MV Pentalina-B - Layout

Layout

MV Iona bore hardly any resemblance to a previous Ailsa car ferry like MV Glen Sannox or the 1964 trio of MacBrayne ferries. The most obvious influence was her intended rival, MV Sound of Jura, built in Norway for Western Ferries in 1968 – the first drive-through ferry in west coast waters.

MV Iona was ten feet longer than MV Hebrides, and of greater draft, but twin rudders gave her greater manoeuvrability than the earlier MacBrayne ferries. She was the company's first vessel without traditional teak decking. Her vehicle facilities impressed, but passenger accommodation compared poorly with the 1964 ships. She had very little open deck space for passengers. Forward on the boat deck ('B' Deck), there was a full-width lounge for 101 passengers with seating upholstered in blue until they were recovered with sick coloured vinyl in 1984. High bows obstructed the forward view for seated passengers. Aft of this, a deckhouse held a cafeteria. On the lower deck ('E' Deck'), below the car deck were a smoke-room/bar (no longer used) and crew quarters. Unusually for a large MacBrayne ship, Iona had no sleeping accommodation for passengers.

MV Iona's main machinery was twin Paxman engines, each driving a fixed-pitch propeller through a gearbox, reducing an engine speed of 900 rpm to a propeller speed of 300 rpm. The first ship in the company's history to have such geared transmission, these gearboxes were a regular source of trouble throughout her career. She was equipped with Denny-Brown retractable stabilisers and a bow-thrust controllable-pitch propeller. Engine Control was possible from the consoles in the engine-room, in the wheelhouse, in the bridge wings, or at the aft end of the navigation bridge deck, for astern working.

MV Iona's car deck could take vehicles up to 16.5 feet in height and 32-ton in weight. She had a bow visor, a stern-and side-ramps with a hoist that could handle 27.5 tons. Traffic for the hoist was marshalled by automatic barriers. Her bow-visor, raised by a racking system, rather than a hinge, was not watertight, limiting her passenger-carrying capacity later in her career. The bow-ramp was in several sections, which coiled back into the vehicle deck, reducing available car spaces.