- Container, Fuel, LNG, Noncontainerised, Tanks
This report covers the study to the development of standardized components for best available LNG technologies, and specifically the LNG fuel tank containers and non-containerised tanks. The corresponding sub-activity LNG fuel tank containers and non-containerised tanks prescribes a study to:
– Non-containerised fuel tanks
– Technical compatibility with other systems
– Fuel tank containers
Technically the first step was to define a the standard which could work for the transport, the storage as well as a fuel tank for inland waterways transport (IWT) vessels. The standard specifications for LNG fuel containers would be the best and economically the most interesting option for Trifleet to use where it is able to reach the goal to supply tanks with at least 10% cost saving compared with the tanks used on the current vessels.
For technical issues it is necessary to find a manufacturer who was not only able to do the engineering, but also was able to perform the whole approval process. Many manufacturers did offer a solution, but in the end none of them could provide the approval documents.
Gascon South Africa has worked together with Bureau Veritas Marine and Offshore towards a design where tank containers could receive an approval for the use as fuel tanks on board inland waterway vessels. This design differs from the standard design by Trifleet since a bottom discharge was not possible without introducing the issue with the double walled piping. For this reason a top discharge was introduced. For the discharge an additional pumping/pressure system to empty the tank is necessary. With the additional system and the corresponding controls, the tank container is commercially less interesting.
Furthermore the requirements regarding the materials of each component of the tank container would need to meet higher standards and certifications. Due to this, each material and each part would need to be tested and investigated and inspected by an independent authority. This will introduce many extra cost to the material, making it more expansive than the regular transport tank.
The requirements regarding the calculations of the dynamic loads on the tank are different as those from a standard transport tank. With a standard transport tank it is enough to take, for example Fatigue calculations into account based on the loads acting on the tank during transport by Rail road and sea. In general the rail traffic is the worst case regarding the fatigue loads. According to the ISO rules and the CSC rules transport tanks need to be impact approved. Similar calculations are asked with the type C tanks but then the manufacturer need to show those calculations for each different ship, and even locations on the ship making a standard more or less impossible.
In practice it means that for each ship the fuel tank needs to be approved separately making a standard impossible. And again, even when a standard UN Portable tank will pass those calculations, the fact that it needs to be done with each new ship makes it less interesting. Engineering cost on a ship are proved to be the highest cost.
Based on the previous results and necessary additions to the tank containers, Trifleet decided to stop the research towards an approved certified standard fuel tank. The conclusion is that under the current circumstances a standard like described, is not feasible and type approval is not possible.
The full analysis can be found under downloads