in the dark, page-35

Newdepths,

Heavy Haul Railway is named because it carries the heaviest payloads and depends upon an axle load. When we say a 37t axle load, this is the maximum load which can be carried PER axle. each ore wagon has 4 axles and with a 37t axle load means that 148t is the maximum loading for that rail head. By the time you take into account the tare weight of the wagon it leaves the payload wieght - which in this case is around the 125t

37t axle loading is enormously high and the rail head required for this loading is the largest BHP make at around 68-70kg per m. Also the sleepers are reinforced concrete approx 200x200mm rough shape by 2.6m long and weight approx 340kg each with spacing of around 620mm.

Just giving some perspective!

Regards....Maxi
DYOR!