The Immeasurable Value of Underwater Inspections


Published Sep 5, 2016 6:05 AM by The Maritime Executive

Building upon conventional technical skills and know-how while also taking advantage of the latest technology, Hydrex offers a unique hull monitoring service to its customers. This gives shipowners total control of their ship's hull condition and consequently its performance, with only a minimum of work on their part. Underwater inspections represent a small investment and, if properly done, have the potential to save an owner a great deal of money.

Competent underwater inspections, particularly if carried out regularly can detect: 

•    Problems with the propeller such as bent or damaged blades (which can put undue strain on bearings), roughness due to fouling, cavitation damage or bad polishing which can reduce the propeller’s efficiency.
•    Anodes which have wasted away, rendering the cathodic protection system unworkable, leading to corrosion and added hull friction
•    Hull cracks or other damage which, if not rapidly arrested, can worsen and increase the cost of any subsequent repair
•    Ropes inside the stern tube assembly which may cause seal problems if neglect
•    Leaking stern tube or thruster seals which can cause an environmental problem in port and lead to costly changes to a ship’s schedule if not caught quickly and repaired.
•    Clogged sea chest grids (preventing proper cooling of the ship’s engines), or loose or damaged grids.
•    Loose or broken grids on thruster tunnels which can result in damage to thruster propellers
•    Damaged, bent, broken or detached bilge keels which again can become much worse if not caught early.
•    A damaged rudder which will continue to deteriorate if not addressed rapidly, resulting in the need for much more costly repairs and representing a safety hazard in extreme cases.

Regular inspections carried out by competent divers and followed by comprehensive and accurate reports can detect any of these or other problems so that they can be corrected early and prevent more costly repairs and further damage. Because we have over 40 year experience in both maintenance and repair services, we can carry out any required follow up repair very fast without any unnecessary loss of time. Planning in a new date is not needed as all our diver/technicians are skilled to perform the repair work as well.

 If the damage found during an inspection can be anticipated, the required equipment can be mobilized in advance. Otherwise it can be transported to the location of the vessel immediately from one of our fast response centers where a large stock is available for our teams at all times.

 This was demonstrated last month when a rope guard had come loose, which was revealed during an underwater inspection. The Hydrex team secured the rope guard without any delay for the owner.

Inspections before drydocking

There is another important way for underwater inspections to be used to save costs. A thorough inspection carried out a week or two before a ship is due to go to drydock can save a great deal of money in drydock. An accurate estimate of work required can lead to efficient scheduling. If thrusters are to be repaired in drydock they can be removed prior to the ship’s drydocking and can be repaired and ready for reinstallation when the ship is in drydock, rather than waiting until the docking to find out and then having to extend time in drydock in order to repair and replace the thruster.

An accurate report on the state of the rudder can lead to effective repair and recoating of the rudder so that it does not suffer further damage.

The all-too-frequent scenario of a low estimate for drydocking which grows exponentially once the drydock gate has closed and the ship is out of the water can thus be avoided.

Easy to combine with other operations

Because an underwater inspection is a small operation, it can be combined with one or more other operations very easily. This can be another maintenance operation like a propeller buffing or any type of repair job. By doing this, the shipowner is saved the hassle and cost of multiple mobilizations and possible delays to his vessel’s sailing schedule.

Speed is of the essence

Hydrex diver/technicians can carry out inspections underwater and on-site very swiftly without disturbing the vessel’s sailing schedule. A good example of this are the inspections of the bow thrusters carried out recently on two ferries in Calais. Because of the nature of these vessels, the time frame was extremely short. Both times all three bow thrusters needed to be inspected in the small window available. A change to the schedule was out of the question as it would do great harm to the reputation of the owner.

We have always put great effort into minimizing the impact of our services to the schedule of a vessel. Our teams are trained to adapt themselves to the agenda of the ship and not the other way around.

The products and services herein described in this press release are not endorsed by The Maritime Executive.