The hovercraft as we know it has been in existence since the SRN1, developed by Sir Christopher Cockerell and built by Saunders Roe, first hovered on 11th June 1959. The first passenger-carrying hovercraft to enter regular service was the Vickers VA-3 in the summer of 1962, carrying passengers along the north Wales coast from Moreton, Merseyside, to Rhyl. The Hovertravel service between Ryde, Isle of Wight, and Southsea commenced on 24th July 1965 using 38- seat SRN6 craft and, in 2016, entered a new era with the delivery of two state-of-the-art 12000TD hovercraft to replace two ageing AP1-88 craft in frontline service. East Cowes on the Isle of Wight, was a thriving centre of hovercraft production for Saunders Roe/Westland with the SRN2, SRN5, SRN6 and cross-channel SRN4 (1968) variants all being born here plus the BH-7. The SRN2 had also been trialled between Southsea and Ryde in 1962 among other areas. In 1966 Saunders-Roe and Vickers joined forces as the British Hovercraft Corporation (BHC) with other U.K. manufacturers of the time including Cushioncraft and the Woolston (Southampton) based Hovermarine. Hovercraft were generally constructed using aircraft industry methods until the ubiquitous AP1-88 was developed jointly by Hoverwork, BHC (British Hovercraft Corporation) and the NRDC (National Research Development Council) from 1981.

The first pre-production prototype, the Tenacity, was built and tested in 1982 using shipbuilding techniques and materials (welded aluminium structure and 2x Deutz BF12L 513FC air-cooled turbo-diesels for propulsion and 2x MTU V12 water-cooled 800hp turbo-diesels for lift) prior to entering service with Hovertravel in July 1983 when the AP1-88s began to replace the smaller and noisier SRN6 craft. The Tenacity’s aluminium hull was produced by Fairey Allday at their Gosport boatyard and fitted out at Hoverwork’s base in St. Helen’s. Hoverwork began operations in December 1965 to support Hovertravel and to maintain/build craft, firstly at Dinnis Yard in Cowes and then at Woodnuts Yard in St. Helen’s on the shores of Bembridge Harbour from 1974. Hovercraft construction and maintenance at the BHC/GKN Westland East Cowes premises was phased out leaving just Hoverwork representing the industry on the Island. In 2008, the Bland Group increased its shareholding in Hovertravel from 25% to 99.92%, and also purchased Griffon Hovercraft Ltd, a hovercraft manufacturer based in Southampton. The Bland Group can trace its history back to 1810 when a small shipping agency was established in Gibraltar by Marcus Henry Bland. This company was later acquired by the Gaggero family, and today, over 200 years later, it continues to trade, evolve and prosper under that one family. The Gaggero family has managed the Bland Group since 1862, whilst owning and developing this remarkable company since 1891. Over four generations, the family has successfully steered the Bland Group through momentous, and often turbulent, periods in the history of the world and its resulting economic vagaries. In March 2009, Hoverwork and Griffon were merged to create Griffon Hoverwork Ltd., a world leading hovercraft producer with over 40 years of experience in the design, development, manufacture and operation of hovercraft.

The last complete craft built at Hoverwork in St. Helen’s was the Canadian Coastguard’s Mamilossa with the final passenger craft being Hovertravel’s BHT-130 Solent Express of 2007. The Canadian Coastguard’s Moytel was fabricated at Hoverwork’s I.o.Wight premises and then taken to Southampton for fitting out when the company’s base was moved across the Solent. The newly combined Griffon Hoverwork Ltd. relocated to Merlin Quay, Woolston, Southampton from Hythe (Griffon Hovercraft) and St. Helen’s (Hoverwork Ltd.). The new yard, the former 4.37 acre Vestas site, officially opened on 11th November 2010. Griffon Hoverwork Ltd. has sold, and has in service more than 150 hovercraft in over 35 countries worldwide, operating in environments ranging from the jungles of South America to the freezing conditions of the Arctic. The hovercraft produced are used for passenger ferries, survey work, to support civil engineering support in the oil and gas industries, in logistics and also for Navy, Army, Coastguard and Paramilitary customers worldwide.

Craft Evolution

Hovertravel employed a total of five SRN6 craft on the Ryde- Southsea service between 1965 and 1983 and then a total of eight AP1-88 craft between 1983 and 2016 (Tenacity/Resolution/ Perseverance/Double-O-Seven/Freedom 90/Courier/Idun Viking and Island Express. The Freedom 90 (rebuilt/lengthened to become an AP1-88/100 in 1999) and AP1-88/100 Island Express remained in service at the time of writing. The Idun Viking is understood to have been the last hovercraft to use the slipway at the former BHC Columbine Building in East Cowes. The original project to replace the 95 seater AP1-88s was in the form of the larger I.o.W built 29.3m long/131 passenger capacity BHT-130 craft Solent Express. The hull was fabricated at Aluminium Shipbuilders in Fishbourne, I.o.Wight. Her service was short-lived (2007-2011) following a port side propeller failure on 30th October 2011.

The craft also proved to be less economical than the AP1- 88s. At the time of writing she remained at Woolston for sale with modified propellers and skirt. So, from late 2007 the Hovertravel fleet reverted to just two craft, the Freedom 90 (built 1990) and the Island Express (rebuilt/upgraded from the Freya Viking of 1983 in 2001). By this time both craft were beginning to show their years with minor and major breakdowns becoming a little more regular with the added problem of there being no third craft on hand to cover for breakdowns when a two craft schedule was required. Up to 70 flights a day across the Solent are offered, each one taking under 10 minutes. On 9th August 2013 came the welcome news that Hovertravel had placed an order for two new hovercraft with Griffon Hoverwork Ltd. The latter, which also traces its roots back to the 1960s, had been developing a new passenger hovercraft known as the 12000TD, the 12000 representing the 12,000kg payload and the TD standing for Turbo Diesel. This became the 8th craft type to be designed and built by the manufacturer, who also offers a range of 5 monohull Enforcer and Cougar fast craft. At the time of the announcement the craft was still in the final design and development stage with capacity stated as 85-95 passengers. On 26th November 2014 the construction of both craft, each costing £5 million, was unveiled at Griffon Hoverwork in Woolston. Guests were taken there by Hovertravel’s Freedom 90 from both Ryde and Southsea. A mock-up of the front of the craft and cockpit was on show as well as the two hulls at various early stages of construction. During the week beginning 18th January 2016 the first of the pair of 12000TD craft hovered for the first time on the apron outside of the building hall and took to the waters of the River Itchen and Southampton Water for the very first time on 28th January.

On 18th February the craft travelled to the sandbanks off Ryde for tandem manoeuvres with the 26 year old AP1-88 Freedom 90. This occasion was used to gather data on the performance of the new propellers among other trials. The first month of trials were heralded a success with the craft making her first visit to Southsea hoverpad in force 7 gales on 2nd March. This allowed the Test Pilot to develop the best technique for landing at Southsea and also evaluate the craft’s skirt in these conditions. This trial proved very successful with several landings and departures completed in challenging weather. A full evacuation trial was also staged on 26th February using volunteers, taking 8 minutes, which is actually half the time to meet the regulatory requirements with The Maritime Coastguard Agency observing the procedure. This occasion marked the first time that the craft had been united with its leather seating. Hovertravel had searched the world to source MCA regulatory, comfortable, durable and stylish seats for the new craft with the best option, to fit this high level of requirements, being manufactured in Perth, Australia. The final passenger capacity was confirmed as 80 and the hovercraft remained white until the branding was revealed.

The big reveal took place on 18th March with the names announced as Solent Flyer and Island Flyer. The livery consists of a striking design which is a dynamic representation of the union flag, celebrating the Britishness of both the hovercraft and the operation. The vinyl image that adorns the front of the craft’s passenger cabin (with the sides remaining white) was applied by Signwork using a 3M Envision wrap film. The vehicle wrapping market is continuing to expand, with companies such as Signwork pushing the boundaries as to how far this sector can go in terms of the vehicles that can be wrapped and, potentially, discovering new revenue streams. Indeed, Red Funnel’s new Red Jet 6, built in East Cowes within the Columbine Building that had spawned both flying boats and hovercraft (and featured in the September issue), also carries a vinyl wrap instead of paint on its hulls and superstructure.

Hovering Home

Having completed the initial sea trials, passing with flying colours, the Solent Flyer made her first visit to the hoverpad at Ryde at around 14.00 on 21st March 2016, departing that evening. Trials continued with the newbuild and, on 11th April, Hovertravel announced that the Solent Flyer was officially part of the fleet having arrived at Ryde that day. Pilot, Engineer and Crew training commenced thereafter with frequent crossings to Southsea and even visits to Seagrove Bay and Totland Bay/Alum Bay among the Solent sorties. A three month period for staff to be familiarised with the new technologies and efficiencies had been planned from the outset including a one to one training for Pilots, training from Griffon’s construction teams to the engineers plus one to one training with the crewmembers. The Solent Flyer was shown off to invited guests and media on 27th July, an event that included a trip on the new vessel to Osborne Bay, Lee-on-Solent and back to Ryde via the Solent Forts. The Island Flyer took to the water in early June prior to making her Ryde debut on 23rd June during trials. Her Union Flag vinyls were applied shortly after that occasion.

The 80-seater 12000TD duo are 22m long, 10m wide and 7m high compared to the 95-seater AP1-88/100s which are 25.40m long, 10.06 wide and 7.92m high. The 12000TD hovercraft delivers the advantages of low running and maintenance costs, as well as a fully flexible internal layout. Production improvements on the 12000TD mean noise levels are significantly reduced when compared with the AP1-88 craft. The average reading taken in the public space was 74dB, equivalent to that of office noise. The 12000TD’s main cabin can be configured depending on the operator and journey times so as to balance the number of seats with passenger comfort and facilities. Three large windows are on each side of the cabin plus one smaller forward on either side. The cabin dimensions are 14m long, 5.8m wide and 2.5m high. The main cabin and engine bay cover superstructure is an aerodynamically designed composite panel structure fixed to a fully stressed aluminium frame. This design provides an extremely light-weight and stiff main cabin structure which is robust enough to survive years of commercial service in either configuration. Three levels of air-conditioning and heating are available for the wheelhouse and the passenger cabin depending on climate.

The 12000TD is designed and built in a modular method which delivers the commercial benefits of a standardised platform. The wheelhouse in the standard passenger craft is centrally mounted above the main cabin to provide excellent 360 degree visibility for the pilot. Access is gained from the main cabin via a vertical ladder and two crew seats are fitted as standard. The wheelhouse structure is a fully composite modular design suspended from the main cabin aluminium frame on resilient rubber mountings to improve ride comfort and reduce vibration. The windows are all heated glass and fitted with approved sun-blinds. The wheelhouse deck has A30 grade insulation against fire and noise to provide an excellent working environment. Two over the bow loading ramps are fitted for easy self-loading of passengers and light cargo. The port side clam door reveals step access whilst the starboard side offers ramped access for wheelchairs, prams, bicycles and freight trollies. Seats in front of the starboard side door are folding to allow wheelchair access plus an aircraft cabin style jump seat is situated at the front of the passenger seating for a crewmember. The front loading system does mean that the passenger cabin lacks forward facing windows but the interior is so light and spacious thanks to LED lighting and the large windows that this does not matter. Forward views can be provided by the four monitor screens installed, via a GoPro at the Pilot’s discretion, otherwise these screens show safety video & adverts only. A centrally located luggage stowage locker, which is compliant with HSC Code safety requirements, is available immediately inside of the passenger access doors. Fitted with roller shutter doors, the area offers bicycle, pram and trolley stowage plus luggage etc. Two collapsible shelves increase the versatility of the locker space. The 12000TD is designed and built to comply with Lloyds Register Special Service Craft Rules with a notation set of 100A1 SSC Passenger (A) ACV HSC LDC G2 MCH, and is also compliant with UK MCA High Speed Craft Regulations based on the applicable sections of the IMO High Speed Craft Code 2000. The main hull structure is built of marine quality aluminium alloys 5083 plate and 6082 extrusion. The buoyant volume of the lower hull structure is transversely framed and sub-divided into watertight compartments to comply fully with the HSC Code intact and damaged stability requirements. The bottom and side shell plating is thick enough to provide excellent impact resistance to the everyday service expectations of a commercial hovercraft service.

The hull is fitted with landing skids in favour of feet, with replaceable wear surfaces, and is protected with a high quality paint scheme. The side bodies are an evolved mix of composite buoyant bolt-on modules to provide excellent crash impact zones and are easily replaceable. Lightweight side decks provide easy access to the inner skirt and lower hull for ease of maintenance. The external decks have a non-slip surface finish. The most vital component to a hovercraft is of course the skirt and that fitted to the 12000TD is the latest development of a bag and finger type manufactured from materials proven during thousands of operating hours in the harshest environments. It is tapered from front to rear to improve sea-keeping whilst ensuring that the best possible obstacle clearance is achieved. To aid routine maintenance all the fittings are simple largescale fastenings which do not require special tools so that fingers can be replaced without lifting the craft. The skirt on this new generation of craft is also free of dividers within the air cushion area. The usual hovering height is 1.6 metres. Unlike the AP1-88/100s the Solent Flyer/Island Flyer have a highly developed integrated lift and thrust system, driven by two reliable and economic MAN D2862 diesel engines each developing 793kW. The engines are fitted with a cold starting system to -5 degrees centigrade. Each engine is supplied with fuel from a separate tank located under the side-deck which can be cross connected if required. The fuel lines are fitted with the required emergency shut-off valves and market leading water and particulate filtration systems. The four highly efficient lift fans are mounted in pairs outboard of the engines and are driven through rigid and robust belt cage arrangements. The air intakes for the mixed flow lift fans are located aft either side of the passenger cabin.

The forward movement is provided by a pair of extremely low speed (approx. 60rpm less than an AP1-88 propeller) 5-bladed 3.5m variable-pitch ducted propellers. These have been specially designed for this application and produce substantially less noise than any other hovercraft of a similar size and are also driven from the same belt cages that connect the engines with the lift fans. The exceptionally long drive belts are custom made for the purpose. The propulsion modules are fully redundant and the craft will operate at reduced performance to return safely to base on one engine. Primary yaw control is provided by a fly-by-wire rudder system operated by the pilot from the wheelhouse (rudder pedals or joystick can be fitted). The fast response rudders are fitted directly behind each propeller duct to provide excellent manoeuvrability and control. Alternative directional control can be achieved with differential thrust from the variable pitch propellers. Elevators are fitted in each propeller duct which are controlled separately by a fly-by-wire system so that they can either roll the craft to assist with directional control or rapidly change trim. The 12000TD also utilises a water ballast system to provide the pilot with complete control of craft trim and heel angles caused by offcentre loads or wind. The four tanks situated in the corners of the hovercraft hull are interconnected using very high capacity pumps that can transfer their entire contents in less than two minutes. All machinery systems are controlled from the wheelhouse. Engine throttles and propeller pitch are controlled with levers between the operator positions. Engine monitoring and alarms are provided on separate displays for each engine. System controls and alarms are also provided at the operator positions and are connected to the craft’s CANBus system.

The AP1-88s use “puff ports” either side of the wheelhouse that can turn 360 degrees to aid manoeuvrability at the craft’s bow. However, the 12000TD has a rigid transverse propeller thruster located either side of the wheelhouse to perform this task, rather like a transverse tunnel thruster on a ship only the hovercraft’s uses air rather than water! The hovercraft’s electrical system is 24V DC supplied via two independent banks of maintenance- free batteries plus an inverted 220-240V AC system is provided for domestic services. Two alternators on each engine plus a 220-240V AC Shore Supply connection provide the standard options for power generation and supply. Unlike their predecessors, the 12000TD craft offer covered and walk-in engine bays accessed via the A60 firewall doors at the rear of the passenger cabin. The firewall between the compartments can also be removed to provide a commodious working environment. The 12000TD has a laden weight of 42 tonnes (42,000kg) and a maximum payload capacity of 12 tonnes (12,000kg) whilst the standard endurance time is 5 hours without refuelling. The new craft can generally operate in winds of up to 35 knots and seas of up to 1.5m wave height at service speeds of up to 45 knots.

Double Celebration

With the Solent Flyer effectively being the prototype for this new class of passenger craft, the period for trials and training was much longer and more intensive than for new vessels of a preexisting design. Each Pilot also had a 25 hour training course to undertake not to mention all the Crew and Engineer training. The Solent Flyer was handed over to the Hovertravel fleet in April 2016 as mentioned above but, at the time of writing (August 2016), the Island Flyer was still based at Griffon Hoverwork’s Woolston facility for trials and refinements. The first passenger flights took place on the afternoon of 1st July with an ad-hoc entry into service following on from there to gradually build up the service hours. A passenger carrying charter ran on 9th July and two days later both craft were united on Ryde’s Hoverpad for a joint dedication and naming ceremony. The state-of-the-art passenger hovercraft were christened by Sir Ben Ainslie CBE who took a break from his training for the America’s Cup event off Southsea later that month to attend the event. The new craft have a long tradition to uphold with the service now being in its 51st year. Hovertravel operates approximately 70 crossings per day/450 per week, carrying in excess of 900,000 passengers per annum. The Millionth passenger was carried way back on 8th October 1968! The company will also continue to run unscheduled charters for Weddings, Parties and Business Meetings to alternative locations such as Priory Bay, Bembridge and Sandown. The expected craft life of a 12000TD is at least 20 years with a midlife refit and rigid maintenance regime. The week beginning 14th August looked likely to feature a day when both new craft were trialled in service together.

Special thanks must go to Stephen Forster, Loretta Lale (Hovertravel Marketing), Neil Chapman (Hovertravel MD), Neil Pennycook (Hovertravel Engineering Manager), Doug Coulson and David Ingham for their invaluable assistance with information and images for this feature. Full details of the hovercraft range built at Woolston can be found at www.griffonhoverwork.com.

Technical Specifications