Customising a successful design

Izar?s Seville yard recently saw the launch of the 6,300 DWT ropax Murillo, the largest ship in Trasmediterranea?s fleet even exceeding the dimensions of the recently delivered 172m long ropax sisters Sorolla and Fortuny. The ship?s hull is identical to that of the vessels built for Cenargo, Dawn Merchant and Brave Merchant, except that the Transmediterranea vessel does not have a bow door. However, the hull is also where the similarity between the vessels ends as the Murillo has what Izar describes as some substantial improvements in cargo and accommodation capacities. The Merchant vessels had a total lane length of about 2,000m spread over two decks while the Murillo has an additional 396 car lane metres spread over an additional two decks. The lower car deck is located on the tank top with the upper one mounted directly above it. Access is provided by a fixed ramp between the decks, which in turn, can be accessed via a fixed ramp from the main deck. Two lifting ramps provide access to and from the upper deck as on the Merchant ships. The accommodation has also been more than doubled with the Murillo having 123 cabins compared with the Cenargo vessels? 57. This has increased Murillo?s passenger accommodation to 396 passengers in cabins and 150 in seats. Izar claims that the success of the Merchant series of four vessels previously built for Cenargo was the reasoning behind Transmediterranea requesting a similar vessel. Having all the design work and tank testing already done on an off-the-shelf design must have also been an incentive as it has allowed a fairly quick construction time and as Miguel Angel Fernandez Villamandos, Transmediterranea?s president says, “an incredible price.” He said at the launch “the shipyard price and my price are not the same”. Izar says that the 185m long ropax will be delivered ahead of time in February or March, giving about a 20-month construction time, and will join Trasmediterranea?s fleet next year on the Spain to Balearic Islands overnight run. However, this was before Izar?s unions announced they will stage two-hour strikes twice a week for the rest of October and a 24-hour strike on November 16 in an effort to improve pay and conditions in the group?s commercial sector. Fernandez Villamandos said that no decision had been made yet as to whether it would operate from Barcelona or Valencia. At 24.3m wide, Murillo is about as wide as the Seville yard can currently build although length can be increased further. A 25m wide lock downstream from the yard restricts a further increase in beam, although Izar says that Autoridad Portuaria de Sevilla, the port authority, intends to increase this to 35m and Izar is planning to replace two 80 tonne cranes with 100 tonne cranes at the end of this year to take advantage of the increased capacity. Different power trains Although both sets of ships are powered by four Wärtsilä 9L38 four-stroke engines developing 5,940kW at 600 rev/min arranged in pairs in separate engine rooms with separate feed systems, the Schelde DH 2800 gearboxes have been discarded in favour of Flender gearboxes on the Murillo. This, combined with the extra weight of the additional cars and cabins, has reduced the speed from 23.3 knots at 90% MCR on the Merchant ships to 22.8 knots at a lower rating of 85% MCR on the Murillo. The propellers on the Merchant vessels were of a Wärtsilä-Wichmann design, whereas Lips propellers are used on Murillo. All the vessels incorporate two Brunvoll bow thrusters. Stabilising the vessel is done via an Intering anti-roll system, which again differs from the Merchant vessels that were equipped with a Framo system. This is further enhanced with the addition of Mitsubishi retractable hydraulic fin stabilisers ? something that was not fitted onboard the Merchant ships. These had to be fitted after the vessel passed through the lock down at Izar?s Cadiz yard because of the width restrictions. Slipway launch Conventional ship launches are becoming rarer as the costs are considerably higher than that of a float out from drydock, says Izar. Whereas a floated out ship just has to have the dock flooded and be floated out a considerable amount of preparation has to proceed a ship sliding down the ways into the water. As well as trying to restrict how fast the ship enters the water, which is usually achieved by dragging chains, frameworks supporting the bow section have to be cut away after the launch. Seville investment plan IZAR Seville is presently implementing an investment plan (budgeted at over Ä20 million) to improve its competitiveness in the medium-sized vessel market (roro and passenger ferries, asphalt tankers, etc). While at the launch, chairman Jose Casanova said that Izar had won the tender to build two ferries for Algerian owner ENTMV and would sign the contract at the end of November or the middle of December at the latest. The Seville yard has been working closely with H J Barreras on the design for the 1,300 passenger vessels which will be capable of carrying 42 freight vehicles or 300 cars and will operate on the service linking Marseilles with Algiers plus a stopover in Alicante. Casanova said that Izar knew ENTMV well and that financing was currently being discussed with each vessel to be financed separately. IZAR and Barreras have cooperated before, most recently on the construction of the above mentioned sisters, Sorolla and Fortuny for Transmediterranea. Like a number of Izar?s yards, Seville?s 350 workers are now turning their hands to making blocks for the LNG carriers the group has on order.