30/12/2012 UK
Why The Bulbous Bow Is Getting The Chop
Recent shipbuilding innovations turn popular wisdom on its head

Maersk ships being retrofitted with modified bows. The BALTIMORE emerged with a new name ( SEAGO FELIXSTOWE ) as wel l as a new bow!
Back in the good old days, which we thought were the baddest of days, changes in shipping and shipbuilding were coming thick and fast. Being in a shipbuilding area, our schools were quick to assure designers were forging a new era that would bring future work and prosperity.

One such innovation was the bulbous bow, that ugly protuberance that slowly, but surely, became one of the accepted necessities in an increasingly aesthetically challenged world.

So common is it now that ships without them look odd, as if something is missing, and pretty soon, there's going to be a lot of ships with this bit missing, if latest hull innovations prove to be the new black.

Maersk, for example, is redesigning the nose of some of its giants, and recently a slew of new designs have emerged from shipyards, racing to become leaders in the 'greener ships' era and proclaiming the lack of bulbous bow as if the thing had been added on as a superfluous legacy battering ram in the past anyway.

So what's going on?

The bulbous bow is indeed a proven improvement. Typically it shaves five percent off the costs of steaming at certain speeds and can be considerably higher. It has to be very carefully worked out though, the size and shape of the bulb must be just right and factors such as speed and length of ship matter.

And here we have it in a nutshell. Ships are getting bigger, longer and speed is no longer quite as essential as it once was. Back in the fifties and sixties shipdesigners were thinking ahead in terms of speed as well as efficiency and they would never have dreamed we would ever build the monsters we have now, or at least, if we did, such giants would be rare.

At lower speeds the bulbous bow can be a hindrance and can reduce efficiency. Nowadays slow steaming is becoming a preferred option. It reduces consumption and emissions. Container ships and bulkers now are so large that they need not go fast because their attractiveness is the amount of cargo they can shift, reducing shipping costs.

So these giants can lumber along their preset lines, timetabled to deliver their goods at a steady, more economical rate. The bulbous bow then becomes superfluous and can actually hamper efficiency as the ratios no longer mean it does its job.

This is why Maersk is currently retrofitting ten of its ships. These vessels will have their current bulbs removed and a modified replacement that is less protuberant put in their place. Maersk say they will save 1 to 2 percent on fuel consumption when the ships are slow steaming. That may not sound a lot, but if you consider the huge quantities of fuel these massive ships gobble up (in a large fleet this bill runs into the billions annually) then 1 to 2 percent can mean the difference in a highly competitive world between profit and loss.

Chinese shipbuilders Shanghai Waigaoqiao Shipbuilding Co Ltd have recently announced a new series of Capesize bulk carriers that will emerge without bulbous bows at all, and they say European shipowners are flocking to them for the ships.

These vessels, like Maersk's container giants, will be used as slow steaming merchants, so off with the bulb (or at least whittle it down a bit in Maersk's case) and along with improvements to hull shape, the result is a slower but greatly more efficient ship, burning less fuels and emitting less harmful gases.

So is it the end of the ghastly bulb? Probably not! These new designs and innovations are specifically for very large slow-going cargo carriers. Ships that require speed as well as efficiency will still benefit from having the bulbous bow...horrible as it is to look at!