Isn’t it more practical to have DMUs as opposed to pulling locomotives?
This would be in regards to commuter passenger rail.
New Jersey Transit uses the pulling locomotive.
Long Island uses the DMU.
There must be some reason for the difference.
Good question – DMUs are excellent and very easy to join together in varying length formations, as well as that each coach has its own engine and/or traction motors which makes for a more reliable train (if one engine or motor fails the other(s) can still move the train along the track).
BUT…
DMUs are very expensive to buy – a train formed of locomotive and coaches can be shortened and coaches put in a siding, or lengthened using coaches from a siding or shed. These coaches, having no expensive engine and usually no expensive computer system and cabs, are much more economical to maintain for occasional use than keeping one or several multi-million dollar DMUs sat around for occasional heavy loading days.
However, DMUs usually cost less per seat per mile to run.
So presumably New Jersey Transit has worked out its business plan based on 100% use of expensive locomotives together with varying use of coaches, whereas Long Island’s plan is based on varying use of DMUs, but where most are in traffic most or all of the time.
Incidentally another common problem with DMUs is a lack of through corridor connection between ’sets’ – meaning lost revenue for the rail company unless a conductor is provided on each set.
New Jersey Transit Arrives At Long Branch, NJ
