Increased maintenance interval from 2 to 39 weeks

The Port of Singapore Authority increased maintenance intervals from 14 days to 9 months after installing a new seawater cooling system on board one of its tugboats.


When Norwegian technology company Hydroniq Coolers a few years ago had completed the development of its “Pleat” seawater cooling system and tested it on smaller installations, it searched far and wide for a vessel operator that was willing to try out the new system. Hydroniq Coolers had two main criteria: a large-scale test under challenging conditions.

In Singapore, one of the world’s busiest ports, the company found the challenging conditions it wanted. Plus, in the Port of Singapore Authority’s (PSA) subsidiary company PSA Marine (Pte) Ltd. it found a cooperation partner willing to try out the new technology on board one of its busy tugboats that operated in Singapore Bay. PSA was formed on 1 April 1964 to take over the functions, assets and liabilities of the Singapore Harbour Board.

The deal was that Hydroniq Coolers would provide its Pleat seawater cooler and install it on board PSA’s tug vessel – free of charge. In return, PSA would test the cooler for six months and allow Hydroniq Coolers to witness the maintenance of the system.

Marine cooling systems are utilised to reduce temperatures in the ship’s engines and other auxiliary systems through use of seawater.

The tug in question had two diesel engines. The Pleat cooler was installed on one of the engines. PSA kept its existing cooling solutions – plate heat exchangers – on the other engine.

Growth and particles in the seawater will over time clog any seawater cooling system. Hence, the cooling system will need to be cleaned in order to avoid clogging, which will result in reduced system pressure that worst case could cause the engine to overheat.

PSA had to clean the plate heat exchangers onboard the tug 2-3 times per month, with a maintenance interval of maximum two weeks.

“After nine months the vessel crew had still not received any notification of pressure loss in the Pleat cooler installed at the second engine. However, the vessel crew then chose to open up and inspect the Pleat cooler. Even after all this time it was quicker and easier to clean the Pleat cooler compared to plate heat exchanger onboard the tug. The vessel crew had never experienced anything like it,” says Rune Myklebust, vice president operations at Hydroniq Coolers.

After this experience, PSA immediately purchased a Pleat cooler for the tug’s other engine too. PSA and Hydroniq Coolers also entered into an agreement to replace the plate heat exchangers with Pleat coolers on the rest of its tugboat fleet, apart from on the oldest vessels that were reaching the end of lifetime.

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“Today, all of PSA’s new and newer tug vessels run solely with Pleat seawater cooling. The company has become one of the most loyal users of the Pleat,” says Myklebust.

For further information about the Pleat, read the feature article “Meet the Pleat”.

For more information about the Pleat, please contact Hans Robert Almestad at Hydroniq Coolers.

Hydroniq Coolers AS