>Yes, but I think the point is that the union can't tell a worker what he/she can or can't do.

To much an all encompassing, blanket statement. The union can tell a worker what he/she can and can't do because it's one of its purposes (although you have to ask your local chairman about it). For example, if you try to claim something which is not in concert with what has already been agreed upon (union contract, local agreements, etc.) or ruled on by a board that you can't, the union is obligated to advise you of this when you ask it. If do you go ahead and claim something which has been determined to be a no-no, you can be disciplined, and there's not much recourse for the union to fall back on. What the union can't do --not to mention won't-- is to instruct you to violate a Rule or statute/regulation. The Company can --and you better obey those instructions-- but it better be prepared to pay any subsequent fines assessed by the regulatory authorities (FRA/PUC) for instructing you to do so.

>They can only fight to reinstate after an unjust firing.

What about recovering underpayment of claims?

>For example if the company refuses to allow a sick layoff (I've seen it happen!)

Which they can't do. There are a number of Board decisions about this. From time to time the company tries these antics, but when push comes to shove, they will lose (again). What they can do is make it onerous for you to mark back up (you will lose out on earning money in the process), but even so they don't have carte blanche in this regard either. Regardless, whatever you do, don't try to lay off, be refused, and then in the same phone call try to lay off sick. Make the lay-off-sick a separate phone call.

Back in them days, when the Company would try this tactic, occasionally someone would go down to an offeeeshul's office and sneeze in his face or general direction. That usually solved the problem for a while.

>The union can't tell the employee that they can refuse service

Whatever you do, don't subject yourself to charges of insubordination (of which laying off sick is not necessarily one).

>I've noticed here and in person that the UP has buffaloed employees into not violating the hours of service law to the point where they are afraid to secure a train after there time is up.

Once the HOS catches up with you, you're done, which includes tying hand brakes. The solution is to stop your train with enough time to tie those brakes. Keep in mind that if the Company instructs you to violate the HOS, they get fined. If you do in on your own volition, you can get fined. Translated: if you tie hand brakes after becoming dead on the law, and the comapny didn't istruct you to do so, you will be subjecting yourself to getting fined.