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Onboard hull-cleaning ROV set to save huge fuel costs

Wed 12 Jul 2017 by Rebecca Moore

Onboard hull-cleaning ROV set to save huge fuel costs
A hull-cleaning ROV on board a cruise ship would allow operators to bypass the logistics of arranging third party cleaning

The first hull-cleaning ROV onboard a cruise ship has been trialled and is poised to be a game-changer. The company behind it has spoken to PST

A remotely operated vehicle (ROV) that can clean hulls is being considered for the first time for installation onboard newbuild cruise ships. The follows a trial in December 2016 and conceptual design work with two prominent European shipyards.

One of the key players involved in the project is GAC EnvironHull, which is behind the HullWiper ROV. Its solution uses adjustable-pressure water jets instead of brushes to remove marine fouling from hulls but this project challenged the company to take its concept one step further.

It was at SMM exhibition in Hamburg in 2014 that “we came up with the idea of putting HullWiper onboard newly-built LNG carriers,” GAC EnvironHull managing director Simon Doran recalled. “That led us to the conclusion that it would have obvious appeal for time-sensitive cruise ships – and we were then approached by a European shipyard.”

As part of the project, GAC conducted studies with selected cruise lines and concluded that using an ROV would mean they could clean the hull more often and  potentially save each vessel around US$1 million in fuel per year, depending on bunkers costs at the time.

The proposal is for HullWiper to be installed in the auxiliary machines area of the engineroom onboard ships, giving the option of launching it either port or starboard side, depending on conditions.

Mr Doran said there were many benefits for cruise ships and he highlighted the time-saving and flexibility it brings. “It’s a time-critical business,” he said. “Having an ROV permanently onboard means that a cruise ship does not have to wait in port for the solution to arrive – they can clean as and when convenient; starting and stopping when they want.”

Greater control and autonomy

He said that the onboard ROV also gives greater control over the hull coating, allowing vessels to determine their own efficacy by cleaning as and when they want without having to arrange all the logistics for a third-party hull cleaning, such as the divers required for a traditional brush cleaning. “It’s a solution that eliminates the need for major and costly human logistics,” Mr Doran summed up.

Having the device onboard brings all the benefits of a standard HullWiper service solution when the ROV would be brought to a port to clean the hull while the ship is at a berth. It is low-risk, he said, and with no divers needed, it is safer than other methods and there can be no human error.

Cleaning can be carried out in a growing number of ports round the world that have approved the use of HullWiper. The risk of pollution or cross-species contamination is eliminated as the removed fouling is collected and disposed of in an eco-friendly way, rather than being left on the seabed.

Unlike traditional methods which use brushes, HullWiper uses seawater under adjustable pressure to clean the hull, leaving a smoother finish that extends the time before another clean or expensive coating repairs are needed.

It reduces the hull’s resistance, which improves the vessel’s fuel efficiency. “Even an increase in slime can make a vessel 5-10 per cent less efficient,” Mr Doran noted. “And by not cleaning the hull in between coatings, the use of fuel can increase by one to 10 tonnes a day.”

Having a permanent ROV onboard a cruise vessel would give greater autonomy. The system would only have to be set up to match the specifications of a single vessel, unlike the current semi-autonomous HullWiper solution, which is used on a wide range of vessel types. Theoretically, all that is needed is for a crew member to press a green button to launch the ROV and a red button to recover it.

Mr Doran said that GAC EnvironHull was close to a cruise company commissioning HullWiper onboard, which he predicted would be a “game-changer” both for the cruise industry and other time-sensitive operators. Tests to date have produced positive results and GAC EnvironHull is waiting to hear (at time of writing: July) if the company wants to commission the ROV permanently.

“We are currently at a tipping point solution,” explained Mr Doran. “Companies can be hesitant to be first to adopt a new solution, but the smart ones will recognise it as a good idea. Once one decides to use it, we anticipate a domino effect.”

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