Tohid Tunnel

Last updated
Tohid Tunnel-wrwdy twnl twHyd - panoramio.jpg
Tohid Tunel map.png

Tohid (or Towheed) Tunnel is a tunnel in Tehran, Iran, the third longest urban tunnel in the Middle East. Towheed Tunnel Project is an urban underground structure, located within the area of Chamran Highway, Towheed Square, Jomhouri Square, and Navab Highway, with a length of about 3 km (Tunnel + entry ramps). Tohid Tunnel broke construction records when it was opened in less than 30 months. The interior designs met the highest safety requirements. [1] It includes installation of utilities equipment in the Tunnel, and manufacture and mobilization of north and south fans combined ventilation equipment, and control building and Niyayesh shaft.


Towheed Tunnel Construction Project

The construction site of this Project was located within the distance between Fatemi Ave. in the north of Towheed Square, and Navab Highway in the south of Azerbaijan street junction. [2]

Subsequent to studied on the Comprehensive Plan of Tehran, in order to make an easy access from the north to the south of Tehran and vice versa, along the north-south corridor, between Chamran Highway constructed during the 70s, and Navab Highway constructed during the 90s, sufficient studies were made by Tehran Municipality in 1998 so that the connection of the said two Highways, i.e. to fill the gap between Towheed Square to Jomhouri Square becomes practicable and operational.

The significance of the above issue, the congested traffic on Tehran highways, and the intense exigency of Tehran as a metropolitan city to have the above Highways connected, made Tehran Municipality to launch exhaustive studies to tackle such purpose, and by comparing the existing alternatives, the best alternative which was construction of a tunnel similar to Tehran Ressalat Short Tunnel, was adopted and approved.

To this end, in early 2007, a Contractor (Perlite) was assigned to construct the Project, and on 11.06.2007 the contract to kick off the Project was signed and notified to the Contractor, whereby on 19.06.2007 the construction works of Towheed Tunnel Project were actually commenced.


70 jet fans, each powered at 30 KW. North fan combined ventilation equipment: 3 axial fans, powered at 600 KW. Niyayesh fan combined ventilation equipment: 2 axial fans (to let in fresh air into Tunnel) powered at 410 KW. 4 axial fans (to let out exhaust air from Tunnel) powered at 500 KW. South portal fan combined ventilation equipment: 3 axial fans powered at 990 KW. Air washing system at the air entering Niyayesh fans.


Total number of lights in the Tunnel: 1,064 lights powered at 550 KW. Length of cables for the utilities: 220 km. Special and standby power generators (in case of a power cut in Tehran Power Grid, the lighting system of the Tunnel fed by these generators will be automatically switched on and the power will be compensated). Smart firefighting system. Traffic alarms. Intercom telephones. Closed-Circuit TV. Vehicles counter. Road closing system. Traffic signs. Thermal sensors. Air pollution sensors and other facilities.

Tunnel Drainage System

Towheed drainage system operates by various channels. The surface water accumulated around and the Tunnel will be drained into the canals installed along the Tunnel wall, and will enter into a channel which is installed exactly in the middle of both twin tunnels. The drained water will be conveyed through the latter channel to the south part of the Tunnel, and it will be carried away from the Tunnel by some kanats.

General Specifications

Tohid Tunnel Local street (Tohid Street) connections

Pfeil unten.svg From North to South Pfeil unten.svg
Expressway in Iran.svg Chamran Expressway
Zeichen 102 - Kreuzung oder Einmundung mit Vorfahrt von rechts, StVO 1970.svg Street in Iran.svg Fatemi Street
Zeichen 102 - Kreuzung oder Einmundung mit Vorfahrt von rechts, StVO 1970.svg Street in Iran.svg Baqer Khan Street
Sinnbild Kraftomnibus.svg Tehran BRT Line Bagher Khan Station
France road sign A17.svg Street in Iran.svg Sattar Khan Street
Street in Iran.svg Nosrat Street
France road sign A17.svg Street in Iran.svg Azadi Street
Sinnbild Kraftomnibus.svg Tehran BRT Line Azadi Station
Tehran Metro Logo.svg Tehran Metro Line 4.svg Tohid Metro Station
Sinnbild Kraftomnibus.svg Tehran BRT Line Jomhuri Square Station
Square in Iran.png
Jomhuri Square
Street in Iran.svg Jomhuri Street
Zeichen 102 - Kreuzung oder Einmundung mit Vorfahrt von rechts, StVO 1970.svg Street in Iran.svg Azarbaijan Street
Tehran Metro Logo.svg Tehran Metro Line 2.png Navvab Metro Station
Zeichen 102 - Kreuzung oder Einmundung mit Vorfahrt von rechts, StVO 1970.svg Street in Iran.svg Dampezeshki Street
Expressway in Iran.svg Navvab Expressway
Pfeil oben.svg From South to North Pfeil oben.svg


Related Research Articles

<span class="mw-page-title-main">Big Dig</span> 1991–2007 megaproject in Boston, MA, US

The Central Artery/Tunnel Project, commonly known as the Big Dig, was a megaproject in Boston that rerouted the Central Artery of Interstate 93 (I-93), the chief highway through the heart of the city, into the 1.5-mile (2.4 km) tunnel named the Thomas P. O'Neill Jr. Tunnel. The project also included the construction of the Ted Williams Tunnel, the Leonard P. Zakim Bunker Hill Memorial Bridge over the Charles River, and the Rose Kennedy Greenway in the space vacated by the previous I-93 elevated roadway. Initially, the plan was also to include a rail connection between Boston's two major train terminals. Planning began in 1982; the construction work was carried out between 1991 and 2006; and the project concluded on December 31, 2007, when the partnership between the program manager and the Massachusetts Turnpike Authority ended.

<span class="mw-page-title-main">Holland Tunnel</span> Tunnel between New Jersey and New York

The Holland Tunnel is a vehicular tunnel under the Hudson River that connects the New York City neighborhood of Hudson Square in Lower Manhattan to the east with Jersey City in New Jersey to the west. The tunnel is operated by the Port Authority of New York and New Jersey, and carries Interstate 78; the New Jersey side is also designated the eastern terminus of Route 139. The Holland Tunnel is one of three vehicular crossings between Manhattan and New Jersey; the two others are the Lincoln Tunnel and George Washington Bridge.

<span class="mw-page-title-main">Rotherhithe Tunnel</span> Road tunnel under the Thames river

The Rotherhithe Tunnel, designated the A101, is a road tunnel under the River Thames in East London, connecting Limehouse in the London Borough of Tower Hamlets north of the river to Rotherhithe in the London Borough of Southwark south of the river. It was formally opened in 1908 by George, Prince of Wales, and Richard Robinson, Chairman of the London County Council. It is a rare example of a road tunnel where road traffic, pedestrians and cyclists all share the same tunnel bore. Transport for London took over ownership and maintenance of the tunnel in 2001.

<span class="mw-page-title-main">Sydney Harbour Tunnel</span> Motorway tunnel in Sydney, Australia

The Sydney Harbour Tunnel is a twin-tube road tunnel in Sydney, Australia. The tunnel was completed and opened to traffic in August 1992 to provide a second vehicular crossing of Sydney Harbour to alleviate congestion on the Sydney Harbour Bridge. It is one of two tunnels under the harbour, the other being a set of rail tunnels for the Sydney Metro.

<span class="mw-page-title-main">Roxburgh Dam</span> Dam in Central Otago, New Zealand

The Roxburgh Dam is the earliest of the large hydroelectric projects in the lower half of the South Island of New Zealand. It lies across the Clutha River / Mata-Au, some 160 kilometres (99 mi) from Dunedin, some 9 kilometres (5.6 mi) to the north of the town of Roxburgh. The settlement of Lake Roxburgh Village is close to the western edge of the dam.

<span class="mw-page-title-main">Shaft sinking</span> Process of excavating a vertical or near vertical tunnel from the top down

Shaft mining or shaft sinking is the action of excavating a mine shaft from the top down, where there is initially no access to the bottom. Shallow shafts, typically sunk for civil engineering projects, differ greatly in execution method from deep shafts, typically sunk for mining projects.

<span class="mw-page-title-main">Nam Wan Tunnel</span>

Nam Wan Tunnel is a tunnel in Hong Kong opened to traffic on 20 December 2009, along with the West Tsing Yi Viaduct, East Tsing Yi Viaduct and Stonecutters Bridge. The road tunnel, which forms an important part of the HK$15 billion Route 8, linking Tsing Yi and Sha Tin in the city, began construction since 2003 and was completed in 2007.

<span class="mw-page-title-main">Eagle's Nest Tunnel and Sha Tin Heights Tunnel</span>

Eagle's Nest Tunnel and Sha Tin Heights Tunnel are road tunnels in the New Territories of Hong Kong. Both tunnels were officially opened on 21 March 2008. The tunnels connect Cheung Sha Wan through Eagle's Nest hill to Tai Wai, and are linked by a shared toll plaza. Eagle's Nest Tunnel is connected at its southern end to Stonecutters Bridge and Ching Cheung Road, whereas Sha Tin Heights Tunnel is linked at the northern end to Che Kung Miu Road and Tai Po Road. The tunnels are part of the Tsing Sha Highway of Route 8, and were constructed in anticipation of future traffic demands generated by development in the northeast New Territories. The combined toll for the two tunnels is HK$8.

<span class="mw-page-title-main">Squirrel Hill Tunnel</span>

The Squirrel Hill Tunnel is a tunnel in Pittsburgh, Pennsylvania, United States. It serves as an eastern gateway to the city for I-376 and was completed in 1953 after 8 years of construction and at a cost of US$18 million. At the time of opening it was the single largest investment by the State of Pennsylvania Transportation Department (PennDOT). It is 4,225 feet (1,288 m) long and is a twin-bore tunnel with 8 cross passages.

<span class="mw-page-title-main">Papago Freeway Tunnel</span> Tunnel in Phoenix, Arizona

The Papago Freeway Tunnel, better known to Phoenix residents as the Deck Park Tunnel, is a vehicular underpass built underneath Downtown Phoenix. It was built as part of Interstate Highway 10 in Phoenix, Arizona.

Tutor Perini Corporation is one of the largest general contractors in the United States. At the end of 2013, it reported annual revenue of approximately $4.2 billion. Tutor Perini is headquartered in Sylmar, California, and works on construction projects throughout North America. Specific areas of focus are civil infrastructures such as bridges, highways, tunnels, airports, and mass transit systems, building infrastructure, and specialty contracting.

The Caracas–La Guaira highway is a highway that connects Caracas, the capital of Venezuela, to its principal port city of La Guaira, capital of the Vargas state. It was designed as an alternative to the old highway linking Caracas with La Guaira, the Carretera Vieja, a circuitous route with dangerous curves and steep drops. The end-to-end journey on the old highway had taken one hour while the new highway allowed the same trip to be made in 20 minutes.

The Posey and Webster Street Tubes are two parallel underwater tunnels connecting the cities of Oakland and Alameda, California, running beneath the Oakland Estuary. Both are immersed tubes, constructed by sinking precast concrete segments to a trench in the Estuary floor, then sealing them together to create a tunnel. The Posey Tube, completed in 1928, currently carries one-way (Oakland-bound) traffic under the Estuary, while the Webster Street Tube, completed in 1963, carries traffic from Oakland to Alameda.

<span class="mw-page-title-main">Lyttelton road tunnel</span>

The Lyttelton road tunnel runs through the Port Hills to connect the New Zealand city of Christchurch and its seaport, Lyttelton. It opened in 1964 and carries just over 10,000 vehicles per day as part of State Highway 74.

<span class="mw-page-title-main">Fan (machine)</span> Machine used to produce air flow

A fan is a powered machine used to create a flow of air. A fan consists of a rotating arrangement of vanes or blades, generally made of wood, plastic, or metal, which act on the air. The rotating assembly of blades and hub is known as an impeller, rotor, or runner. Usually, it is contained within some form of housing, or case. This may direct the airflow, or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors, handcranks, and internal combustion engines.

<span class="mw-page-title-main">State Route 99 tunnel</span> Highway tunnel in Seattle, Washington

The State Route 99 tunnel, also known as the Alaskan Way Viaduct replacement tunnel, is a bored highway tunnel in the city of Seattle, Washington, United States. The 2-mile (3.2 km), double-decker tunnel carries a section of State Route 99 (SR 99) under Downtown Seattle from SoDo in the south to South Lake Union in the north.

<span class="mw-page-title-main">Heroes Tunnel</span>

Heroes Tunnel is a 1,200-foot-long (370 m), twin-tube tunnel carrying Route 15 through West Rock Ridge in New Haven, Connecticut, opened in 1949. It is the only highway tunnel to pass beneath a natural land feature in New England, although there are other types of vehicular tunnels in the region.

The Niayesh Tunnel Project is a road traffic tunnel in the north of Tehran, Iran.

Ventprom is a Russian machine building plant located in Artyomovsky, Sverdlovsk Oblast, Russia. The factory produces ventilation equipment, such as main mine ventilation fans, for a number of large mining companies, including Lukoil, SUAL Group and others. The full name of the company is Joint Stock Company Artyomovsky Machine Engineering Plant VENTPROM. It is a private company. The name ВЕНТПРОМ means "fan industry".

<span class="mw-page-title-main">Dr. Syama Prasad Mookerjee Tunnel</span> It road tunnel in the Indian union territory of Jammu and Kashmir on NH 44 (

Dr. Syama Prasad Mookerjee Tunnel, also known as Chenani-Nashri Tunnel is a road tunnel in Jammu and Kashmir, India. It is located in the Lower Himalayas, on National Highway 44. Construction started in 2011 and was completed by 2017.


  1. "Tohid tunnel". Archived from the original on 2008-12-07.
  2. "Tohid tunnel". Archived from the original on 2008-12-07.
  3. "Home".

Coordinates: 35°41′34″N51°22′44″E / 35.69278°N 51.37889°E / 35.69278; 51.37889