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

"D7666" wrote

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.

Whilst I agree with much of this, and am not convinced that auxiliary
traction power is justified, there is also the scenario where failure of the
power supply traps trains between stations. While stations are close
together between Farringdon and Blackfriars, so it is difficult to conceive
circumstances where more than one train could be trapped on each road
between each pair of stations, between Farringdon and Kentish Town stations
are more widely spaced. Kings Cross Thameslink has been retained as an
emergency evacuation location, but I can imagine the difficulties if say
three peak trains were trapped between Kentish Town and St Pancras, and 3000
or more passengers had to be evacuated on foot. It would be useful if
feasible to be able to move a train to a platform, or out of a platform to
clear it for a following train.

Peter

On Jul 16, 1:31 pm, "Peter Masson" wrote:

or more passengers had to be evacuated on foot. It would be useful if
feasible to be able to move a train to a platform, or out of a platform to
clear it for a following train.

In concept yes - but this sort of thing tends not to happen *that*
often.

If DfT or H&S are really that concerned about moving trains in this
way to evac passegners, then they need to do so for all EMU of every
spec for every train of every railway to cover every just in case, if,
but, and maybe.

And this will have to include future LU stock.

--
Nick

On 16 Jul, 14:05, D7666 wrote:
If DfT or H&S are really that concerned about moving trains in this
way to evac passegners, then they need to do so for all EMU of every
spec for every train of every railway to cover every just in case, if,
but, and maybe.

It's nowt to do with evacuation - it's in the "Reliability" section
and is about getting failed trains out of the way. Where and why and
in what circumstances is another matter. I've also just noticed it's
in a list titled "This functionality might include...", which would
appear to make it optional. Sadly the full spec isn't online, only the
summary.

U

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

On Jul 16, 9:29 pm, Mr Thant
wrote:

appear to make it optional. Sadly the full spec isn't online, only the
summary.

Indeed.

--
Nick

There are diesel locomotives that can use their 'starting' batteries to
move them selves - intended for workshop moves and short 'light' yard
moves - so the main diesel plant doesn't have to be started up (and
warmed up, etc, etc) just to move the engine to another maintenance road.

Just how much extra battery would an EMU have to carry (over what it's
already carrying to run the lights, control and safety systems) to move
the train a low speed to the next station platform to allow an orderly
evacuation ?.

Providing enough auxiliary power to run at service speed is just plain
stupid in an EMU, and even an small diesel aux is a maintenance hassle.
If nothing else the fuel will keep going off in the tanks as it doesn't
get used.

Providing enough battery to allow a set to limp to the next platform
might be some what useful and not that expensive in the grand scheme of
things.

"Matthew Geier" wrote in message
...
There are diesel locomotives that can use their 'starting' batteries to
move them selves - intended for workshop moves and short 'light' yard
moves - so the main diesel plant doesn't have to be started up (and
warmed up, etc, etc) just to move the engine to another maintenance road.

Just how much extra battery would an EMU have to carry (over what it's
already carrying to run the lights, control and safety systems) to move
the train a low speed to the next station platform to allow an orderly
evacuation ?.

Providing enough auxiliary power to run at service speed is just plain
stupid in an EMU, and even an small diesel aux is a maintenance hassle.
If nothing else the fuel will keep going off in the tanks as it doesn't
get used.

Providing enough battery to allow a set to limp to the next platform
might be some what useful and not that expensive in the grand scheme of
things.

But as we have already discussed, it flys completely in the face of the
DfT's light weight requirements...

Paul

On Jul 16, 10:57 pm, "Paul Scott"
wrote:
"Matthew Geier" wrote in message

...



There are diesel locomotives that can use their 'starting' batteries to
move them selves - intended for workshop moves and short 'light' yard
moves - so the main diesel plant doesn't have to be started up (and
warmed up, etc, etc) just to move the engine to another maintenance road.

Just how much extra battery would an EMU have to carry (over what it's
already carrying to run the lights, control and safety systems) to move
the train a low speed to the next station platform to allow an orderly
evacuation ?.

Providing enough auxiliary power to run at service speed is just plain
stupid in an EMU, and even an small diesel aux is a maintenance hassle.
If nothing else the fuel will keep going off in the tanks as it doesn't
get used.

Providing enough battery to allow a set to limp to the next platform
might be some what useful and not that expensive in the grand scheme of
things.

But as we have already discussed, it flys completely in the face of the
DfT's light weight requirements...

Paul

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.

B2003

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.

--
Andy Breen ~ Not speaking on behalf of the University of Wales, Aberystwyth
Feng Shui: an ancient oriental art for extracting
money from the gullible (Martin Sinclair)