Configure Now
Items in Your Cart0
0Items in Your Cart
Start building your packageShop Now
The video provided must clearly show the condition of the hull markings, all sea chests, inlets and discharges, rudders, pintles and propeller. Any points of corrosion or damage must be examined further internally and thickness testing may be required by the Surveyor.
Although thickness testing is not required for all UWILDs, the surveyor is very likely to request this data when an area of suspicion is located. The video above shows Deep Trekker's DTG3 equipped with a thickness gauge to perform these measurements.
The goal of having certified vessels versus suspended or non-certified vessels is to protect owners, employees, insurers and the companies who depend on the ships getting to their destinations. These classification societies know that credibility is the main source of business for them and they have no commercial interest in any side of the shipping industry.
The classification societies that implement these certifications for vessels are ABS, DNV-GL,Bureau Veritas, and Lloyd's Register, among others. ABS has a very comprehensive program that we have summarized below, other classification societies use similar criteria making it relevant to all owners and stakeholders of the shipping and offshore drilling industries. Mobile Offshore Drilling Units (MODUs) have very similar guidelines to vessels as well.
A full, thorough inspection similar to the 5 year inspection is required to become ABS certified. Once classed, ABS uses a Hull Inspection and Maintenance Program to make it easier for vessels to stay certified or become reclassified if a suspension takes place. The program is the most important part of a classification because it ensures long term sustainability of the vessel.
All inspections, above board and below the surface, are to be completed by the ABS certified inspector from the vessel's company with a ABS employed surveyor in attendance. The surveyor's responsibility is to ensure that all visuals of the vessel's hull, motors, ballast tanks and maintenance equipment are in operating condition. If an area is suspected of needing repair, the vessel can be placed on temporary suspension without losing certification, while a repair is made and reassessed by the inspector and surveyor once again.
The inspections occur annually, with additional focuses in three and five year time periods. These are referred to as Annual, Intermediate and 5 Year Inspection Intervals.
Deploy a ROV to perform quick, safe and affordable hull inspections
The following checklist outlines what submerged areas and components of a vessel should be inspected in an underwater survey of a ship. Operators are looking for defects, scratches, discolourations, dents and any other imperfections. All information should be recorded in an underwater inspection report.
This is the point where the surveyor does not have direct visualization of the plating and submerged structures. The only way that this inspection is approved is if there is two way communication from the inspector to the surveyor and all parts of the inspection are recorded. The time at which the diver or ROV inspection commences to the end of the inspection must be documented.
Dry docking is a complicated, expensive, and very time-consuming process. It involves taking the vessel to a designated facility, having it lifted from the water to allow access to the parts of the ship that are typically submerged underwater, and placed in the dry dock for maintenance, repairs, inspections, and other related activities. This process can range from a few days, to several weeks, or even months, depending on the scope of maintenance and repairs required.
Once out of the water, keel blocks are set into position, and lines are used to support the boat. This transition from the water to setting the vessel on the blocks is the most dangerous part of the process. If not supported properly, the vessel can tip, potentially causing extensive and costly damage, and even injury to workers.
Prior to dry docking, the ship must also be prepared by the crew, which involves removing equipment, cargo, and stores to reduce weight and ensure the safety of personnel and the ship during the process.
Once maintenance and repairs are completed, the ship must go through testing and certification to ensure compliance with safety regulations and class society requirements. This can involve sea trials, testing of equipment, and certification checks.
The frequency in which dry docking is required depends largely on the type of vessel, its operational profile, and regulatory requirements. For commercial vessels, such as container ships, bulk carriers, and oil tankers, dry docking is performed approximately every 2 to 5 years, depending on the ship's age, its trading patterns, and the classification society's rules.
For naval vessels, such as warships and submarines, dry docking is scheduled for maintenance, repairs, and equipment upgrades every 5 to 10 years, depending on the navy and the specific vessel class, but can be more frequent if the vessel has sustained damage or requires extensive modifications.
For pleasure crafts such as small recreational boats and yachts, dry docking is typically performed every 3 to 7 years.
Though the inspections are of the entire vessel, the tricky part for owners is the inspection of the hull and the interior of the liquid filled tanks because they are submerged. The hull of the ship is crucial to maintain to get the longest life cycle out of the ship. However, inspecting said hull is difficult. In the past, dry-docking has been performed to ensure thorough inspection of the hull. This process is extremely time consuming and expensive to perform.
Classification societies then began allowing Underwater Inspections in lieu of Dry Docking (UWILD). These UWILDs are the most scrutinized by the surveyor because the inspector is the only one with direct access to the hull in these situations. These have been performed by ABS certified divers traditionally. This method is still costly and places humans under the hull of a ship with no direct access out of the water. This is a dangerous scenario and is avoidable with the use of a ROV.
Operated via a handheld LCD screen controller, Deep Trekker ROVs empower users to take control of their underwater assets. Quick to deploy and battery operated, Deep Trekker vehicles allow for quick, easy and accurate UWILD operations. By using an ROV, human divers do not have to enter dangerous waters to conduct a routine inspection. Furthermore, the straightforward operation of Deep Trekker vehicles requires minimal personnel to get the job done quickly - allowing teams to save time and money.
The modular design of Deep Trekker ROVs allow users to conveniently add tools for enhancing inspections.Sonar options provide clear pictures for accurate inspections regardless of water turbidity. Using the Cygnus thickness gauge integration, operators can evaluate the thickness of ship hull’s and compartments to determine structural integrity. Finally, the laser scaler adds value by helping users estimate the size of any cracks, dents or defects.
Yearly inspections of the entire vessel, including the hull and prop are a key part of the passing or failing of necessary surveys. This process has in the past meant a full dry dock of the vessel or an UWILD (Underwater Inspection in Lieu of Drydocking) - both expensive and time consuming options. To assist in this costly and regulated process, surveyors may accept historical time stamped data, like that created by Deep Trekker ROVs, as part of the evaluation process.
The other "forgotten" advantage of having a ROV on staff instead of hiring a diver to perform the inspection is that you are able to have a inspection rehearsal or a quick inspection before the official, supervised one. The advantage of this is that if a problem is found or a possible area of contention with the surveyor, a solution could be implemented beforehand without having to pay for a diver twice. If a problem is not found until the surveyor is in attendance, this could result in a classification suspension or removal, which costs the vessels' owner tremendous amounts of money and time to get their unit back up and running.
As always, our team of experts is here to answer any questions you may have. If you’re ready to take the leap and get a vehicle of your own you can get your own customized quote today.
July 30th, 2021
Learn all about remotely operated vehicle pilots: how to become one,...
November 5th, 2024
Learn more about what sonar is and its many uses. Read...
December 23rd, 2021
ROVs and sonar can be used to inspect underwater structures such...