Osman Gazi Bridge

(Redirected from İzmit Bay Bridge)

The Osmangazi Bridge (Turkish: Osmangazi Köprüsü) is a suspension bridge spanning the Gulf of İzmit at its narrowest point, 2,620 m (8,600 ft). The bridge links the Turkish city of Gebze to the Yalova Province and carries the O-5 motorway across the gulf.

Osmangazi Bridge

Osmangazi Köprüsü
Osmangazi Bridge at the Gulf of İzmit, July 2016
Coordinates40°45′19″N 29°30′57″E / 40.755153°N 29.515712°E / 40.755153; 29.515712Coordinates: 40°45′19″N 29°30′57″E / 40.755153°N 29.515712°E / 40.755153; 29.515712
Carries6 lanes of O-5 motorway
CrossesGulf of İzmit
LocaleKocaeli, Turkey
Official nameOsmangazi Köprüsü
Other name(s)İzmit Bay Bridge
Named forOsman Gazi
Maintained by
  • Nömayg - Nurol, Özaltın, Makyol, Yüksel, Gocay
Pier constructionconcrete
Total length2,682 m (8,799 ft)[1]
Width35.93 m (117.9 ft)[1]
Height234.425 m (769.11 ft) (pylons)[1]
Longest span1,550 m (5,090 ft)
No. of spans3
Piers in water2
Clearance below64 m (210 ft)
DesignerIHI Corporation
Contracted lead designerIHI Corporation
Engineering design byCOWI A/S
Construction start30 March 2013 (2013-03-30)
Construction end30 June 2016 (2016-06-30)
Construction costUS$ 1.2 billion[2]
Inaugurated1 July 2016 (2016-07-01)
Daily trafficapprox. 6000 PCE/day [3]
Toll₺184,50 (2022- Passenger Vehicles)

The bridge was opened on 1 July 2016 to become the then-longest suspension bridge in Turkey and the fourth-longest (seventh-longest as of 2022) suspension bridge in the world by the length of its central span.

The length of the bridge was surpassed by the Çanakkale 1915 Bridge across the Dardanelles strait, which became the longest suspension bridge in the world when it was opened on 18 March 2022.


Construction and operation of the bridge was awarded to a joint venture (NOMAYG JV) formed by five Turkish companies (Nurol, Özaltın, Makyol, Yüksel and Gocay) and one Italian construction company Astaldi following the international Build–operate–transfer tender that took place in April 2009.[4][5] In 2010, a contract was signed for the project that was estimated to cost 11 billion for the entire highway from Gebze to Bursa.

On 30 March 2013 Prime minister Recep Tayyip Erdoğan laid the ground stone for the bridge.[6] After the completion of the bridge, the distance between Istanbul and İzmir shortened by about 140 km (87 mi), bypassing the lengthy distance around the Gulf of İzmit. The 420 km (260 mi) highway and bridge reduced the travel time between the two major cities from around six hours to five. The bridge and connecting highway provides three lanes of traffic in each direction. Construction was completed on 30 June 2016.[7][8]

Two lanes of high-speed railway were also planned to run through the middle of the bridge, but were scrapped in favor for a fourth lane for both ways. The decision lead to criticism and sparked people being suspicious of politicians being involved with automobile lobbyists.[9]

EPC Bridge ContractorEdit

The US$1 billion privately financed bridge was awarded to the Japanese firm IHI Infrastructure System Co. on 16 July 2011 as EPC basis with FIDIC Silverbook contract. IHI, which was one of the contractors of second Bosphorus bridge, also completed the seismic reinforcement projects for Halic and Mecidiyekoy viaducts. IHI subcontracted the design works to Danish engineering design firm COWI A/S, which collaborated for the aesthetic design with Dissing+Weitling. Notice to proceed was given by NOMAYG JV to IHI on 1 January 2013 and the expected total project duration was 37 months.

The dimensions are:[5][7]

  • main span length: 1,550 m (5,090 ft)
  • side spans length: 566 m (1,857 ft)
  • clearance: 64 m (210 ft)
  • tower height: 252.0 m (826.8 ft)
  • tower size (at the base): 8 m × 7 m (26 ft × 23 ft)
  • deck size: 35.93 m × 4.75 m (117.9 ft × 15.6 ft)

The 34,000 tons of steel used to build the bridge was obtained from ArcelorMittal Galaţi, Romania.[10]

The bridge is fourth longest suspension bridge in the world.[11]

Accident at construction siteEdit

The bridge after the accident.

On 21 March 2015 a catwalk broke away from its bolted joint cable on the south tower during the construction at the bridge and fell into the water. Added in February 2015, the catwalk was needed to allow workers access to the other side of the bay. No one was harmed by the accident as work was interrupted at this section due to windy weather. Marine traffic to and from İzmit Bay was suspended following the accident for security reasons and resumed after recovering the cable in the morning of 23 March.[12][13]

Kishi Ryoichi, the 51-year-old Japanese engineer of the IHI-Itochu Consortium, who was in charge of the construction at site, committed suicide after the accident. He was found dead at the entrance of a cemetery near his lodging in Altınova. He left a note saying that "...this failure ends my private and professional life. This project was mine and my country's pride. No one else is responsible for this failure."[8][13][14][15]


As of 8 October 2021 the bridge tolls are:[16]

Vehicle class Toll ₺ (TRY) Toll $ (USD)
Vehicles with 2 axles, wheelbase <3.2m 195.50 ~18
Vehicles with 2 axles, wheelbase >3.2m 337 ~28
Vehicles with 3 axles 280 ~34
Vehicles with 4 or 5 axles 371.50 ~45
Vehicles with 6 or more axles 468.50 ~56
Motorcycles 103 ~12

In popular cultureEdit

The five-time Supersport World champion Kenan Sofuoğlu from Turkey made a show of a motorcycle speed trial in the early morning of 30 June 2016, right before the official opening of the bridge. He crossed the 1.5 km (0.93 mi) distance in 26 seconds reaching a top speed of 400 km/h (250 mph) on his Kawasaki Ninja H2R track-only motorcycle.[17][18]

See alsoEdit


  1. ^ a b c "Archived copy". Archived from the original on 2013-10-03. Retrieved 2013-08-15.{{cite web}}: CS1 maint: archived copy as title (link)
  2. ^ http://www.brodag.dk/Synopsis/2014/11%20IZMIT.pdf Cost of bridge (page 4)
  3. ^ "Vapur lobisine çalışıyor". Yeni Şafak (in Turkish). 2016-07-30. Archived from the original on 2016-07-30. Retrieved 2016-07-30.{{cite news}}: CS1 maint: bot: original URL status unknown (link)
  4. ^ Turkey Infrastructure Report Q4 2009 Archived 2011-10-05 at the Wayback Machine
  5. ^ a b "Körfez köprüsü dünya dördüncüsü olacak". Radikal (in Turkish). 2012-05-27. Retrieved 2013-03-31.
  6. ^ "İzmit Körfez Geçişi Asma Köprüsü'nün Temeli Atıldı". Son Dakika (in Turkish). 2013-03-30. Retrieved 2013-03-30.
  7. ^ a b "Izmit Bay bridge". Dissing+Weitling architecture. Archived from the original on 2013-10-02. Retrieved 2013-03-31.
  8. ^ a b "Japanese engineer commits suicide after İzmit bridge cable snaps". Today's Zaman. 2015-03-23. Archived from the original on 2015-03-24. Retrieved 2015-03-24.
  9. ^ "Hızlı tren unutuldu para otoyola akıyor". www.sozcu.com.tr (in Turkish). Retrieved 2022-11-21.
  10. ^ (in Romanian) 34.000 de tone de oțel de la ArcelorMittal Galați, folosite la construcția podului Osman Gazi din Turcia, July 4, 2016
  11. ^ "Bu otoyolla İzmir-İstanbul 3.5 saate iniyor". Radikal (in Turkish). 2009-06-20. Retrieved 2013-03-31.
  12. ^ "Körfez Köprüsü'nde kablo koptu". Hürriyet (in Turkish). 2015-03-21. Retrieved 2015-03-24.
  13. ^ a b "Dev projenin mühendisi ölü bulundu". Milliyet (in Turkish). 2015-03-23. Retrieved 2015-03-24.
  14. ^ "Körfez Geçiş Köprüsü'nde çalışan Japon mühendis intihar etti". Hürriyet (in Turkish). 2015-03-23. Retrieved 2015-03-24.
  15. ^ "İzmit Körfez Geçiş Köprüsü Halatı Koptu, Japon Mühendis İntihar Etti". Habertürk (in Turkish). 2015-03-23. Retrieved 2015-03-24.
  16. ^ "Bosphorus and Second Bosphorus Bridge Tolls".
  17. ^ "Kenan Sofuoğlu, Osmangazi Köprüsü'nde 400 kilometre hıza ulaştı!". Hürriyet (in Turkish). 2016-06-30. Retrieved 2016-07-01.
  18. ^ "Production Bike World Record 0-400 kmh in 26 sec. HD". YouTube. July 1, 2016. Archived from the original on 2021-12-13. Retrieved June 30, 2016.

External linksEdit