Revelin Revels in Dirty Water with Solution Keeping it Clean

China’s Qingshan Shipyard has delivered AP Revelin, the second in a series of two environmentally sustainable handy-size bulk carriers, to Croatia-based shipping company Atlantska Plovidba d.d. from Dubrovnik. The 38,700dwt ‘ecoship’ will join first of class AP Dubrava, which was delivered in July 2015.

Each 180m (591ft) long tramp trader, built to the Green Dolphin 38 design unveiled by Shanghai Merchant Ship Design & Research Institute (SDARI) in 2012, features Thordon Bearings’ (Canada) seawater-lubricated COMPAC propeller shaft bearing system and a Thordon Water Quality Package (WQP). This will provide a clean and consistent supply of seawater to the bearings even when the vessel is docked downstream of the current in shallow waters.

“These energy-efficient vessels are ocean-going but will also operate in river entrances where the seawater is highly abrasive,” said Thordon Bearings’ Business Development Manager Scott Groves. “But running Thordon’s WQP 24/7 means the propeller shaft bearings can be lubricated even when the sea chest is drawing in filthy river water.”

Explaining the reason for specifying a water-lubricated bearing system, Atlantska Plovidba’s Vice-President, Ship Management, Marin Matana, said: “Our vessels trade globally, including the USA. With the Vessel General Permit in effect, we felt that the seawater-lubricated system was the perfect solution. It meets the U.S. VGP requirements and is the right choice for the environment.”

Mr Matana revealed that a conventional white metal bearing for use with an environmentally acceptable lubricant had been considered but an unproven track record prevented their take-up.

“Some EALs can react negatively with stern tube seal lips which could lead to costly dry-docking, affecting the profitability of the vessel. We insisted on Thordon Bearings’ COMPAC because we wanted to benefit from its 15-year wear life guarantee, he said.

“I have worked with Thordon Bearings and its Croatian distributor Skoring for more than 20 years and have a lot of experience with Thordon’s SXL rudder bearings, which have a perfect track record. A single source for the design, product quality and installation support was deemed essential to ensuring the COMPAC system will perform as required and keep my vessels on the high seas,” Mr Matana added.

Craig Carter, Head of Marketing & Customer Service, Thordon Bearings, said: “The Qingshan Shipyard had little experience of a COMPAC installation before this project and initially resisted, but Thordon Bearing’s distributor in China, CY Engineering, was instrumental in explaining the benefits of the system, resulting in one of the smoothest installation processes we have seen. We’ve had excellent feedback from both the yard and owner.”

In addition to the award-winning COMPAC bearing system and WQP, CY Engineering also supplied bronze shaft liners and a Thor-Coat corrosion protection system to both vessels.

The Green Dolphin bulk carrier concept was introduced during the Posidonia Exhibition in 2012 following a joint research project between SDARI, Det Norske Veritas (DNV) and Wärtsilä. It features a hull form and machinery configuration designed to optimise fuel consumption and reduce emissions.

Atlantska Plovidba’s AP Dubrava and AP Revelin, delivered in January, however, are powered by MAN B&W 5S50ME-B9.2 engines and built to Bureau Veritas class.

AP Dubrava, the first vessel in the series, has been operating “perfectly” for six months and is now on duty in the Black Sea. Vessel options are being considered.