Two-tier linkspans for bigger ferry

After just two years operational service, Stena Line will replace Stena Forwarder with a larger capacity ferry on its Irish Sea service between Dublin and Holyhead this summer. It will introduce the 44,200g Stena Adventurer in July, following its delivery from Korean shipbuilder Hyundai Heavy Industries.

“We have been frustrating freight capacity in the late night sailings from Dublin and Holyhead,” explains a Stena Line spokesman about the deployment decision. While stressing the importance of freight, the spokesman adds that the company will still need to take a reasonable mix of cars (tourists) and freight to make the increased capacity service profitable.

Stena Adventurer has a roro deck capacity of 3,400 lane metres, which is 70% more than Stena Forwarder>. This is provided on four fixed decks (No.?s 1, 3, 5 and 7) and a hoistable car deck on the starboard side of Deck 5. The ship has double tier bow and stern loading through wide doors installed on Deck 3, with two fixed ramps connecting this deck with Deck 1 and a tiltable ramp connecting it with Deck 5. The stern of Deck 5 and the whole of Deck 7 are exposed to the weather and are designed as a dangerous cargo area.

To maintain the same service frequency and port turnaround offered by the much lower capacity Stena Forwarder, Stena Line?s Ports division is undertaking a £12.3 million ($19.4 million) redevelopment at the Port of Holyhead, which includes construction of a new berth with twin-tier loading and unloading ramps.

Dublin Port Company is also developing a twin-tier loading and unloading system to accommodate Stena?s increased requirement. Dublin will recoup its investment through higher port charge income brought about by the increased vehicle traffic that the larger ferry will bring through the port, says Stena.

“Fluidity will be much better in terms of the traffic movement,” says the Stena spokesman about the operational impact of the two port developments.

Stena Adventurer has a published speed of 22 knots, which is 2 knots slower than Stena Forwarder. However, Stena says it will still operate to a 3 hours 15 minutes crossing timetable with Stena Adventurer, the same schedule it currently operates for Stena Forwarder. If heavy seas delay the crossing, Stena says its timetable allows a generous three hours to turnaround in port ? plus it has the new twin-tier loading/ unloading at both ends ? so it can easily regain time.

Stena Adventurer will have a passenger capacity increased by 50% to 1,500 compared to Stena Forwarder. It will have 148 cabins, up from 78. Facilities will include restaurants, bars and lounges for tourists and a dedicated lounge and restaurant for up to 200 freight

drivers.

The new ship will, at 210.8m loa, be (by a small margin) the longest vessel ever to operate on the Holyhead-Dublin route. It will operate on the Irish Sea in tandem with the 40-knot catamaran HSS Stena Explorer, which has capacity for 1,500 passengers and 375 cars (50 x 16m trailers). This has a scheduled crossing time of 99 minutes. The HSS uses a different berth at Holyhead and calls at Dun Laoghaire in Ireland, about 10km south of Dublin. Irish Ferries, Stena?s principal competitor on the service, also uses different berths in Dublin and Holyhead for its 50,938g, 4,076 lane metre, 1,875 passenger capacity ferry Ulysses and for its fast cat Jonathan Swift. Stena Forwarder, when introduced to the Dublin-Holyhead service in April 2001, increased freight capacity by 30% over its predecessor Stena Challenger. Stena Line has Stena Forwarder on charter from its registered owner, Levantina Transporti of Italy. The vessel will be sold when Stena Adventurer commences operation.

A sistership to Stena Adventurer, called Stena Britannica, was introduced onto the Harwich-Hook of Holland route in January in place of a smaller ship of the same name, subsequently sold to Finnlines.

Stena Adventurer ? technical outfit

Stena Adventurer has a diesel mechanical propulsion arrangement. Two pairs of MAN B&W 9L40/54 medium-speed diesel engines generate power. Each engine produces 6,480kW at 500 rev/min. Each pair of engines turns a 4,850mm diameter Rolls-Royce CP propeller at 150 rev/min through a Renk NDSHL-3000 twin input, single output reduction gearbox.

Additional power is taken off from each gearbox by a Hyundai Heavy Industries alternator, with each alternator outputting 2,400kW at 1,800 rev/min. These provide power for two 2,200kW Rolls-Royce bow thrusters. Additional manoeuvrability at the stern is given by a pair of twin flap rudders mounted behind the CP propellers.

In addition to the two PTO-driven alternators the ship has four MAN B&W 8L23/30H diesel generators, each delivering 1,280kW at 900 rev/min. Steam is produced by a pair of KangRim/Kawasaki HI vertical cylinder water tube boilers at a rate of 3,500kg/h each and at a pressure of 7 bar.

The ship has a bridge control and navigational outfit designed by Kongsberg. A pair of fin stabilisers mounted near mid-ships counter roll at sea, while a pair of anti-heeling tanks, each fitted with a heeling pump operating at a rate of 1,700m3/h, maintain stability while loading/unloading.

Tank capacity includes 9,600m3 for heavy fuel oil, 400m3 for marine diesel oil and 3,000m3 for water ballast.

The roro outfit described above, on a ship that can carry 9,400 dwt on its design draught of 6.3m, or 9,900 dwt on its scantling draught of 6.4m, is supplied by MacGregor. It enables the carriage of up to 1,000 cars and incorporates electrical sockets for 120 trailers. A mooring system comprising eight Hydralift BLM (formerly Brissonneau & Lotz Marine) electric winches is fitted.

A CAE Valmarine integrated alarm control and monitoring system is fitted comprising a propulsion plant remote control system, power management system, standby automation of pumps, remote valve control and remote control of pumps/fans. The ship is fitted with a Semco Maritime/ Consilium Marine fire detection and extinguishing system. A Hamworthy KSE ST25 waste disposal plant handles sludge and solid waste.

The UK-flagged Stena Adventurer is classed by Lloyd?s Register with notations +100A1, +LMC, UMS, ICE1A, SCM, NAV1, Ro-Ro cargo/passenger vessel. It is built using 40 per cent high tensile steel and is designed to comply with the Stockholm Agreement and IMO A 265 for damage stability.