Feature 2 | RO-RO FERRY


that for existing berths the bow and stern fit would have to be offset, for future wider berths the offset arrangement could be removed and centre line alignment of ship and link span restored, this offset meant wider cargo doors. “Te longer length required a tighter


Spirit of Britain and Spirit of France pass in The Channel. But, the experience was at least put to


good use while Spirit of France was under construction, and it finally met the full design specification for vibration on sea trials in early January 2012, with the ship being delivered later that month. In the meantime, Spirit of Britain is


to go back to the shipyard in April for rectification work to meet the same status as Spirit of France, and is due to resume service on 25 April, although prior to this a temporary solution was found, by operating the first ship at reduced power the company was able to provide reduced vibrations and yet still run to schedule. As a result of the work that is scheduled


to be done to Spirit of Britain, P&O Ferries has decided to keep the 26,500gt Pride of Calais running on the cross-channel route, rather than put


the vessel into


lay-up, which it had been scheduled to do. Tere have also been other challenges


facing the new vessels including more stringent regulations that were introduced by the IMO through its Safety of Life at Sea (SOLAS) regulations as passenger vessel sizes have ballooned in recent years. Te Safe Return to Port programme, which officially came into force in mind-2010, posed numerous challenges, says Langley. “The engine configuration, with the


port prop shaft going through the aft engine room in an A60 tunnel, meant a new type of water tight seal on the shaft bearings [and] early designs caused local overheating of the shaft bearings, which has now been solved with a new seal design.” He also says that the commissioning the first vessel proved to be very


of


challenging, “Quite often when the system was tested for real, we discovered some issues”. He also confirms that the process of training crews and checking routines to


56


Starboard engine of Spirit of Britain seen from the top level.


He adds that a further challenge is


where existing SOLAS requirements are enhanced, thus making the previous SOLAS requirement redundant. But, perhaps the greatest challenge that


P&O Ferries faced with the deployment of the new vessels was their sheer size, and the fact that they are the largest possible to operate in the existing ports of Dover and Calais, both ports also have ambitious expansion plans. It was a case of deigning a vessel that would provide the maximum economies of scale in the present port dimensions, but also future-proofing them so they would continue to be commercially viable aſter the expansion projects have been completed. “Te ship had to fit both existing and future port infrastructure, which meant


be compliant with the new regulations is ongoing. “With both ships now in service, we are


drilling each Safe Return to Port scenario and discovering more information. “We are also investigating how


individual machinery failures may impact on Safe Return to Port capability, and drawing up a matrix to assist the management of a Safe Return to Port ship.”


swing within Calais harbour, to minimise the associated risk, we ensured the design incorporated the manoeuvring requirement a 50knot wind force capability. “The larger vehicle decks and the additional deck for


tourist cars and


caravans, provided a challenge to achieve a similar turnaround time as our current fleet, this was achieved by moving the storing process down to deck two, wide freight lanes, and wider cargo doors,” he says, adding that the company has used a simulator to familiarise its captains in manoeuvring, and also used the same model to verify the 50knot wind capability. But, his assertion that scrubber


technology is not able to make ships emissions compliant with the 2015 regulations might be


disputed by


manufacturer Hamworthy Krystallon, which was acquired by Wärtsilä at the end of January. A month earlier it had delivered the


world’s first commercial scrubber system to Italian owner Ignazio Messina & Co, which had ordered the systems for four of its 45,000dwt ro-ro vessels. Te first was successfully launched on the Linea Messina in December. Te ship now has five scrubbers – four 2MW units for the auxiliary engines and one for the auxiliary boiler. All are housed within the ship funnel casings, and the delivery also includes a control system, combined wash-water treatment plant and a new range of super duplex stainless steel pumps. Installation took place over last year


and was approved by classification society DNV, while RINa has given it its first Green Plus notation. Hamworthy managing director Sigurd


Jenssen claims: “By 2015, ship owners and operators operating in ECAs will have a simple choice - either pay the US$300 to US$400 price differential for costly distillate fuel or install a scrubber, which typically has a payback of less than two years.” NA


The Naval Architect May 2012


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80