The Australian National BU Class is a class of four B-units that were rebuilt from four Australian National 600 Class diesel locomotives in 1994.
History[]
In all, a total of four locomotives of what became the Australian National BU Class were ever rebuilt in 1994.
The way how they were constructed was obscure and the way how they rebuilt four of them, is that they removed the prime movers of the locomotives and replaced it with 30-tons of concrete, and they also put concrete in the fuel tanks, the bogies which were formerly a Co-Co wheel arrangement were replaced with an A1A-A1A wheel arrangement. They were designed to be operated as traction units as they kept their traction motors and were designed so that whenever they would be used on a lash-up that they would boost the traction on the trains.
After they all entered service on the Australian National Railways, things started to go downhill for the Australian National BU Class, when they were placed on the trains that were operated by the Australian National Railways, they constantly added more weight to the cars they were pulling, their traction was prone to dropping and caused wheel slip, it had also caused the dynamic brakes that they were fitted with to constantly catch fire which was caused by a lack of ventilation. The Australian National Railways did fix the issue on all four units, but that never worked.
They had failed so badly that they were all placed into storage, until all of them were subsequently scrapped in 2008.