Mohammad Ahatsham Qureshi
Regional Manager Sales-West, Dextra India
The proposed Mumbai Trans Harbour Link (MTHL) has been planned to facilitate decongestion of the island city by improving connectivity between the Island city and the mainland (Navi Mumbai) and the development of the Navi Mumbai Region. The link was envisaged about 35 years back. A project driven by MMRDA is estimated to cost `14,262 crore (US$2.0 billion). On completion of this project, the commuters travelling from Mumbai towards Navi Mumbai, Navi Mumbai International Airport, Jawaharlal Nehru Port, Panvel, Alibaug, Pune and Goa will not only be saving travel time but will also have in terms of fuel.
The First Step
There was a formal tender floated by MMRDA which was participated by almost all the leading and sonic pipe suppliers of the town. Further, being India’s longest bridge – the durability of the products was the main aspect that the client was looking at. However, Dextra Group an ISO 900:2015 certified Bureau Veritas was awarded the two packages considering Dextra’s technical expertise, long-lasting durability and ease of flexibility to customize the products as per the client’s and contractor’s requirements.
- GI (galvanized) Sonitec pipes to all three packages.
- Fusion bonded epoxy coated couplers as per IS 13620 specifications.
For L&T-IHI JV Pkg -I, couplers were supplied by Dextra India, and fusion bonded epoxy coating was in the scope of L&T, while as for Tata-Daewoo JV for Pkg – II, fusion bonded epoxy coated couplers were supplied by Dextra India.
Execution Of The Project
The major portion of the MTHL structure is on marine stretch and hence corrosion was one of the painstaking factors that was being evaluated. And the structure had been designed for more than 100 years, so the client and the consultant wanted to ensure its durability and execution. Hence, as per the specifications, galvanized coated Sonitec pipes 50mm and fusion-bonded epoxy couplers were to be used.
- It was for the first time in India that an innovative method of using galvanized coated sonic pipes for cross-hole sonic logging test was being implemented.
- There were more than 2000 piles including both land and marine piles. First time in India, couplers are being used for pile cages 1.5/2.2m dia and length varying from 18m to 54m. Cages in lengths of 12m were prepared and then lowered in the pile location and had to be joined with precision and accuracy.
- And these piles had to be completed within 24 to 30 months. So, there was immense pressure to match up the speed of the project and the supply of the pipes had to be uninterrupted to ensure that the project doesn’t suffer.
- A set of engineers was also deployed at the site to provide the training to the contractor’s engineers to help in the implementation part.
- Further, the couplers used were also fusion bonded epoxy couplers which were not a standard catalogue product for Dextra India. But we are committed to provide world-class services to our clients and also give the ease of flexibility by enabling the customization of the products. Hence, our technical team was engaged in looking for an agency that can coat our couplers with fusion bonded epoxy. Several agencies were shortlisted and various testing requirements were set. Finally, the one which met all the pre-requisites and technical specs was approved.
- A proper modus operandi was formed right from the production of the couplers –to be sent for epoxy coating – receipt of the couplers – quality checks and finally submitting a quality product to the client. Each process was closely monitored and executed within the postulated timeline to avoid any delays in supplies.
- The maintenance and commissioning of the threading machines at the site was dealt professionally and timely support was endowed to the client.
Contributing (even though in a little way) in the development of a country’s infrastructure is not only a matter of pride but also carries an emotional value for us. The insights and learnings on the innovative techniques that were used helped to add a new product line to our catalogues. It is indeed a great privilege to work with the best construction giants of India – L&T & Tata Projects.
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