A century-old story of a Birbhum-born engineer, an unrealised railway beneath the Hooghly, Asia’s pioneering underwater utility tunnel, and the long road to Kolkata’s first underwater metro

There is a remarkable chapter in Kolkata’s history that begins long before the first Metro train entered service in 1984. In fact, more than six decades before the city’s Metro became a reality, British planners were already imagining an underground railway beneath Calcutta—and even an underwater railway beneath the Hooghly River connecting Calcutta with Howrah. At the centre of this extraordinary story was a Bengal-born British civil engineer, Harley Hugh Dalrymple-Hay, who was born in the Bengal Presidency and is identified by contemporary accounts as a native of Birbhum, West Bengal. His 1921 scheme imagined a modern underground railway system for a city that, at the time, had no metro at all.

But there is an important historical distinction to make at the very beginning. The 1921 Calcutta Tube Railway was proposed and designed, but it was never built. The railway beneath the Hooghly therefore cannot accurately be described as the first tube railway constructed in West Bengal or Asia. What was actually constructed a decade later was the Hooghly Tunnel built for the Calcutta Electric Supply Corporation (CESC)—an underground utility tunnel carrying electric cables beneath the river. It was completed in 1931 and is widely described in historical and engineering sources as Asia’s first underwater utility tunnel; IEEE historical material describes it as an engineering first in South Asia. Much later, in 1984, Kolkata became the first Indian city to operate a Metro railway.

That distinction does not make the story less extraordinary. It makes it more interesting: the railway was imagined first, the underwater tunnel came next, and the underwater Metro finally arrived almost a century later.

The story begins in 1919

The origins of Kolkata’s underground railway story can be traced to September 1919, when the Imperial Legislative Council was in session at Simla. A motion associated with Sir W. E. Crum led to the formation of a committee to investigate the possibility of a tube railway for Calcutta. After 14 sittings, the committee concluded that the rapidly expanding city needed direct communication between suburban railway stations and the commercial centre without requiring passengers to change vehicles.

The committee’s central recommendation was an east–west tube railway connecting the Eastern Bengal Railway with the East Indian Railway. The proposed alignment would eventually connect the Calcutta side with the Howrah side, passing beneath the Hooghly. The very idea was striking for the period. London’s Underground had already been operating since 1863, but in colonial Calcutta the underground railway was still an essentially futuristic concept.

The motivation was not purely technological. Calcutta was expanding, and railway-connected suburban districts were becoming increasingly important. Planners were concerned that people moving to places such as Dum Dum and Barasat would still have difficulty reaching workplaces in the central business districts efficiently. An underground system was therefore being considered as both a transport solution and a means of shaping the future growth of the metropolis.

1921: Harley Hugh Dalrymple-Hay enters the story

The decisive figure appeared in 1921.

Harley Hugh Dalrymple-Hay, a Bengal-born British civil engineer with extensive experience in underground railways in Britain, was asked to investigate the possibility of a tube railway in Calcutta. He had already built an impressive career in the world of subterranean transport. He had worked on the Waterloo & City Railway, the Bakerloo and Hampstead tube lines and the Piccadilly system, and later served as a consulting engineer on London’s Post Office Railway. He was also involved in the reconstruction of Piccadilly Circus station in the 1920s.

His connection with Bengal is one of the most fascinating details in the entire story. Rather than being an engineer who simply arrived from Britain to work on an Indian project, he was born in Bengal, in the Birbhum region, before pursuing his professional career in Britain. Kolkata’s proposed underground railway was therefore being designed by a man whose own life connected Bengal with the technological world of London’s Underground.

Dalrymple-Hay prepared a detailed scheme and published his findings in 1921 in a book titled Calcutta Tube Railways: Report on the Tube Railways and Preliminary Estimate of Cost of Construction of Proposed Tube Railway between the East Indian Railway near Benares Road, and the Eastern Bengal Railway near Bagmari Road. The book was published in London by R. J. Cook & Hammond.

The proposal was not merely an abstract sketch. It represented an attempt to apply contemporary London tube engineering to the very different geological and urban conditions of Calcutta.

The proposed route beneath the Hooghly

The principal east–west proposal was designed to connect the Eastern Bengal Railway near Bagmari Road in Calcutta with the East Indian Railway near Benares Road in Howrah’s Salkia area. The route would cross beneath the Hooghly River.

Historical sources differ slightly in the exact figures because the proposal appears to have existed in more than one formulation. The route is variously reported at approximately 10.4 to 10.6 kilometres, while reports describe either nine or ten stations. The difference appears to reflect different descriptions or revisions of the scheme rather than two completely unrelated projects. The 2014 Telegraph account, based on documents available from the Calcutta Municipal Corporation, gives a 10.4-kilometre route with nine proposed stations, while the Institution of Civil Engineers’ later research describes a blueprint approximately 10.6 kilometres long with ten stations.

The plan was remarkably close in geographic concept to the modern East–West Metro. It was meant to join the two sides of the metropolis under the river rather than forcing all cross-river traffic to remain dependent on surface infrastructure. The old railway proposal therefore anticipated, in broad geographical terms, the modern idea of using the Hooghly as a crossing beneath the city rather than above it.

Dalrymple-Hay also looked beyond the immediate east–west connection. His report argued that Calcutta would eventually require a north–south underground line, with the possibility of a branch toward the south-western districts and the docks. In other words, he was not simply proposing one tunnel: he was already thinking about the beginnings of a metropolitan underground network.

A very modern idea in a very difficult city

The greatest challenge was not the concept of railway operation. It was the ground beneath Calcutta.

The city stood on deep layers of soft, water-bearing alluvial soil, and the Hooghly presented another level of difficulty. Later historical accounts describe concern about Calcutta’s “alluvial, clayey” subsoil and the engineering uncertainty of excavating below a major navigable river. The project required technology and financial commitments that were difficult to justify in the circumstances of the early 1920s.

The projected capital cost was enormous for the period: approximately £3,526,154. Contemporary accounts also suggested that construction could require about four and a half years, with an anticipated completion around 1925–26 under the earlier scheme. A full journey was expected to cost approximately three annas.

The financial problem proved decisive.

1923: The dream is shelved

Dalrymple-Hay’s report was ultimately forwarded to the Government of Bengal in January 1923. The surviving documentary trail indicates that the project was not to be financed as a centrally supported railway project; the government position was that, if the scheme were ever carried out, it would have to be financed locally as a provincial undertaking. The financial burden proved too great, and the proposal was abandoned.

The Times of India’s archival reconstruction likewise records that the project failed to move forward because the economics were not considered viable. A separate agency examining the business case had concluded that the proposed three-anna fare would not cover the costs involved.

It is important to be precise here: the railway tunnel was not started, and no train ever ran through Dalrymple-Hay’s 1921 tube railway. There was therefore no completed railway construction workforce for which a reliable Indian-versus-British headcount exists. Any article claiming an exact number of Indian and British railway workers on that 1921 project would be inventing information.

And yet, the story did not end beneath the Hooghly.

1928: The engineer returns to the river

By the late 1920s, Calcutta had a different problem.

The Calcutta Electric Supply Corporation—better known as CESC—was expanding its electricity infrastructure on both sides of the Hooghly. The river was a major navigational artery, and simply laying power cables on or across the riverbed presented practical risks. CESC therefore turned again to the underground solution.

In 1928, CESC consulted Harley Dalrymple-Hay regarding the construction of a tunnel beneath the Hooghly to carry electric cables. Unlike his earlier railway scheme, this was not a passenger railway. It was a utility tunnel designed to connect the power system across the river. The Institution of Civil Engineers’ history of the Calcutta–Howrah subterranean connections records that CESC asked Dalrymple-Hay to design a tunnel below the lowest scour level of the river, with inspection facilities for the electrical cables.

This was the moment when Dalrymple-Hay’s underground vision moved from paper into the physical ground of Bengal.

The Hooghly Tunnel: 1930–1931

Construction began in March 1930.

According to contemporary and later accounts, workers first excavated a shaft or well near the river beside the Indian Botanic Garden in Howrah. About a month later, a corresponding shaft was started on the opposite bank at Metiabruz in Calcutta. These shafts provided access to the underground works.

The tunnel itself was approximately 538.8 metres long, while other historical descriptions give its length as 690 yards—essentially the same measurement rounded differently. It was about 6 feet in diameter and ran roughly 90 feet below the riverbed/ground level, depending on the reference point used in the source. CESC historical material and the Census District Handbook both record the 690-yard, six-foot-diameter and approximately 90-foot-depth figures.

This was not a tunnel created by a modern tunnel-boring machine.

There was no giant mechanised TBM cutting through the Hooghly as there would be nearly ninety years later. Instead, workers excavated the tunnel manually, using comparatively simple tools, while constructing the underground passage with cast-iron lining rings. The work required compressed-air techniques, and the historical medical literature from 1930 contains a remarkable direct record of the hazards faced by the men working underground.

One medical paper published in the Indian Medical Gazette in December 1930, written by Nripendra Nath Ghose, the resident medical officer attached to the Hooghly Tunnel contract, documented a fatal case of compressed-air sickness involving a 20-year-old Punjabi Sikh worker. The paper identifies the contractor as Messrs. John Cochrane & Sons Ltd. of Westminster, London.

That detail is historically important because it reveals something that is sometimes lost in retellings of the project: the tunnel was not simply a British-designed structure executed entirely by British workers. The physical labour depended heavily on Indian workers, including labour recruited from Punjab.

Who designed it—and who built it?

The surviving evidence allows us to distinguish several different roles.

Harley Hugh Dalrymple-Hay was the principal engineer associated with the tunnel and is described in later accounts as the project chief. The commemorative Hooghly Tunnel medal from 1931 specifically names H. H. Dalrymple Hay as engineer.

John Lochrance, described in the Times of India account as a boiler specialist, was associated with the tunnel’s design. Some historical references therefore present Lochrance as the designer while Dalrymple-Hay acted as project chief.

The actual construction contractor was John Cochrane & Sons Limited. The surviving 1931 commemorative medal is unusually valuable evidence because it explicitly identifies the tunnel as “THE HOOGHLY TUNNEL CALCUTTA 1930–31,” names H. H. Dalrymple Hay as engineer, and names John Cochrane & Sons Limited as the constructors.

And then there were the workers.

Indian labourers were responsible for the difficult physical excavation and construction work. The surviving accounts specifically mention workers recruited from Punjab, while the engineering and supervisory structure included British personnel. A 1999 Yojana account summarising the project describes the arrangement broadly as British engineers handling design and supervision while Indians carried out the remaining construction work.

How many Indians and how many British?

This is one of the areas where a responsible historical account has to resist the temptation to create a neat number that the surviving sources do not provide.

No reliable source located for this history gives a complete headcount of all Indian and British personnel employed on the Hooghly Tunnel. What can be documented is that Indian labour formed the bulk of the physical workforce, particularly workers brought from Punjab, while British engineers, supervisors and contractor personnel were involved in engineering and management.

The records do, however, preserve a grim human detail. Later accounts state that two Indian workers and one British worker, named Normal Smith, died during construction.

The medical literature also records at least one Indian worker’s death from compressed-air sickness in 1930, providing unusually direct evidence of the physical danger of the work.

So the most historically defensible formulation is not “X Indians and Y British worked on the tunnel,” because such a figure has not been reliably preserved. It is that the project employed a predominantly Indian manual workforce under British engineering and contracting leadership, and at least three worker deaths are documented in later historical accounts.

July–September 1931: The Hooghly is finally crossed underground

After approximately 17 months of construction, the tunnel was completed in July 1931, according to the detailed construction account published by the Times of India. Other CESC historical material records the transmission system as completed by September 1931. These dates can be reconciled by understanding July as the physical completion of the tunnel and September as the completion or commissioning stage of the wider cable-transmission system.

The completed tunnel carried electrical cables beneath the Hooghly from the Calcutta side toward Howrah. CESC later continued to use the tunnel as part of its electricity infrastructure, and modern CESC annual reports still refer to the power cable tunnel constructed in 1931 under the Hooghly.

That continuity is extraordinary. A structure excavated almost entirely by human labour in the early 1930s became a working piece of Kolkata’s infrastructure for generations.

The forgotten railway dream returns

There is an almost poetic twist to the story.

The British had failed to build Dalrymple-Hay’s railway beneath the Hooghly in the early 1920s. But only a few years later, the same engineer and the same river became part of one of the most remarkable underground engineering projects in Kolkata’s history.

The CESC tunnel effectively demonstrated that an underground crossing beneath the Hooghly was possible, even if the original railway scheme had been considered too expensive and technically challenging.

The tunnel became an engineering reference point decades later. Accounts of the modern East–West Metro project note that engineers studied the old CESC tunnel while preparing for the new underwater railway crossing.

1949–1950: The underground idea returns after Independence

The idea of an underground railway did not disappear completely after the British scheme was abandoned.

Following Independence, the Government of West Bengal revisited the idea around 1949–1950, and French experts carried out a survey of underground railway possibilities in Kolkata. Once again, however, the idea did not immediately become a functioning railway.

Kolkata would have to wait another two decades before a large-scale Metro project moved beyond preliminary ideas.

1971–1972: The Metro becomes a national project

The next major turning point came with the creation of the Metropolitan Transport Project (Railway). By 1971, a master plan had been prepared for a network of approximately 97.5 kilometres of rapid-transit routes. Three corridors were selected for detailed planning, including the eventual north–south route that became Kolkata Metro’s original line.

The foundation stone for the Metro project was laid in 1972, and construction subsequently began. The first phase was not an easy undertaking: the project faced shortages of funds, utility shifting, legal obstacles and difficulties in construction.

24 October 1984: India’s first Metro railway

On 24 October 1984, Kolkata entered a new era.

A 3.4-kilometre section between Esplanade and Bhowanipur, now Netaji Bhawan, opened for commercial service with five stations. The official Indian Railways history describes Kolkata as the first Indian city to receive a metro rail system, while KMRC’s own historical account identifies the same date and stretch as the first Metro line in India.

This is another point at which wording matters. Kolkata did not become the first city in Asia to have an underground railway—London’s Underground was already operating from the nineteenth century, and several Asian metropolitan systems preceded Kolkata. What Kolkata became was India’s first city with a Metro railway system.

2024: A century-old underwater vision finally becomes reality

The most remarkable chapter came on 6 March 2024.

More than a century after Dalrymple-Hay’s 1921 proposal, Kolkata’s East–West Metro finally began operating through the Hooghly River’s first under-river Metro section. The Howrah Maidan–Esplanade stretch was inaugurated on that date, bringing the old concept of connecting Kolkata and Howrah by rail beneath the river into actual passenger service.

The modern underwater railway is technically very different from the 1930–31 CESC tunnel. Modern tunnel-boring machines were used, with twin tunnels approximately 520 metres long beneath the river. The tunnels were constructed using Earth Pressure Balance Tunnel Boring Machines through predominantly stiff clayey silt.

The contrast is extraordinary. In 1930, men worked underground with basic tools, compressed air and cast-iron lining rings. In the twenty-first century, giant mechanised TBMs bored through the riverbed with computerised engineering and modern monitoring systems. Yet both projects were solving essentially the same geographic problem: how to move beneath the Hooghly instead of across it.

A century of continuity beneath Kolkata

Seen separately, these events can seem like disconnected pieces of engineering history.

The 1919 committee.
Dalrymple-Hay’s 1921 railway scheme.
The abandonment of the project in 1923.
The CESC underwater tunnel of 1930–31.
The return of the underground railway concept after Independence.
The Metro foundation stone of 1972.
India’s first Metro service in Kolkata in 1984.
And finally, the underwater East–West Metro in 2024.

Seen together, however, they form a single remarkable story.

The first railway proposal never became a railway. The first successful underwater crossing beneath the Hooghly was built not for passengers, but for electricity. The first Indian Metro eventually emerged in Kolkata in the 1980s. And the underwater passenger railway imagined more than a century earlier finally became reality in the twenty-first century.

At the heart of that story stands a particularly Bengal connection: Harley Hugh Dalrymple-Hay, a civil engineer born in Bengal’s Birbhum district who spent much of his professional life working on London’s underground railways, but whose name returned to the Hooghly in one of the most ambitious infrastructure stories in Kolkata’s history.

The heritage of an idea

Kolkata’s history is often told through its grand buildings, colonial streets, trams, bridges, clocks and railway stations. But heritage also lives in ideas—especially ideas that arrived decades before their time.

The story of the Calcutta Tube Railway is one of those ideas.

In 1921, the Hooghly stood as a formidable physical and financial barrier. Beneath it existed only an engineering imagination. Ten years later, a small utility tunnel proved that the river could indeed be crossed underground. More than half a century after that, Kolkata became the first Indian city to operate a Metro railway. And more than a hundred years after Dalrymple-Hay first imagined the connection, passengers finally began travelling beneath the Hooghly by Metro.

That is why the history of Kolkata’s underground railway is not simply a story about trains.

It is a story about vision, engineering, geography, risk, labour and time.

It is also a reminder that some of the most enduring landmarks of a city begin not with the opening of a station, but with a drawing on an engineer’s desk.

And somewhere in that century-long journey—from Birbhum to London, from London’s Underground back to Calcutta, from an unrealised 1921 plan to a working railway in 2024—the Hooghly became more than a river.

It became a line drawn through time.

A century after Calcutta first dared to imagine a railway beneath its river, the city finally travelled through the future it had once drawn on paper.

Historical Timeline

1919 — The first formal tube-railway initiative

During the September session of the Imperial Legislative Council at Simla, a committee associated with Sir W. E. Crum was constituted to examine the possibility of an underground railway for Calcutta. After 14 sittings, it recommended an east–west tube railway linking the Eastern Bengal Railway with the East Indian Railway.

1921 — Dalrymple-Hay prepares the Calcutta Tube Railway scheme

Harley Hugh Dalrymple-Hay, the Bengal-born British civil engineer associated with London’s underground railways, prepared the detailed Calcutta scheme. His proposal connected the railway systems near Bagmari Road and Benares Road/Salkia, with an underground crossing beneath the Hooghly and a larger vision for future north–south expansion.

1921 — Calcutta Tube Railways is published

Dalrymple-Hay’s report was published in London by R. J. Cook & Hammond as Calcutta Tube Railways. The estimated cost was about £3.526 million. Different historical accounts describe the route as approximately 10.4–10.6 km with nine or ten stations.

January 1923 — The railway scheme is abandoned

Dalrymple-Hay’s report was forwarded to the Government of Bengal, but the project was not taken forward. The financing burden and the economics of the proposed fare structure were major obstacles.

1928 — CESC turns the underwater idea into an engineering project

The Calcutta Electric Supply Corporation consulted Dalrymple-Hay about creating a tunnel under the Hooghly to carry electricity cables between Calcutta and Howrah.

March 1930 — Construction begins

Work began with the excavation of a shaft near the Indian Botanic Garden in Howrah. A corresponding shaft was begun approximately one month later at Metiabruz on the Calcutta side.

1930 — Manual tunnelling and compressed-air work

Indian workers, including labourers recruited from Punjab, excavated the tunnel and installed cast-iron lining rings. The work involved compressed air, and contemporary medical literature records a fatal case of compressed-air sickness among a Punjabi Sikh worker.

July 1931 — The Hooghly Tunnel is completed

The approximately 539-metre utility tunnel was completed after roughly 17 months of construction. Historical descriptions record a diameter of about six feet and a depth of around 90 feet.

1931 — The Hooghly Tunnel becomes a working power link

The completed tunnel carried electrical cables between the two sides of the Hooghly and became part of CESC’s infrastructure. Modern CESC records still refer to the power cable tunnel constructed in 1931.

1949–1950 — Underground railway studies return

After Independence, the West Bengal government revisited underground transport for Kolkata, including a survey by French experts.

1971–1972 — The modern Kolkata Metro project takes shape

A master plan envisaging 97.5 km of rapid transit was prepared, and the north–south corridor was selected for implementation. The Metro project’s foundation stone was laid in 1972.

24 October 1984 — India’s first Metro railway begins service

The first 3.4-km Kolkata Metro section, between Esplanade and Bhowanipur/Netaji Bhawan, opened to passengers. Kolkata thereby became the first Indian city to operate a Metro railway.

6 March 2024 — The Hooghly is crossed by passenger Metro

The Howrah Maidan–Esplanade stretch of the East–West Metro was inaugurated, bringing passenger railway service beneath the Hooghly River more than a century after Dalrymple-Hay first proposed the concept. The under-river twin tunnels are about 520 metres long.

A final historical clarification for publication

For CWC’s heritage archive, I would recommend not describing the story as “Asia’s first tube railway built in Birbhum” or “the first tube railway built in West Bengal,” because that would conflate three separate historical milestones.

The historically defensible sequence is:

1921: Kolkata’s proposed East–West Tube Railway, designed by Birbhum-born Harley Hugh Dalrymple-Hay — proposed, not built.

1931: CESC’s Hooghly Tunnel — an underwater power-cable tunnel, not a railway, widely described as Asia’s first underwater utility tunnel and identified by IEEE historical material as an engineering first in South Asia.

1984: Kolkata Metro — India’s first Metro railway system.

2024: East–West Metro — India’s first underwater Metro section, finally making the century-old concept of passenger rail beneath the Hooghly a reality.

For a heritage brand such as Calcutta Watch Company, that distinction actually gives the story greater depth: the remarkable legacy is not simply that Kolkata built the first thing—it is that Kolkata imagined it, attempted it, proved it possible, and eventually completed the journey across generations.

Primary research basis: Institution of Civil Engineers’ History of the subterranean connections between Calcutta and Howrah; Indian Railways and KMRC historical records; CESC historical/annual-report material; the 1930 Indian Medical Gazette paper on the Hooghly Tunnel; historical reporting by The Telegraph and The Times of India; Historic England records on Dalrymple-Hay’s London Underground work.