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Old July 17th 08, 02:51 PM posted to uk.railway,uk.transport.london
ANDREW ROBERT BREEN ANDREW ROBERT BREEN is offline
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Default Thameslink Rolling Stock

In article ,
Recliner wrote:
"Andrew Robert Breen" wrote in message

In article
,
wrote:

Why are new trains so much heavier? All they have over the old ones
is better crash protection and air con. Would those really make that
much difference to the overall weight? I can imagine it adding on a
few tons but not the huge excess we see in new stock.


Why would you imagine that: consider that the typical weight of a
family
car has close on doubled over the last 35 years - almost all due to
crash protection (with some down to NVH supression and some to a/c and
such). The weight growth of trains looks very modest by comparison.


Except that they've also (in some cases) switched to aluminium monocoque
construnction, which should make them lighter, just as it has in cars
such as the Jaguar XJ and XK. I have an XJ, and although it's much
bigger and has more gizmos than my previous BMW, it's also a fair but
lighter, and gets away with a smaller engine without loss of
performance. But the aluminium trains are heavier and use more power
than their steel predecessors.


Hmmm..

1968 Jaguar XJ6 4.2: weight 1537 kg.

2008 Jaguar XJ-R: 1659 kg.

Much less of a difference than with the F*rds (much less of a difference
in NVH too, I'd suspect), but in spite of the XK boat-anchor in the old
Jag and the new 'un's alloy structure, the old'un is still lighter.

So: the aluminium cars are heavier and use more power than their steel
predecessors...

--
Andy Breen ~ Not speaking on behalf of the University of Wales, Aberystwyth
Feng Shui: an ancient oriental art for extracting
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