The Dart Underground is a proposed underground rail system that will run under the city centre, and connect Heuston Station with Pearse Station a distance of 4 kilometres. At the proposed St Stephen’s Green interconnection Station, on the route, passengers will be able to transfer to the Metro North and go to the Airport.

1. Dart Underground, Rail Network, Dublin €2bn? - Construction
Included
Programme
Construction
3D images
Photos
Details
Cost
Heuston Station
Christchurch
St Stephen’s
Green
Pearse Station
Purpose of presentation to give the Public, Stakeholders and
Politicians an understanding of the Construction, Cost and Timeline
Details
Length in Tunnels 5 km
Stations 3 Nr.
Cross passages 15 Nr.
Evacuation Shafts 6 Nr.
David H Moloney
16th May 2016
ⓒ David H Moloney

2. Locations of Proposed Dart Underground Stations
Heuston Station St Stephen’s Green Pearse Station
ⓒ David H Moloney

3. Cost Comparisons of Projects
Dubai Route
2020
UAE
(To Start)
Red Line North
Doha
Qatar
(In Progress)
Red Line South
Doha Qatar
( In Progress)
Metro North
Dublin
(Proposed)
Dart
Underground
Dublin
(Proposed)
Port Tunnel
Dublin
(2005)
Overall Cost €2,450 million €1,803 million €1,500 million €2,400 million €2,000 million ? €752 million
Cost per km €158 million / km €140 million / km €108 million /k m €134 million / km €400 million / km
?
€134 million / km
Overall Length 15.5 km 13 km 14m 18 km 5 km 5.6 km
Tunnel 4 km
Single Tunnel
11.6 km
Twin Tunnels
14 km
Twin Tunnels
7.5 km
Twin Tunnels
5 km
Twin Tunnel
4.5 km
Road Tunnels
Cut & Cover 0 2.7 km 0
Elevated 10.5 km 2.2 km 0 na
Road Level 0 5.5 0
Stations 7 Nr. 7 Nr. 5 Nr. 14 Nr. 3 Nr. na
Capacity 13,000 Passengers
per hour
19,800 Passengers per
hour
? naⓒ David H Moloney

4. Heuston
Christchurch
St Stephen’s
Green
Pearse
Station
Ramp
Tunnel
Underground Station
ⓒ David H Moloney
Programme
Schematic Longitudinal Profile

5. 3D Underground Station Construction
Tunnel Boring Machine
ⓒ David H Moloney

6. Underground Station Construction

7. Underground Station Excavation

8. Secant Pile Construction - Sequence, Plant & Methods
Underground Station Excavation
ⓒ David H Moloney

9. Piling Construction - Plant & Methods
3D image to show Plant. For construction details see my YouTube Channel
Plant & Equipment
Crawler Crane
Piling Hammer
Casing
Piling Rig
Concrete Pump
Concrete Mixer Trucks
Tremie Pipe
Reinforcement Cage
ⓒ David H Moloney

10. Diaphragm Wall Construction - Sequence, Plant & Methods
3D image to show Sequence, Method & Plant.
For construction details see my YouTube Channel
ⓒ David H Moloney

11. Station Excavation - Soil on Rock Situation
Rock Nailing, Rock breaking & Excavation
ⓒ David H Moloney

12. Bed Rock - Type & Depth

13. Ramp Construction
Sequence -Traffic and utilities are diverted, excavate, construct and backfill to sides.
To prevent the faces of the excavation from collapsing, different measures are used – batter
faces, diaphragm walls, secant piles or a combination of soil nailing and shotcreting.
ⓒ David H Moloney

14. Tunnel Design
Twin Tunnels single track with
Cross passages at 250m intervals
for emergency evacuation.
Ventilation & Evacuation Shafts
along the route
Tunnels in rock to avoid ground &
building settlement.
Depth 25 metres on average ⓒ David H Moloney

15. Tunnel Boring Machine (TBM)
Cutting Head Rotates
Excavated material removed
by conveyor belt
Lifting muck to surface
with skip
Placing Concrete
Segments

16. Tunnel Boring Machine (TBM)
Cutting Head rotates
7 nr. Precast segments
form rings that line the
tunnel Excavated material removed
by conveyor belt
ⓒ David H Moloney

17. Tunnel Wall Segments Casting
Clean Mould
Lift Precast Segment out of mould
after 18 hours.
Reinforcement
fabricate
Reinforcement
into Mould
Concreting
Segment Storage
Cycle Time
24 hrs
ⓒ David H Moloney

18. Tunnel Precast Segments
ⓒ David H Moloney

19. Rock Excavation Underground
Excavate with Roadheader
Drill & Fit Rock Bolts
Spray Mortar as Lining
Excavators with Rock Breaker
& Rock Rotary Cutter
Roadheader

20. Tunnelling Methods

21. Tunnel Fit-out Rail, Electricals, Ventilation

22. Tunnel Fit-out
Install Sleepers & Rails
Concrete Batching Train for Floor Slab
Drilling Machine for Utilities Brackets

23. Commissioning, Testing, Handover & Opening
Purpose to test and ensure that everything (e.g. trains, escalators, lifts, ticket barriers) works as it should.
ⓒ David H Moloney

24. Diverting Existing Underground Utilities
ⓒ David H Moloney

25. Bed Rock - Type & Depth
Ground Conditions
The limestone bedrock is between 5 and 25 metres below ground level. The overlying deposits are generally boulder clay with thin layers of sand and gravel. The water table is
between 2 and 4 metres below ground level.
The Bedrock Geology Map of Ireland, gives the rock as limestone and mudstone, along the tunnel route.

26. Rock - Excavability
The excavability of rock depends mainly on the rock strength and the layer thickness.
This diagram shows excavation methods for rock of various strengths and thicknesses,
with a free face.
ⓒ David H Moloney

27. Vehicular & Pedestrian Traffic Diversions
Saint Stephen’s Green O'Connell Bridge
ⓒ David H Moloney

28. Ways to ease Traffic Congestion Benefits of Metro to commuters
1. Time saving for commuters 4. Reduction in accident
2. Reliable and safe journey 5. Reduced fuel consumption
3. Reduction in atmospheric pollution 6. Reduced traffic congestion

29. Contractor’s Temporary Site Facilities
ⓒ David H Moloney

30. Quarry & Aggregate Production
3D image to show Sequence, Method & Plant.

31. Concrete Batching Plant David H Moloney
ⓒ David H Moloney
Concrete batching plant comprises - concrete mixer, control cabin, silos for cement
and fly ash, aggregate bins and conveyor belt system to feed the mixer. Also
aggregate storage bays and water storage tanks.
The mixing is computer controlled and has a dynamic screen display, showing the
process. Material storage capacity to match two days concrete production

32. Main Quantities, Resources & Schedule of Outputs used to Programme
Activities Main Quantities Outputs
• Tunnelling 5km 12 to 20 metres per 24hour day per TBM
• Resources – TBM, Conveyor for removing excavated material, Crane at Launch Shaft
• Piles 900mm diamater 25m long xxx Nr.
• Resources Piling Rig, Crawler Crane, Bentonite Mixing & Storage
• Excavation for Stations in Clay Top Down xxxxx Cu M
• Tracked excavator 30 tonne
• Excavation for Stations in Rock Top Down xxxxx Cu M
• Resources
• Excavation Rock Underground xxxx Cu M
• Resources
• Concreting xxxx Cu M
• Truck mounted concrete pump, shuttering,

33. Histogram Charts for Resources & Outputs
used to programme
Concrete, Manpower, TBM,
Manpower per Discipline Concrete per Location
Numbers for each month of the Project Quantity for each month of the Project
ⓒ David H Moloney

34. Progress Monitoring & Reporting - Dashboard
ⓒ David H Moloney
Dashboard is a single page, graphical representation of current progress and historical trends

35. Plant & Equipment List & Job Titles ⓒ David H Moloney

36. Luas Dublin’s Tram / Light Rail Network

37. Luas – Dublin, Tram / Light Rail System Construction Sequence & Methods
Install Traffic Control Fencing & Welfare Facilities Divert Underground Utilities Excavate
Prepare Formation Reinforcement & Rails Paving
Paving Information Sign Trams in Operation Trams in Operation
Reinforcement & Rails
ⓒ David H Moloney

38. Metro North Project Details Summary David H Moloney
Schematic Longitudinal Profile ⓒ David H Moloney

39. Notes - DART Underground, Dublin
• The Dart Underground is a proposed underground rail system that will run under the city centre, and connect Heuston Station with Pearse Station a distance of 4
kilometres. At the proposed St Stephen’s Green interconnection Station, on the route, passengers will be able to transfer to the Metro North and go to the Airport.
• Programme. This graphic representation of the Construction Programme has a time line and 3D image. A motion animation effect is used to move the time bar in time
with the highlighted areas of works, examples are, for the cut and cover ramp, station construction and tunnelling
• Station construction, illustrated is the sequence, methods and plant used to construct an underground station using secant piles. Alternatively diaphragm wall could be
used.
• Tunnelling Operation and resources, sequence and methods. The proposed design is for twin tunnels with cross passages at 250 metre intervals, for emergency
evacuation. Generally the tunnels will be 25 metre deep and in rock to minimise the probability of subsidence of buildings.
• Rock Excavation Underground. Roadheaders and excavators with hydraulic rock breakers are used. Rock Bolts are used to tie the exposed rock back into the self-
supporting rock. The exposed rock is lined by blasting a mortar or concrete using a hose and nozzle. Wire mesh may be used.
• Underground Utilities Diversion. Will be necessary at the locations of Stations, Ventilation Shafts and cut and cover ramps.
• Vehicular & Pedestrian Traffic Management. The aim is to allow construction to proceed efficiently while minimising the level of inconvenience and disruption that the
work will cause.
• Video Communications are ideal for Stakeholders and Politicians, to get an understanding of how a project will be constructed and its timeline.
• The DART, an acronym of (DublinArea Rapid Transit) is an existing electrical rail system that runs North South, along the coast from Malahide in north Dublin to
Greystones in Co. Wicklow.
• The trains are known as EMU i.e. (Electric Multiple Unit) that consist of self-propelled carriages, powered by overhead electric cables

40. Construction Infographics
Runway Construction – Methods, Sequence & Plant
Bridge Construction – Methods, Sequence & Plant
Motorway Construction – Methods, Sequence & Plant
Seaport Construction – Methods, Sequence & Plant
See my YouTube channel for further details
My YouTube Channel link: https://www.youtube.com/channel/UCeJR9J7svhBd-C0ZoAH2fhQ
ⓒ David H Moloney

41. See my YouTube Video on Dublin Metro North
My YouTube Channel link: https://www.youtube.com/channel/UCeJR9J7svhBd-C0ZoAH2fhQ
By David H Moloney