British Infrastructure Legacy in Pakistan-5

Mountains, passes and difficult terrain made tunnels essential, particularly in Balochistan and the North-West Frontier.

These tunnels were not constructed primarily for civilian convenience. They were closely connected with military strategy, administration, trade and the movement of troops and supplies towards Afghanistan.

By Ramesh Raja

The British developed an extensive system of railways and roads in the territory that became Pakistan in 1947. Mountains, passes and difficult terrain made tunnels essential, particularly in Balochistan and the North-West Frontier. These tunnels were not constructed primarily for civilian convenience. They were closely connected with military strategy, administration, trade and the movement of troops and supplies towards Afghanistan.

The greatest concentration was on strategic railway routes leading towards Quetta, Chaman and the Khyber frontier. British engineers used tunnelling to overcome mountain barriers that could not practically be crossed by conventional railway gradients.

Khojak Tunnel, Balochistan: Railway Tunnel

The Khojak Tunnel is the most famous British-era tunnel in Pakistan. Constructed between 1888 and 1891, it passes beneath the Khojak Pass in the Toba Achakzai range on the Quetta-Chaman railway line. Its length is 3.912 km. When completed, it was reportedly the fourth-longest tunnel in the world. The Department of Archaeology and Museums describes it as a historic monument.

The tunnel was built as part of the railway intended to connect the British strategic network with the Afghan frontier. Approximately 4,000 workers were involved, including 65 Welsh miners brought for specialist underground work. The railway eventually reached Chaman rather than Kandahar, but Khojak became the critical passage through the mountains.

Bolan Pass Tunnels, Balochistan: Railway Tunnels

The Bolan Pass railway was another extraordinary British engineering undertaking. The railway connected Sibi with Quetta, crossing the difficult Bolan mountain region. Surveys began in 1876 and railway construction started in 1880. After several attempts and flood damage, an all-weather alignment was inaugurated in 1897. The route contains 17 tunnels and repeatedly crosses the Bolan River.

These tunnels were therefore railway tunnels, constructed to enable the strategic Sibi-Quetta railway to climb through the mountains. The complete railway journey from Sibi to Quetta is approximately 141 km, with the principal mountain section extending from Ab-i-Gum through Kolpur towards Quetta.

Kala Chitta “Seven Sisters”, Punjab: Railway Tunnels

The Seven Sisters are seven British-era railway tunnels through the Kala Chitta hills of Attock. They were constructed between 1896 and 1898 on the railway route between Attock and Mari Indus.

Together, the seven tunnels have a combined length of approximately 9,046 feet, or 2.76 km, although the tunnel group extends across a wider five-kilometer section of the railway. Individual tunnels range from approximately 855 feet to 1,776 feet.

These were railway tunnels, designed to carry trains through the difficult Kala Chitta terrain. Their construction demonstrates how British railway engineers adapted the alignment to mountainous geography rather than attempting steep gradients.

Khyber Pass Tunnels, KP: Railway Tunnels

The British Khyber Railway was constructed through the historic Khyber Pass between Jamrud and Landi Khana. The railway itself was approximately 26 miles, or 42 km, long. British archival records state that the line contained 34 tunnels with an aggregate length of about three miles, or 4.8 km, as well as 92 bridges and culverts.

These were railway tunnels, not road tunnels. Their purpose was to carry the railway through the steep and strategically sensitive Khyber terrain towards the Afghan frontier.

Chhappar Rift and Harnai Railway Tunnels, Balochistan

The British also developed the Harnai Railway through the difficult terrain between Sibi and the Balochistan interior. The Chhappar Rift section required substantial engineering works, including tunnels, cuttings and bridges. The railway formed part of the strategic network that ultimately connected with Quetta. British railway records describe the difficult mountain barrier and the extensive engineering undertaken to overcome it.

These were railway tunnels, constructed to maintain a railway route through rugged mountain country.

Malakand and Frontier Tunnel Works: Railway and Strategic Communications

British frontier engineering also included tunnel and cutting works around the Malakand region and other difficult sections of the North-West Frontier. These works were associated with strategic communications and railway or transport proposals. Unlike Khojak, Bolan and Khyber, however, surviving sources do not provide a sufficiently reliable consolidated figure for their total tunnel length.

They should therefore be regarded as part of the wider British frontier transport engineering system, rather than assigned an unsupported national tunnel total.

Were There British Highway Tunnels?

An important distinction must be made. The great British tunnels in present-day Pakistan were overwhelmingly railway tunnels. Roads generally crossed mountain passes through open cuttings, gradients, bridges and switchbacks rather than long enclosed tunnels.

The Khojak Pass, for example, was historically a passage used by travellers and military forces, while the British tunnel beneath it was specifically constructed for the railway. Today, the modern N-25 highway also crosses the Khojak region, but that does not make the historic Khojak Tunnel a highway tunnel.

A Remarkable British Engineering Legacy. The British tunnel legacy in Pakistan can therefore be summarized as a network of strategic railway tunnels: Khojak Tunnel at 3.912 km, 17 Bolan Pass tunnels, seven Kala Chitta tunnels with a combined length of about 2.76 km, and 34 Khyber Railway tunnels with an aggregate length of about 4.8 km, in addition to smaller tunnel works elsewhere.

These structures were built primarily to solve the transportation problem of crossing Pakistan’s most difficult mountain barriers. More importantly, they reveal the strategic purpose behind British infrastructure: railways were engineered not simply to connect towns, but to connect ports, cantonments, administrative centers and frontier passes, particularly towards Afghanistan. The tunnels remain among the most impressive physical reminders of that engineering era.

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The author of this article, Engr. Ramesh Raja, is a Civil Engineer, visionary planner, PMP certified and literary enthusiast with a passion for art and recreation. He can be reached at engineer.raja@gmail.com