Underwater inspections of vessels  are done on a regular base in the harbours of Antwerp, Flushing, Rotterdam, Terneuzen, Zeebrugge or Gent.  With a properly applied underwater inspection, shipping companies avoid costly underwater repairs.

 

So, what is involved in underwater inspection of vessels?

Aside is container vessel berthed of about 350 meters long. Your assignment: perform an underwater inspection, tell what’s happening. Video images and audio are recorded via the camera and the speaker in your helmet. You have contact with the dive supervisor, who is above water and will record your findings. Piece of cake right ? Sometimes, not always…

You’re about to inspect a steel area of a few football fields. Swimming upside down, or on your side, with your dive helmet not too far from the ship’s  hull.  There is a lot of noise because a generator is roaring in the ship.  As a diving team you work closely together. There are many things involved  to perform an IWS  in a good and safe way.

 

Underwater propellor and rudder inspection is not like this!                    photo credits:  Van der Velden Marine Systems

 

Underwater inspection can be divided into 3 parts: preparation, performing and reporting.

Preparation of underwater inspections:


First, something about the term in water survey. This can be an Uwild, or a grounding survey. There are several types of surveys. An Uwild is an alternative to avoid dry dock inspection.

Imaging a ship runs into the port of Antwerp and an inwater survey has to be carried out.
The first concern is to find a dive company that performs the work in a good way at a good price. This service supplier must be qualified according IACS certification bodies to be able to carry out water surveys. The qualification process: qualification of divers and materials, competence documents, training plans, procedures and guidelines, etc.

 

Performing of underwater inspections:


A surveyor of a qualifying body is present during the inspection. To perform an acceptable inspection, sufficient underwater visibility is needed. And safety measures are important. Risks assessment and dive permits must be applied in the right way.

 

checking of sea-chest during underwater inspection
Checking of sea-chest during underwater inspection

 

The diver inspects the vessel for damage by grounding, ice damage, collisions and cracks etc. He checks bio-fouling, coating and corrosion levels. Anodes are assessed, and the seachests are checked for sufficient waterflow. Possibly there are pintle clearance, and stern bush measurements to be taken. Video and photos are important in underwater inspections. Close ups are made when details need to be visible. And the determination of corrosion pitting or cavitation. Damages are securely measured and reported.

 

underwater inspection
Damage found during propellor inspection

 

Video and photos are important in underwater inspections. Close ups are made when details need to be visible. And the determination of corrosion pitting or cavitation. Damages are securely measured.

 

Cavitation damage found during underwater rudder inspection

 

Bending and cracking of blade tip during underwater propellor inspection

 

Reporting, and results delivery of  underwater inspections.

This is where you as a customer paid for. Expecting a clear report with easy-to-understand information. Completed with pictures and video footage.
You want to know the status per component. So you can take the necessary measures in case of damage or for future maintenance.

Pro-Sea  develops standard underwater inspection methods for your vessels. These are used for every inspection, wherever your ship is located in the world. And whichever dive company is performing the survey. This includes a template that contains all the parts listed,with timestamps when they are inspected. This template can be  supplemented with dry dock photos and general arrangement drawings.

Video’s which are made during the inspections, can be real time viewed by the surveyor on mobile devices. These video’s are also accessible over the internet to be viewed by several parties like ship owner, surveyor and dive contractor.

 

Report structure with links to video files

 

Inspection criteria

A reporting template contains the following features:

  • Particulars of the ship, hull drawings, dry dock photos;
  • Project info;
  • Per component a timestamp with links to video and photos;
  • Links to criteria, permits, standards;
  • Connection with biofouling records;
  • Propellor sheets to mark anamalies.
  • Reporting templates can be adapted for hull management software of shipowners.

Viewing, delivery and storage of inspection results:

  • Real time video viewing by dive supervisor, surveyor, ship owner and dive contractor over the internet.
  • Multi media reports send by file transfer service or cloud storage.

 

 

About Zeeland Underwater Work:

Diving company ZEEUW B.V. is situated in Zeeland in the Netherlands. We are small and flexible, and therefore able to help our clients with their underwater challenges in an efficient way. We carry out diving work in the area Rotterdam, Moerdijk, Antwerpen, Gent, Terneuzen, Vlissingen. And beyond. ZEEUW employees completed many assignments worldwide in inspection work or other diving activities.

ZEEUW BV has fully equipped diving vans. We handle all kinds of underwater work. A team of experienced divers, inspection engineers and other professionals are at your service. We deliver the following services:

  • Underwater inspections of ships, quay walls, foundations, construction pits.
  • Underwater welding and cutting.
  • Sealing of seachests or other hull apertures.
  • Ultrasonic wall thickness measurements.
  • Biofouling, coating and corrosion inspections.
  • General underwater inspection, repair and maintenance work.

 

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