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

On Jul 14, 7:29 pm, John B 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).

Self propelled? Wtf is that all about? And how would you achieve it
without dragging around a barn full of batteries slung under one of
the cards?

B2003

On Jul 14, 5:38 pm, John B wrote:
Yes in the short term. In the long term, it's likely to be more cost
effective to not give a single manufacturer a monopoly in the supply
of UK suburban rolling stock (and Siemens would've been justifiably
****ed off, given that a batch of dual-voltage 350s would be pretty
much equivalent to a batch of 37xes).


Who has copyright of the designs of these trains? Is it retained by
the manufacturer or is it owned by the DfT? If the latter couldn't
they just farm the work out to a number of seperate builders as has
been done in the past on BR and LUL?

B2003

wrote:
On Jul 14, 7:29 pm, John B 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).

Self propelled? Wtf is that all about? And how would you achieve it
without dragging around a barn full of batteries slung under one of
the cards?


You've summed up the flawed thinking of the DfT quite well there. Please
refer to the Thameslink Rolling Stock spec for other conflicting
requirements:

http://www.dft.gov.uk/pgr/rail/pi/th...levespecif.pdf

Section 9.3 includes inter alia "The capability to move a short distance
without the traction supply being present"

LOROL

Paul

On 15 Jul, 13:05, "Paul Scott" wrote:
You've summed up the flawed thinking of the DfT quite well there. *Please
refer to the Thameslink Rolling Stock spec for other conflicting
requirements:

Roger Ford guesses a 200 hp diesel generator will need to be included
under one of the carriages in each unit. It's not a terrible idea but
I can't imagine a cost benefit analysis on it is positive - how often
is the track navigable but the traction supply unavailable?

U

--
http://londonconnections.blogspot.com/
A blog about transport projects in London

On Jul 15, 1:39 pm, Mr Thant
wrote:
Roger Ford guesses a 200 hp diesel generator will need to be included
under one of the carriages in each unit. It's not a terrible idea but

Can't see that happening. They'd have to install diesel fuel supplies
and engine maintenance facilities in the depots. Not cheap or perhaps
even practical. Also Thameslink has some steep sections (eg city
thameslink to blackfriars) and I'm wondering if 200hp would be enough
to propel a 140 ton unit up them.

B2003

gurgled happily, sounding much like they were
saying:

Roger Ford guesses a 200 hp diesel generator will need to be included
under one of the carriages in each unit. It's not a terrible idea but

Can't see that happening. They'd have to install diesel fuel supplies
and engine maintenance facilities in the depots. Not cheap or perhaps
even practical. Also Thameslink has some steep sections (eg city
thameslink to blackfriars) and I'm wondering if 200hp would be enough to
propel a 140 ton unit up them.

The diesel engine wouldn't actually be propelling the train, of course -
merely generating enough electrickery to enable the motors to do so. I'm
assuming there'd be batteries involved, too, so if there was insufficient
charge available to do the climb, it'd merely be a question of waiting at
the platform at City Thameslink, with the diesels going full tilt, until
enough sparks had been made and were waiting to be used...

Adrian wrote:
gurgled happily, sounding much like they
were saying:

Roger Ford guesses a 200 hp diesel generator will need to be
included under one of the carriages in each unit. It's not a
terrible idea but

Can't see that happening. They'd have to install diesel fuel supplies
and engine maintenance facilities in the depots. Not cheap or perhaps
even practical. Also Thameslink has some steep sections (eg city
thameslink to blackfriars) and I'm wondering if 200hp would be
enough to propel a 140 ton unit up them.

The diesel engine wouldn't actually be propelling the train, of
course - merely generating enough electrickery to enable the motors
to do so. I'm assuming there'd be batteries involved, too,

Those will be the special DfT designed batteries that still allow the unit
to be lighter than anything previously built of course...

Paul S

On 15 Jul, 13:56, Adrian wrote:
gurgled happily, sounding much like they were
saying:

Roger Ford guesses a 200 hp diesel generator will need to be included
under one of the carriages in each unit. It's not a terrible idea but
Can't see that happening. They'd have to install diesel fuel supplies
and engine maintenance facilities in the depots. Not cheap or perhaps
even practical. Also Thameslink has some steep sections (eg city
thameslink to blackfriars) and I'm wondering if 200hp would be enough to
propel a 140 ton unit up them.

The diesel engine wouldn't actually be propelling the train, of course -
merely generating enough electrickery to enable the motors to do so. I'm
assuming there'd be batteries involved, too, so if there was insufficient
charge available to do the climb, it'd merely be a question of waiting at
the platform at City Thameslink, with the diesels going full tilt, until
enough sparks had been made and were waiting to be used...

I can't see that working, particularly if the lack of current is down
to snow or something. I've already bored everyone with my anecdote of
a 319 failing twice to get up the slope in snowy conditions before
reversing to the north end of City Thameslink and finally making it
with long runup.

On 15 Jul, 13:53, wrote:
200hp would be enough to propel a 140 ton unit up them.

Depends how fast you want to go. At 2mph you only need 55 hp to
counteract gravity, which leaves you the rest for friction, rolling
resistance, etc. Though it'd be far more sensible to send a failed
train north from the central section.

Batteries aren't part of the base spec. It does say "Some level of
onboard energy storage may provide an optimal solution overall", with
regard to maximizing the use of regenerated energy. Which is just an
invitation for bidders to look into whether they're a good idea or
not.

U

--
http://londonconnections.blogspot.com/
A blog about transport projects in London