The original order for 55 locomotives later extended to 64.
The world speed record for steam locomotives was held by a 4-6-4 at least twice.
The strategy paid off and the company was awarded the contract for six locomotives in 1976.
Thus when a further order for five locomotives was placed they were given extended side tanks.
The site consists of a two track shed which has enough space for around 4 locomotives.
This system was mainly used for locomotives working in tunnels.
Part of the reason was the need for new locomotives, but the small production at the mine couldn't defend the necessary investments.
The initial order for locomotives was for two of the 2-2-0 type.
The original order had been for twenty locomotives, but this was followed by three further orders from the same manufacturer between 1919 and 1922.
It was intended to use this type classification system for electric locomotives as well.