Offshore
Figure 4: Typical View During the Exit Stage
About the Authors Marc Beerendonk is Lead Engineer and Naval Architect at NMA Maritime and Offshore Contractors. He is responsible for transportation related engineering and naval architecture. Capt. Nigel Groves is Marine Superintendent at Noble Denton Consultants Limited. He is responsible for the planning and execution of loadouts, transportations and float-overs. Richard Palmer is Principal Engineer and has worked at Noble Denton Consultants Limited for 10 years. He is responsible for transportation related engineering and naval architecture.
THE SPECIALISTS IN MARITIME SECURITY
Securewest International is a worldwide specialist maritime provider of security services to commercial, cruise, government shipping and port facilities. Security Officers are all former armed forces personnel maritime trained, providing security services worldwide on short or long term contract. Maritime Security Officers Cruise Ship Qualified Ship Security Officers Approved SSAS monitoring and management ISPS/MTSA Assessments, Plans Drills and Exercises MCA and DNV/MARAD Approved ISPS/MTSA Training courses
timetres clearance between the side of the vessel hull and the jacket pins. Figure 4 shows the Bunga Raya E topside on the Kang Sheng Kou entering the jacket slot The Rong Doi installation was planned as a conventional installation although the procedures used were based on those originally written for Bunga Raya A with one major difference. The jacket leg fenders were dispensed with and the final clearance between the vessels side fendering and jacket leg reduced to 100mm, 50mm on either side. The installation demonstrated one of the real advantages of DP installations. With a planned installation period of 14 hours (subsequently reduced to 12 hours) the allowable reference period was only 24 hours. On arriving at the location the weather conditions were unsuitable and few immediate windows were forecast. After discussions onboard with the charterer and marine warranty surveyor, approval was given to proceed with a reduced weather window subject to the operation being fully conducted on DP. The Rong Doi topside was installed in less than three hours on DP alone; the time was measured from vessel entry to exit of the jacket.
A viable alternative
nificant when compared to a lifted installation or mooring assisted floatover. Operational experience of the vessel's DP capabilities and also the competence of the vessel crew have increased with each successive project allowing for progressive savings to be made. A further five float-over contracts have been secured for these vessels that will be performed using their DP capabilities.
SM
SECUREWEST INTERNATIONAL
Maritime Security Specialists since 1987
+44 (0)1548 856001 +1 757 461 4343 24 hour service: +1 757 461 4343 info@securewest.com www.securewest.com
UK Office: USA Office:
Principal offices in the UK, USA and Singapore
Using a DP vessel for a float-over operation is a relatively new technique and a very valuable alternative to the traditional mooring-assisted float-overs. The additional advantages of relatively high-speed transports and shorter exposure time means less probability for the environment to pose a threat to safety. Additionally the cost savings are sigAugust 2008 www.marinelink.com 43