Integrity in a New Era
As the first containerships officially credited with capacities topping 8,000-TEU. the series of newbuilds ordered at the start of the year by Vancouver-based Seaspan for long-term charter to China Shipping Group embodies a design, which has been the subject of the most thorough structural analysis.
The boxship sector has always been characterized by a propensity for driving developments to the limits of technical possibility. Its outstanding structural safety record over the years is testament to the industry's unflagging efforts to ensure long-term vessel integrity in combination with advancing scale.
The considered technical approach expressed in current projects in the 8,000-9,000-TEU category, the focus of a major investment drive by the industry this year, demonstrates that the nascent generation of linehaul vessels represents more than an extrapolation of design and engineering systems proven at a smaller unit scale.
The five 8,100-TEU post-Panamax vessels contracted by Seaspan from Samsung Heavy Industries, will rank among the largest containerships ever to have been built in Asia. It is understood that two of the newbuildings have since been sold to Danaos Shipping of Greece, and that one of the series will now be owned outright by China Shipping Group. Seaspan, part of the Washington Marine Group, was also linked with earlier studies at Samsung into a 9,200-TEU vessel design, in a project involving a European operator.
Powered and formed for a laden speed just under 26- knots, the 8,100-TEU design has been dimensioned for 19 forty-foot bays in the hold and 20 above deck, with the weatherdeck stow encompassing 17 stacks across in a maximum of seven tiers.
A lashing bridge arrangement is to be adopted in the interests of improved cargo security and turnaround time, while the hatch covers have been specified with four panels instead of the usual three to promote con- taine r - h a n - dling flexibility.
Shipment scope will be enhanced by provision for up to 700-FEU integral, aircooled type refrigerated boxes.
Lloyd's Register has undertaken a comprehensive structural analysis of the vessel type as part of the plan approval process from the society's Busan office in South Korea. It takes the view that a robust and proven structural analysis methodology is crucial with ships of this size. The extensive list of class descriptions under which the new series will be built include the ShipRight notations SDA(structural design assessment), FDA(fatigue design assessment), and CM(condition monitoring).
The primary structure has been assessed using a full ship model created by Samsung and analyzed by LR.
Fine mesh models of the critical hatch coaming and upper deck details have been investigated. The aft end of the hatch coaming has been tapered into the upper deck instead of connected to the front of the deck house, as is common on containerships, in a bid to ensure superior fatigue performance. The primary structure of the fore part of the ship has been reinforced following a bow plunging analysis carried out by LR, and out of consideration of the high loads imposed when large, fast containerships are driven through heavy seas. As studies have indicated the susceptibility of such vessels to stern slamming when operating at reduced speeds, the 8,100-TEU type also incorporates strengthening of the stern.
Given the very substantial breadth, transverse strength has commanded greater attention than that typically required for Panamax vessels. Large angles of roll have been examined as part of the structural analysis, and some additional reinforcement was deemed necessary.
The manner in which the design process has been managed is an evolution of previous projects. All design comments have been exchanged between LR, Seaspan and Samsung by e-mail, and the classification body reports that a commitment to transparency by all parties has enabled design issues to be quickly identified and resolved. Such an approach is pertinent to the development of even larger containerships under design by the South Korean builder.
Other stories from October 2003 issue
- Blount Delivers 130-ft. CAT page: 10
- 10,850-HP AHTS Joins Seabulk Offshore Fleet page: 11
- Sibu: Ferries for Asia page: 12
- Grimaldi-Naples Launches RoRo Grande Amburgo page: 14
- U.S. Territorial Sea and Other Lines in the Water page: 16
- Varian, PARC Receive Security System Funding page: 22
- Wartsila to Concentrate on Marine and Service page: 22
- LPG Tanker Repaired, Modernized and Converted page: 24
- Financier Calls for a New Approach on Standards page: 26
- Bollinger Completes Major Conversion of Ned Ferry page: 27
- SENESCO Becomes Senesco Marine page: 28
- SPS Overlay: Fix Steel Decks Faster page: 30
- Team UMC Helps Navy Ship With Innovative VSP Switch page: 33
- B+V Reports Busy Repair Docks in August page: 34
- Extensive Fantasy Refurb page: 35
- New Tooling, Training Solutions Target Shipbuilding page: 36
- Dubai Drydocks Completes Conversions page: 38
- Solutions in Panama page: 38
- Insurer Not Liable for Repairs Beyond Warranty page: 39
- The Evolution of Marine Painting page: 40
- Grand Bahama Shipyard Receives Quality Mark page: 41
- Brunei Develops New Coating System page: 42
- New Marine Technology Set for Debut at Amsterdam Exhibition EURO PORT 2003 page: 46
- Gesilco: Built to last page: 48
- Radio Holland page: 51
- Nauticast AG page: 51
- Autoship Continues To Make Waves page: 54
- Maxsurf Links with ShipConstructor page: 54
- Provide Solutions Introduces 3D Laser Scanning page: 56
- Nupas-Cadmatic Offers Versatile Shipbuilding Applications page: 57
- ABS President Discusses Bulk Carrier Safety page: 58
- Integrity in a New Era page: 60
- More Power to the Dredgermen page: 60
- CNG Carrier One Step Closer page: 61
- JJMA on LSC Team page: 63
- A Legacy Spanning Three Generations page: 64
- World Maritime Tech Exhibition Set for San Francisco page: 66
- Juniper's Hinges Go Low and High page: 68
- Long Beach Pilots Go Far Out With New Boat page: 72
- Urethane's Products Are Thick-Skinned page: 76
- SES Launches "Smart" Solution page: 77
- BP's Shafts are Oil-Free page: 80
- Vosta Debuts Universal MK3 Bow Coupling Installation page: 81
- Safety Not Optional page: 81
- VENTIQ Offers Innovative Approach to Cargo Tank Venting page: 82
- Walform M Plus: Leak Free pipe connections page: 82
- Employees' Invention Improves Valve Process page: 83
- New High-Pressure Pumps page: 83