An introduction to LP fenders
Low pressure (LP) pneumatic fenders have been in use in the offshore and port services industries for over 40 years, and have been utilized extensively for both large and small scale port operations and ship-to-ship transfers, including successful use in the Exxon Valdez oils-spill clean-up.
LP fenders are used by the UK and US Navies and the US Coast Guard, as well as by commercial organizations such as Svitzer, Fuji Trading, BP and Total Marine for a number of applications including STS transfers, offshore mooring, jetty mooring, and salvage and cargo recovery.
These fenders can be tailored to meet customer performance requirements, across a broad range of diameter and length, and are selected not only for their robustness, durability and high performance, but also for their unique, light-weight design which allows for ease of handling, packing and transportation and is not practicable with other types of fender system. This combination of attributes means that the LP fenders can be deployed quickly and efficiently via air, land or sea, and as such it is ideal for emergency ship-to-ship transfer scenarios. For example, similar energy absorption performance can be obtained with an LP fender that is a fraction of the weight of an equivalent High Pressure (HP) pneumatic fender, even when the HP fender chain and tire net is not included.
It is also possible, unlike other forms of fendering, to roll up the LP fender and transport to the required operational location. Moreover, long-term storage is made possible due to the use of robust aluminum packing cases, which can be lifted with commonly available mechanical handling equipment such as forklift trucks and cranes.
Manufacture & implementation
LP fenders are cur rently being manufactured at Dunlop GRG’s fabrications facility in Manchester, UK, for an existing requirement for emergency Ship-to-Ship operations of the world’s largest operating LNG tankers.
Comprehensive product support services include working closely with the client, a globally renowned salvage operator, offering them full support including an exhaustive training schedule covering the use and operation of LP fenders. Terra Firma training has already been conducted, consisting of general fender handling techniques; unpacking and unrolling procedures, methods for packing and rerolling, inflation of the fender units using the custom-built, heavy-duty diesel-driven blower unit, and refurbishment and general maintenance (see Figure 1). Moreover, as part as an ongoing collaborative training program, further Prata Neptunia training is planned to practice various deployment scenarios to allow for the most efficient and rapid response to any demand of emergency transfer requirement.
Furthermore, continuous dialogue with the client has been maintained to ensure all specific design and associated contract requirements are met in order to suit all operational needs. An example of this is the custom-built end closure plate; the main interface between the end-user and the fender unit. It has been specifically requested that this component include secondary rigging points, increased lug clearances and a continuous handling ring for manoeuvring and manually handling the fender when floating (Figure 1). It has been possible to meet these requirements in the short timescale allowed during the manufacture of the LP units whilst, through the use of 3D CAD and finite element analysis, able to ensure optimum performance of the assembly design.
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