I think that much smaller obstacles hit by train can cause derailment. But definitely we shouldn't compare 9 locomotives to this crane. This is very "clever calculation" to call this crane 900 tonnes. Of course it's own weight is around one locomotive ;)

@@krzysztofadc2363 wen a train is on the track its wheels only touch the rail about the size of a English fifty pence piece them cow catchers at the front of locomotives save them a lot from derailment because if a car goes under the train odviously it gets munched up but the cars Axel can derail a wheel of the train in the right place if the trains going fast then its a wreck I don't know too much about all this I am chatting about but I am learning lol godbless you,

Makes sense. You answered my question, I always had. I was telling myself, that the crane couldn’t weigh 900 tons. So all together. I calculated, that the crane must weigh 150 tons, so it can lift 750 tons.I’m just guessing here.

We only go by what our client calls it. I can say the Liebherr web site says the 1750 max load is 800 tons but that is not with a boom/jib package set up on it. Nonetheless, the client is always right. :-)