sweep not working at all on this..

 From:  jehan
1894.1 
basically i'm trying to sweep the short line along the two long rails, the one in the middle is the scale rail. it takes an extremely long time to calculate, so much so that i've given up. also- the two rails have a large number of points because they are projections, but i tried the sweep before on rails with only a few points (before i projected them) and it still took a very long time. even after the surface was created, it slowed down the model to a standstill. i've included the file for your perusal.