Full Range of 7800 DWT DF Multi-purpose Vessel Perfect Delivery!

Recently, the third vessel of the 7,800 DWT DF multi-purpose vessel constructed by Wuhu Shipyard for Finnish shipowner Langh Ship Oy Ab officially set off "home", opening the journey to conquer the ocean, so far, the construction task for this series of multi-purpose vessel has been successfully completed and delivered.

Ship Form Parame

This vessel is a new type of 7800 DWT multi-purpose vessel with a number of advanced features. She is classified in the DNV classification society and flies the Portuguese flag and has navigability in unlimited navigable areas. As an ice strengthening type of vessel, it is driven by a single propeller and serves all regions of the globe. The design uses a double shell structure with continuous deck, lift off hatch cover and grain bulkhead to accommodate diverse transportation needs. The propulsion machinery is located at the stern of the vessel, while the accommodation is also located there, providing the vessel with good navigational performance and operating convenience.

In terms of power system, the vessel's main engine design uses LNG (DF) as fuel, while compatible with light fuel oil with a sulphur content of only 0.1% and Marine light diesel, ensuring a viscosity of between 3 and 6 cst at 40 °C. The engine meets IMO Tier II in fuel mode and fulfilling the IMO Tier III in gas mode. The auxiliary engines also meet the IMO Tier II emission standards when using Marine light diesel and light fuel modes, and meet the Tier III emission requirements in SCR mode, reflecting the great importance of environmental protection.

The propulsion system consists of a medium-speed four stroke diesel engine, a gear box, CPP, a bow thruster with 600KW and a PTO with 660KW. In addition, she has two main generators with 500KW each and a harbor and emergency generator with 120KW. Ensure the vessel's power supply and emergency needs, demonstrating the safety of the vessel's design and performance.

Construction Process

Steel Cutting

Keel Laying

Launching

01 Reasonable planning, ensure efficiency priority

The construction experience of the first vessel is covered to the subsequent vessels, and the general assembly mode is optimized from the original 12 general sections to 5 general sections (including the accommodation general section), so as to realize the modular construction of the cargo hold, the aircraft hold, the bow and the accommodation construction area, the two lines constructed simultaneously, and the construction cycle of the slipway is reduced.

02 Innovative management, strictly adhere to the bottom line of safety

The project team adopts a points positive and negative assessment mechanism to consolidate the main responsibility of safety, ensure that each link is implemented in place, all staff participate in safety management, strictly observe the safety bottom line, and the control degree of the safety process of the whole series of vessels reaches the level of five stars.

03Optimize the block assembly and improve the launching integrity

The block assembly carries out accurate site measurement and positioning in the early stage to realize the general assembly of the front and back of the general section of the cargo hold. The use of a unified center line and baseline for positioning, and the removal of residual after welding, saving the crane unhook time, reduce the scaffolding and overhead car during the residual cutting process. Meanwhile, the integrity of the cabin of the engine room and the main section of the bow has been achieved as far as possible, which saves time for the delivery of the engine room and the coating of the outer plate in the later stage of the slipway and shorts its cycle. The integrity and data collection of the general section of the engine room provide a strong basis for the subsequent delivery of the vessel on the general platform.

"By summarizing the problems encountered in the hoisting process of the LNG tank of the first vessel, after communicating with the design team, the obstacle structure of the S11PS block was removed in advance, and the base installation process was fully prepared, and the hoisting was successfully realized in place. During the sea trials, we complete the fuel and gas trials in one go."

——Construction manager

Design Highlights

In order to ensure the economic benefits of the vessel, "7800 series vessels have separated an LNG tank between the engine room and the cargo hold, and increased safety measures such as forward ventilation, oxygen monitoring and dangerous gas detection, which can greatly improve the utilization efficiency of the cargo hold." According to the chief designer of the vessel, "This vessel fully combined with the previous LNG design experience, the traditional self-pressurization into variable frequency control pressurization, all indicators meet the IGF CODE requirements, LNG pressure, temperature, flow can achieve accurate control, can reduce operating costs." Commendably, the 7800DWT dual fuel multi-purpose vessel has eliminated the structural bracket design through calculation during the design phase, effectively avoiding the transmission of structural vibration sources through the bracket to the damped and floating floor. This design significantly interrupts the propagation of the vibration source. The test results show that the vibration noise level of the ship is far better than the requirements of ISO 33741 standard.

That’s another type of vessel has been added to the list of LNG dual-fuel ships built by Wuhu Shipyard. In the future, Wuhu Shipyard will continue to build core competitiveness, consolidate management results, constantly promote product transformation and upgrading, and introduce more high-quality ships to the market.