Wednesday, November 30, 2016

Specialist Propeller Engineers Warn Ice Damage to Freight and Container Ships Has Started Early

Cold Winter Offers Likelihood of Vessel Repairs in Months to Come
Shipping News Feature
WORLDWIDE – Specialist propeller repairers Hydrex Underwater Technology has already registered an increase in the number of freight and container vessels experiencing propeller damage this year as a result of ice. The company states that, whilst the winter months usually result in an increase in propeller repairs, this normally occurs between January and March, however the company reports this year it has already responded to call outs to inspect of a number of vessels suffering with propellers broken or damaged by ice.

The Hydrex inspection and repair teams have deployed several times this month already. To repair bent blades, Hydrex deploys its cold straightening equipment and a dive team so as to repair the blades without disruption to cargo operations and the vessel’s ongoing schedule. Failing that, the damaged area of the blade can be cropped and ground down to restore hydrodynamic balance.

Initially a detailed underwater inspection is carried out to assess the extent of the damage and to calculate the ideal cutting line. The blade is then cut underwater, ground and polished using Hydrex’s patented blade repair tool. Dave Bleyenberg, Hydrex Production Executive, explained:

“We often encounter blades that have been severely damaged, chipped or completely broken off during ice navigation. In most instances, they can still be repaired in-situ by grinding and cropping the blades. If five-bladed propellers are damaged, the repair is more complex as extensive calculations have to be made to take the right amount off each blade to restore balance and prevent vibration.”

Pic: A Hydrex diver repairs a propellor with cold straightening equipment.