Mumbai Metro’s Sahar Station Built with Water Pipes Running Across
There’s something unique about each one of Mumbai Metro Line-3’s 26 underground stations which are being built throughout the length of the city to connect South Mumbai with the western suburbs.
This post is all about Sahar Road Station which is located on the 4.45 km package UGC-06 (CSIA T1 – CSIA T2), towards the northern-end of the line, and is under construction by J Kumar – CRTG JV with just one tunnel breakthrough pending at CSIA T1 Station.
The station is 218m long, 25m wide and 29m deep. When ready, this cut & cover station will have 3 entry/exit points to provide connectivity to Airport Colony, Sahar Village and JB Village.
Besides the 227m NATM Crossover Cavern on its east where excavation was completed last Friday, this station has historic water pipelines, some as old as 50 years, running right across the middle of it. These highly pressurized utility pipes supply water to the entire region and run from Upper Vaitharna Dam all the way to the southern tip of the island city.
Typically underground stations are planned away from such pipelines or the pipelines are diverted, but given the strategic location of the station and other reasons, the pipelines had to be kept intact.
A unique steel support structure was designed by Tandon Consultants. Here’s what one of its senior designers had to say:
Typically an underground station will be re-planned away from such hindrances or the pipeline will be diverted around the station. But, the station location is strategically placed to have maximum catchment of riders and due restriction in tunnel alignment because of Mumbai International Airport runway and land makes shifting infeasible.
Diverting these pipelines was also not feasible due to space constraints because of the presence of public buildings and airport land near it. Providing a bend in the pipes to route it around to the other side of the station was also not feasible as it will lead to creating bend in pipe thus lowering the pressure of the water pipe. Also diversion cannot happen without interrupting the flow of water until diversion is completed.
Thus these larger diameter water mains had to be supported at its place before commencement of excavation to enable construction of Sahar Road Station.
As the station is constructed using bottom-up method, the water pipes have to be supported before excavation for the station or water pipes. The utility support system consists of a series kingpost planned on the envelope of the water pipe system along the length of pipe at certain spacing.The king posts are connected with longitudinal girders and on top of it trusses are erected.
A series of 36 nos of steel truss of 20m span each supports the entire pipe line along the length. Water pipelines are suspended from the truss using a steel section as a suspender connecting a cross girder and pipe cradle at the bottom of the pipe and the truss at the top. The water pipeline support system being a sensitive and critical structure is being monitored daily during construction progress for this performance and safety.
Here are some historic images shot at the station over the past 24 months:
Satellite imagery of the station with the pipelines can be viewed here on Google Maps.
For more updates, check out the Mumbai section of The Metro Rail Guy!
– TMRG
What happens if the pipelines develop a leak after Metro3 is operational? Besides possibly causing serious flooding/damage in the station thereby bringing the metro line to a halt, won’t they have to dig up the station concrete to access and repair the pipes?
I guess they will put up sensors to warn against any such leakages which will shut the pumping station pump immediately.
Post-construction, they’ll restore the old road above it. If a leak happens, I guess they’ll have to rip up the road. Below the pipes, the roof-slab level of the station will be waterproofed like this:
https://twitter.com/TheMetroRailGuy/status/1228880649190334464
Hi friend,
I think all the station of Patna metro will be structurally unique..
Most of the places where there is a proposed station there is a high possibility of land shortage.
All the station of patna metro will short width of platform because of land problem.
Dear Sir, an error. The Metro 3 is being constructed not to connect south Mumbai to the western suburbs, but to connect south Mumbai to the Airport.
Each station is a landmark by itself, so I used geography to describe its northern end 🙂
Only developing Mumbai will not fulfill the purpose, other areas which are nearerby to Mumbai should also be developed. Mumbai is conjusted now. 50% migrant have already left Mumbai due to Lockdown, 25% left Mumbai as everything is now work from home, so why to stay in Mumbai. Left only 25% of which 20% are corporates and filmy personals and just 3% is the middlclass and 2% are poor.
Like it will be better if they take more place around the construction like cisf buliding and even the houses that are around it it will be really helpful for the Engineers to build