JUNE 5, 2015 — MAN Diesel & Turbo’s Propeller & Aft Ship organization has won an order to retrofit and upgrade a series of eleven 37,500 dwt vessels from the Odfjell chemical tanker fleet. The vessels are of the Kværner Class and are due to dock during 2015-17, at which time the upgrades will be implemented. The first vessel, M/T Bow Clipper, will dock and be upgraded in August 2015.
The following Kværner Class vessels are currently scheduled for upgrade: Bow Flower, Bow Clipper, Bow Fortune, Bow Cecil, Bow Flora, Bow Cardinal, Bow Faith, Bow Cedar, Bow Fagus, Bow Chain and Bow Firda.
Each vessel has an MAN B&W two-stroke engine powering a four-bladed, controllable-pitch propeller and a PTO-driven shaft alternator. The vessels’ new service speed at reduced main-engine output – combined with the implementation of MAN’s highly-efficient Kappel propeller blades, a fairing cone and a pre-fabricated rudder bulb kit – will all contribute to power savings and reduced exhaust-gas emissions.
The Kappel blades, fairing cone and rudder bulb are designed and customized for the tanker’s hull and rudder designs.
The calculated power saving has been verified by tank-test analyses at MARINTEK (Norwegian Marine Technology Research Institute) as reported in preliminary results.
“It’s a very exciting project and we are proud to be part of it. With our new design possibilities, we are furthermore looking forward to offering this fuel-saving concept to other fleets with similar operational patterns,” said Kjartan Ross, Business Development Manager of MAN Diesel & Turbo’s Propeller & Aft Ship organisation. “With the long lifetime expectancy of Odfjell’s high value, quality vessels, this upgrade investment is straightforward and very attractive”.
Odfjell embarked on the ambitious Kværner Class newbuilding program in 1991. The 37,500 dwt ships feature 52 fully-segregated stainless-steel tanks and piping systems . The first vessel was delivered in 1994 and the new series was packed with new technology: controllable pitch propellers, shaft alternators on main engines, bow thrusters, fixed tank-cleaning machines and radar positioned in each tank to gauge ullage. Odfjell was also a pioneer in the area of fully computer-controlled engines. The last ship in the series, M/T Bow Firda, was delivered in 2003 and has a main engine – an MAN B&W 7S50ME-C type – with electronically controlled timing and no camshaft – a world first.Principal particulars
Vessel type Chemical tanker – double hull
Dead weight tonnage (mt) 37,500
Length overall (m) 183.10
Breadth (m) 32.20
Draught (m) 10.65
Engine power (kW) 14,160
Max. engine and propeller speed (r/min) 117
Shaft-alternator power (kW) 850
Propeller diameter (mm) 6,300
Graphic from MAN Diesel & Turbo’s CFD simulation of the new Kappel propeller blades, fairing cone and rudder bulb – customized for the existing aft ship and fishtail rudder