Friendship tunnel(also called Kohat tunnel) is Pakistan’s longest road tunnel and the second longest tunnel in the country over all. It is located between Kohat and Peshawar on 1264 kilometer long highway N55 (also called the Indus Highway). N55 provides a 410 kilometer shorter and an alternate route between Karachi and Peshawar as compared to N5.
First feasibility study of Kohat tunnel was carried out in 1973. Later on siesmic survey was carried out by OGDC (Oil and Gas Development Corporation) in 1990, parallal to the current alignment of tunnel. A reanalysis of this survey was done in 1997. Official ground breaking of the construction work happened in February 2000 (reference 2 below) and the completed tunnel was opened for traffic on June 10, 2003.
The map to the left shows the location of Kohat tunnel with respect to the geography of the region.
The tunnel has been dug in the hills consisting of lime stone dating as far back as Jurassic era.
It is estimated that Kohat tunnel reduces the travel time between Peshawar and Kohat by 40 minutes. The distance between Peshawar and Kohat is also reduced by approximately 25 kilometers.
Who Paid For the Tunnel:
Kohat tunnel is built by the monetary and technical assistance from Japan therefore it was offically renamed as Pakistan-Japan Friendship Tunnel. Technical assistance for the tunnel also came from Malaysia. 100% funding for the tunnel was provided by the Japan Bank for International Cooperation (JBIC). This is the same forum which has been touted as the source for providing funding for the Lahore Rapid Mass Transit (LMRT) Rail System.
Before Kohat tunnel project was started the amount of loan sanctioned by JBIC was Rs 6.626 billion. I still have to research what was the final amount the this project ended up costing (readers can help us here). The original loan is payable in 30 years with 10 years grace period at an annual interest rate of 2.3%
The Ministry of communications is the sponsoring agency of the project while National Highway Authority (NHA) is the executing agency.
Longest Tunnels of Pakistan
Currently, and also for the past 117 years ( since 1891) Pakistan’s longest tunnel has been the 3.912 kilometer long Khojak Railway Tunnel. Kohat tunnel with 1.885 kilometer length is the longest road tunnel and 2nd overall longest tunnel of Pakistan to date. However, both Khojak Tunnel and Kohat Tunnel may lose their respective titles as early as 2009 when the longest tunnel in Pakistan, the 8.75 kilometer long Lowari tunnel is scheduled to be completed.
By 2010, Kohat tunnel is expected to carry a volume of 11279 vehicles every day. In 2005 this volume was an average of 6149 vehicles per day.
The map to the right is a simple schematic of Kohat tunnel project alongwith north and south approach roads. Looking at the curvy-twisty old highway towards the left of the image, one can appreciate how much distance is being getting cut by new road and tunnel complex. Notice the locations of Toll booths, management offices, staff residences, control buildings, the tunnel itself and the link road.
Following two photos show the main toll booth and the central control center of Kohat tunnel.
Kohat Tunnel Cross-Sectional View:
Length of Kohat Tunnel: 1.885 kilometer.
Width of Pavement: 7.3 meters - There is one lane in each direction.
Pavement Type: Concrete
Ventilation System: 11 Jet fans
Safety Facilities: Emergency Phones, Fire Extinguishers and Emergency bays.
Vehicle Weight Limit: 10 tons per axle
Height of Vehicle: 5.1 m
Width of Vehicle: 2.5 m
Approach Road Length: 7.79 km (north) and 20.955 km (south)
Approach Road Pavement Type: Asphalt
Width of Approach Roads: 7.3 m
Width of Shoulders: 3.0 m
The approach roads to Kohat Tunnel also include construction of seven bridges and four under passes. The largest bridge is constructed over Toi River, South of Kohat town
Speed Limit: 90 kmph on level pavement, 80 kmph on hilly pavement and 40 kmph inside the tunnel.
Commemorative Stamps of Kohat Tunnel
In 2003 Pakistan Post Office issued following set of commemorative stamps to celebrate Pakistan-Japan friendship as well as Kohat tunnel
Photos From the Construction Phase:
The photo to the right below shows the process of ribs installation.
The photo to the left below shows drilling by the wheel jumbo, where as to the right below is the process of shortcreting by a shortcreting robot.
The two photos below show the process of concrete lining.
Water Seepage in Tunnel During 2002 Earthquake
A low intensity earthquake in november 2002 caused two cracks in the tunnel. The engineers claimed that the damage was of a very minor nature; the three-metre-long cracks had developed only in the concrete. The crevices had appeared at 57th metre from the Kohat side. The hills through which Kohat tunnel is built are full with water reservoirs and consist of a loose rock structures at various places. The earthquake also caused water seepage in the tunnel. A dawn report of this news wrote:
The Project Director informed that the water from the three springs inside the tunnel was gushing out at a speed of 200 litters per minute and had been so far under control. He said that earlier the experts thought it was a seepage which they expected would stop after a few months but only the pressure had decreased during last eight months from 2500 litters per minute down to 200 litters. He said that the springs would be the permanent feature of the tunnel and were of no harm to the structure.
The photo to the left below shows jet air fans installed for ventilation, where as to the right below is the process of installing lighting ducts and fixtures.
2008 Damage to the Tunnel
In January 2008, people who had no regards of public property and national infrastructure of Pakistan did heavy damage to the tunnel. Vehicles were burned inside the tunnel, light fixtures were broken and Control room consoles were smashed.
Feasibility of Second Kohat Tunnel is Underway:
In July 2007, the Japanese International Co-operation Agency (Jica) started conducting feasibility of second Kohat tunnel and access road project under the Pakistan Transport Plan Study (PTPS) phase-II. The idea is to use one tunnel in each direction.
Toll Collection at Kohat Tunnel
A company called VisualSoft, which is a provider of Electronic Toll and Traffic Managment Systems (ETTM) was selected by National Highway Authority(NHA) to provide their trademark HyPass ETTM solution for Kohat Tunnel. HyPass is based on RFID technology. I am unable to confirm if this RFID based electronic toll collection system is still in use at Kohat Tunnel or not. Looks like the webpage of Visualsoft which was the provider of HyPass has not been updated since 2004. I’ll need some confirmation from readers here.
1. National Highway Authority Pakistan
2. Construction of Kohat Tunnel at pakistaneconomist.com
4. Analysis of Predicted and Actual Geology in a Tunnel Project
5. Quake Causes Cracks in Kohat Tunnel
6. Kohat Tunnel Construction Paroject (I)-(III) – Field Survey November 2005