More. Of Everything. WIDENING of Containerships
Too young to die
It is often difficult to keep older boxships competitive in today’s market environment. Vessel even built in 2010 are currently scrapped due to non efficient operation. Panmax containerships for example were the backbone of container sea transport for more than 30 years. They were impressive vessels - at their time. With a length of 294m and a width of 32.2m, they filled the locks of the Panama Canal. They were equipped with a twin-screw steam turbine propulsion plant providing a speed of up to 28kn. These vessels once had a slot capacity of 3,000 TEU.
With technical advances, the Panmax ships were later optimized with a slot capacity of 5,000 TEU and a cost-efficient single screw 2-stroke diesel propulsion system. With this TEU-capacity and the restricted width, these vessels required a considerable volume of ballast water, which reduced the weight of cargo that could be carried.
Today these vessels still sail the seas. Other ship sizes followed and similar problems occur: Too small to trade efficiently - and too young to die. To ensure profitable operations of older fleet, REEDEREI NSB together with Technolog Hamburg have developed and successfully implemented a concept to widen ships that is the firstof its kind worldwide.
The WIDENING will increase the TEU capacity of a ship by 30%, and the IMO Energy Efficiency Design Index (EEDI) achieved will equal that of a new building and meet EEDI regulations as per 2025.
Results:More cargo/less ballast water, higher stability, steady operating costs.
Room for Improvement
Step 1: Preliminary Pocket Plan
NSB makes a feasibility study based on the following drawings:
• General Arrangement
• Capacity Plan
• Midship Section
The result is a preliminary pocket plan with a rough estimation of all relevant data to find a potential charter.
Step 2: Initial Design
The next step is an initial design by NSB and the engineering partner. This study contains longitudinal strength, damage and intact stability of the widened vessel based on the modified hull lines of the original vessel. Speed predictions have to be made with the potential theory software. The result is a pocket plan with all relevant data to find a charter.
Step 3: Basic Design
This step contains all necessary strength, hydrostatic and hydrodynamic calculations and design work. The outcome is a complete set of structural key drawings, for approval by the relevant class society. As it is a major conversion, several meetings and discussions are necessary with the class and the relevant flag state (service included). This set of drawings with a detailed conversion specification is the basis to find the right shipyard with regard to
costs and capability.
Step 4: Building Supervision at Shipyard
This step includes all building supervision by our team at shipyard. A project coordinator based in our head office is appointed for the job. He performs his task in close coordination with our local team at shipyard as soon as the right shipyard is chosen until finalization of all widening works and delivery of the vessel to the owner. Our team on site permanently supervises the works of the shipyard workers regarding quality aspects and performs the final acceptance of the construction stages. In order to execute the extensive steel and modification works, several meetings and discussions on shipyard site are necessary as well as close coordination with class.