Client consultation and a full internal technical review have prompted Vestdavit to refine lifting speed vs power options available across its entire davits range. The boat handling specialist has been focusing on how best to optimize equipment hoisting and lowering speeds within available power constraints, or reduce power while maintaining speeds.
“Optimizing the handling speed/power balance is a precondition for our equipment, but customers have different priorities,” says Thomas Nordin, the Vestdavit Senior Project Engineer with responsibility for the review. “For some, market conditions have made it imperative to save power. Others are focusing on achieving higher hoisting speeds because their priority is the safety gain of lifting boats more quickly clear of the waves. Customers have been asking us for the same handling speeds with lower power consumption, or higher handling speeds with no increase in power.”
Where accumulators are used to store the hydraulic power used during davit lifting and lowering, increasing the hoisting speed may only be a matter of boosting accumulator specifications, Nordin explains. If the customer’s priority is to save power, the capacity of the HPU (hydraulic power unit) can simply be reduced for lower speed operations.
“The Vestdavit view is that the performance standards formulated for davits by IMO include operating speed guidance that we don’t think is optimal for safety, particularly when lifting boats clear in rough seas,” Nordin says. “Customers are asking us for higher speed operations using the same power, particularly in the offshore and naval markets.”
In the case of already operational davits, market conditions are encouraging customers to seek power consumption savings while maintaining existing speeds, he adds. “In this case, options could include retrofitting accumulators or, where accumulators are already installed, assessing the need for additional valves or valve capacity to improve oil flow
. Space can be a constraint if the HPU needs a larger tank volume, so it is always a case of precise calculations and close consultation with our customers.”
Given the precise nature of the speed/power trade-off, Nordin says a generic solution is not appropriate. Vestdavit is trialling equipment at its own test facilities in Bergen and Poland
to support the calculations covering available speed/power gains for both newbuildings and retrofit solutions, he says.