Stena Bulk, which operates a number of in-house designed Suezmax tankers, has adopted slow steaming as well as a number of technological innovations to keep its fuel costs as low as possible. These have included adjusting a vessel’s propeller and bulb to its actual projected service speed, as well as adding stern tubes and fins to enhance water flow. This is because of the high cost of bunker fuel, which now accounts for more than 60 per cent of the freight cost in today’s market.

Companies are trying to operate their vessels as energy-efficiently as possible. In the case of a 160,000dwt Suezmax tanker, the freight rate must average $40,000 per day over time to justify a speed increase of just 0.5 knots. In other words, the freight rate must be doubled before even a small speed increase can be made. This is resulting in vessels spending more of their time sailing at an ‘optimum speed’. JS

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