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

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...

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 Jul 15, 2:12 pm, MIG wrote:


gurgled happily, sounding much like they were
saying:
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.

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.


Todays Thamelink operations - and all those of the greater operation
post 2015 - seem to work OK without any resort to self propulsion.
There are no significant engineering blocks where diesel working would
be useful - lines tend to be closed outright rather than OLE
isolations, and the SR zone tend not to indulge in traction only
isolations.

It is the central sections BF-City-KX that would be most vulnerable to
a train failure. But the service will be so intense through there that
rather than **** around with alternative power (that will be so
infrequently used it will itself be a liability) you simply bring up
the train behind and push out.

And as others have quite rightly pointed out, the central section has
some fierce grades - that from City to BF is the steepest on the
network for practical purposes (although ?? might change with the
upgrade ??). Bearing in mind that an EMU with more than 50% motors cut
out will struggle up there, I don't see how piddly 200 hp power packs
will help any.

Since the new TL is supposed to be about longer trains, the chances of
a train with more than 50% out reduces - because to get to that state
with modules of 4car EMUs you need multiple motor failures across the
train affecting more than one unit. Thats pretty rare. Even with a
complete disablement of a whole train, you push out with a fully
functioning train, so unless a farce arises where it just happens that
it is a 4car following a failed 12car, probability suggests its a fair
risk to not bother with alternatives.

I have to wonder if the person who wrote this into the spec just
happens to be a TL commuter and got caught one day in one of those
rare events of an AC/DC changeover failure at Farringdon and has gone
for sledge hammers to crack nuts approach. Those failures are very
rare, I've never been involved in one in regular travel on the route
ever since it opened.

On top of all this, won't these days of H&S paranoia demand extraction
and filtration equipment in the tunnels to remove noxious gases from
diesel engines, bionic duckweed trurbines or Swordfish power packs ?

--
Nick

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 Tue, 15 Jul 2008, Paul Scott wrote:

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...

Hydrogen fuel cells, presumably. Hydrogen's light, right? WHAT COULD
POSSIBLY GO WRONG?

tom

--
As Emiliano Zapata supposedly said, "Better to die on your feet than
live on your knees." And years after he died, Marlon Brando played him
in a movie. So just think, if you unionize, Marlon Brando might play
YOU in a movie. Even though he's dead. -- ChrisV82

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