Halmatic won the order through the competitive tendering process and the Clyde Ports Authority, with its pilot boats steaming out of the Firth of Clyde into what are often some of the most difficult sea conditions in the British Isles, is a most appropriate owner for the first Halmatic Cara 52. This large 52ft 5in LOA (16.0m) pilot boat, on a beam of 4.6m, replaces an even larger 1970s built Nelson 60 for the Authority, which has held faith with the adage that in their part of the world, size matters.

Mount Stuart is a twin screw fast pilot boat in GRP and classed Lloyds Register Special Service Craft Rules. It meets MCA Code of Practice for the Safety of Small Workboats and Pilot Boats to 24M loadline, sea area category 3 to 20 miles from safe haven and is designed and built to Lloyds Register Special Service Craft Rules for SSC HSC Mono Pilot G2.

Power is provided by twin Scania DI 12-41M turbocharged and aftercooled marine diesels rated 301kW (409hp) at 1,800rpm, set to run up to 3,000 hours per year at intermittent power. Drive is via close coupled Twin Disc MG 5114A down angle gearboxes with a 1.5:1 reduction ratio driving through conventional shafts and four bladed NAB fixed pitch propellers. The craft displaces 23.5 tonnes with a fully loaded draught of 1.22m. Equipped for a crew of two and up to six pilots, maximum speed of 24 knots.

A fuel capacity of 1,750 litres provides a range of 250 nautical miles at top speed, including a 5% reserve. Diesel fuel is stored in two equal size, cross-connected 875 litre tanks located port and starboard in the tank space.

Halmatic is vastly experienced at laying up GRP hulls so this first effort with a Cara design was a straightforward process, with Halmatic engineers linking with their counterparts at Cara Marine via email and CAD as required. The one piece hull is a single skin laminate structure of chopped strand mat and woven roving reinforcements in 'E' glass impregnated throughout with polyester resin. The hull shell is stiffened using a system of longitudinal girders, stringers and transverse frames, and is subdivided by transverse watertight bulkheads. Special reinforcement is built into the boarding area of the topsides and deck to accept extra loads applied during pilotage activities.

Watertight transverse bulkheads subdivide the hull into Forepeak, Store, Toilet/Store, Machinery Space, Tank/Void Space, and Aft Peak areas.

The deck is of one piece plywood sandwich construction with the sandwich core of 18mm BS1088 plywood. Deck beams are constructed from a polyethylene of PVC foam cores and are positioned and aligned with the hull frames. The beams are tied to the bulkheads and other structure by strong hanging knees.

The raked windscreen superstructure is one piece sandwich construction moulding again utilising a complex of chopped strand and woven roving 'E' glass impregnated with polyester resin. In this instance, the sandwich core is end grain balsa. For the engines, their is an unobstructed single point lift through a large hatch in the coachroof.

Each main engine and gearbox has its own secondary cooling circuit, with seawater passed through heat exchangers via engine mounted pumps before being injected into the exhaust system. Each engine exhausts independently underwater. The exhaust system is specially designed to allow seawater used for engine cooling to be injected into the exhaust gas stream. The resultant mixture of cooled gases and seawater is conveyed to the sea through exhaust outlets located in the machinery space.

The wheelhouse features three double glazed forward windscreens, each fitted with a Hepworth wiper mounted below with dual speed controls and washer nozzles. Three further double glazed units on each side of the wheelhouse and another in the wheelhouse door insure good all-round visibility. Two Ardic three speed fan heaters connected via a 29 litre calorifier to the port engine cooling water system feed eight outlets at the base of the forward screens for demisting and heating the wheelhouse.

The port side helm seat and the crew seat are KAB 301 KHB type and are fitted with suspension control, arm rests, head rests and lap belts. The four pilot seats are KAB 514 type also with suspension control, arm rests and lap belts plus reclining back rests. For heavy seas, internal handrails are fitted at each pilot seat position between the seat base and deckhead while two overhead rails run the length of the wheelhouse.

Throttle and gear lever as well as engine start/stop are mounted at the helm position accompanied by a comprehensive set of instrumentation set into consoles.

Visible lights and audible signals indicate low oil pressure and high cooling water temperature for each engine. A console mounted monitor is linked to a CCTV camera mounted in the engine space, where Pyrogen aerosol extinguishers are situated that can be operated remotely from the wheelhouse.

The Wagner electro-hydraulic steering is engine driven and provides the direct and positive feel essential for precise pilot boat operations.

The wheelhouse is fitted with a comprehensive package of navigation and communication equipment which includes a Simrad model CR42 TFT with GPS, which has a range of 24 nautical miles and consists of a 10in CRT daylight vision monitor in the wheelhouse and a 4kW radome mounted on the wheelhouse roof. A Simrad RFC fluxgate compass with rate sensor is mounted under the console and there is a Raytheon ST60 tri-data depth log/echo sounder with a bronze transducer.

There is an Offshore 105 magnetic steering compass and a Marco 24V DC compressed air single trumpet siren mounted atop the wheelhouse with a control switch on the console.

For communications there is a Simrad RD68 VHF/DSC class D radio fitted with integral DSC as well as a waterproof Icom ICM21 portable VHF radio.

A Raymarine 430 loudhailer system includes a roof-mounted DNH speaker. One Jotron SART is bulkhead mounted in the wheelhouse.

Safety equipment reflecting the precarious nature of pilot transfer is appropriately thorough.

Continuous stainless steel handrails run at constant height along both sides and across the front of the superstructure, following the shape of the coachroof to maximise the boarding area. A manually operated hinged folding stainless steel recovery platform with stainless steel grillage is arranged in the transom recess and is tested to a proof load of 400kg. A stainless steel tubular 'A' frame man overboard gantry is arranged aft over the platform to assist in MOB recovery and is tested to a proof load of 240 kg. Mount Stuart is also packed with the full complement of liferaft, life jackets, lifebuoys, safety harnesses, line and quoit throwers, a matesaver and a pilot boat flares pack.

Subtle in presentation but providing essential protection during the controlled collisions at sea which are a pilot boat's lot is a fendering package with an upper single band of 200mm 'D' section rubber incorporating a toe rail section from bow to transom secured with stainless steel bolts and fender washers.

A lower single band of 9A82 'D' section rubber fendering is fitted directly to the hull by the same method. There are two vertical lengths of 9A82 at the transon corners port and starboard between the upper and lower fender while eight fender diagonals per side of 6A81 'D' section rubber are arranged between the sheer and lower fender along the topsides.

The Mount Stuart is clearly built for comfort and for speed to a very high standard, but most importantly, it is built to perform and endure throughout the arduous working life which lies ahead of it.

MJInformation No: 18000