Martin,
If you are in a pool assignment, or on the extra board, you get called based on first rested man in the order.
First rested, first called or first out, last rested, last man called out and then they start over at the top of the board and the first rested man in the order…some times a man may work all twelve hours plus deadhead time, and he “loses” his slot in the order, he will not be called till he has been off on rest time according to that locals contract.
As for those of us on regular assigned jobs, we work the days that job normally work…if that happens to include a holiday, well, that’s the way it goes…but holidays are 8 straight time hours plus 8 overtime hours, so you don’t mind too much.
Regular jobs are bid on by the employees, and assigned to the person who bids and holds the highest seniority…the longer you have been there, the better your choice of jobs.
A lot of little things can be changed or might be a little different based on the local union contract, but that’s the basic way it works.
The railroads/carriers don’t decide who gets what job, the unions do, based on your seniority.
If you are a new hire, or haven’t been there very long, you will either ride the extra board and work the jobs in the order you fall on the board, or you work pool assignment, which is a modified extra board covering a division or district.
Extra boards usually cover assigned jobs where a man marked off sick or on vacation, and can cover the pool assignment jobs when the pool runs out of men and no one is rested.
Some men like the extra board and pool assignments; it allows them to make quite a bit of overtime and money, but they are away from home most of the time.