16 Aug 2022
Author: Simon Doran, HullWiper MD
History is based on facts. In most cases, we need to learn from the past to change the future. In today’s blog, I’m going to dig a bit deeper into the past, present and future of biofouling on vessel hulls and the evolution of hull cleaning methods.
For context, let’s look back at how shipping started. Merchants who realised that exporting goods to foreign shores by sea was more affordable and efficient than sending them by land came up with the concept of shipping in the third century BC. In the beginning, items were crammed onto wooden ships in wooden crates, barrels and sacks and were stored on deck or in cramped quarters below. Although resourceful, well-organised processes were not yet in place which meant that ships frequently spent more time in ports than at sea.
Before 1956, not much had changed until an American trucker, Malcolm McLean, came up with a new concept that completely revolutionised the industry. He loaded 58 metal boxes onto a ship sailing from New Jersey to Houston: containerised goods were kept safe and allowed truck beds and freight trains to transport them without repackaging when the ships anchored at ports.
Today, around 80-90% of goods are transported by sea. Shipping is the main transport mode for global trade and the backbone of the planet’s global economy. Simply put, we cannot do without it. But our reliance on this trade has birthed a biofouling crisis which, until very recently and relatively speaking, was overlooked by the shipping industry. Biofouling is the accumulation of unwanted aquatic microorganisms on ocean-faring surfaces (yep, vessel submerged hulls). These freeloaders are transported from their natural habitat to foreign waters which threaten the health of the local marine eco-system.
Marine fouling has always been around and will continue to be around. But how we manage it is changing. Industry associations, regulatory bodies, ports and governments around the world are implementing mandatory rules and regulations for the sustainable management of biofouling on vessel hulls.
So, let’s take a rewind and look at how we got to this point.
In the 17th and early 18th centuries, wooden ships were in use during the Golden Age of Piracy, and they required constant maintenance - especially in a tropical climate. Pirates (no, not Captain Jack Sparrow and the Black Pearl crew) understood the advantages of a clean ship. Knowing that a lighter hull would make them faster in the water and enable them to catch commercial vessels trying to flee or avoid navy vessels assigned to sink them, they would careen their ships in low-lying coves of the Caribbean islands in order to clean the bottoms of their buccaneer ships.
Lord Horatio Nelson was a supreme tactician. Prior to the Battle of Trafalgar in 1805, he is known to have ordered hull cleaning for his entire fleet of 27 vessels. Nelson knew the advantage clean hulls would give him in speed to even the odds against the 33 French and Spanish ships. With speed and agility now on his side, he famously maneuvered his fleet into two columns directed perpendicular against his enemies and with a decisive onslaught, won the five-hour battle by destroying 19 enemy ships without a single British loss.
Clearly, the benefits of a clean hull were well known in the early days. But what wasn’t in the uppermost mind of seafarers was the spread of invasive aquatic species (IAS). Charles Darwin first raised questions about biofouling on vessel hulls when sailing on the HMS Beagle around the Galapagos Islands in 1835, where he is said to have recorded in his diaries that “fouling of a ship’s hull could be the other means of transport of marine organisms from one location to another”.
Over the centuries, different anti-fouling methods have been employed. The first documented ship efficiency measure dates back to an Aramaic scroll from around 142 BC which states that arsenic and sulphur, mixed well with Chian oil, and applied evenly to the vessel sides will allow her to speed through waters freely and without impediment. By the third century, Romans and Greeks were known to have coated their ships’ bottoms with tar and wax. Vikings treated their hulls with pitch, oil, resin and tallow between the 8th and 11th centuries. The Chinese used a mixture of lime and toxic oil during the 13th and 15th centuries to keep worms away from the wood. Near the end of the 20th century, hull coating using Tributyltin (TBT) was once thought to be the best method for preventing the development of biofouling. TBT was eventually banned by the IMO in 2013 after studies quickly revealed the damage it was inflicting on aquatic life. Divers with brushes or karts then became the typical method of hull cleaning and is still in use today. However, fouling is removed using abrasives or chemicals with much of the removed residue falling back into the sea.
The first remotely operated vehicle (ROV) was introduced to commercial shipping in 2003 as a result for the need of an eco-friendly hull cleaning solution with marine fouling collection technology capabilities. Technological advancements for ROV hull cleaning solutions continues to make significant progress in ensuring that the units are more precise, efficient and eco-friendly. Some of the developments include underwater wireless communication, improved battery technology to remove the use of umbilical cords and complete 3D mapping of vessels utilising specialised camera software.
HullWiper’s green, efficient, diver- and brush-free hull cleaning solution was launched in 2013 in response to the need for sustainable solutions within the shipping sector. Our first operational base started in Dubai, UAE and we have since grown with strategically located hubs at ports around the world.
Rise (and shine) of HullWiper
The features of our ROV were developed in line with the results of our year-long engagement and survey with major shipping lines to seek their thoughts on the optimal development of current hull cleaning technologies. The findings indicated that ship owners desired solutions that produced both observable operational and sustainable outcomes. In place of scrubbing, harsh chemicals, or abrasives used in conventional methods, HullWiper is a unique, environmentally friendly brush-and-diver-free underwater hull cleaning technology that employs adjustable pressure seawater to remove fouling from vessel hulls. Our unit is the only ROV that collects all removed fouling with our onboard filter unit. HullWiper, as opposed to conventional brush cleaning, doesn't damage the fragile marine environment and preserves pricey anti-fouling surfaces.
R&D plays a critical role in the ongoing design and production of HullWiper’s ROV. We are specifically looking into:
• Removing human input to carry out self-directed hull cleaning
• Increasing the effective size of fouling that can be removed and reclaimed
• Improving video image quality to provide higher resolution video and images for our customers increasing biofouling identification
• Enhancing efficiency of the ROV to clean faster while maintaining an effective cleaning operation on the vessel hull
• Making the ROV smaller and operationally easier to handle
• Allowing the ROV to operate in stronger sea currents
• Enabling the ROV to follow a cleaning line automatically without the need of the operator to do adjustments
• Smaller sized filtration system with improved capabilities
• Cost-effective ROV without compromising on quality and reliability
Compliance with port and shipping authority's biofouling regulations and meeting BIMCO reclamation standards requires a proactive management plan from ship owners and operators. At this point in time, we cannot look back and “do business as usual”. We must look forwards and change the course of history for the sake of our oceans because as Sylvia Earle, a world-renowned expert on marine biology, has said “We need to respect the oceans and take care of them as if our lives depended on it”.