Chennai Metro Rail's phase II project halts two tunnel boring machines
Flamingo and Eagle, the two TBMs, started their tunnelling journey nearly two years back from the Light House station and are scheduled to reach the Thirumayilai Metro Rail's phase II station shortly. After passing through nearly 160 buildings, which include an old church, school and an embassy, Flamingo TBM and the Eagle TBM are currently taking a break from the tunnelling work.
According to officials in the Chennai Metro Rail project, both the TBMs are now going through a process called cutter head intervention. 'Cutter head, an important unit in a TBM endures a lot of wear and tear while boring the earth. Hence, we are now carrying out the cutter head intervention process wherein the tools of the cutter head are changed. This will take some time and then the machines will resume their drilling work,' an official said.
Both Flamingo and Eagle have to drill a total of 1.9 km to build twin tunnels linking Light House with Thirumayilai. This 1.9 km stretch currently getting shaped is an underground section in corridor 4 of the phase II project which connects Light House with Poonamallee via Thirumayilai and T-Nagar.
'We encountered difficult soil strata along this Light House-Thirumayilai stretch. Initially, closer to the Marina Beach, there was sandy soil, and then subsequently, there was some clayey soil and rock at some points. But in many locations, there was abrasive sand which made tunnelling pretty difficult. We had to change the parts of the cutter head as many as 25 times,' he added.
This 1.9 km tunnelling stretch covers three underground stations — Light House, Kutchery Road and Thirumayilai. While the Flamingo TBM commenced the drilling work first in September 2023, it will be the second TBM Eagle which will complete the tunnelling first, make a breakthrough first, and be taken out in the first week of October.
This is because the Kutchery Road underground station has been planned as a stacked station — wherein the tunnels are one above the other. The TBM Eagle is on top, and Flamingo is below it. 'If Eagle is taken out first, then we can proceed with the Kutchery Road station construction,' he added. While Flamingo is nearly 100 metres from Thirumayilai, Eagle is a little far, about 550 metres away.
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The Hindu
4 days ago
- The Hindu
Chennai Metro Rail's phase II project halts two tunnel boring machines
Two tunnel boring machines (TBMs) deployed for Chennai Metro Rail's phase II project to build an underground network between Light House and Thirumayilai have been temporarily stopped now. Flamingo and Eagle, the two TBMs, started their tunnelling journey nearly two years back from the Light House station and are scheduled to reach the Thirumayilai Metro Rail's phase II station shortly. After passing through nearly 160 buildings, which include an old church, school and an embassy, Flamingo TBM and the Eagle TBM are currently taking a break from the tunnelling work. According to officials in the Chennai Metro Rail project, both the TBMs are now going through a process called cutter head intervention. 'Cutter head, an important unit in a TBM endures a lot of wear and tear while boring the earth. Hence, we are now carrying out the cutter head intervention process wherein the tools of the cutter head are changed. This will take some time and then the machines will resume their drilling work,' an official said. Both Flamingo and Eagle have to drill a total of 1.9 km to build twin tunnels linking Light House with Thirumayilai. This 1.9 km stretch currently getting shaped is an underground section in corridor 4 of the phase II project which connects Light House with Poonamallee via Thirumayilai and T-Nagar. 'We encountered difficult soil strata along this Light House-Thirumayilai stretch. Initially, closer to the Marina Beach, there was sandy soil, and then subsequently, there was some clayey soil and rock at some points. But in many locations, there was abrasive sand which made tunnelling pretty difficult. We had to change the parts of the cutter head as many as 25 times,' he added. This 1.9 km tunnelling stretch covers three underground stations — Light House, Kutchery Road and Thirumayilai. While the Flamingo TBM commenced the drilling work first in September 2023, it will be the second TBM Eagle which will complete the tunnelling first, make a breakthrough first, and be taken out in the first week of October. This is because the Kutchery Road underground station has been planned as a stacked station — wherein the tunnels are one above the other. The TBM Eagle is on top, and Flamingo is below it. 'If Eagle is taken out first, then we can proceed with the Kutchery Road station construction,' he added. While Flamingo is nearly 100 metres from Thirumayilai, Eagle is a little far, about 550 metres away.
The Hindu
23-07-2025
- The Hindu
Chennai Metro Rail completes tunnel between Panagal Park and Kodambakkam for phase II project
After 14 months underground, Chennai Metro Rail's tunnel boring machine 'Peacock' made a breakthrough at Kodambakkam on Wednesday, successfully creating a two-km tunnel between Panagal Park and Kodambakkam as part of the upcoming phase II project. In a couple of years, when the track is laid and stations get ready, you will be able to hop onto this underground line and travel from Kodambakkam to T. Nagar. This section is part of corridor 4 of the phase II project which traverses from Poonamallee to Light House via T. Nagar. Work began last year In May 2024, TBM Peacock began boring the earth from Panagal Park. In the last 14 months, the machine created a tunnel under Usman Road flyover and Kodambakkam flyover and the Kodambakkam Suburban Railway Station and snaked its way till Kodambakkam, near Meenakshi College for Women, covering a distance of two km and made a breakthrough on Wednesday afternoon. The corridor 4 which starts as an elevated section takes a plunge at this point in Kodambakkam, opposite to Meenakshi College for Women, and turns into an underground section till Light House. T. Archunan, director (projects), Chennai Metro Rail Limited (CMRL) said no other tunnel in the city is as long as this stretch (between two stations)and the breakthrough was achieved without unsettling any of the establishments close by. 'The diaphragm wall at Kodambakkam was built just three metres away from the Kodambakkam Suburban Railway Line. This was no easy feat. When the TBM bored under the Kodambakkam Suburban Railway Line, the trains passing through the track had speed restrictions of 15 -25 kmph for 15 days. Apart from tunnelling under flyovers and the railway track, the TBM bored under nearly 190 buildings, and a sizable number of them were pretty old, dilapidated ones too,' he said. Dibyendu Choudhuri, former project director for this stretch with ITD Cementation India Limited, said they dealt with mixed soil conditions between Panagal Park - Kodambakkam stretch, which was quite challenging. 'In T. Nagar it was a combination of clayey and sandy soil. Beyond that, it became rock. In some parts in Kodambakkam, while the upper layer was clayey, the lower part was rock which made it a bit difficult to tunnel through. We also had to change the cutter discs on 18 occasions,' he recalled.
Time of India
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- Time of India
Raj Bhavan nod for underground 1.6 km stretch of Purple Line
1 2 3 Kolkata: Following Raj Bhavan's clearance, RVNL has completed survey of the Purple line's 1.6 km extension to Eden Gardens. The metro tracks will travel through the edge of the Governor House lawns before crossing over to the opposite flank where the corridor's fifth underground station is being planned. Rarely do agencies seek the governor's approval for surveys that are prerequisites to drawing a new Metro route. Rail Vikas Nigam Ltd (RVNL), the implementing agency of the Purple line, which is being extended 1.6 km beyond Esplanade and 1.2 km on the southern fringes to IIM-Calcutta, has now finished the topographical survey. needed to finalize the alignment of the proposed Eden Gardens metro line. "Such surveys are typically conducted to ensure the project is feasible and well-planned. They help in understanding the terrain, soil conditions, and other relevant factors crucial to determining the alignment, construction methods, and overall project cost," said an engineer. You Can Also Check: Kolkata AQI | Weather in Kolkata | Bank Holidays in Kolkata | Public Holidays in Kolkata "The survey was done to understand the status above and under the ground in the metro path of the 1.6 km beyond Esplanade to Eden Gardens. The tunnel boring machines (TBMs) will curve past the East-West Metro (Green line) Esplanade station, cross over to Raj Bhavan's edge (covering around 250 m of the garden area) before curving across the road to the Eden Gardens station, which will come up on the site opposite Gate No 1. Based on the survey, the best (shortest) alignment will be mapped out," a Railways official said. RVNL intends to deploy the same TBMs, Durga and Divya, being used for the construction of the 1.7 km Kidderpore-Victoria Memorial section. The borers will be launched again for the second drive (950 m from Victoria Memorial to Park Street). The 640 m from Park Street to Esplanade will be built in cut-and-cover method (building tunnels inside underground trenches) since most of this stretch is free of infringement. From Esplanade, the TBMs will be launched for the third time to burrow and build the 1.6 km to Eden Gardens station. This section, too, has no overhead structures. TOI on Jan 12 had reported that " Kolkata metro plans to extend Joka-Esplanade Purple Line to Eden Gardens." By extending the Purple line to Eden Gardens, Metro Railway is looking to draw passengers from the BBD Bag area, offices on Strand Road, Babughat and Calcutta High Court. Sports enthusiasts can simply walk to the proposed Eden Gardens station to access the city's lifeline or the North-South (Blue) corridor, by availing the Esplanade interchange. The earlier plan was to link Eden Gardens to Esplanade by a long subway.
