spent their whole working lives restricted to just 6.4 km (4 miles) of track although they allowed to run through to Rockhampton for major services and overhauls.

The first of these two Abt tank engines was written off in 1916 and the second one was written off in 1922.

Technical Details
Gauge:
1067mm (3ft 6in)
Wheel Arrangement:
0-4-2T

Cylinders:
29 x 51cm (11.5 x 20 in)

Boiler Pressure:
1206 kPA (175 lb)

Coupled Wheels:
91cm (3ft)

Tractive Effort:
76 kN (17,000lb)

Weight:
24 tonnes (24.4 tons)

 

References
Oberg, L Locomotives of Australia – 1850s ~ 1900s Third Edition 1996, Kangaroo Press

The Qrig.org website –  http://www.qrig.org

Photo courtesy of State Library of Queensland