Monorails and A.E.M.'s (Automated Electrified Monorails) A Monorail system is an arrangement of single or "mono" rails, containing one or more carriers/trolleys which provide an overhead path for material movement. A monorail system may consist of straight rails, curves, switches and interlocks that provide a means of transportation of a load along a fixed route between pickup and delivery points within a plant or warehouse. It's a unique form of a system as it has an unlimited sense of direction and can be "snaked" throughout the plant and is most often used for repetitive, production jobs.