Dargan Project

mgmt

Dargan Proposal Summary

Summary

Dargan takes full advantage of Dublin’s existing rail infrastructure by joining, extending and upgrading it to full Metro standards. The preferred route options, as of May 2008 are as follows:
· Completion of a city centre Circle Line 12 km of which 56% exists;
· Two new radial railway lines which form a new cross-city line that extend from the RPA’s Metro West at Newlands Cross to Templeogue to Dublin City Centre to Cabra (Templeogue Line) 14.1 km and then to the Airport and to Swords where it joins onto the Belfast Line (Airport/Swords Line) 18 km;
· A new Blanchardstown Circle Line 5.0 km and upgrading the existing Blanchardstown Cabra line 8.8 km.
The interlinking of the above may be seen on Preferred Route Options and further detail on Preferred Circle Line, Templeogue Clondalkin Line , Airport Swords Line, Blanchardstown Line and Line Diagram - Direct Routes

Dargan directly connects all Dublin’s Mainline Rail, DART and Arrow services & extensively integrates with existing Luas and Bus services. The Circle Line is intersected by 8 radial rail lines (4 Irish Rail, 2 Luas and 2 Dargan) and also by over 11 radial quality bus routes.

Before selecting preferred routes Dargan consider many alternatives.
See: Route Map, Circle Line & Airport Swords Line.
The effects of the selected routes on those considered include that:
· Dargan will supersede both RPA’s Metro North and Irish Rail’s Metro Interconnector;
· Dargan’s alignment through Finglas is shelved for the moment.

Dargan’s all-in* Capital Cost in 2006 prices is €2.6bn This figure will be adjusted to take account of the recent preferred route options and 2008 prices. The figure is based on discussions with and details from world wide tunnel builders and metro operators and consideration of outturn expenditure for the Dublin Port Tunnel and repeated Madrid Metro schemes. A Sensitivity Analysis shows that cost and revenue used can be relied on and are safe.

*For clarity ’all-in cost’ includes the following: procurement due process; design; supervision; electrical, mechanical & civil works; rolling stock; depots; system commissioning; financing charges; interest on all expenditure during construction; & VAT.

It is possible for Dargan to be totally self-financing and profitable because its capital cost per patron gained is highly economical. Said another way, Dargan by providing an extensive integrated transport network has the ability to attract a large number of patrons at a relatively low Capital Cost simply because much of Dargan is just joining-up (better utilizing) what is already there.

It is envisaged that Dargan will be developed by State Agencies. Should State Agencies not consider Dargan then Dargan will apply for a Railway Order (the right to build & operate a railway).

http://www.darganproject.com/


So, what do you think of the Dargan Project. Seems fairly well thought out and he some fairly detailed drawings on the website.

Logico

Walter Mitty strikes again.

Neworder79

I'm not an engineer so can't verify their claims regarding the Spanish examples cited or cost, but the Dargan double level single tunnel proposal looks like a far more elegant and affordable solution than the complex dual tunnel Metro with all it's crossing tunnels, vents and complex expensive station designs.

They claim several benefits in terms of simplified in-tunnel stations, smaller less complex station footprint and construction method, easier line crossing options etc. It seems the more complex a project is, the less likely it is to succeed in this country, more so with our new economic reality. So I think it should at least be evaluated, especially now with the sword hovering over Metro.

L1011

I seriously doubt the RSC would allow a double level tunnel due to there not being easy escape from one to the other.

dynamick

The RSC doesn't seem to rule out single bore tunnels in their guidelines

RSC guidelines

Twin single-track tunnels equipped with modern signalling systems may have advantages for
railway safety compared with double-track tunnels in that the risks of collisions and secondary
collisions resulting from a train derailment between trains travelling in opposite directions are
minimised. This safety environment may also be achieved by a single bore tunnel partitioned
between the two tracks. Where twin single-track tunnels are provided, they will normally aid
emergency evacuation and ventilation arrangements with the non-incident tunnel providing a
safe refuge
...
Current practice indicates that distances between access points should be in the order of 1 km
where there are twin single-bore tunnels with adequate intermediate cross-passages. In other
circumstances this distance may need to be reduced. A full risk assessment would be required
to determine the appropriate spacing. Where the emergency access is to be used as an
evacuation route as well, these needs should be included in the determination of the spacing
required.

paulm17781

dynamick wrote: »

The RSC doesn't seem to rule out single bore tunnels in their guidelines

RSC guidelines

I think they have to be separated and presumably a way to get across in an emergency.

AngryLips

This obsession with a pointless circle line to nowhere crops up time and time again and, despite the dubious arguments going for it, it's a concept that simply refuses to die.

AugustusMinimus

Can someone please explain to me why after everything is built we will have 4 different versions of rail transport in Dublin.

1. Standard rail
2. DART
3. LUAS
4. Metro


For a start, why the hell build both the LUAS and Metro. Not not just build one which was fully integrated. What a bloody mess.

antoinolachtnai

AngryLips wrote: »

This obsession with a pointless circle line to nowhere crops up time and time again and, despite the dubious arguments going for it, it's a concept that simply refuses to die.

The point of it is that a circle line provides a lot of city centre capacity and links the entire train network with a key destination, i.e., the south city centre and to a lesser extent, the north city centre. It links up all the existing commuter lines which are basically disparate with different terminating stations.

This makes increased services on the Maynooth and Hazelhatch (for example) lines in particular far more attractive and viable.

The interconnector was a similar sort of idea, but it did not allow as much flexibility of routing.

AngryLips

What kind of journeys does the circle line service cater for that isn't already being met in the existing plans?

The only thing it does, above and beyond what's provided for in the official plans, is connect Heuston with Maynooth line services without the need to interchange in the city centre. Any advantage that has, over a connection at Pearse, is eroded by the fact that two connections will have to be made instead of one.

The proposed circle line is an idiotic concept without any thought given to who might actually use it (no one) and is nothing beyond a spruced up exercise in crayon drawing with maps. I love the way the schematics shown have included the plans for Dart Underground even though that proposal makes this one totally redundant.

antoinolachtnai

This plan is clearly an alternative to Dart Underground. It provides for all the same routes as Dart Underground whilst opening up additional options.

It also caters for a station at Cabra and Phoenix Park, giving a fast city centre connection from this area to the south and east of the city. It also allows clockwise journeys from the south-west to the north-east area of the city (for example served by Phibsborough or Summerhill) with a single change.

AngryLips

Running with the notion that it's an alternative to Dart Underground for a minute here; the reality is that everyone traveling into Heuston and bound for the city centre will be forced to connect at Heuston for the circle line in place of a Dart Underground plan that provides for through-services. What's the point?

It also forces two connections for anyone traveling from the Kildare line to any point on the northern line in place of a direct service that the DU project is intended to facilitate. It's connectivity for connectivity's sake.

It's only unfortunate that the real plans are about as doubtful as this pie in the sky concept in the current climate.

antoinolachtnai

As I understand it, this would allow through services as well, similar to DART Underground. I think there is a diagram of proposed junctions there somewhere.

As well as allowing a direct service between Kildare and Northern Line, it also would allow a more direct connection with the Western Line and this should reduce reliance on the Loop Line.

It would be less expensive to build, basically because the underground section is shorter.

dowlingm

It's not enough to say it can deliver the routings of DU etc - capacity is important too. If all these junctions mean trains every half hour rather than every 5-10mins per direction at peak you're talking very different objectives.

antoinolachtnai

The junctions wouldn't reduce capacity. There are junctions on DART underground too. The frequency depends more on the switching and signalling than on the number of junctions. There is no reason not to be able to operate a service in the tunnel every two or three minutes with that configuration.

By opening up access to the Phoenix Park Tunnel and the Western line, you are opening up the possibility of having high frequency services on that stretch too.

Cormac Rabbitt

AugustusMinimus wrote: »

Can someone please explain to me why after everything is built we will have 4 different versions of rail transport in Dublin.

1. Standard rail
2. DART
3. LUAS
4. Metro


For a start, why the hell build both the LUAS and Metro. Not not just build one which was fully integrated. What a bloody mess.

Dargan Answer:

It’s a really good question. For me it boils down to rail gauge and rolling stock width...

A Senior Department of Transport Official who had the responsibility to recommend the rail gauge for Luas informed the Dargan group that the sole reason why he chose the standard European gauge was that the EU were giving a substantial grant. Where he got the width of rolling stock from I don't know.

Other reasons for the gauge were given subsequently. They are summarised in Dublin Railway Track Gauge.

Rolling stock width issues are summarised on Dublin Railway Rolling Stock Width. If anyone has other information let me know.

Dargan believes that some questionable decisions were made.
For example, if the Luas Red Line was to Irish gauge then a service could run from Heuston to Docklands then on existing Irish Rail line through Drumcondra, Croke Park, Phibsborough, Cabra, Phoenix Park and Heuston again - which completes a circle. After all, international experiance is that public transport is all about Xs and Os (cross city and circular routes).

AngryLips

antoinolachtnai wrote: »

As I understand it, this would allow through services as well, similar to DART Underground. I think there is a diagram of proposed junctions there somewhere.

As well as allowing a direct service between Kildare and Northern Line, it also would allow a more direct connection with the Western Line and this should reduce reliance on the Loop Line.

Again, through services from Heuston and connections between Kildare and Northern lines ...sounds like the existing plans to me rendering any business case for a circle line obselete. It's also questionable as to why anyone would want to dedicate capacity on any cross city link to a circle line service at the expense of Heuston-bound services.

antoinolachtnai

Well once you have built the line the capacity is very very big, 60 tph between the two directions.

By utilizing the network in this way you double the amount of capacity available to Maynooth or Kildare trains toward Spencer Dock. There are now two options for them as they reach the city. That's the benefit of a circular configuration.

You wouldn't necessarily have a circle line service. You might, it depends on how the modeling of passenger demand works out. On the face of it though, it looks like there would be demand for a 10 minute service from Cabra or Phibsboro to/from St Stephen's Green or Kilmainham.

dynamick

It has taken 11 years to get MN and DU through planning. Realistically, we are not going to start that process again to investigate a variation of those plans that is marginally different from DU/MN/BXD.

The Dargan project was given a hearing at the Oireachtas 5 yrs ago.

There is always a temptation in public transport projects to choose indirect routes that pass through more areas but curving routes are less attractive than straight routes to commuters. Circle line in London has fewer passengers per zone 1 km than cross city routes because it goes in a frigging circle. It's still useful but it's of secondary importance to the cross city routes.

antoinolachtnai

The Circle line route itself in London carries 70m-odd people a year. Add to that the other trains that run on the same rails, and that's more like 140m - that figure would be more analogous to what we are talking about here -. (In fact, the circle train's route is now more of a spiral than a circle).

You can't really run a pure hub-and-spoke transport system. It's just not practically possible to get all the routes to coalesce in one place. You always end up with a crossover grid of central stations somewhere. I think the concept with Dargan is to make that crossover work as flexibly as possible.

kc56

The circle line does not serve Heuston! It passes almost 1km to the west of the main Heuston station.

No-one is going to walk 1km for a connection when Luas and DB are waiting at the front door. DU proposes a station under Heuston providing real connectivity.

As regards different rail types, Standard and DART are mainline heavy rail and totally unsuitable for on-street systems and too expensive for metro north.

For various reasons, it's not possible to mix light (Luas) and heavy rail vehicles. If the Irish guage, 1600mm, had been used for Luas, then custom trams would have been required rather than off-the-shelf trams at extra cost and there would have been issues with sharp turns. Most cities separate heavy and light rail system but have good interchanges.

antoinolachtnai

There is a connection with Luas at St James's Hospital There is no walk for a connection with Luas. Buses can easily serve a stop on St John's Road.

Fewer trains and passengers would terminate at the main Heuston platforms in this arrangement.

(Stating the obvious, you cannot put the station any closer to the existing Heuston platforms and still be able to enter the Phoenix Park Tunnel.)

markpb

kc56 wrote: »

As regards different rail types, Standard and DART are mainline heavy rail and totally unsuitable for on-street systems and too expensive for metro north.

Unpopular maybe but some cities have on-street heavy rail. Of course the H&S people don't like it very much

dubhthach

What's ironic about the "unsuitable" for street usage is that the old Dublin tram network was all built to Irish gauge (5"3") the main reason for not building the Luas to that gauge was they wouldn't be able to buy off the shelf trams etc given that we don't have a tram/train building industry -- which is a fair enough point.