I work at a rail transport infirmary. Have you heard of this?
I know that a rail transport is a means of transferring people or goods on rails or tracks, but what's an infirmary? 
Yes you're right. Infirmary is just a storage area for transport parts. 
Oh that's neat! Do you mostly handle electric locomotives or engines that are run by diesel?
My work mostly involves electric locomotives since these are the most efficient and used almost everywhere!
or produce their own power, usually by diesel engines. Most tracks are accompanied by a signalling system. Railways are a safe land transport system when compared to other forms of transport. Railway transport is capable of high levels of passenger and cargo utilization and energy efficiency, but is often less flexible and more capital-intensive than road transport, when lower traffic levels are considered.
The oldest known, man/animal-hauled railways date back to the 6th century BC in Corinth, Greece. Rail transport then commenced in
Rail transport
Rail transport is a means of transferring passengers and goods on wheeled vehicles running on rails, which is also known as tracks. It is also commonly referred to as train transport. In contrast to road transport, where vehicles run on a prepared flat surface, rail vehicles (rolling stock) are directionally guided by the tracks on which they run. Tracks usually consist of steel rails, installed on ties (sleepers) set in ballast, on which the rolling stock, usually fitted with metal wheels, moves.