PIANC speed checks to aid designers
Ascertaining accurate berthing loads forms the backbone of successful mooring aid design
PIANC - the global organisation providing guidance for sustainable infrastructure for ports – is part way through a study of vessel approach speeds that will be invaluable for fender designers.
If speeds are underestimated, the lateral force-resisting system may be undersized, leading to recurring maintenance problems and a shorter lifespan of the structure or fender. Overestimation of approach speeds may lead to unnecessary capital costs in construction.
Current “rule of thumb” approach speeds tend to be based on data which is quite old and its suitability for current vessels and facilities may be questionable.
Elizabeth C Burkhart, regional manager and director of Federal Programs for Collins Engineers in Fairfax, Virginia, says the PIANC Marine Commission Working Group 145 is aiming to produce a report that provides data on actual recorded vessel approaches under a range of environmental conditions.
“This will provide clear guidance to designers in the selection of appropriate design approach speeds. The Working Group is focusing on larger ships for which quantitative berthing velocity data can be obtained.
“These ships include cruise ships, containerships over 30,000 tonnes deadweight, and bulk carriers and tankers over 100,000 tonnes deadweight. Port facilities from around the world have agreed to participate in the study, including several in the US, Japan, and Europe.
“Currently, the Working Group is collecting information regarding which facilities, shipping companies, or other agencies already collect approach speed data in day-to-day operations.
“Data provided to the committee will be pooled for analysis with regard to the size and type of the ship, as well as the level of sheltering afforded by site topography and bathymetry,” she says.
All collected data will be kept confidential and will be unattributed to specific ports in the analysis and reporting. The Working Group anticipates publication of the study in 2013.
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