|
Comment |
Hyperbaric Tunnel Construction and Diving |
|
Manufacturer |
|
|
Model designation |
|
|
Year of manufacture |
|
|
Condition |
|
|
Price |
|
|
 Location |
|
Country |
Germany |
|
City |
Ammersbek |
|
| Terms of shipment |
|
|
| Terms of payment |
|
|
| Description |
Below a depth of 40 metres (which equals 4.0bar over pressure) compressed air technicians enter a zone where it is no longer effective to carry out compressed air work under conventional conditions. However, because the next generation of tunnels will be longer and deeper than anything we have at present, it can only be a matter of time and opportunity before divers and compressed air technicians start playing a key role in hyperbaric work.
When Nordseetaucher GmbH was asked to cooperate on this project to build two tunnels under the Westerschelde in the Netherlands, we didn’t hesitate a moment, knowing that it would be an ideal opportunity to put to use the skills and expertise we had gained during our 4th Tube of the River Elbe Crossing and the Wesertunnel, Germany contracts. However, the problems we could expect to face were on a slightly different scale. In the 4th Tube of the River Elbe Tunnel we were working under pressures of up to 4.5 bar, while work in the Wesertunnel was carried out at 5.0 bar. The brief for the two tunnels of the Westerschelde Tunnel Project called for us to work at pressures of up to 8.5 bar.
It is impossible to work at 8.5bar pressure with compressed air, because the nitrogen contained in breath causes narcosis. Accordingly, from the very start we planned to work using mixed gases.
For several decades, a number of methods and procedures have been tested and applied in international commercial offshore diving which can also be used in machine-driven tunnel construction projects carried out in hyperbaric pressure in excess of 5.0bar. For instance, the use of mixed gas. These gases are a mixture of oxygen and various inert gases, blended according to the specific pressure spectrum to allow the divers to work for days and weeks under pressurised conditions (saturation method). At hyperbaric pressures of between 3.0 and 6.0 bar compressed air can be used as working gas with the saturation method, and may indeed be the method of preference in future. In order to use mixed gases safely and successfully, meticulous preparations to the tunnel boring machine and logistical processes are necessary.
Due to the relatively thin clearance above the tunnel it would have been dangerous to lower the bentonite level in the cutter head chamber, the excavation chamber. Accordingly, specially trained diving personnel were on hand to carry out inspections and tool changes in the event of repair and maintenance work becoming necessary.
|
|
Get in contact |
|
|
|
|
|
|
The advertiser speaks the following languages: |
  |
|
Direct contact |
| Contact |
Claus Mayer |
|
Phone |
+49 4102 23180 |
|
Fax |
+49 4102 231820 |
|
Mobile |
+49 172 4300598 |
|
|
|
Service Links |
|
|
|
|
|
|
offer 
new 
1132.pdf
