September 17 2004
CRP Azipod slashes ferry fuel bills
Last April, we reported that ABB had been awarded a contract to supply CRP Azipod propulsion systems for two ferries under construction for Japan's Shin Nihonkai Ferry Co, Ltd. (SNF),
SNF took delivery of the two ferries, Akashia and Hamanasu, from the Nagasaki Shipyard of Mitsubishi Heavy Industries (MHI) in June.
Instead of a conventional rudder, each of the two 224.5 m, single-skeg vessels is equipped with a steerable 17.6 MW Azipod unit installed in a contrarotating mode aft of the mechanically driven main propeller.
The length of the route is 1,061 km (573 Nautical miles). Both ferries travel from Maiduru on the Honsyu Island to Otaru on Hokkaido in 20 hours and back in 21 hours. The unloading and loading time is 4 hours in Maiduru and 3 hours in Otaru.
This schedule is made possible by a 30.5 knot service speed.
Two older fast ferries operated by SNF, Suzuran and Suisen, feature conventional diesel-driven twin shaft lines.
The service speed of these ships is 29,4 knots, and the transportation capacity is about 15% less than that of Akashia and Hamanasu.
The older vessels were earlier temporarily in operation on the Maiduru Otaru route. The schedule was about the same as the operation was done on the basis of a 24-hour schedule.
This gives an excellent opportunity for full-scale comparison of the fuel economy of CRP Azipod propulsion and that of a conventional shaft-line arrangement:
After three months of operation with Akashia and Hamanasu, SNF reports that the two shaft line ships (with 15% lower transportation capacity) consumed over 20% more fuel to perform the same service as the new ferries with CRP Azipod propulsion. Operating costs of the new vessels are expected to be further reduced through decreased costs related to maintenance