Journey of TBM Mavala: Digging beneath the Arabian Sea for Mumbai Coastal Road Project

The completion of the Mumbai Coastal Road Project (MCRP) has been a monumental feat, made possible by the dismantling of the Mavala tunnel boring machine (TBM). This colossal machinery played a pivotal role in the excavation of twin tunnels spanning 2.07 kilometers beneath the Arabian Sea. Let's dive into the incredible journey of TBM Mavala and the challenges it overcame to pave the way for enhanced connectivity in Mumbai.

Engineering Marvel: TBM Mavala Takes the Spotlight

TBM Mavala, weighing an astounding 2,800 tonnes and boasting a diameter of 12.19 meters, stands as India's largest tunnel boring machine to date. Manufactured by China Railway Construction Heavy Industry Company Limited (CRCHIL), this engineering marvel was an integral part of the Mumbai Coastal Road Project. Its remarkable size and capabilities positioned it as a game-changer in the realm of infrastructure development.

Overcoming Adversities: Assembling Amidst a Pandemic

The journey of TBM Mavala began with 70 containers arriving at Mumbai's Jawaharlal Nehru Port from Shanghai in April 2020. These containers contained the various components that would ultimately assemble into the colossal TBM. Originally, Chinese experts were expected to facilitate the assembly process in Mumbai. However, the unprecedented travel restrictions imposed by the Covid-19 pandemic posed unforeseen challenges.

A Puzzle of Parts: Piecing Together TBM Mavala

Overcoming obstacles, the disassembled TBM Mavala was transported in parts to Priyadarshini Park via 17 different trucks. There, a team of engineers from Larsen and Toubro (L&T) and BMC undertook the daunting task of assembly. This intricate process spanned three months, culminating in the impressive feat of assembling the mammoth machinery. Subsequently, the BMC orchestrated its transportation to the launch site using a 200-wheel self-propelled transporter and freight wings.

TBM Mavala's Journey Underground

In January 2021, TBM Mavala embarked on its tunneling journey from Priyadarshini Park at Nepean Sea Road. The first breakthrough occurred on 11 January 2022, marking a significant milestone in the project's timeline. It is worth noting that the TBM was named "Mavala" after the soldiers in Shivaji's army. Every soldier in Shivaji's army was referred to as a "Mavala."

Overcoming Milestones: Pushing Boundaries

After its initial breakthrough, TBM Mavala's trajectory took an impressive turn. The hydraulic-jack powered turn-table facilitated a 180-degree rotation, enabling the commencement of excavation for the second tunnel. The second tunnel's breakthrough was celebrated on 30 May 2023 at Priyadarshini Park's northern end.

Overcoming Challenges: Setting Global Records

TBM Mavala's journey wasn't devoid of challenges. In August 2022, it etched its name in history by excavating a remarkable 456.72 meters in a single month. This feat shattered the previous global record for monthly tunnelling, set by a 13-meter single shield EPB (Earth Pressure Balance) TBM.

A Future Unveiled: Uncertain Horizons

With its monumental task accomplished, the future of TBM Mavala hangs in the balance. After more than 4 kilometers of excavation through complex geological strata, the machinery's next mission remains uncertain. The dismantling process, completed in July 2023, paves the way for structural stability testing. The decision on the machinery's future utilization will be informed by the results of this test.

Paving the Way for Connectivity: The Next Chapter

Speculation abounds regarding TBM Mavala's potential deployment in a 3.8-kilometer twin tunnel road between Orange Gate and Marine Lines. This possibility emerges from the alignment requirements of the tunnels, which match those of the Coastal Road. This road project, part of the Rs 6,000 crore initiative by the Mumbai Metropolitan Region Development Authority, holds immense promise in enhancing connectivity.

In conclusion, TBM Mavala's journey beneath the Arabian Sea symbolizes the spirit of innovation and determination in India's infrastructure development landscape. As it transitions to its next chapter, the legacy of TBM Mavala continues to inspire and shape the future of urban connectivity.

About Mumbai Coastal Road Project

The Mumbai Coastal Road Project, soon to bear the official name of Chhatrapati Sambhaji Maharaj Coastal Highway, is a remarkable infrastructure project currently in progress. Spanning 29.2 kilometers, this 8-lane grade separated expressway is poised to stretch along Mumbai's western coastline, seamlessly connecting Marine Lines in the southern reaches to Kandivali in the northern expanse. Anticipated to accommodate around 130,000 vehicles on a daily basis, the Coastal Road holds the potential to dramatically transform commutes. The envisioned outcome is a reduction in travel time between South Mumbai and the Western Suburbs, slashing it from a laborious 2-hour journey to a mere 40-minute drive.

The project's estimated cost stands at ₹13,060 crore (equivalent to approximately US$1.6 billion). Its initial phase, which is currently under construction, encompasses a 10.58-kilometer stretch, commencing from the Princess Street flyover and extending to the Worli end of the Bandra-Worli Sea Link.