Is it a boat, is it a plane? A WIG craft sets sail amongst the 4000 ships in the Singapore Registry of Ships

30 04 2010

Watching the newly christened Airfish 8-001 leave its berth for the weekend at the Promenade at VivoCity on Monday, not flying as it should really have been, but moving on the surface due to port limit speed restrictions, it struck me that it looked like a stingray, gracefully moving through the water, not below the surface as a stingray does, but on the surface. It was sight to behold, leaving against the backdrop of surreal world of Resorts World Sentosa, with its airscrews spinning. There were several fast ferries awaiting their berths at the cruise centre, gathered as if in a salute to a significant moment – the first voyage of a WIG craft as a registered ship.

Airfish 8-001 leaving the Promenade at VivoCity on 26 Apr 2010.

The shipping world and maybe the world at large is sometimes slow to accept technology for what it is and this seems especially so for the Wing-In Ground Effect technology. It is one that has taken many years since when the phenomenon was first discovered. Ground effect is actually seen in all aircraft as they come close to the ground and is used very much in nature, as it is in non aircraft applications. Many large birds such as the Albatross and Geese are able to fly long distances by conserving energy flying close to the ground – something that was realised during the Second World War when Allied bombers low on fuel were able to return to their bases in the British Isles by flying close to the ground. In motor racing, ground effect is used to create a downward force to generate a stabilising force.

Airfish 8-001 gracefully moving past Sentosa.

Ground effect is said to be the most efficient form of flight and is a technology that has been waiting to be exploited. Ground effect vehicles have actually been with us for a while, the idea being exploited to lift sea borne vehicles off the surface of the sea to minimise drag, while at the same time flying close to the ground such that the efficiency that flying in ground effect provides can be exploited. Examples of these are X-112 built by Dr. Alexander Lippisch for Collins, and the huge Soviet built Ekranoplans during the Cold War for military use. Commercially however, exploitation has taken a long time in coming. Flying close to the sea surface, there was for a long time a reluctance by legislators uncertain about which civil authority to govern the design, construction and operation of such craft, to determine if it should be seen as a boat of a plane. Why not, one may ask, fly a plane then in Ground Effect? The answer lies in the fact that planes, designed to operate in free flight, are unstable when in ground effect and pilots are trained to counter the effects by having to actively control the plane during take-off and landing. A purpose built Ground Effect vehicle on the other hand can be designed such that it is stable in ground effect without the need for active control. A feature of WIG craft is the large horizontal tail that is provided for this purpose.

Speech made by Mr Lam Yi Young, Chief Executive of MPA during the christening ceremony of Airfish 8-001 on 25 Apr 2010.

The wrangle over whether a WIG craft was a boat or a plane was finally settled with the publication of the Interim Guidelines on WIG Craft by the International Maritime Organisation (IMO) in 2002. While that paved the way for the acceptance of WIG craft as a sea craft, it has taken another 8 years before we now see the first WIG craft in the world to be registered as a ship, Airfish 8-001. This is certainly a significant milestone for the technology, one that as David Hughes in an editorial in the Business Times on 28 April 2010 noted, that has been done with “the right support structure in place to develop and exploit new technologies”, the support structure being the Maritime and Port Authority (as Singapore’s Civil Maritime agency), Lloyd’s Register, and several other government agencies and partners. Mr Hughes also outlines the plans of the company behind Airfish 8-001, Wigetworks, including its future R&D efforts.

Business Times editorial on 28 Apr 2010.

All this leads to pretty exciting prospects for the WIG craft, once seen as a poor cousin to the aircraft. Those that were present for the christening ceremony and for its first voyage, as the fast ferries in attendance off VivoCity on Monday, have perhaps witnessed an especially significant moment in maritime transportation history.

Article in My Paper on 26 Apr 2010 relating to the entry into registry.

Singapore Registry of Ships record showing Airfish 8-001 as a registered ship.


Taking flight on the future of maritime transportation: a WIG Craft seen at the Promenade at VivoCity

25 04 2010

Those of you who were down at the Promenade at VivoCity this weekend might have noticed a strange looking craft moored along the Promenade and perhaps may have speculated as to what it is. Looking somewhat like something out of a sci-fi movie, the craft was captured moving along past the Marina at Keppel Bay by a contributor to Stomp on Friday, and caught the attention of a crowd of curious onlookers as it pulled up at the promenade, who perhaps expecting to see a crew of aliens emerge as the side door opened, were greeted instead by a group of young men and women dressed in lifejackets and white overalls.

The arrival of the strange craft at the Promenade at VivoCity on Friday attracted much attention.

The brilliant white craft with its large horizontal tail quite prominently sticking out, features two large anhedral triangular shaped wings which sweep forward (as opposed to delta wing aeroplanes with swept back wings) – a feature of what is known today as Wing-In Ground Effect (WIG) Craft designed by the illustrious aerodynamicist Dr. Alexander Lippisch, a pioneer of the delta-winged aircraft who contributed much to the field of aircraft design having made designs for the Luftwaffe during World War II and later contributing to the advanced in US aircraft designs. WIG Craft are said to work on the principle of ground effect in which due to the finite distance between the lifting surface (being the wings) and the ground, a cushion of highly pressurised air increases lift as well as help in artificially increasing the span of the wing reducing wing tip vortices which are responsible for a loss of energy or induced drag. There are in effect two schools of thought in WIG craft, which in the past have been referred to Ground Effect Vehicles (GEV), the German based on Lippisch’s designs and the Russian, which features a square planform wing – looking much like a stub sticking out from the craft. While the Russian version had perhaps the advantage of simplicity and have widely been adopted for WIG designs, the Lippisch designs have the advantage of a more forgiving shift in the centre of pressure that occurs in ground effect (a phenomenon that all aircraft experience on landing) which helps greatly in maintaining the stability of the craft in flight. Lippisch designs are also said to be more efficient, and operate well at heights of one-third to one-half the wingspan, compared to the Russian version, referred to as Ekranoplans, which operate at one-tenth of the wingspan. This provides greater room to bank and hence reduce turning radii allowing for better manoeuvrability and more importantly allowing a greater clearance to be maintained over the sea and hence can operate at heavier seas.

Is it a boat or a plane?

Ground effect contributes greatly to what can be considered to be a more efficient form of flight (from an energy consumption point of view) and is used widely in nature by large bodied birds such as the albatross to conserve energy allowing them to fly over long distances. It is also known that bombers on missions over Europe which were low on fuel were able to return to their bases in the British Isles by flying low, and more information on this can be found at website of the company that owns the WIG craft seen at VivoCity. Using it in combination with a seagoing craft, allows the craft’s weight to be supported (as is necessary to reduce drag to allow for higher speeds at sea to be achieved – for example hovercraft and hydrofoils). In this case the craft can be completely lifted out of water, not just reducing drag tremendously, but also, by avoiding contact with the water’s surface, interaction with the waves is minimised allowing for a much more comfortable ride.

The futuristic looking craft features a reverse delta shaped anhedral wings, a large horizontal tail, and two air screws.

The WIG Craft now at the Promenade, the AirFish 8-001, is marked with markings which includes the company behind the craft, Wigetworks, as well as that of their partners, among which are Lloyd’s Register and the Singapore Maritime Academy, as well as Creative Technology. Interestingly, the craft is also marked with the Singapore flag as well as a number which starts with the prefix “IMO”. That it features these is significant in itself, being the first WIG Craft in the world to be registered with the national maritime authorities as a sea going vessel, IMO being the abbreviation for the International Maritime Organisation. For a long time, the technology has met with many obstacles preventing it from taking off fully, none larger that the issue of whether it was to be governed by the civil aviation authorities or the maritime authorities. Having an IMO number, which all ships entering into registry are required to, in pretty significant in itself, and represents a clear sign that the technology is about to take off.

The Airfish 8-001 seen on trials off Changi in 2008.

In a symbolic ceremony today, the Airfish 8-001 would be christened, to commemorate the significant event – a milestone in Singapore’s history as a maritime nation perhaps, the entry into registry as well as into class of a WIG craft as a seagoing vessel. Perhaps it is the start of a new chapter in maritime transportation. Other players are also known to be working on WIG craft, including the Koreans in an effort that is heavily funded by the Korean government – and we may soon take this flight – no longer a flight of fancy, but one that would propel us into the future of maritime transportation.

The Airfish 8-001 could propel WIG craft into the future of maritime transportation.

Off Changi in 2008 - the airport control tower visible in the background.

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