The first Aquabus 24, ‘Hydro 1’, heralds the arrival of a new concept for small fast passenger vessels. The 9.75m aluminium catamaran was commissioned and built by Cardiff Baylink Ltd of Cardiff Bay to fulfil a need for modern, safe, fast and stable water transport to service Cardiff Bay and the rivers. The design was entrusted to their favoured naval architect, Colin Silvester, after the completion of their 18m corporate hospitality steel catamaran from the board of the same designer. That vessel has been in very successful operation for four years in Cardiff for sister company Cardiff Bay Cruises Ltd.

Cardiff Bay was formed in 1999 by constructing a barrage between Cardiff and Penarth, thereby forming a 500 acre freshwater lake fed by the rivers Taff and Ely. Access to the Bristol Channel is via three sea locks in the barrage.

The formation of the bay has given rise to a tremendous amount of building, regeneration and development of the area, especially along the water’s edge. This in turn has made a water transport system a real possibility as the Bay’s depth is kept to a level of 4.5m. Water bus landings have been constructed by Cardiff Harbour Authority (part of Cardiff Council) and the Authority is actively encouraging the development and use of water transport.

Because of the size restrictions in the River Taff (draught and air draught especially), the designer was tasked to come up with a high speed, low wash catamaran hull in aluminium to carry 24 passengers, two crew, and with full wheelchair access. This was done with the 9.75m hull, which has a draught of only 0.5m.

The resulting design is a Class V British Passenger vessel that has achieved a speed of 28 knots (lightweight), powered by a pair of VW TDI 150-5 diesel engines driving MerCruiser Bravo 1 legs. The propellers are three bladed stainless steel of 15½” diameter and 17” pitch. The engines, filters and batteries are accessed via flush hatches in the aft deck giving plenty of space for servicing and maintenance.

The Aquabus 24was constructed for sister company Cardiff Baylink by Aquabus Water Transport Solutions from an aluminium kit supplied by Jordans from CAD by Deri Jones & Associates.

The bottom plates are of 4mm marine grade aluminium, the hull and topsides of 3mm marine grade aluminium, and the transom is 6mm aluminium. The two fuel tanks are constructed of stainless steel with a capacity of 220 litres each.  

The vessel was built at an engineering workshop in Taffs Well, South Wales. Plans are now being made to construct a further two vessels (Aquabus 24 Mark 2), which will be 10m long and will feature VW V6 engines driving water jets to give a similar, if not better, performance than the Aquabus 24  Mark 1. Theseboats will join the water transport system in Cardiff Bay.

Aquabus Water Transport Solutions wishes for people to relate to the vessel as being another form of public transport, so the interior is designed to look like a bus, with comfortable bus seats, carpet-lined bulkheads and deckheads, and high-visibility hand rails. The interior is light and airy, with windows supplied by Cheshire Vehicle Windows. There re two large sliding windows which double as emergency escapes as well as giving the feel (in the summer) of being on an open boat.

Boarding is through an aft gate (either side) of 820mm width, opening at a height of 500mm above the waterline to allow easy access for wheelchairs. Bicycles can be accommodated on the aft deck. Entry into the cabin is via double doors. There is provision for a roof mounted air conditioning unit if required.

Equipment includes Raymarine C chart plotter with radar overlay and a smart heading sensor, Backeye rear view colour cameras, VHF radio, remote control searchlight, Webasto heating system with demisters and a Pyrogen fire extinguishing system in each engineroom.

Passenger counting is facilitated using Aquatrack, jointly developed by Aquabus and a local electronics firm. This system enables complete tracking and monitoring of the vessel at all times (position, speed and number of persons on board).

Safety equipment include a 30 man liferaft with HRU supplied by Cosalt, two lifebuoys with lines, two lifebuoys with lights, 31 inflatable lifejackets, one fixed hand operated fire pump with hose and nozzle and a portable hand operated bilge pump capable of pumping out the six watertight compartments (three in each hull) via pump-out fixtures in the deck. Each watertight compartment has an electric bilge pump (six in all) with a float switch which can be operated manually or automatically. The cabin is equipped with two foam extinguishers and one dry powder extinguisher. Fire protection in the engineroom is to A30 standard and was supplied by Insulfrex.

The main cabin is supplied by four main flush mounted bus lights, and four night lights. The aft boarding area is served by individually switched boarding lights. The helm position is forward of a central bulkhead on which is mounted an aft-facing 26” TV screen which displays the safety information and advertisements. The house battery is situated immediately below and behind the helmsman’s seat. A 240V sinus wave inverter is supplied to run the TV and associated computer.

Hydro 1has undertaken exhaustive trials since it was launched on 19 May of this year. It has performed as expected and required, providing a fast, stable and comfortable water transport system which would be suitable and timely for many locations in addition to Cardiff Bay.