Difference between a DMU and a railcar?

[pcuser42]

This one has puzzled me. Wikipedia says that only two classes of DMUs operate on New Zealand's railways (ADL/ADC and ADK/ADB), yet the Silver Fern (RM class) looks like a DMU to me, but it's a railcar!

So what exactly is the difference?

[Flying Pig]

I don't know the specific traction, but I'd be inclined to look at the 'Multiple' aspect.

The implication of the phrase suggests that it can work in multiple. So is one Silver Fern unit capable of being coupled to another one, and once this is done, can all the units be controlled (ie, throttle, brake, doors, etc) by the driver from the leading cab ?

If not, then maybe that's why it qualifies as a Railcar.

Just a thought,

FP

[Deathbyteacup]

A DMU is a form of railcar.

A form of railcar is a railbus, such as the Pacer, which is also considered a DMU. Many texts also refer to DMU's as railcars in the same sentence and vice-versa.

You could call a DMU a DMU or a Railcar, but I think when we have something that is a single coach with a cab at each end with no articulation, or more importantly, can't be used in multipul, then it would simply be refered to as a railcar.\

The only flaw in my perception which I have always held is the Silver Fern which you hold up as an example, since not only does it appear to articulate, it also appears to have couplers, so I fail to see why you would not class it as a DMU, unless it can't work in multipul with other units!

[pcuser42]

I found this page, which shows two Silver Ferns coupled together (last photo), but whether they're both operational or not it doesn't say. So based on what you guys said they could be DMUs.

[Flying Pig]

Well certainly over here in Blighty, the definition of a Multiple Unit is one which can work in multiple with others (as in the definition of my previous post) ....nothing very difficult about that.

Wiki itself has a definition here http://en.wikipedia.org/wiki/Multipl..._train_control , but as always you need to remember that different countries may have significant variations.

Whilst the Railway itself is usually quite specific about definitions, there are always alternative names for things floating about in the 'lay' world. I certainly wouldn't lose any sleep over it.

Best wishes,

FP