Carbon fibre construction has been used for the trio of catamarans Brødrene Aa has delivered to Zhongshan Hong Kong Passenger Shipping Co-op, leading to savings of up to 40% on weight and fuel
Norwegian shipbuilder Brødrene Aa has delivered is third carbon fibre sandwich catamaran to Chinese ferry operator Zhongshan Hong Kong Passenger Shipping Co-op. Seven Brødrene Aa carbon vessels are now operating in the Pearl River Delta area.
The third vessel differs to the first two vessels the Norwegian shipyard delivered.
The first two have capacity for 300 passengers, a length of 42 m and a maximum operating speed of 42 knots. The third vessel also measures 42 m in length, but has capacity for 230 passengers and a maximum operating speed of 37 knots. While the first two vessels have twin-deck saloons, four engines and four waterjets the third, Zhong Shan 26, is a single-deck design powered by two engines and two waterjets.
Zhongshan Hong Kong Passenger Shipping Co-op chairman Xuetao Liu says “Brødrene Aa delivers advanced luxury vessels and the fastest carbon fibre high-speed passenger vessels in the world. We are so proud of building up a ﬂeet of four carbon fibre vessels in three years, becoming the new benchmark in the Guangdong, Hong Kong and Macao high-speed passenger transport industry.”
The ferries operate between Hong Kong and Guangzhou.
Zhongshan Hong Kong Passenger Shipping Co-op is 40% owned by Chu Kong Shipping Enterprises, which acquired 40% of the equity of Brødrene Aa in 2015. When the Zhongshan order was announced, Brødrene Aa said, “One objective of the partnership was to establish a joint composite manufacturing facility in China, as well as providing market opportunities for completed vessels from Brødrene Aa’s yard in Hyen.” While the joint facility is not yet complete, Brødrene Aa has already outfitted three vessels at the yard in Nansha.
Brødrene Aa chief executive Tor Øyvin Aa tells Passenger Ship Technology “In China, vessels should not be more than 25 years old in operation so the company needed new vessels to replace the old vessels. They have operated very successfully in this area for many years.”
Carbon fibre crucial
He singles out how using carbon fibre was a crucial factor in the ferry operator deciding to use Brødrene Aa. “More than three years ago, the company tested two of our carbon fibre vessels and these two vessels were the reason why they found carbon fibre so interesting – these vessels used 40% less fuel than conventional vessels in the same category. A lot of Chinese operators are testing these carbon fibre vessels and are convinced these are the most economical and environmentally friendly vessels to use for their operations.”
The shipyard builds all its vessels out of carbon fibre. “We started using carbon fibre in 2001 on vessels, at that point it had not been used as a production method for ferries before and we found it very interesting, especially for fast ferry production.”
He explains that by using carbon fibre, weight savings of around 30-40% are achieved compared with using aluminium, the most commonly used material to construct fast ferries.
“Aircraft companies have also found the same thing – aluminium is the most used material but they can save 30-40% by replacing aluminium with carbon fibre,” says Mr Aa.
Brødrene Aa started building smaller vessels out of carbon fibre, before increasing the size gradually. The shipbuilder has now produced more than 60 vessels since 2001. He says “Ferry operators were a little bit sceptical at first as carbon fibre was a new material, but in Norway all the big operators have bought carbon fibre and they have been shown through new projects that it really saves fuel and delivers more environmentally friendly vessels.”
He adds that maintenance costs are very low, with no corrosion or condensation inside the vessel because carbon fibre is a composite material.
Mr Aa says that while Brødrene Aa is not the only shipbuilder to construct ferries out of carbon fibre, “we are currently at the forefront, as we have the most experience developing new solutions and we are very competitive”.
Using carbon fibre is not the only fuel efficient and environmentally friendly feature of Zhongshan Hong Kong Passenger Shipping Co-op’s new catamaran.
Rolls-Royce provided its Kamewa waterjet propulsion units and MTU engines for the ferry, as it did for the first two ferries. On the new catamaran, two MTU 16V 2000 M72 diesel engines are deployed, which are rated at 1,440 kW with two Kamewa 56 S4 waterjets used.
Mr Aa says, “Using two engines at 1,440 kW each, with capacity for 240 passengers and reaching a speed 37 knots with 26 tonne deadweight is extremely good and as far as I know, no vessel can compete at that speed.”
He says that waterjets have been chosen rather than propellers because “in this area the waterjets are the best solution as long the vessel is travelling at 32 knots and over. This is because of the higher efficiency; you get lower noise and vibration. In a carbon fibre build you can use propellers but there is a higher chance of more noise and vibration with speeds of more than 35 knots.”
He adds that in terms of manoeuvrability, the operator is “very satisfied”.
He says “Water jets are very good for manoeuvrability. There are also interceptors on the vessels, which are related to loading conditions and are important for speed.”
Brødrene Aa is keen to build on its success in China. As well as three vessels to Zhongshan Hong Kong Passenger Shipping Co-op, the shipbuilder has delivered a further three vessels to another Chinese ferry operator and is currently constructing a 40-knot speed fast ferry for another company in China.
The shipyard has also made an impact in the battery-powered ferry market. It built The Fjords’ electric-hybrid Vision of the Fjords and sister ship all-electric Future of the Fjords, and is currently constructing Legacy of the Fjords, which is a copy of Future of the Fjords, with its 2-MWh battery package. Slated for delivery in May next year, it will operate in and around Oslo.
Mr Aa says that while using battery technology is more challenging for fast ferries (The Fjords’ ferries have a conventional speed), use of this technology will come.
He comments “Battery technology is developing very quickly and in a few years we will see more fast ferries using batteries. The problem is that batteries are currently very heavy so the vessel needs to be built lighter. The energy density on batteries is increasing every year and that is very important for fast ferries.”
Carbon fibre sandwich/ Vinylester
|Length oa||42.8 m|
|Length pp||41.9 m|
|Width oa||10.8 m|
2 x 16V2000 M72 - 1440kW @ 2100 rpm
|Propulsion||2 x Kamewa 2 x S63-4|
|Reduction gear||ZF 5000|
|Generator||Volvo Penta D5A-B / Stamford|