Differences between Class 150s

[172212]

The 150/1s seem to started at a lower notch on the Hereford - New Street line, they used to be very loud on the Snow Hill Lines, they're very much missed. But the 172s are a godsend

 

[ed1971]

I have previously read that the ZF gearboxes on the Class 172s are not unlike the Wilson ones on the first generation DMUs, but are of course fully automatic.

Apparently, there is a 10% fuel saving on routes with many stops, compared with the Voith hydraulic version fitted to most other current DMUs in service.

 

[Class172]

To my ears the /2s sound very different to the /1s, especially from inside. I'll use two Youtube clips I've found as examples.

The /1s tend to make a whining sound when revving up, like this:

http://youtu.be/H6fNNq-4-6A?t=1m45s

Whereas the /2s tend to have a constant wailing over the top, which changes pitch depending on the throttle position:

http://youtu.be/j5nRg6hc6sQ?t=39s

Personally I love the sound of 150s, definitely preferred to the constant vibrating/rattling/buzzing on a 172!

I would disagree with the differences between the the /1 and /2's sound. I have always heard LM's 150s sound like in the former video; if I heard one like that Northern unit in the video, I'd have suspected a fault.

 

[150001]

The latter Northern didn't sound too healthy actually.
This 150/2 with London Midland sounds much more normal

http://www.youtube.com/watch?v=t3RZHSm1aCc