A 22 tonne axle load is a 132 tonne locomotive, which is pretty much the norm for SG freight trains these days. So that should be the targeted benchmark.
For some reason, axle loads are measured in tons, not tonnes....
In theory they should be in kiloNewtons, since a Tonne is a measure of mass and not a measure of force.
So it appears axle loads missed the national metric conversion of 1973.
Anyway, 22 tons is the figure, which gives a locomotive mass of 132 tons which is 134.15 tonnes
This is about 219 kN axleload.