Maintenance crews work on trains, tracks, switches and signals. For any kind of work to be done you need to call the maintenance supervisor, who will coordinate the work assignments among the crews for you, and even call in a crew if none is available right now – if you feel that this is warranted. Crews are, of course, a limited resource – as is any staff. Once a crew’s shift is over it needs to rest – so it cannot be called in until the resting time is over.
When a crew has been assigned some work, it needs to travel to the site. When it has arrived there, you’ll get a call, telling you they are ready to work. When the work is finished, you’ll get another call, and the crew will work on the next assignment or return to the headquarter.
You can have more than one crew to work on the same issue – just call the supervisor again. Two crews will have the work done in half of the normal time, but of course the 2nd crew cannot work on anything else. They will coordinate the work among themselves. You will get only one call about the work being finished, however.