As far as i know hydraulics are not prohibited. (at least not in holland and not in the USA, but this can differ from state to state). But, you are not allowed to use very powerfull hydraulics, there is a limit set on them and i recommend you to look this up
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For the launch system you could also do something with elastics, its less sophistacated and a lot easier to build. Brakes. Well, you could try it with magnets like the real one, but on a lighter note: Put one + magnet in the train, and lots of - magnets in the track. Make sure they are not to strong
. Just run the train over it and put in as much till it nearly stops. Just some thoughts
. I think its going to be a hard project, but looks very fun to do
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