High-capacity commuter railways are only possible with the power that only electric trains can provide. The typical acceleration of an electric multiple unit (EMU) is 1 m/s2 which is over twice the typical 0.4 m/s2 acceleration of a diesel multiple unit (DMU). Hence, on a line with frequent stops, acceptable journey times are only possible with electric traction. As a result, electrifying commuter lines has always seen a high increase in ridership.
Cork, the Republic of Ireland’s second city, is expected to increase its population by 50% to 60% by 2040. With limited scope to increase road traffic, the city is planning for a sixfold increase of passengers on the city’s railways. The city’s transport strategy shows that this will bring significant benefits by, for example, better co-ordinating land use and transport planning such as walkable and cycleable catchment areas for existing and proposed stations.
Cork’s rail network currently has 10 stations and comprises routes to Cobh (12km), Midleton (20 km), and Mallow (29km). The service frequency is every 30 minutes, though for Mallow this is only at peak times. The trains are operated by 8 x 2-car DMUs built by the Japanese Tokyu Car Corporation and introduced in 1994. Each car is powered by a 260kW Cummins diesel engine.
The Cork Area Commuter Rail (CACR) programme plans to build an additional eight stations and operate a 10-minute frequency service on all routes. For the reasons described above, these services will be operated by electric trains. 21 x 5-car EMUs are to be ordered to provide a more than sixfold increase in passenger capacity. The power of these sets is expected to be 600kW per coach i.e. more than twice that of Cork’s existing DMUs.
Why 25kV?
The 53 route-km of overhead electrification for Dublin’s 1.5kV DC DART network is Ireland’s only railway electrification. This makes it one of the least electrified rail networks in Europe with just 3% of its network electrified. When it was proposed to extend the DART network, a 2018 study of the respective benefits of 1.5kV DC and 25kV AC electrification was undertaken. With countries such as Slovakia and the Czech Republic replacing their 3kV DC system with 25kV AC it was felt that the 25kV option should be considered for future DART services.
This study concluded that, for unelectrified lines, only the 25kV AC should be considered as it has fewer capital and running costs than the DC system. With a much lower pantograph current, 25kV requires a lighter overhead line system and can also deliver more power per train making it better suited for Inter City services. 25kV also requires significantly fewer substations than the much lower voltage DC system.
However, for Dublin’s DART service it was concluded that the benefits of 25kV electrification were outweighed by the cost of converting the existing 1.5kV DC network. Yet, as our report on the All-Ireland Rail Summit in Issue 219 (Mar-Apr 2026) described, the All-Ireland Strategic Rail Review has recommended 850 route-km of 25kV electrification. This includes the 266km route between Dublin and Cork. As the last 29km of this route is the Cork commuter line to Mallow, the remaining Cork commuter lines are also to be electrified at 25kV AC.
Having decided on 25kV electrification, the option to use Battery EMU (BEMU)s with discontinuous electrification was considered. The CACR public consultation report explains that the BEMU option was rejected for reasons of operational costs and resilience. In addition, half the commuter network will require full electrification as it is on an Inter-City route. Furthermore, the All-Ireland Rail Summit was advised that the CACR programme will take advantage of Network Rail’s work on voltage-controlled clearances to significantly reduce the cost. As a result of the 34 structures affected by electrification work, only four will require bridge redecking.
Phase 1
The CACR programme is projected an investment of €1.8 billion and is being delivered in two phases. The first phase is largely complete and consists of a new and extended platforms at the city’s main station, Cork Kent, double tracking to Midleton and signalling improvements. The second phase is for new stations, electrification, a new fleet maintenance depot and new electric trains.
Work at Cork Kent station to facilitate through services between Mallow and Midleton started in 2023. It required the construction of a new 215-metre Platform 6 and the extension of Platform 5 by 50 metres, making it 215 metres long. This required the slewing of tracks 4,5, and 6 and the extension of a retaining wall. This work was completed in April 2025 at a cost of €23 million.
Double tracking of 10km of the line between Glounthaune to Midleton started in 2024. This required the removal of four turnouts, the installation of two new crossovers on the approach to Midleton, a turn back facility at Midleton, widening a river bridge deck, closing one level crossing, and widening another as well as the installation of new cable routes. This work took about two years to deliver at a cost of €90 million and was physically completed in late 2025 but awaits signalling commissioning before it can be brought into use.
In 2023, Alstom was awarded a €78.5 million contract for a full signalling and telecoms renewal of the 62km Cork commuter network which is expected to be completed in 2027. This will replace two solid state interlocking and relay interlocking with Alstom’s Smartlock Computer-Based Interlocking system and provide an ETCS Level 1 overlay. This will provide headways for the required 10-minute train service frequency and a five-minute frequency between Cork Kent and Glounthaune. This work will remove the Cork East signal cabin and see the Cork network controlled from the National Control Centre in Dublin.
CACR programme phase 1 was partly funded with a €164 million grant from the European Union Recovery and Resilience Facility.
Stations
Of the eight proposed new stations, three are on the line to Mallow where there are currently no intermediate stations. These will be at Blackpool, Monard, and Blarney. The proposed station at Blackpool is on Irish Rail’s land and so offers an opportunity for accelerated development so that it can be opened prior to completion of the CACR programme.
Although Monard will have local park and ride facilities, Blarney will have a strategic Park & Ride facility off the adjacent national primary road. The station will have three platforms as there will be a loop here to avoid conflicts between InterCity and commuter services. A new passing loop will also be required at Rathduff between Blarney and Mallow.
The busiest part of the Cork network is the line between Cork Kent and Glounthaune which carries services to both Cobh and Midleton. Two new stations are proposed for this section at Tivoli and Dunkettle. The Port of Cork is to move operations at its 65-hectare Tivoli site to new facilities downriver which will free this land for future development that will be supported by the new station at Tivoli.
Dunkettle is another station site subject to accelerated development. It is adjacent to a major road junction and so will have a 300 space Park & Ride facility to intercept traffic before it enters the city.
On the line to Cobh there is to be a new station at Ballynow while the line to Midleton will have two new stations at Carrigtwohill and Water-Rock. As with all other stations these will have access from both sides and be integrated with access and car parking with access prioritised in this order: walking; cycling; bus; taxi; drop off/pick up; and car parking.
Mallow station will be provided with a new two-sided platform to separate the operation of intercity and commuter trains. Cobh station is to have a second platform to improve operational resilience and accommodate special events such as cruise ship arrivals.
OLE, depot, and trains
As the CACR programme is delivering Ireland’s first 25kV AC electrification, it will be a pathfinder for the future electrification of the country’s main routes. Hence, a working group has been established to consider key technical requirements as there are no Irish Rail 25kV electrification standards as the only experience is with 1500v DC on DART. The working group is considering lessons from the decades of delivery experience across the UK & Europe.
At the All-Ireland Rail Summit, CACR Programme Delivery Manager AJ Cronin advised that being first gives the CACR programme the opportunity for an innovative approach to shape the roll out of electrification nationally. He also stated that there is also close collaboration with the Irish grid and electricity supply network.
The CACR electrification will require 125 single track kilometres of 25kV AC electrification with overhead line equipment (OLE). It will have two 110kV supply and traction substations at Ballygibbon, on the Mallow line and at Ballyrichard More adjacent to the new depot. An electrification maintenance compound will also be needed adjacent to the new Dunkettle station.
Thirty-four structures have been found to have insufficient OLE clearance. Track lowering is the preferred option for 24 structures while four will require their bridge decks to be raised. Of the other structures, station canopies will need to be modified, and the Cork tunnel shaft guards will need to be replaced. Around 44 bridges will need their parapets to be raised.
With the application of the voltage-controlled clearance technology developed by Network Rail, it is currently considered that continuous electrification is the best solution.
The new fleet maintenance depot between Carrigtwohill and Midleton will have a main building comprising a maintenance shed, wheel lathe, workshop area, storage area, offices, and a building services area. The depot will also have an Automatic Washing Plant and Automatic Vehicle Inspection. It will have the capacity to stable 16 EMUs. The depot building will be designed to achieve Nearly Zero Energy Building standards and so will have high-efficiency HVAC systems, renewable-ready technologies, heat recovery, water recycling, and intelligent building controls.
The CACR programme is to order 21 x 5-car DMUs which will provide more than six times the train seats of the existing fleet. It is expected that this order will be placed in 2028 so that they might enter service in 2031. It is understood that this fleet will be ordered under Ireland’s existing framework procurement contract with Alstom who have provided the new DART BEMUs. Therefore, it is likely that Cork’s new commuter trains will be Alstom’s X’trapolis EMUs which have an acceleration of 1 m/s2.
As these will be Ireland’s first ever 25KV AC EMU fleet, testing and commissioning, for which specialised staff and facilities are required, will have to be done locally. Cork will then have to host a captive fleet until national electrification expands.
Justifying €1.8 billion
Following last year’s first public consultation on the emerging CACR preferred option, a detailed second public consultation on the preferred option was launched in May. Feedback from this consultation will be incorporated into the design development required for the submission of a Railway Order application.
Before the Railway Order application is submitted there is also a requirement for Government approval of the Preliminary Business Case (PBC). As required by Ireland’s Public Spending Code, the PBC must include the strategic case and economic case.
Although CACR will be transformational, its €1.8 billion capital cost is €3,600 per capita for Cork’s projected population in 2040. In comparison, Dublin’s proposed €8.8 billion metro, which has an approved PBC, has a €6,800 per capita cost.
The CACR programme’s PBC is expected to be published later this year and will need to demonstrate that CACR has a strong case though its cost is part of Ireland’s National Development Plan.
From published national and Cork city documentation, CACR’s strategy case is that:
- Cork’s economy and its population need to grow as Ireland’s economy is over reliant on Dublin.
- Rail is the only mode capable of absorbing Cork’s planned 50-60% population growth by 2040 without catastrophic congestion.
- Without CACR, Cork faces a structural road network failure as the network is already at, or near, capacity.
- CACR enables high density, rail served development at its new stations which cannot be supported at scale without an electrified railway.
- CACR is an essential part of Cork city’s decarbonisation plan to reduce transport emissions.
CACR’s economic case is:
- Time savings from more frequent, faster train journeys.
- Modal shift from car to rail reduces fuel consumption, road maintenance, and congestion.
- Increased productivity from improved connectivity between city businesses.
- Better access to employment, education, and healthcare.
- Reduced transport poverty in suburban and peri urban areas.
- Reduced carbon emissions and noise, improved air quality.
It is good to see how Cork is planning to dramatically increase the use of its rail network and how the Irish Government has strategies that support the required investment.
Rail Engineer wishes CACR success with its PBC and Railway Order and looks forward to reporting on the delivery of Ireland’s first 25kV electrification.
Image credit: David Shirres