Bussiness News

Set to introduce unprecedented levels of passenger comfort compared to regular high speed craft, particularly in adverse weather conditions, the vehicle-passenger ferry proves a fitting debut for Austal’s second-generation trimaran hull form. By incorporating lessons learnt from the success of Austal’s inaugural 2005 trimaran "Benchijigua Express" and the Austal designed and built Littoral Combat Ship "USS INDEPENDENCE", recently delivered to the US Navy, the company’s latest trimaran delivers innovation without risk.

Austal Technical Manager James Bennett said improving on a product as successful as “Benchijigua Express” was an exciting challenge.

“One of the most outstanding features of “Benchijigua Express” has been her ability to deliver passengers to their destination in comfort no matter the weather conditions.”

“We wanted the second generation trimaran to not only take passenger comfort to new levels but also to optimise performance, sea keeping, fuel efficiency and payload.”

Before proceeding with a successor to the company’s inaugural trimaran, Austal conducted a complete review of “Benchijigua Express” to establish where improvements could be made. This was followed by a detailed market study on the commercial ferry industry looking at the size and capacity of existing fleets.

Based on the data collected from this study, it was determined that 102 metres, 1165 passengers, 254 cars were the approximate specifications
most applicable to the existing market.

Because the vessel was being built on speculation, the design of the vessel’s interior and vehicle deck has been pitched at a level that permits the eventual owner to easily modify the vessel to suit their particular market.

The final design achieved a number of key improvements over its predecessor including;

·         Refined waterlines to improve sea keeping, passenger comfort and reduce resistance

·         A new and simplified ride control arrangement and operating system to deliver improved control over the vessel’s motions and handling characteristics

·         Simplified, three engine power train

·         New series water jets with improved cavitation margins

Trimaran Technology – The Competitive Advantage

The vessel’s unique trimaran hull form combines the softer roll of monohulls with the low resistance, stability and carrying capacity of catamarans to deliver proven advantages over conventional designs.

These advantages include greater speed for the same installed power, an ability to operate in higher wave heights and maintain higher speeds in waves, greater resistance to damage and reduced wake which reduces impact on the environment.

Most importantly, the trimaran’s lower roll speed means lower accelerations experienced by passengers, significantly reducing passenger sea sickness.

Studies show that motion sickness on the trimaran will be approximately 56 per cent lower than on a 100 metre catamaran operating in head seas. Even larger benefits are realised in other headings.

For operators, this means higher passenger satisfaction, greater customer loyalty and positive word of mouth marketing.

It also means higher revenue from onboard sales resulting from the ease of movement onboard and reduced sickness. Improved revenue potential from the trimaran’s ability to sail in a larger range of sea conditions (fewer cancellations) is another significant advantage.

Increased comfort also provides operators with a competitive marketing advantage compared with other high speed craft.  Greater customer satisfaction due to fewer cancellations equals more repeat business and improved revenue potential from a more viable roster.

Effectively, the trimaran becomes the “preferred alternative” in a competitive market situation.

Performance Efficiency

The most immediately noticeable change to its predecessor is the existence of a straight-stem bow - designed to maximise the vessel’s waterline length and deliver greater speed and efficiency.

Another significant improvement is the adoption of a three-engine propulsion train which combines with the trimaran’s unique hydrodynamic hull form to deliver fuel efficiency across a range of operating conditions.

The three engine arrangement also means lower fuel consumption, less emissions and reduced maintenance compared to fast ferries of a similar size which have four engines.

A speed of 39 knots (at 90% MCR) with 340 tonnes deadweight was achieved during sea trials, as well as a maximum speed of 45 knots, and a 760 nautical mile range (at 90% MCR) with fuel consumption of only 4.90 tonnes per hour.

Powering the vessel are three class-leading MTU 20V 8000 Series diesel engines, which offer high power-to weight ratio and are established as a low risk propulsion engine option for many leading high speed ferry operators.

Propulsion consists of three new-series Wartsila LJX 1300 water jets chosen for their improved cavitation margin (greater efficiency), each driven through a ZF 53800 reduction gearbox.

Austal’s focus on maximising redundancy is evident throughout the vessel’s machinery spaces, with two separate main fuel and day tanks and each of the vessel’s three engines located in separate engine rooms. The vessel’s four MTU S60 generators are split between the engine room and the starboard side of the main deck, again for redundancy.

The vessel’s double retractable bow thruster arrangement delivers improved manoeuvrability in harbour along with redundancy in the event that one is damaged.

A new and simplified ride control arrangement and operating system delivers improved control over the vessel’s motions and handling characteristics in all sea conditions. Along with a central T-foil on the main hull forward, the new ride control system includes T-foil roll control fins on each of the vessel’s amahs. All foils have been designed to permit removal and servicing without the need to dry-dock the vessel, reducing maintenance cost and down time.

Flexible Payload

The vessel has four decks - a main vehicle deck, mezzanine vehicle deck, upper passenger deck and bridge deck.

A cavernous vehicle deck has space for 245 cars or 190 truck lane metres plus 145 cars.

With flexibility in mind, the mezzanine deck is a mixture of fixed and hoistable decks that allow the carriage of up to 132 cars with a clear deck height of 2m.

When hoisted there is a height on the main deck below of 4.3m and 2.3m when lowered, and hoisted in two different sections at the same time.

This flexibility gives operators the capacity to change the traffic mix on a sailing by sailing basis.

As one of many measures aimed at reducing maintenance costs or the need to dry dock the vessel, a bow thruster hatch on the forward mezzanine deck allows the equipment to be serviced while the vessel is afloat. 
 

A similar approach is evident at the aft end of the main deck where a large hydraulically operated hatch opens when the vessel is not operating, permitting access to the vessel waterjet compartment and machinery spaces. This access is complimented by bolted hatches over the main engine rooms for machinery component removal.

These design features mean the vessel spends more time in service and reduces maintenance costs for the operator.

The aft end of the vessel is strengthened to accept a conventional ramp, an optional bi-folding ramp or a shore based link span ramp. Spray curtains are installed on the main vehicle deck aft to protect vehicles from exposure to light sea spray.

Vehicle turnaround occurs at the front of both the main vehicle deck and mezzanine levels ensuring fast loading and unloading. The vehicle deck is designed to carry dangerous goods.

Comfort at the Next Level

To maximise accessibility, passenger access is achieved via staircases located both port and starboard of the vehicle deck, with a disabled persons lift on the port side.

In order to isolate noise and vibration to the main deck, the vessel’s entire superstructure has been resiliently mounted below the passenger deck.

This important design feature provides a quieter, more comfortable passenger environment, reducing exposure to vibrations and stresses and allows for the large panoramic windows evident throughout the upper deck.

All passenger seating is located on the upper deck, which is separated into three lounges and can be customised to seat between 950 and 1165 passengers. Onboard amenities are designed to maximise accessibility and include wheelchair-accessible toilets, lift and four independent passenger entry points.

A business class lounge located on the forward upper deck is equipped with Beurteaux Ocean Club seats and dedicated bar and offers panoramic views over the bow.

The extensive range of high quality facilities on the passenger deck include two bar areas, a food preparation room and service counter, baby change room and disabled person toilets. The upgradeable bar design features hot / cold servery and attractive black granite bench tops, a design feature repeated throughout the vessel. High quality wool carpet and wood laminate offer both style and durability.

In a first for large high speed craft, the upper deck is installed with high efficiency LED lighting, which requires significantly less electrical power and produces far less heat that traditional lighting, along with bulb life of up to 30,000 hours. This reduces both the vessel’s overall running costs and emissions.

An IMCOSS^tm integrated PA and entertainment system with DVD, CD and MP3 player ensures passengers and crew are informed and entertained, with a backup emergency unit situated within a separate protected compartment. Messages and entertainment are broadcast via the vessel’s many ceiling mounted high-definition Toshiba LCD screens.

Throughout the vessel, a passenger-friendly seating density ensures rows are limited to no more than 2-3 seats, increasing comfort and accessibility, which is important during longer journeys. The amidship lounge features Beurteaux Tourist high back seats and room for an additional bar or shop. An open passenger sundeck with bench seating - a popular facility in warmer climates – is situated on aft upper deck.

The highest levels of passenger and crew safety are assured with the availability of four Liferaft Systems Australia MES systems using twin track slides for faster and safer side-by-side passenger evacuation to canopied 100-man inflatable rafts.

A separate crew mess with lounge, table and well-equipped kitchen is located amidship alongside stair access to the vessel’s upper bridge deck.

Superior Control and Monitoring

Featuring a similar design to the successful arrangement on “Benchijigua Express”, the bridge deck includes separate engineer’s console with MarineLink equipment monitoring system and CCTV to all vehicle and engineering spaces.

A dedicated aft facing control console with duplicated engine, waterjet and bow thruster controls allow stern docking manoeuvres can be conducted safely.

Quality Alutech seating provides added comfort for the Captain, who is positioned with a 360 degree panoramic view around the vessel. The bridge features an ergonomic design housing state-of-the-art navigational equipment including Kelvin Hughes X-band and S-band radars, chart plotter, eco-sounder, gyrocompass, auto-pilot and night vision.

A separate work desk and GMDSS Area A3-compliant radio console are also located on the bridge deck.

PRINCIPAL DIMENSIONS

Length overall............................................................. 102.0 metres

Length (waterline)........................................................ 101.4 metres

Beam (moulded)........................................................... 27.4 metres

Hull depth (moulded)....................................................... 7.6 metres

Hull draft (maximum)....................................................... 4.5 metres

PAYLOAD AND CAPACITIES

Passengers......................................................... 1165 in 3 lounges

Cars.......................................................... 254 (4.5 x 2.35 metres)

Truck lane metres................................................ 188 plus 145 cars

Trucks................................................... 12 tonne double wheel axle

................................................................ 9 tonne single wheel axle

Hoistable mezzanine ramps

Stern ramp (optional)

Maximum deadweight..................................................... 680 tonnes

MACHINERY

Main engines.......................... 3 x MTU 20V 8000 M71L (9,100 kW)

Gearboxes................................................................ 3 x ZF 53800

Waterjets........................................................ 3 x Wartsila LJX 1300

Generators................................................................. 4 x MTU S60       
Ride Control System:

.................................................................. 1 x 10m² T-Foil forward

........................................................... 2 x 2.5 m² T-Foils on amahs

2 x 41kN retractable bowthrusters

1 x ‘T’ Max rudder

TANKAGE

Diesel...................................................................... 144,000 litres

Fresh water.................................................................. 7,000 litres

Black & grey water......................................................... 7,000 litres

Lube oil....................................................................... 1,000 litres

PERFORMANCE (with Ride Control fitted)

Speed....................... 39.0 knots (90% MCR, 340 tonnes deadweight)

Fuel consumption.......................................................... 4.90 t/hour

Range..................................... 760 nm @ 90% MCR + 20% reserve

CLASSIFICATION

Germanischer Lloyd

HSC 2000 MSC.97(73)

100 A5, HSC - B OC3 H_s=5m

High Speed Passenger / Ro-Ro Type, MC, AUT

Bahamian Flag Authority