Dart underground alternative

Thrashssacre

With the imminent introduction of 10 minuite darts and the success of the new Phoenix park servives+ uncertainty over the future of dart underground could this alternative be feasible

Electrification of the the Newbridge to Connolly line + electrification of the maynooth line dart patterns may then run as follows + line to docklands

Off peak:
malahide to greystones 3tph.
Maynooth to bray 2tph
Newbridge to dun laoghaire 1tph
Howth branch served with a dart shuttle service to howth junction to connect with malahide to greystones services

Peak:
Maynooth to docklands 3tph
Use any remaining paths to run malahide and maynooth services to connolly only using platforms 4 and 7 for turn back and run an enhanced Newbridge to grand canal docks every 20 minuites or so.

Limits any future growth of the northern and south east line and will require the purchase of more darts but it seams like this is the only way to force the government's hand into some kind of action. It would also improve journey times on the Phoenix park tunnel services and maynooth line which can only be seen as a possitive thing. And it would free up intercity set to be used for their intended purposes

Sam Russell

You do not appear to use GCD at all.

Thrashssacre

Sam Russell wrote: »

You do not appear to use GCD at all.

Only at peak hours for services from Newbridge.

thomasj

I thought the phoenix park tunnel in its current setup could not be electrified?

end of the road

electrification of the maynooth line must happen anyway eventually. it won't though.

DU is the only actual option along with quad tracking wherever feasible. the only way this will happen is by making it an election issue, encouraging fellow users of the services to also make it an election issue. if enough people do it, they can't ignore us any longer.

thomasj wrote: »

I thought the phoenix park tunnel in its current setup could not be electrified?

that's my understanding also.

goingnowhere

Tunnel is far too tight (well its the road bridge at the Heuston side that causes the height issue)

Its a very tight squeeze currently to get two trains through side by side, for several years the tunnel was operated on a single train in tunnel at a time basis due the clearances, this was addressed last year by lowering the track level to get the clearance but subject to a speed limit

kc56

goingnowhere wrote: »

Tunnel is far too tight (well its the road bridge at the Heuston side that causes the height issue)

Its a very tight squeeze currently to get two trains through side by side, for several years the tunnel was operated on a single train in tunnel at a time basis due the clearances, this was addressed last year by lowering the track level to get the clearance but subject to a speed limit

Wasn't this restriction brought in to cater for 9'6" containers on flat wagons?- std containers are 8". To get the two way operation back, the tracks had to be moved closer together than normal and thus the speed restriction. Probably no room for electrification as a result.

flyingsnail

goingnowhere wrote: »

Tunnel is far too tight (well its the road bridge at the Heuston side that causes the height issue)

Its a very tight squeeze currently to get two trains through side by side, for several years the tunnel was operated on a single train in tunnel at a time basis due the clearances, this was addressed last year by lowering the track level to get the clearance but subject to a speed limit

The tunnel is very tight, up until the recent works there was two tracks but only one was permitted to be in use at any time due to insufficient clearance. The track works and the speed limit reduction to 20 allow most trains to pass in the tunnel. You would need massive engineering works to enable electrification.

murphaph

Is it really just the Islandbridge portal that's the problem?

MJohnston

This is a purely hypothetical question because I don't think it'll ever happen and its fairly impractical, but would DART trains not be able to run for short sections on a live third rail or a storage battery on board?

flyingsnail

murphaph wrote: »

Is it really just the Islandbridge portal that's the problem?

I don't believe so, I remember reading before how many feet they would have to lower the rail by throughout the tunnel to fit the OHLE but I cant find it now.

goingnowhere

Even if you could lower, you have the Liffey bridge to deal with which means you can't lower by much

3rd rail is very much out for anything new and the cost of implementation would be crazy

Might as well just build DART underground...

Grandeeod

murphaph wrote: »

Is it really just the Islandbridge portal that's the problem?

Yes.

flyingsnail wrote: »

I don't believe so, I remember reading before how many feet they would have to lower the rail by throughout the tunnel to fit the OHLE but I cant find it now.

The Islandbridge portal is the problem with lowering the rail in the tunnel. But not insurmountable.

Jamie2k9

ROI from electrification of PPT (can't be done( would be very poor.

Off peak:
malahide to greystones 3tph.
Maynooth to bray 2tph
Newbridge to dun laoghaire 1tph
Howth branch served with a dart shuttle service to howth junction to connect with malahide to greystones services

I don't see the benefit of Newbridge to Dun L, just use just the bay in GCD.

You also also reduce N of Connolly from 4 to 3 per hour in terms of DART service, good for Belfast but would required N Commuter to stop more places.

MJohnston

Just to follow up on my previous hypothetical, can DARTs run for any distance at all without overhead power? Aside from momentum obviously.

LeinsterDub

MJohnston wrote: »

Just to follow up on my previous hypothetical, can DARTs run for any distance at all without overhead power? Aside from momentum obviously.

No. They need to be powered

murphaph

LeinsterDub wrote: »

No. They need to be powered

I'm sure they can run on momentum for a few yards. Trains all over the world have to lower their pantographs in motion when moving from (eg an AC to DC overhead system) or when passing through an isolator section.

It wouldn't be safe however to use this as some trick to get DARTs through as any mishap and a nasty accident could occur.

If it's just the portal then sorry, that's a trivial problem that in any other western European country would be solved by replacing the portal. It's not the great pyramid we're talking about.It would make you cry what a fuss is made about relatively small infrastructure (especially railway related stuff). There's just no will there for any of it.

LeinsterDub

murphaph wrote: »

I'm sure they can run on momentum for a few yards.

Well of course Newton and his conservation of energy sees to that

MJohnston

I'm surprised they don't have *any* kind of local battery storage on board for that kind of thing.