Hapag-Lloyd explains why the retrofit of Sajir is important for the whole shipping industry
Hapag-Lloyd wants the maritime world to learn from its world-first conversion of a large container ship to LNG.
This pioneering project will see LNG-ready 15,000-TEU Sajir converted to dual-fuel LNG in what Hapag-Lloyd calls a “pilot project for the entire industry”.
Sajir is one of 17 vessels inherited from UASC which is LNG-ready. Hapag-Lloyd director of technical fleet management Lutz-Michael Dyck says “These vessels were built around five years ago. UASC was interested in using LNG as fuel and developing future technology, but at the time, shipyards and engine makers were not able to finalise this project, so UASC decided to construct them so they could be converted in the future.”
It uses DNV GL’s LNG-ready notation to construct the ship, which has:
Mr Dyck comments “It is good to already have the dual-fuel A/E engines on board. If we did not have these, it would add to our investment for the conversion. It can cost US$1M for just one auxiliary to be modified to a dual-fuel engine.”
The main aspects of the retrofit include:
Mr Dyck adds “special crew training and respective certificates are necessary. We also need to develop the bunker procedure, together with the supplier, to get class approval.”
When the MAN ME engine already installed is converted to an ME GI engine, it will operate with LNG. The LNG in the tank has a temperature of -162°C and needs to be brought to + 35°C and 3.0 bar for the A/E and 350 bar for the M/E to burn it. Modifications to the main engine to make it fit for LNG include changing pistons, covers and liners. Mr Dyck adds that a gas control block, high pressure pipes and GI engine controls must be installed.
He says the biggest challenge when it comes to the conversion is integrating the LNG tank into the existing structure. The 1,300-tonne tank will hold around 6,700 m3 of LNG. “The tank will be prefabricated and lifted into the vessel by a crane. That is one of the biggest challenges we have. The tank will be placed in front of the engineroom to be close to it, as this means a shorter piping distance to connect the tank with the engines. This will reduce the piping works and minimise the extent of the hazardous areas.”
The space taken up by the tank means that close to 300 container spaces will be lost. But it was “taken into consideration in the design that these would be lost at a later stage,” says Mr Dyck.
A GTT Mark III membrane tank is being used. Mr Dyck says “A GTT type III fits best into the existing structure and GTT is a world leader in this design. The prefabricated tank will be encased in an exoskeleton structure designed by Technolog. Mr Dyck says “this frame will connect the hull side and tank side and the tank will give us optimum space to carry as much LNG as possible in a defined space.”
Another challenge is the multiple stakeholders involved in the project. When UASC decided to build LNG-ready vessels, it formed a consortium of industry partners including:
Mr Dyck comments “The integration and co-ordination of the multiple stakeholders was and is very challenging.”
Another challenge is the tight schedule for the conversion. Mr Dyck explains that the modification must be completed in 105 days at HuaRun DaDong Dockyard. Steel cutting took place at the end of July and the vessel is due to arrive in June 2020.
The ship will be bunkered via a bunker barge. Mr Dyck comments “For container vessels we are pioneers. Before it was forbidden to bunker operations simultaneously with cargo operations (SIMOPS). But we are in discussions with Rotterdam and Singapore ports to define what is necessary to do so and are in discussion with suppliers like Shell, ExxonMobil and others. It takes around nine months to get approval from port authorities so that SIMOPS can be performed.
“At the moment we are focused on performing two bunker operations, one in Rotterdam and one in Singapore.”
He points out that there are many bunker barges under construction to ensure demand for LNG can be covered from 2020.The first of these will be in service from mid-2020.
Hapag-Lloyd will deploy three lines to connect its bunker station within the vessel to the bunker barge (ship-to-ship). These will consist of two liquid LNG lines and one for vapour return according to international standards for gas terminals. The connector between the pipes and the barge needs to be six inches. Mr Dyck says Hapag-Lloyd is close to making a bunker barge contract, but this has not yet been finalised.
Bunkering challenges include SIMOPS as outlined above, harmonising vessel and bunker barge manifolds and that the bunker procedure has to be approved by a recognised authority.
The ultra large container ship size and shape is also a challenge. Mr Dyck explains “The flat body length ends at the bunker station and the shape is changing here. It can be a problem for some bunker barges with connections at just one side to moor their vessel properly.”
Hapag-Lloyd is also carrying out some designs to replace current mooring equipment on deck so it can connect to LNG bunker barges.
Mr Dyck sums up “The project is important for the entire container ship industry and we want the whole maritime world to learn from it. We want to show it is possible to convert a vessel of this size. We have to prove it also makes economic sense to do a retrofit. We know a lot of people are looking to our project and have had to fight hard to find solutions.”
Hapag-Lloyd says the experience gathered from the conversion will pay off when it is considers building new vessels.
Depending on how the conversion goes, the carrier may retrofit more of its LNG-ready vessels.
Snapshot CV: Lutz-Michael Dyck (Hapag-Lloyd)
Lutz-Michael Dyck studied engineering and became a ship operations engineer. He has been with Hapag-Lloyd since 1991 and has been head of the ship inspection department, including the head of Hapag-Lloyd´s newbuild department, since 2005.