wrote in message
On Wed, 12 Aug 2009 09:32:22 +0100
"Colin McKenzie" wrote:
Technology moves on. Even if it didn't, priorities would.

For example, low energy consumption should be given much higher
priority now than it was in the 95/6 stock.

If low energy consumption is a priority now (why it wouldn't have
been in 1995 I don't know but anyway..) why are LUL having to upgrade
the power supply on the victoria line to cope with the new 09 stock?
I wouldn't call using more power that the old trains energy efficient
would you?

True, but the new Victoria line trains are longer, faster and more
frequent, so that may account for some of the extra power.


Occasionally a 5-year old design may be the best option, but not
often.

Even car designs last longer than 5 years and even then most of the
changes in the new model are cosmetic. What is so radical in train
designs that they must change even more often?

Cars typically have an eight year production life, but the technology is
often updated during that time. Right now, most new cars are markedly
more fuel efficient than their predecessors, so there really are major
technology changes happening. For example, engines themselves are
cleaner and more economical, they may shut down when the car is stopped,
they may only power the alternator when the car is not accelerating,
etc. And there's lots more to come.

I don't see why trains shouldn't also get significantly more efficient,
more comfortable and more reliable over time (though, of course,
sometimes they get worse, like the 1983 stock, which was the last
LU-designed train).