TBM S-704 Makes Final Breakthrough for Chennai Metro’s PH1 Project

December 11, 2017 was a historic day for Chennai! 🙂

On that day, TBM S704 – a Ø6.6m Herrenknecht tunnel boring machine operated by Afcons Infrastructure made its final breakthrough today at Chennai Metro’s AG-DMS Station after a 54 month long journey to build the 4.5 km up-line tunnel on package UAA-02 of the 32.10 km Line-1 between Chennai Airport and Wimco Nagar.

With this development, 3 contractors working on 5 packages have completed all 42 breakthroughs scheduled for the entire 45 km Phase 1 project in 65 months since tunneling works began in July 2012 from Nehru Park towards Egmore. More details on each package are at the bottom of this post.

Coming back to S-704, the earth pressure balance machine (EPBM) was originally commissioned by the Gammon – Mosmetrostroy JV from the May Day Park Shaft in June 2013 for excavating 3616 meters, and made successful breakthroughs at Government Estate Station in January 2014 & LIC Station in September 2014 before being abandoned in May 2015 due to financial issues. After conducting two rounds of bidding, the Chennai Metro Rail Corporation in May 2016 awarded Afcons Infrastructure with a contract to complete the balance tunneling work under package BW-UG-02 towards Thousand Lights Station and onward to AG-DMS Station.

Tunneling works by S-704 resumed in August 2016 with the TBM soon entering the Thousand Light Station’s box in November where its damaged cutterhead & cutting tools were completely refurbished. Tunneling towards AG-DMS resumed towards the end of December with Afcons proceeding with caution after S-703 on the parallel down-line caused a cave-in on Anna Salai due to loose top soil.

In total, the TBM built 2625 rings throughout its journey of which 1468 were built by Afcons Infrastructure.

UAA-02 section (May Day Park Shaft – AG-DMS) of Chennai Metro – view Chennai Metro map & info

Some images –

Photo Copyright: Durgesh Khodankar

Photo Copyright: Durgesh Khodankar

Photo Copyright: Durgesh Khodankar

Photo Copyright: CMRL

Photo Copyright: CMRL

Photo Copyright: Vikrant Srivastava

News video –

Total Breakthroughs in Phase 1 – 42

• UAA-01 – 10 breakthroughs (May Day Park Shaft/Egmore – Washermenpet – 4445m)
TBMs: Robbins 219-364 and Herrenknecht S-710, S-711, S-717, S-718
Contractor: Afcons Infrastructure – Transtonnelstroy JV
Final breakthrough: Central Station by S-710 in February 2017

• UAA-02 – 8 breakthroughs (May Day Park Shaft – AG-DMS – 3616m)
TBMs: Herrenknecht S-703, S-704
Original Contractor: Gammon – Metrostroy
New Contractor (Tunnels): Afcons Infrastructure
New Contractor (Stations): Larsen & Toubro
Final breakthrough: AG-DMS Station by S-704 in December 2017 (this post)

• UAA-03 – 8 breakthroughs (Saidapet Ramp – AG-DMS – 2868m)
TBMs: Herrenknecht S-701, S-702
Original Contractor: Gammon – Metrostroy
New Contractor (Tunnels): Afcons Infrastructure
New Contractor (Stations): Larsen & Toubro
Final breakthrough: AG-DMS Station by S-702 in September 2015

• UAA-04 – 8 breakthroughs (Shenoy Nagar – Egmore – 3388m)
TBMs: 2 STEC and 1 Hitachi machines
Contractor: Larsen & Toubro –  Shanghai Urban Construction Group JV
Final breakthrough: Nehru Park Station by STEC-1 in April 2015

• UAA-05 – 8 breakthroughs (Shenoy Nagar – Thirumangalam Ramp – 2797m)
TBMs: Herrenknecht S-717, S-718
Contractor: Afcons Infrastructure – Transtonnelstroy JV
Final breakthrough: Thirumangalam Ramp by TBM S-718 in December 2014

Total Breakthroughs in Phase 1 Extn – 4

• UAA-08 – 4 breakthroughs (Washermenpet – Korrukupet – 1820m)
TBMs: Robbins 219-364 and Herrenknecht S-711
Contractor: Afcons Infrastructure
Final breakthrough: Korrukupet Station by Robbins 219-364 in October 2017

Packages of Chennai Metro – view Chennai Metro map & information

For more updates, check out the Chennai section of The Metro Rail Guy!

– TMRG