On 14 Jul, 21:50, Arthur Figgis wrote:
I'm not a procurement expert, but Uncle Roger seems to think that the
DfT specification is far too complicated/hard to achieve (not least
the self-propulsion).

The Thameslink EMUs aren't IEP, just bog-standard 20m 4-car EMUs.

That doesn't stop the spec being "ambitious" as well.

Indeed - I got the self-propelled bit confused with the onboard-
storage-of-regenerated-energy bit. Still, the combination of weight
and performance requirements appears to be tough enough that it'd be
hard to achieve based on minor changes to the Desiro or Electrostar
base design.

32 tonnes per car is required - that compares to 33 tonnes average for
a 313, 35.5 for a 319, and 43 for a 350 or a 377. The 315s are the
only postwar British AC EMUs to have achieved 32 tonnes; they only go
at 75mph and aren't built to current crash standards.

Meanwhile, the performance requirement is for 'best in class'
performance (presumably = at least as good as a 350 or 377).

--
John Band
john at johnband dot org
www.johnband.org