DMU and DEMU
============
A Diesel Multiple Unit (DMU) can be of one of the following types:
Diesel Mechanical Multiple Unit (DMMU)
Diesel...
more... Hydraulic Multiple Unit (DHMU), or
Diesel Electric Multiple Unit (DEMU)
.....
They are basically divided into such categories on the basis of the mode of transmission of energy from the diesel engine to the wheels.
.....
In the DMMU and DHMU, the diesel engine is normally under-slung (mounted under the under-frame of the car); whereas the diesel engine in a DEMU is on-board (mounted above the under-frame of the car).