Scientists predict that the main thrust toward using the Oceans and seas will become a matter of Economics. It will promote heavy construction of marine structures. Today design and construction of maritime projects constitutes the entire activity of large groups of scientists and engineers, working to conquer the problems of over water and underwater engineering. These projects concern building newer and larger drilling platforms for marine oil fields, underwater oil and gas storage facilities, tidal- and wave-power electricity generating stations, underwater pipelines, building artificial harbours and ports, distillation plans for drinking water and valuable chemicals, and much more.

Extending the general network of transportation has resulted in the construction of great bridges above marine straits or tunnels beneath them. The creation of such large thoroughfares will greatly allow a reduction in existing ferry transportation and an increase in the safety of navigation. Activities in this area continue to grow rapidly.

In the near-term perspective, projects connected to renovation of already existing or new canals are already underway. There are already numerous designs for large bridges and tunnels between islands, and between islands and continents. Their realisation is already a fact in many cases as we approach the 21st century.
 
 

Operational and planned marine construction projects

1. The Florida peninsula canal project (Gulf of Mexico - Atlantic Ocean).
 
 

2. Tunnel under the English Channel (La Manche). The idea for the construction of a tunnel under the English Channel (La Manche) was first proposed by Napoleon in 1802. Many designs have been developed since that time, but were never pursued to the point of beginning the project. In 1986, an agreement made between England and France allowed the project to begin for the first time. In 1994, the “Chunnel” (channel-tunnel) was opened for commercial use. The “Chunnel” is actually 3 tunnels, with lengths of approximately 50 km (two for trains and one as a spare or for future use).
 
 

3. The bridge project over the Large Belt strait(entrance to the Baltic Sea).
4. The tunnel or bridge project across the Sund (The Sound) strait (entrance to the Baltic Sea).
5. Bridge across Kalmarsund (Sweden) in the Baltic Sea. The bridge is 6 km long.
 
 

6. Project for a bridge or tunnel across the Bering Strait.
7. The longest tunnel in the world, Seikan Tunnel, connects the Japanese islands Hokkaido and Honshu. Its length is 53.8 km. The construction project took 26 years to complete.
8. The Onaruto bridge links the Japanese islands of Awaji and Shikoku. This route will connect the islands of Honshu and Shikoku, when the construction of the Akasaka bridge between the islands of Honshu and Awaji is completed.
9. The Seto-ohashi route, linking the islands of Honshu and Shikoku, consists of 6 bridges connecting 5 small islands. The total length of all of the bridges is 37.3 km.
10.Omishima bridge, connecting the islands Honshu and Shikoku, is the largest arched bridge in Asia.
11. The Kammon bridge over the Strait of Shimonoseki, connecting Honshu and Kyushu, was built in 1974. The length of the bridge is 1608 m.
 
 

12. Project for a canal through the Isthmus of Kra in Thailand.
 
 

13. Project for modernising the Suez Canal. After renovation, vessels displacing up to 260,000 tons will be able to use the canal. Construction estimated to take 4 years.
14. Project for a bridge over the Gulf of Aqaba (northern end of the Red Sea). The designed length is 8 km. Construction is expected to take 3 years.
 
 

15. A bridge over the Bosphorus strait was opened in 1974. A second bridge is under construction. A project for building of a tunnel under the Bosphorus strait will be 9 km in length.
16. Project for a tunnel under the Straits of Messina. The designed width is 40 m, and the length will be 3 km. Projected construction time is 8 years.
 
 

17. Project for a tunnel under the Straits of Gibraltar.
 
 

18. The Maracaibo bridge in Venezuela opened in 1968. The length is 8,672m.
19. Project to renovate the Panama Canal. In 1983, negotiations between Japan, the USA and Panama regarding the design for a second canal, without locks through the Isthmus of Panama were completed. Its length will be approximately 98 km, with a depth 30.5 m.
20. Project for an inter-ocean canal across Nicaragua.
 
 

Tunnel under the English Channel / La Manche
 
 

Seikan Tunnel
 
 

Omishima bridge
 
 

Onaruto bridge
 
 

Delivery of caisson (bridge footing)
A footing-support for a bridge is a gigantic steel box - a caisson, weighing about 20,000 tons. This caisson is buoyant is being delivered to a site by towing vehicles, where it will be sunk into place.
 
 

Designed route of a lock-free Panama Canal

 1.Route of the present canal

2.Designed route of the lock-free canal

 
 

Information provided by HDNO:  http://www.oceansatlas.com/unatlas/about/ContactInfoForHDNO.html