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Extend the DART - Technical information

The Dublin rail plan requires substantial engineering work to complete. A 8 km long tunnel will bored from Spencer Dock under the south quays to beyond Heuston station. The closed Clonsilla Navan line will be reopened at least as far as Dunboyne. A new station will be built at Spencer Dock, Dublin Hazelhatch, Dublin Balbriggan and Dublin Maynooth/Dunboyne will be electrified, this will necessitate replacement of a substantial number of bridges to gain clearance for the overhead wires. Unlike the DART project the track, signaling and stations are modern and recently upgraded in most cases, as such some work and not wholesale replacement will be required.

From Where To Where

The tunnel is approximately 7.2 km in length, starting at Inchicore Works and proceeding underground under Heuston station, the south quays, crossing the Liffey close to the site of the new Macken Street Bridge and surfacing at a location known as Church Rd junction to the rear of Spencer Dock.

Originally it was planned to surface the tunnel in the freight yard in Heuston but this was not practical and as a result the much superior option of surfacing the tunnel west of Inchicore Works was chosen.

Signaling will be provided capable of accommodating 20 trains an hour. External contractors will be required to build the tunnel. There are several experienced companies capable of the construction of the tunnel, these companies have worked on the London Underground and Paris Metro for example.

Iarnród Éireann are going to do all this, that can't even run a decent service as it is

The main problem Iarnród Éireann and the CIE group of companies in general have suffered from has been a chronic lack of investment, consistently governments have refused to adequately fund the company. As recently as 1987 the Government saw fit to refuse any further capital investment. Following a serious derailment to a Westport bound train at Knockcroghery, Roscommon in 1997 and several highly critical safety audits that followed the Government authorised a massive EU backed capital investment program. Until the commencement of the On Track 2000 program vast swathes of the rail network consisted of jointed track on wooden sleepers some dating back to the 1920's and 1930's, some in extremely poor condition. Safety depended on a signaling system dating from the Victorian era. It was nothing short of a miracle Iarnród Éireann could sustain any kind of service on a shoe string budget in this environment, especially in the face of substantial year on year growth in passenger numbers.

All this investment however is just a catch-up exercise to return the network to a safe, reliable condition suitable for the 21st century. Passengers can only see limited benefits and it provided limited capacity improvements at best.

The view today following the completion of the On Track 2000 program is very much different the entire intercity network is continuously welded rail on concrete sleepers. A state of the art computer controlled signaling system is being progressively introduced on secondary routes. The December 2003 timetable saw significant improvements including for the first time off peak suburban services to Arklow and Longford as well as significant improvements on the Drogheda line. All recent projects have been accomplished on time or early at or below budget.

The root cause of poor service is mostly due to a lack of capacity through Dublin city centre, with the system operating at or beyond its capacity the slightest delay leads to disruption. The lack of suitable modern rolling stock has also been a significant barrier to improvement. The introduction of new rolling stock built specifically for suburban services in recent years has lead to significant improvements in both frequency and capacity.

Iarnród Éireann have the knowledge in house to undertake this project, the original DART project was handled in house, as was the On Track 2000 project, in addition the majority of the initial planning of Dublin's Luas lines was conducted by CIE. The Mini CTC signaling project was taken in house when external contractors failed to deliver, it is now on time to a revised schedule and costs are under control. Unknown to the public CIE have a successful international transport consultancy arm http://www.cieconsult.ie. They clearly have the knowledge and experience but currently lack the funding.


The DART project is proof that Iarnród Éireann can successfully deliver a large scale capital intensive project. The DART project represented a stunning technical and engineering achievement by CIE. The entire route from Howth to Bray was rebuilt, new track, new signaling, new and rebuilt stations, replaced bridges. Massive technical and engineering obstacles where overcome while a limited service was maintained.

The project was managed almost entirely within CIE by a team lead by the chief civil engineer assisted by the chief mechanical engineer and chief signaling engineer. The DART project was completed on time and 3.3% under budget in real terms. Passenger numbers now stand at in excess of 23 million per year more than three times the number carried in 1984 the year the DART opened to the public.

The DART project made groundbreaking use technology in both project management and also in the control systems used to monitor and manage the system. The trains where specially designed for CIEs needs and represented the absolute state of the art for the early 1980's.

But you can't tunnel under Dublin isn't it all granite and limestone ?

In many areas of Dublin notably south of Donnybrook and Merrion it is. Iarnród Éireann and their consultants are happy that is it possible to bore a tunnel. Plans for similar tunnels have existed since 1975. As the Dublin port tunnel has proven it is possible.

Won't this lead to chaos during construction ?

No, tunnel boring machines will be used so the general public will not be aware that work is ongoing. All the tunneling will be carried out from lands owned already by CIE, which are off limits to the public. Supplies, materials and waste related to the tunneling work could travel by rail since both sites have extensive rail connectivity thus avoiding further traffic on Dublin's congested roads. The general public will experience little or no disruption, there will be some minor disruption where access is provided to new underground stations, this is in stark contrast to the Dublin Port tunnel for example which has lead to chaos on Dublin's northside or indeed the Luas project. Equally the proposed metro terminates at St Stephen's Green where some potentially serious disruption could be expected.

The station at Spencer Dock can be built without effecting any current train services since the site is already rail connected and currently only deals with freight trains, the project can be completed with minimal engineering work. The route is in place and is in the final stages of completion following extensive relaying works which where carried out without effecting passenger services.

Iarnród Éireann have quietly being working away to make this project possible. All new or replaced bridges have been built to allow clearance for overhead wires. On the Kildare line all new bridges have been built to allow for 4 tracks. During the Maynooth line upgrade project in the late 1990's all new and replaced bridges where built tall enough to allow for later electrification. Along with a signaling system designed for electric trains the Maynooth line can be electrified with little or no modifications. By ensuring all work done in the recent past allows for future expansion the cost, disruption and length of time required are significantly reduced.

Why go electric ?

A major part of the Dublin rail plan consists of the electrification of all rail routes into Dublin. Electric trains are vastly superior to diesel-powered trains especially when used for suburban services. Electric trains have much better acceleration and braking. They are significantly quieter and can use renewable energy. The trains themselves can recycle a portion of the electricity they use by using electric braking. Electric trains are significantly more reliable than their diesel cousins. They have significantly fewer moving parts, which means there is less to go wrong and less to maintain. The trains emit no fumes and are safe to operate underground. On cost terms electric trains cost no more than a diesel train to buy, but offer lower operating costs thus saving money over their life.

Timetable and Construction costs

The Dublin Rail plan proposed by Iarnród Éireann is a massive long term project. It consists of two major phases. Phase one is already underway and involves maximising the capacity of the current network. The timetable shown is by no means set in stone. If sufficient funding was provided now the project could be completed significantly faster possibly at reduced cost.

Phase One, 2003-2010

Phase one is currently underway. Commuters will start to see significant benefits in 2005 as additional rush hour services will be provided to Maynooth. By the end 2005 all DART stations will be accessible to wheelchair users and 8 coach DARTs will go into service providing a 33% increase in capacity.

Phase one consists of the following

  • Completion the DASH projects both the current phase 1 and phase 2 which upgrades the signaling on the loop line between Connolly, Tara Street, Pearse and Grand Canal Dock to allow 16 trains an hour up from the current limit of 12.
  • Construction and opening of a station at Spencer Dock. This will provide much needed additional capacity on the Maynooth line as well as providing rail services to the massive Spencer Dock development as well as the IFSC.
  • Provision of 4 tracks on the Kildare line as far as Hazelhatch, providing separation between intercity and suburban services.
  • Provision of new stations at Pelletstown, Phoenix Park, Park West, Fonthill Road, Kishogue and Adamstown.
  • Deliver a 100% increase in Maynooth line capacity.
  • Deliver a 400% increase in Kildare line capacity.

Potential projects which may take place in phase one subject to funding include a DART link from Portmarnock to Dublin Airport, additionally the Clonsilla Dunboyne line may be reopened with a limited diesel service.

Phase Two, 2011-2018

Phase two consists of the construction of the Interconnector tunnel between Spencer Dock and Heuston. In parallel to this work will commence on electrification of the Maynooth, Kildare and Drogheda lines. The Clonsilla Dunboyne section will be electrified also. Provision will be made to allow the use of double decker trains between Drogheda and Kildare.

Upon completion of phase two rail services in the greater Dublin region will be reconfigured to provide a fully integrated network.


Absolutely all in including track, signaling, tunnels, stations, rolling stock and associated engineering works comes to 3.8 billion euro. This represents excellent value when compared to the proposed Dublin Airport metro which was initially costed at 4.6 billion euro without even serving Swords. The proposed metro at less than 10 miles in length did nothing for the transport of the greater Dublin region, Iarnród Éireann's Dublin Rail plan spans up to a radius of 50 miles from Dublin city centre.

Cost Breakdown

  • Upgrades and Improvements to the existing network €700 million
  • Spur to Dunboyne €175 million
  • The Interconnector Tunnel between Heuston and Spencer Dock €2.5 billion
  • Other Works including Electrification Hazelhatch/Maynooth/Balbriggan/Drogheda Dublin €400 million
  • Additional Rolling Stock €700 million
  • Total Cost 3.8 billion

Value for Money ?

This is a phased project each element on its own will bring significant improvements. Each phase is projected to show a return of at least 10%. Combined together the overall internal rate of return is in the order of 16%.

Even though passenger numbers are expected to more than double, with the potential to carry 100 million per year no additional subvention will be required from government over current levels.

There are massive socio economic benefits not included in these figures such as reductions in road congestion, reductions in accidents as well as significant environmental benefits not to mention significant reductions in journey times for commuters. It is hard to quantify the social change that a high frequency reliable rail system can bring. The DART has shown that such a system promotes use, it opens up new opportunities, people make journeys they otherwise would not have thus promoting both trade and leisure activities.

Rail transport offers the ability to move very large numbers of people at speed in safety. The DART is a clear example of what investment in rail transport can bring, a clean, efficient, reliable service used by over 85,000 people a day. More roads are not the answer, there is simply no way to get any extra road capacity into Dublin city. Both the AA and DTO (Dublin Transportation Office) agree. Bus services do not provide the capacity, reliability or efficiency that a rail solution can. The Irish Government has spent many tens of billions on roads but has invested comparatively little in the rail network.

Last Updated: June 30 2010 09:55:00
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