How to make use of the PPT after the Interconnector

Cool Mo D

This is an idea I had to make use of the phoenix park tunnel assuming the interconnector is built. A rail line through a densely populated area is a terrible thing to waste. Apologies if someones suggested this before - I haven't heard it anyway.

The scene: It's 2020. (OK I'm being optimistic). The interconnector has been built. 2 DART lines exist, one running from the Northern line, through the Interconnector, out to Hazelhatch. The other form Maynooth to Greystones, both fully electrified, and a station at Inchicore has been built.

The problem: How does the phoenix park tunnel fit into this plan? Also, the Interconnector and 4-tracking to Hazelhatch has created lots of capacity on the line, that is bottlenecked by the northern line.

My proposal Create a third DART line, running from Hazelhatch, through the interconnector to Spencer Dock. From there it would cross North Wall junction straight towards Drumcondra, instead of heading north, and head around through the phoenix park tunnel, terminating at the Islandbridge platforms in Heuston, forming a hook-shaped route. New stations would be constructed at Phibsboro, and where the PPT line crosses the Navan road.

This would require new stations, some electrification at the North Wall junction, and the PPT route, and probably grade separation at North Wall too.
Also, since the phoenix park tunnel route would be so busy, Intercity and Commuter trains from Sligo, Mullingar and Pace would be sent down by the canal to either Docklands station, or preferably, build a short new link from the canal direct to the terminating platforms at Connolly, where they wouldn't cross paths with the DART.

The entire proposed route would be completely dedicated to the DART, no sharing with any commuter or Intercity.

I would envisage an off peak service of 4 tph on all 3 DART lines, so 8tph Hazelhatch to Spencer Dock, and 8 tph Drumcondra to Heuston Islandbridge. Giving Metro style frequencies in the city centre and inner suburbs.

This route also avoid the timetabling and reliability difficulties of a circle line (see the changes being made to Londons circle line, for example) route, which would not be feasible anyway, with the layout of the tunnel portals for the interconnector and PPT.

The result An all new DART route, segregated from non-DART traffic, serving the dense suburbs around the PPT.

L1011

Is there not problems in electrifying the PPT?

Cool Mo D

Don't think there's a major problem there - very little overhead room is required for a wire - the wire can be attached directly to the tunnel roof, and the pantograph retracted all the way on the train.

The track can be lowered by a metre or so if necessary - this was done for the some of the original DART project I believe.

L1011

It was done under a few bridges, not a substantial length of tunnel - serious risk of bringing the entire thing down on yourself with that!

Cool Mo D

Wasn't it done around Bray head? Wasn't that lowered? Either way, it's a very short cut and cover tunnel only around 500m long. I find it hard to believe that it could have a lower clearance than one dug out of rock on the coast. I think "too low for the wires" is similar to the "not big enough for passenger trains" line spouted by IE before - i.e., conplete BS.

admiralofthefleet

could dart units be modified to take their electrical supply from the ground between the tracks thus eliminating the need for overhead wires in the tunnel?

aliveandkicking

admiralofthefleet wrote: »

could dart units be modified to take their electrical supply from the ground between the tracks thus eliminating the need for overhead wires in the tunnel?

No need for that. The PPT is easily capable of overhead electrification - don't let anyone tell you otherwise. It would be a very small engineering problem.

admiralofthefleet

aliveandkicking wrote: »

No need for that. The PPT is easily capable of overhead electrification - don't let anyone tell you otherwise. It would be a very small engineering problem.

then i cant believe it hasnt been utilised already, that and the old irish cement terminal in cabra. that should be opened up for public use

antoinolachtnai

If you could figure out a way to turn the whole thing into a circle line, the capacity would be immense. There are many good things about circle lines. You could drive extraordinary growth in the North outer city in particular on the back of that.

The question though, is what sort of city do we really want? How much further development should the city undergo? How much do we want the population to grow?

D.L.R.

antoinolachtnai wrote: »

If you could figure out a way to turn the whole thing into a circle line, the capacity would be immense. There are many good things about circle lines. You could drive extraordinary growth in the North outer city in particular on the back of that.

The question though, is what sort of city do we really want? How much further development should the city undergo? How much do we want the population to grow?

A city with adequate mass transit would be good for starters. The question is what sort of Dublin are they creating? If Metro West is anything to go by, I'm emigrating

murphaph

Circle lines can be great alright. I can see my local ringbahn station from my window here. It's so handy for getting around the city and faster than the U-Bahn most of the time.

Nostradamus

MYOB wrote: »

Is there not problems in electrifying the PPT?

Not at all. It is the second widest diameter twin bore Victorian rail tunnel in Europe.

Nostradamus

Cool Mo D wrote: »

This is an idea I had to make use of the phoenix park tunnel assuming the interconnector is built. A rail line through a densely populated area is a terrible thing to waste. Apologies if someones suggested this before - I haven't heard it anyway.

This is more or less the same plan which Platform11 presented to the Oireachtas Transport Commitee.

http://www.gov.ie/committees-29/c-publicenterprise/20030415-J/Page1.htm

Everyone except Irish Rail thought it was a brilliant idea. The Commitee even embrassed Irish Rail in o disproving the line could not be used by forcing them to send them in a railcar from Hueston to the Docks.

A few weeks earily I was in a debate with Barry Kenny on Newstalk were he openly stated that the PPT was too windy and narrow for passenger trains. Yet a GAA special has used it the day before.

This is what you are up against with these people. CIE is a law unto itself.

Nostradamus

MYOB wrote: »

It was done under a few bridges, not a substantial length of tunnel - serious risk of bringing the entire thing down on yourself with that!

Are you an Irish rail manager!

My god I have heard all the excuses not to use this tunnel now...only a matter of time before we are told there are Dwarfs living down there and the are NIMBYs.

Victor

Nostradamus wrote: »

Are you an Irish rail manager!

I'm not singling anyone out here, but just because someone says something you don't agree with, doesn't mean they are a Irish Rail / CIÉ manager / employee / lackey

Nostradamus

Victor wrote: »

I'm not singling anyone out here, but just because someone says something you don't agree with, doesn't mean they are a Irish Rail / CIÉ manager / employee / lackey

It's not my opinion - it was HIS opinion. It is my FACT.

Big difference.

weehamster

Passenger trains can currently go through the tunnel. This has proven many times thanks to the GAA specials from the south west which go through here and the new 22k trains which were pulled through when they arrived from Dublin Port. There was a service which stopped in the early 60's. So diesel passenger trains have no problems and there is no excuse why a service cant use it now.

The tunnel is not capable of the same overhead electrification system that is being used on the current DART - don't let anyone tell you otherwise. :rolleyes:

If you lower the floor, you make the tunnel too narrow. You also have to rebuild the bridge over the Liffey making it lower to line up with a lower tunnel floor and you have to dig down lowering Heuston's platform 10 and the track leading into it.

An electric rail would be the best option but the current trains cant be adapted. So you have to get brand new trains adding an extra cost to them.

The Kildare Commuter and Intercity services would interfere with the loop line services and you would need to 4 track the line from Heuston to Inchicore.

I sorry. A city centre loop line would be nice to have but it is not essential, even at 2020. This idea is a non-starter. You would be better off building a new tunnel spurring off the interconnector and looping back onto the Connolly/Maynooth line.

Why even bother when all you need is a simple interchange at Pearse and you can transfer between the Maynooth line and the Kildare line.

Anyway there are far more important issues to deal with in 2020.

• Light rail to Finglas
• The Metro South from the Green to Tallaght
• The Red line hitting full capacity (Metro South would help to free up capacity).
• The Green line upgraded to a light rail Metro handling 90m trams
• Upgrade the northern line to 3 or 4 track between Fairview and Howth Jtn
• Extending the DART from Hazlehatch to Kildare town
• Extending the DART from Pace/M3 to Navan (if even the line is extended to Navan in the first place by then)
• Twin tracking from Bray to Gorey
• Light rail from Howth Jtn to Metro North

Cookie_Monster

weehamster wrote: »

An electric rail would be the best option but the current trains cant be adapted. So you have to get brand new trains adding an extra cost to them.

Why not? All you need is a length of cable running from the pantograph down to a contact with the rail. Obviously insulated and all that but none the less very easily and cheaply done.

So power is picked up normally by the pantograph and then in tunnel is picked up from rail and fed to existing mechanisms in the pantograph...

Victor

weehamster wrote: »

An electric rail would be the best option but the current trains cant be adapted. So you have to get brand new trains adding an extra cost to them.

They are looking to order 300-500 new EMUs.

aliveandkicking

weehamster wrote: »

The tunnel is not capable of the same overhead electrification system that is being used on the current DART - don't let anyone tell you otherwise. :rolleyes:

If you lower the floor, you make the tunnel too narrow. You also have to rebuild the bridge over the Liffey making it lower to line up with a lower tunnel floor and you have to dig down lowering Heuston's platform 10 and the track leading into it.

An engineer who worked on the DART overhead wire replacement a couple of years ago told me the PPT could use exactly the same system as the DART. The rail would have to be lowered by approx 1 metre to fit the pantograph but he assured me it was small gravy engineering wise. The width argument is a red herring since ther old Park Royal coaches used the tunnel and they were far wider than trains today. I doubt you would have to rebuild the bridge either as there is about 250 metres past the bridge before the entrance to the tunnel - enough to drop 1 metre? http://maps.live.com/default.aspx?v=2&FORM=LMLTCP&cp=swr4k9gg767w&style=b&lvl=2&tilt=-90&dir=0&alt=-1000&scene=29507460&phx=0&phy=0&phscl=1&encType=1

Cool Mo D

antoinolachtnai wrote: »

If you could figure out a way to turn the whole thing into a circle line, the capacity would be immense. There are many good things about circle lines. You could drive extraordinary growth in the North outer city in particular on the back of that.

The question though, is what sort of city do we really want? How much further development should the city undergo? How much do we want the population to grow?

It would be a circle line of a sort - you could transfer from the PPT platforms at Islandbridge to Heuston easily enough, although you would have to change trains. I believe circle lines are problematic to run, because they lack any time waiting at the terminal, which can be shortened to compensate for a late running train - one late train will then delay every service behind it.

ODS

Nostradamus wrote: »

This is more or less the same plan which Platform11 presented to the Oireachtas Transport Commitee.

http://www.gov.ie/committees-29/c-publicenterprise/20030415-J/Page1.htm

Everyone except Irish Rail thought it was a brilliant idea. The Commitee even embrassed Irish Rail in o disproving the line could not be used by forcing them to send them in a railcar from Hueston to the Docks.

A few weeks earily I was in a debate with Barry Kenny on Newstalk were he openly stated that the PPT was too windy and narrow for passenger trains. Yet a GAA special has used it the day before.

This is what you are up against with these people. CIE is a law unto itself.

This is exactly why Dublin Bus's bus gate is not to be trusted. As residents in Mountjoy Square have pointed out, CIE is abusing the north inner city by not providing services with existing infrastructure, such as PPT, while at the same time dumping all over it. Whether it's Dublin Bus, Irish Rail, or Bus Eireann leased coaches dumped in the public domain, CIE is a flaming disgrace and is really pissing people off no end :mad:

antoinolachtnai

Conceptually at least, that's an easy problem to solve. You just never have late trains. The schedule needs to be adhered to down to the second. This is how a high capacity urban train system is operated.

As it is, the system in Dublin is fairly time-sensitive. If everything doesn't hit its timeslot in the city centre, things don't work too well.

If you are going to build a train system to operate without high capacity and tremendously high reliability in mind, you'd probably be better off not building it.

gjim

Everyone wonders about this.

When I thought about it, I also considered that post-Interconnector, the midlands line will be redundant also. It is even more difficult to come up with something viable that would use both. First it would require reworking Liffey junction, preferably grade separating the link. So you have trains starting in Heuston (or further out towards Kildare) going through the PPT along the midlands line and past the North Strand Rd. The question is where to go then? What should be called Sheriff St. Station isn't exactly a popular destination or useful terminus. One option is to create a semi-loop as you suggest by turning south into the Interconnector portal. A while back I suggested here - to a largely negative response - building a new curve to allow trains on this line to turn north at this point instead. The curve would be tight but just about doable I think. Having joined the northern line it would only stop once before Howth Jucntion before terminating in Howth which would lose it's electrified DART. This would then create a third (DMU based) DART line: Hueston, Phibsboro, maybe North Strand Rd., Clontarf Rd, Howth Junction and (all stops to) Howth. Stations would be added between Heuston and Clontarf Rd as usage grew. To get utility out an arrangement like this would probably require adding a new curve from the PPT into Heuston to save passengers from the 500m or so walk. So messy enough I suppose but at least you'd squeeze some utility from these pieces of infrastructure.

If you think about it, it's actually quite difficult to come up with something using the PPT that doesn't just offer an inferior alternative to the two line DART system for the vast majority of journeys. Worse, many ideas would probably cause some operational difficulties for other services so you'd need to be sure that it was going to deliver.

L1011

Nostradamus wrote: »

Are you an Irish rail manager!

Seeing as I've not taken a train in over a year, no. There is a conflict of interests thread for those that would have them, I invite you to see if I'm on it...

loyatemu

MYOB wrote: »

Seeing as I've not taken a train in over a year

well thats one thing you have in common with most Irish Rail managers, the minister for transport, the board of CIE etc. :pac:

Victor

Cool Mo D wrote: »

How to make use of the PPT after the Interconnector

Here's one I made earlier.

Victor

More.

Victor

And the rest.

DWCommuter

I tried this topic out on Politics.ie. Wow!

My opinions are well covered. Unfortunetly most detractors of this tunnel refuse to actually read any post, that explains it in intricate detail, with any degree of concentration. They are too quick to jump in and expouse their "political", "Read it in the paper", "but Irish Rail said..." or "the interconnector does..." opinions.

Some dude on Politics.ie even insisted a reversal was required at Connolly!

I really dont have the patience anymore. Thats why Im writing a book!

dowlingm

You wouldn't necessarily use catenary in a tunnel - a solid overhead bar conductor would probably require less headroom - the Delhi Metro is running underground using them - at 25kV :eek:

Also, you could lower the tunnel a touch but maybe the R109 road bridge could be reprofiled to permit the tunnel entrance to be raised rather than the trackbed lowered at that point.

My concern with the PPT idea is more how you get 8-car bidirectional platforms that are conformant with accessibility at Heuston - Platform 10 might be grandfathered but a putative 11 would not be.