Taking the DART UndergroundDublin’s Interconnector Tunnel

A Presentation to

Dublin City Council

By

Iarnród Éireann

7th July 2008

Presentation Content

Taking the DART UndergroundDublin’s Interconnector Tunnel

• Existing Network

• Capacity requirements, constraints and solutions

• The Interconnector Project

• Construction issues

• Project Appraisal

• Questions

Existing Network

Existing Network

Capacity requirements, constraints and solutions

2004 Demand Forecasts for Interconnector Route

DocklandsPearseSt Stephen’s GreenChristchurchHeuston

A.M. Peak Hour Boarding & Alighting Figures

Prelim Design based on 2004 DTO figures, the Interconnector Study carried out by Parsons Brinckerhoff and RPA modelling

Reference design to incorporate up-to-date DTO modelling

Dublin Commuter Belt Capacity Requirements (DTO)

(Passengers per peak hour)

2020 Estimate

Northern Line 22,000

South East Line 14,000

Kildare Line 12,000

Maynooth Line 14,000

Total Peak 62,000

Terminal Station at Heuston

Northern Line Bottleneck at Connolly

Interconnector – Integral to the Holistic Solution

> Creates an East – West Link,> Maintains the North – South Service > Affords Additional Access

Greater Dublin Rail Network

Interconnector Project Objectives

High Capacity – In excess of 28,000 Passengers per hour in both directions

Frequent – In excess of 20 trains per hr.

Fast – Less than 10 minutes from Heuston to Docklands

Reliable

Accessible

Integrated – Interchange with LUAS, Metro North, Intercity & Commuter Services

Interconnector Project Overview of Current Strategy

PHASE 1 (Feasibility)

To identify the route selection

Completed in 2004

PHASE 2 (Preliminary Design)

To validate the Route, Outline Station Design and Preliminary SI

Completed in 2008

PHASE 3 (Reference Design)

Reference Design, Railway Order, PPP Tender Process

Completion Date Mid 2011

PHASE 4

Construction PhaseCompletion Date End of 2015

Phases

Comple

ted

Comple

ted

Output from Phase 2Preliminary Design

• Preferred Route Alignment

• Identification of station locations

• Cost estimates

• Preliminary project risk assessment

• Develop and optimise design to Reference Design Level

• Submit an application for a Railway Order

• Tender process (3 stage)

• Develop the Cost Plan

• PPP Procurement Process (Financial, Legal)

• Finalise the PPP contract

Output from Phase 3Planning / Procurement Stage

Interconnector Recommended Route

Heuston

Christchurch

St. Stephen’s Green

Pearse

Docklands

Interconnector – Data Summary

• 5.2 km of twin bore tunnel

• 14.4 km of electrified heavy rail track

• 5 Underground Stations

• Average depth of station 30m below ground level

Rolling Stock

• Electrified DART Rolling stock

– 1500vDC installed

– Safeguarded for 25KV AC

• 8 car trains

• Journey time Docklands to Heuston <10 mins

Tunnel Options Considered:

1. Mono-bore mined

2. TBM Mono-bore

3. TBM Twinbore

Benefits in terms of construction risk, spoil volumes & track gradient

Twinbore Tunnels Recommended in Phase II

Phase 2 proposed Construction Methodology for Stations

• Cut and cover

– Heuston (mixed face clay and rock)

• Mined

– Christchurch, St Stephens Green, Pearse (limestone )

• Cut and Cover or Shield Driven

– Docklands (Dublin boulder clay)

Station Details

Heuston Station

Heuston Underground Station and Turnback Facility

Heuston Interchange

Heuston Interchange Access

Turnback facility and underground station

platforms under Diageo land

Heuston Interchange - Plan A

Heuston Interchange - Plan B

Turnback facility and underground station

platforms under Heuston station

Entrance in Heuston station in same location as

Plan A

Heuston Tie-In - Plan B

Christchurch Station

Christchurch Station

Christchurch Station – Construction Site Footprint

Cook Street

Christchurch Final Footprint

St Stephen’s Green Station–Plan at Ticket Hall Level

Common and Overlap Areas agreed between RPA / IÉ

will be Designed and built by RPA

St Stephen’s Green - Shared Concourse with Metro North

St. Stephen’s Green – Phasing Construction Footprint

Underpass Under

Construction

Pearse Station Underground Layout

Pearse Station - Architectural Concept

Docklands Station

Connection to

Northern Line

Preliminary design includes an at grade junction connecting Interconnector to Northern Line

However design to be checked for prudent provision for future grade separated (overpass) junction

Geotechnical Results obtained at 200m intervals along the Route

Heuston

Christchurch

Stephens Green

Pearse

Docklands

TBM Progress

Current Construction Strategy TBMs and Shield Machines

TBMs Dismantled

(Skin Buried)

Heuston East

Tunnelling Site

Docklands Portal Tunnelling Site

Heuston Portal Tunnelling Site

(TBM Dismantled)

1

1

1

2

2

23

3

3

3

34

4

4

4

4

5

NB: All stations are mined with the exception of Heuston

END