LSC Keeps Dutch Patrol Boats Clear

Sonihull, the world’s leading ultrasonic antifouling system, has been installed by Lamers System Care on a series of Dutch Patrol Boats to cure persistent bio-fouling problems in the RWS fleet’s cooling pipework

To cure a recurring problem of marine bio-fouling, the Department of Waterways and Public Works (Rijkswaterstaat, or RWS) in the Netherlands, has fitted Sonihull ultrasonic antifouling systems to the seawater cooling pipework in a series of its patrol boats.

Previously, the cross-over pipework, strainers and valves for the patrol boats’ plate coolers were prone to very heavy fouling by weeds, barnacles and mussels. This impeded water flow around the cooling system, putting extra strain on the engines and adding to RWS’s fleet service costs. This problem has often led to malfunctions and avoidable maintenance.

Below is an endoscope photo of the cross-over pipework in one of the vessels before the Sonihull system was fitted. The pipe was almost totally blocked after 14 months in service.

Here’s a photo of the same section of pipework on one of the same vessels with the Sonihull system installed, after 14-months of operation.

In March 2018, Lamers System Care carried out the first installation on board the RWS 78. This was commissioned by shipyard De Haas Maassluis. The pipes were dismantled and intensively cleaned to start with a 100% clean situation. The Sonihull8 system was then installed on the ship. Every three months, LSC, in collaboration with De Haas Maassluis, checked the pipes by means of an endoscope. After the 6th inspection, it was found that the ultrasonic system did not require any interim cleaning: The result was excellent and the pipes were clear of fouling.

“It was a pleasure to increase the sustainability level of Rijkswaterstaat in collaboration with De Haas Maassluis,” says Bob Lamers, Managing Director of LSC. “The Sonihull8 system reduces the maintenance costs significantly and increases reliability of the patrol vessels.’

“The photos speak for themselves,” says Dominic Findlow, Technical Director of Sonihull. “The same pipework on the same vessels was almost completely free of any kind of fouling. The results have proven that the system is vital for the efficient operation of the RWS fleet and Sonihull is being retrofitted throughout the fleet.”

By fitting the Sonihull system to the cross-over pipework the system can transmit strong ultrasonic pulses throughout the raw water cooling-system and into the heat exchangers, protecting any surface that is in contact with raw seawater from bio-fouling. The pulses create a microscopic layer of micro-cavitation which disrupts the first stages of the food chain and prevents further colonization and attachment of weeds, barnacles and mussels.

“In similar commercial applications, operators are saving up to 95% of their capital and maintenance costs when protecting their box coolers with Sonihull instead of impressedcurrent antifouling systems,” added Findlow. “Sonihull is a zero-harm solution. There are no poisons, or biocides leached into the marine environment, no microplastics are shed from ablative coatings and no toxic metallic ions are left in your wake.”