Three Speed 8HP sprung DCC Traction Engine #55388
Marshall Road Loco "Blackbutt" was built in 1911 and spent its working life in Queensland working variously in forestry, sawmilling and irrigation.
We purchased this engine from Alan Robert in Queensland in 1996. Although the engine had under gone a substantial restoration at Bundaberg Tafe over 10 years and was in sound condition it was very VERY NOISY!
So Noisy that even the spectators needed hearing protection.
We decided that to get full enjoyment of this engine something would have to be done!
It is very hard to tell the origin of gear noise but that the wear in the square section of the second shaft where the gears slide seemed one likely area. You could hear four distinct thuds per revolution. The hex slide for the third gear was also worn though to a lesser degree. The Tafe restoration had included building up worn gears with weld but the resulting profile was less than perfect and the tooth spacing irregular.
We built up the square section on the shaft and sleeved and slotted the square section on the first and second gears to match. We had new third gears cut as this was the simplest way of eliminating the slop in the hex slide. Ross machined up blanks for new gears then we had the the teeth cut in using a modern profile.
Another anomaly with this engine was that the eccentrics had been reversed at some stage and you had to pull the reversing lever back to go forward. All very confusing but easily fixed.
Blackbutt has had rubber fitted over the strakes and front wheels to allow him to run on the road. He has been taken on several road trips.
The depth of rubber on the strakes increased the diameter of the wheel and so increased the gap between strakes. This exacerbated a tendancy for the engine to bounce at certain revs. To overcome this Ross put counter weights on the cranks which made a big improvement.
On the Road
