Is there a weight limit on freight on railcars?

Question

Trucks traveling on the road must maintain a weight limit on their cargo before departing but does this apply to railcars also?

Answer 1

In general you have a heavy axle limitation of 286,000 lbs or 143 tons. But the deal on heavy shipments must be arranged to ensure the track along the intended route can take the load.

http://www.uprr.com/aboutup/maps/grossweight.shtml