Re:A skeptical response to Musk's hyperloop
by Someone on Wednesday August 14, 2013 @04:09PM
(#6213897)
1) I doubt construction cost is a linear function of weight, as costs of material often are only a fraction of them. For example, one will need access ways for repairs, regardless of the weight of the structure.
2) I would expect that wind pressure on a tube is higher than on a rail with an occasional train on it. If so, the supports need to be designed to handle that higher load.
3) I think higher speed trains going through a bend in the track exert higher forces per kg of train than slower speed trains. Again, if so, the design will have to accommodate for that.
4) I don't see how that 0.5^3 makes sense. If both track and train are half the weight, my conclusion would be "total structure to lift is half the weight", not "total structure to lift is a quarter the weight".
2) I would expect that wind pressure on a tube is higher than on a rail with an occasional train on it. If so, the supports need to be designed to handle that higher load.
3) I think higher speed trains going through a bend in the track exert higher forces per kg of train than slower speed trains. Again, if so, the design will have to accommodate for that.
4) I don't see how that 0.5^3 makes sense. If both track and train are half the weight, my conclusion would be "total structure to lift is half the weight", not "total structure to lift is a quarter the weight".
I am not an engineer, so corrections welcome.