New bulbous bows save fuel on slower ships

Bettina Wiebe of the NSB – Niederelbe Schiffahrtsgesellschaft – in Buxtehude told The Motorship on 17 June that two ships had already been fitted with new bulbous bows and that two further conversions were underway as of mid June

.

One ship already modernised, at China’s CIC Shipyards in Shanghai, was the 101,662dwt container ship CMA CGM Hugo

.

Ms Wiebe said the job took 12 days and reports added it was done during a routine class renewal docking and that the new bow was made up of six segments weighing a total 250 tons

.

Ms Wiebe said the similarly sized Pacific Link was getting a new bulbous bow at the end of June at China’s HRDD Shipyartd

.

She said all the company’s managed vessels younger than 15 years were being checked when their drydocking class renewals came up to see if a change of bulbous bow would improve performance

.

The scheme was an ongoing process lasting 2-3 years, she said

.

The reason given for the modernisation is that container ships of the last decade were designed for speeds of more than 24 knots

.

Because of the dramatic increase in fuel prices they are no longer economical today

.

Bulbous bows designed for speeds below 20 knots were in general of smaller volume and with sharper water entrance capability, Ms Wiebe reported

.

The design of individual bulbous bows depended on ship size, speed pattern, block coefficient and draught and thus looked different on different ships, she added

.

Asked if the scheme was proving worthwhile, Ms Wiebe told The Motorship “the target is to save fuel because of current excessive fuel oil prices

.

.

.

.

Possible savings with a modified bulbous bow along with the new service conditions are around 5% of consumption at low load”

.

She said that resulted in a “reasonable” saving of 3 to 5 tons of fuel a day

.

NSB, which manages 69 container ships, tankers and offshore installation vessels, said it was not itself saving costs through modernisation

.

However “we are making our vessels more attractive for the charter market

.

With luck we can increase our charter rates by €1,000-€1,500 a day“, Bettina Wiebe told

The Motorship

.