Article - When is bollard pull not really bollard pull?
Bollard pull – a term that is often misunderstood and misapplied even by the most seasoned tug industry professionals
One of the worst days that a designer or builder of a tug can have is when the bollard test does not meet expectations. After months, even years, of work and anticipation, this is an unwelcomed outcome for all involved in the design, construction, and operation of tugs.
So why does this happen? There are principally two reasons: the term ‘bollard pull’ is misapplied or misunderstood, even by seasoned professionals, and an overly simplistic prediction for bollard pull is used in the design stage. “The broad misuse of the term ‘bollard pull’ to mean ‘towpull’ often leads a well-meaning designer to a conclusion that is not fulfilled in service”, says Don MacPherson, technical director of US-headquartered performance prediction software company HydroComp.
This article is a must-read primer for anyone who needs to clarify the nature of bollard pull and understand what makes up a tug’s real ability to generate towing thrust.
Read the rest of story in the November/December issue of Intl. Tug & OSV!
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