TBM S639 Completes Tunnel Under Hooghly River to Enter Kolkata
This Saturday, TBM S639 operated by the Afcons – Transtonnelstroy JV team completed its journey underneath the Hooghly River and crossed into Kolkata’s city limits near the Armenian Ghat to build the 16.34 km Line-2’s eastbound tunnel. Nicknamed Rachna, this TBM was commissioned from the Howrah Maidan Station in July 2016, passed its sister machine TBM S640 at Howrah Station in March and began tunneling underneath the 460m wide Hooghly River in mid-April at varying depths between 11-15 meters.
The General Manager of Afcons Infra, Virinder Kaul, announced this historic milestone on LinkedIn:
This Wednesday, TBM S640 or ‘Prerna’ is expected to commence its journey underneath the river to build the parallel west-bound tunnel. That TBM made a breakthrough at a temporary shaft inside the Howrah Station’s site in February 2017, went through repairs in which its articulation seal was replaced, and has since passed under the DRM building to approach the river’s western bank.
As mentioned earlier, the future schedule of tunneling works remain highly uncertain. Afcons Infra has mobilized equipment at the ventilation shaft’s site, but is yet to receive a go-ahead for starting its construction. Even though they plan to continue non-stop excavation & ring building activity through it until Lal Dighi Station, they cannot proceed any further as 25 critically weak buildings lie ahead on Brabourne Road of which 9 will require demolition or evacuation. Last week, Afcons Infra filed a petition in the Calcutta High Court seeking judicial intervention to ensure the TBMs continue uninterrupted excavation. In response to that, the HC directed them to slow down excavation works until the Kolkata Municipal Corporation works with locals to get the buildings get renovated or evacuated.
For more updates, check out the Kolkata section of The Metro Rail Guy!
What is the current status of the TBM deployed in Lucknow. Read somewhere that the first TBM will make a breakthrough this month itself?
The first TBM (S52) has reached Hazratganj Station’s diaphragm wall, but the TBM receiving shaft is not yet ready. Will tweet whenever the breakthrough date is announced.
Is it the first time that the tunneling has completed but the shaft isn’t ready to receive?
This has happened in Delhi many times.
It has happened in Delhi too. And its funny that the station happened to be Vinobhapuri, where tunnelling took almost 3 times the usual time taken for such stretch…. and still the receiving shaft was not ready when the TBM had reached the station’s diaphragm after such a long, draining tunnelling.
I enjoy reading your blog and frequently forward links to them to my friends.
I have one suggestion: If technically possible, can you keep a comment section open for the City –> Information page? That way questions like above (concerning Lucknow) can be asked there instead of in a post about Kolkata.
That way all city based questions can then be seen historically also and you may not get repeated questions.
Glad you like the blog! That’s a nice suggestion – and I’ve looked into it earlier, but it’s technically not possible to open up the pages for comments.
In that case, just create a dummy blog post per city only for comments. You can call it FAQ. Link the post from the City — Information page.
ALSO IN THE MEANTIME THE NATIONAL MONUMENTS ACT HAS TO BE AMENDED TO LET THE TBM’S PASS WITHIN 100METER OF THOSE MONUMENTS!in the meantime the west Bengal gov’t is thinking of creating another hindrance damage to writers building
Exactly. It was recently approved by the GoI’s cabinet, but it needs to travel up the chain through the parliament and prez.