23 Mar 2020
Hull robot underwater cleaning company HullWiper Ltd reports a big growth in use of its technology, as an alternative to underwater divers, to remove marine biofouling from ship hulls.
HullWiper, a company providing underwater robots for cleaning ship hulls of fouling reports a big growth in take-up of the technology, which provides a lower cost alternative to human divers.
HullWiper is currently rolling the service out in ports around the world. Looking only at the cost per square metre of hull cleaning, the technology appears initially more expensive than traditional hull cleaning methods such as divers with brushes, which the company roughly estimates to be around $3/m2 compared to $1/ m2 with a diver, this includes attendance by two scuba divers with a wire hand brush so is subjective.
But HullWiper’s cleaning method, with high-pressure seawater jets, is less likely to damage the hull than divers using brushes, and so extends periods between cleaning and it works out cheaper overall, the company says. No harsh chemicals, scrubbing or abrasive materials are used.
“For a vessel with a typical five-year paint plan, hull cleaning with divers/brushes shortens the life of the coating by eight months (or 80u roughness) per clean,” says Simon Doran, managing director of HullWiper. “This paint damage increases the roughness on the ship hull and therefore the drag, but also increases the regrowth of the algae due to better foothold.”
HullWiper catches, filters and compresses the fouling, which is captured onboard the ROV’s unique filter system. The fouling is removed from the robot when it is brought onshore, and disposed of by an approved environmental waste disposal company. The fouling does not fall into the water risking the spread of harmful invasive species.
It is concerns about pollution from fouling removed from hulls which has led many ports to ban cleaning by human divers while a vessel is in port. This means that the vessel cannot be cleaned and loaded/unloaded at the same time. So a vessel must usually be taken ‘off hire’ while it is being cleaned by divers.
With HullWiper you can clean in the port. Also with HullWiper, you can clean the hull at night time, something which can’t be done with divers. And of course it does not need any breaks or rest periods after it has entered the water.
The robot device is known as a “remotely operated vehicle” (ROV), similar to the devices used in oil and gas subsea (seabed) projects. The ROV is “driven” from an operator on a barge or offshore support vessel. This gives more flexibility than operations from a jetty. If it was operated from a jetty, the work would need to be planned around the vessel’s berthing schedule and cargo operations.
Stephan Martinussen, Maersk Line’s head of global vessel performance centre, said in a written testimonial on the HullWiper website, “we place a high degree of focus to ensure world class bunker efficiency and thereby reduce our fleet’s carbon footprint. Hull performance plays a key role in that objective. It uses technology that is both eco-friendly and facilitates diver free hull cleaning of our vessels.”
Jesper D Rasmussen, a former managing director of Maestro Technical Shipmanagement, provided a written testimonial saying it was a “very good initiative”, and aligned with “the way environmental legislation as well as bunkering are going. Hull cleaning is clearly going to be one of the ways of saving a dollar on fuel consumption”.
Having a clean hull improves a vessels speed, or enables it to operate at the same speed with less fuel consumption (and so less CO2). There is an online calculator on the HullWiper website, which will tell you how much it thinks a HullWiper clean will save on your next voyage, taking into account the type of vessel, vessel size, engine type and power, voyage information, chartering rate and fuel type (and so fuel cost).
It will calculate the hull area, how much HullWiper will cost, how much conventional cleaning will cost with divers, and additional costs from divers, including from having the vessel off hire while the work is being done, and paint damage HullWiper thinks diver cleaning will cause. It can also estimate how much extra costs you will incur from having a fouled hull, including from extra fuel costs (which worked out at about 4% more, on an example Tanker Operator tried).
It will estimate additional chartering cost from this speed reduction, calculated by the extra time a fouled ship will take compared to a clean ship (which worked out at about 6% of the fuel cost, on an example Tanker Operator tried).
Where it is available
The service was first launched in 2013 in Dubai and has since expanded to include key locations in the Middle East(Port Khalid – Sharjah, Port Rashid - UAE, Fujairah – UAE, Jebel Ali – UAE) as well as ports in Australia (Brisbane, Bundaberg, Gladstone and Townsville), Egypt (Suez Canal), Mauritius (Port Louis), Panama (Balboa), Singapore and Spain (Algeciras). There is a Gothenburg base covering a wide area of Scandinavia - the Sound, Great Belt and Skaw areas; Copenhagen, Malmoe, Kalundborg and Frederica Havn.
The service in Gibraltar is provided by ship fuel conservation and underwater services provider SCAMP. It plans to have a second unit in operation in the first quarter of 2020, following the first unit doing around 60 hull cleans over 2018-2019.
HullWiper will offer the service in Ras Laffan, Qatar, from early 2020, in a partnership with GAC Qatar, which has a license from the country’s Environment Ministry. Plans are in the pipeline for new locations including Sri Lanka, Korea, South Africa, Chile and Bahamas.
It is approved to work with coatings from Chugoku Marine Paints, Hempel, International Paints, Jotun, PPG Protective and Marine Coatings, SeaCoat Technology. “These coating manufacturers approve of our ROV methodology and cleaning process,” Mr Doran says.
The company has a leasing program to provide the technology to service providers, where HullWiper does not have its own base, interested in offering it to their clients.
Simon Doran HullWiper’s Managing Director Simon Doran is a former diver with the Royal Navy, who has also served with the UK army in the Falklands, Northern Ireland and Operation Desert Storm. As a former diver, Mr Doran says he appreciates how dangerous diving can be. “I am a diver at heart, and I know that what we do reduces the risk to divers. Hull cleaning can be labour intensive and arduous for a diver at the best of times, and you can imagine the unnecessary risks and even shortcuts that can be taken when a dive team is cleaning a VLCC by night, at anchorage.”
“Whilst there are a number of first class diving companies who work to the highest standards with correct equipment, there are still Mickey Mouse outfits that choose to ignore what it means to be a professional commercial diver.”
Source: Tanker Operator