Implementation of the DNV-OS-E406 requirements has become a costly task for oil and shipping companies. Norsafe Group has introduced a davit refit solution that generates significant financial savings when davit and lifeboat replacements are necessary.
“Norsafe’s engineering team has developed a davit cassette adapter that makes it possible to use the new free-fall lifeboats without tearing down existing davit systems. The adapter is installed into the existing davits with minimal lifting and welding processes on site, which is a costly affair offshore,” says Geir Kvalheim, Sales Manager at Norsafe AS.
Norsafe has developed three free-fall lifeboats that meet the DNV-OS-E406 standards: GES45, GES50 MKIII and GES52. Most free-fall lifeboats in use today are not built in accordance with the new requirements.
Must prove “safe evacuation”
The main goal of the DNV OS-E406 is to prove “safe evacuation”. This is actualised by specifying the location, installation and the weather conditions in the area. The standard focuses on three important areas, which is documented by analysing a free-fall drop in three phases.
– Passenger injury evaluation: The entire free-fall phase until the boat hits the surface of the water. In this phase, there are high accelerations and g-forces on the body. How the body reacts to these stress factors and the risks of injury is considered. Simulations in all types of waves and weather conditions provides the answers;
– Strength and structural integrity: The boat hits the surface and disappears under the water before resurfacing, heading away from the evacuation site. In this phase, the boat must tolerate high pressures and stress, while the people inside the boat remain safe. Specialists in dynamic flow and finite element tools analyse these pressures and how the boat reacts to the stress;
– Safe gateway: After resurfacing, the boat needs headway and seaworthiness to minimise the risk of collision with the offshore installation. Advanced simulation tools can analyse and document the boat’s behaviour after resurfacing.
The last and final requirement is that the boats are designed for the rigs/ships where they are installed, and for the wave and weather conditions they will operate in. The documentation gathered from location, weather and simulations determine if the DNV-OS-E406 requirements are met.
Saves 300 million
Norsafe’s first refit project is for Statoil’s Grane field in the North Sea. Statoil have purchased four GES45 freefall lifeboats. They will be installed in their own existing SV40 davits, thus generating total estimated cost savings of approximately 300 million NOK.
“The savings are particularly large on rigs and installations that cannot be dragged into yards. The welding and lifting costs offshore are huge, and our new solution minimise these costs,” says Kvalheim.
The new standards require custom made solutions in a much greater extent than previously.
“The adapters are all going to be different, and Norsafe needs to change their methods to customise the products more than before. In the long run, I believe we have developed a highly profitable solution both for us and our customers,” says Kvalheim.
Press Release, April 28, 2014