Train weight limits.

I am aware of the 11,000 ton limit on Mojave Sub, but are there any other overall weight limits on trains being built or on the other Subs? The reason I ask this is because I'm looking at the upcoming M-BARLAC3 build with 7,500 tons already in departure and another 6,700 tons in the bowl, with 8 more cars yet to be humped. 14,000 tons seems like a bit much, but if it is allowable I will have it built that way. Length is not an issue on this train as it will only be about 6,500 feet. I will hold the build until I receive clarification on this matter. Thanks. 

Clint