Underwater Propeller Blade Straightening

(Press Release)
Wednesday, June 13, 2012

With all five blades of its propeller severely bent, a 290-meter container vessel needed a fast, on-site solution to restore the propeller’s balance and efficiency. Hydrex diver/technicians are trained to carry out repairs underwater in the shortest possible time frame and a team was therefore mobilized to the ship’s location in Diego Garcia in the British Indian Ocean Territory to perform a cold straightening of the blades.

After the equipment arrived at the vessel’s location, the divers installed a monitoring station on a workboat and made all the required preparations. The workboat was then positioned next to the vessel and the team leader went on board to discuss the details of the operation with the captain and the chief engineer of the ship and to go over the safety procedures.

Next the team started the underwater operation with a detailed underwater survey of the damaged propeller blades. Because fouling was present on the blades, the divers carried out a polishing to be able to inspect the blades for stress fractures and cracks. The inspection revealed that the five blades had suffered multiple deformations along the trailing edges and that there were stress fractures and nicks in the same areas. Cracks were also found up to 15 mm deep.

Part of the team started the repair part of the underwater operation with grinding work on the blades to remove the cracks. Once this was done the locations were smoothed to create a hydrodynamic profile on the trailing edges. Meanwhile, the rest of the team also entered the water and prepared the in-house developed hydraulic cold straightening machine for the straightening operation. The divers carefully positioned the machine over the bends of the trailing edges of the first blade and, in close communication with the team leader on the work boat, applied pressure to return the bent blade to its original state. This procedure was then successfully repeated for the other four blades.

When the divers had also completed all grinding and polishing repairs on all identified cracks and gouges of the blades, they made a full inspection of the newly modified condition of the blades for the attending ABS surveyor and the captain of the vessel. With all parties involved satisfied, the divers demobilized their equipment and returned home.

The operation restored the balance and the efficiency of the propeller. By carrying out the straightening on-site and underwater, Hydrex avoided a costly and time consuming drydock visit for the owner of the vessel. 

Maritime Reporter September 2015 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

People & Company News

Woman Medevaced from Cruise Ship off SouthWest Pass

The Coast Guard medevaced a 50-year-old woman from a cruise ship 225 miles southeast of Southwest Pass, Saturday. Watchstanders at Coast Guard District 8 received a call at approximately 9 a.

Demands for Icebreaker Tours Spiral

Plans to terminate commercial tours to the North Pole on the nuclear-powered icebreakers of the Atomflot company in 2016 have surged the demand for these tours.

New Chair for Townsville Port

The Palaszczuk Government has appointed one of Queensland’s most respected businesswomen, Renita Garard as the new Chair of the Port of Townsville. In a statement released earlier today,

Ship Repair & Conversion

S. Korea Keeps Top Spot in Shipbuilding Beating China, Japan in Q3

South Korean shipbuilders have ranked first in the world outpacing Chinese and Japanese rivals in terms of new orders in the third quarter of the year, reports

MN 100: The General Ship Repair Corporation

The General Ship Repair Corporation, a fixture on the Baltimore, Maryland waterfront for nearly a century since its founding by Charles “Buck” Lynch in 1924, has

MARAD to Fund Study on LNG Conversions

MARAD provides funding to further study LNG as marine fuel for containerships The U.S. Maritime Administration (MARAD) announced it has entered a $900,000 cooperative


Debris Appears to Belong to Cargo Ship Missing in Bahamas

Search and rescue teams on Sunday located debris which appeared to belong to the cargo ship El Faro that went missing in the eye of Hurricane Joaquin with 33 mostly American crew members aboard,

Woman Medevaced from Cruise Ship off SouthWest Pass

The Coast Guard medevaced a 50-year-old woman from a cruise ship 225 miles southeast of Southwest Pass, Saturday. Watchstanders at Coast Guard District 8 received a call at approximately 9 a.

Life Ring Found from Cargo Ship Missing off Bahamas

A life ring has been found from the cargo ship El Faro, which went missing on Thursday after sailing through Hurricane Joaquin in the Bahamas, the U.S. Coast Guard said on Twitter on Saturday.

Underwater Engineering

KEP Marine Releases Video Recording Products

KEP Marine releases today the innovative network video recording system and new HD cameras. The plug-and-play KVNR-8001 network video recording system is

Kruszewski Joins Braemar Engineering

Braemar Engineering, the specialist maritime engineering consultancy, today announced the appointment of Chis Kruszewski to the role of Senior Electrical Engineer in its Offshore,

Tuco Debuts New Dive and ROV Support Boats

Denmark’s Tuco Marine has revealed its new dive support and ROV Support boat designs. The two new vessels complement the designer’s range of ProZero workboats and

Maritime Careers / Shipboard Positions Maritime Contracts Maritime Security Maritime Standards Navigation Offshore Oil Pipelines Port Authority Ship Repair Ship Simulators
rss | archive | history | articles | privacy | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.1500 sec (7 req/sec)