Uncle Hugh finally 'knocks up a submarine'

Large viewing windows are a trademark. Hugh Fulton says the complexities of the design are enormous. Photo / Supplied

In a story that could have come straight from the annals of James Bond creator Ian Fleming, an Auckland inventor is about to release a truly revolutionary "recreational" submarine.

Hugh Fulton's Q-Sub, which will be unveiled for the first time at the Hutchwilco New Zealand Boat Show in Auckland in mid-May, will have a surface speed of around 20 knots, be able to dive to a depth of more than 120m and will weigh less than 3.5 tonnes, including its trailer. In addition, it will have large acrylic windows for easy viewing, has been specially designed to reduce the likelihood of seasickness and will be relatively easy to drive.

The story of the Q-Sub and its development is one of typical Kiwi determination, doggedness and a willingness to find new solutions to apparently insurmountable problems.

Designer and inventor Hugh Fulton had long been fascinated by the world of submarines. As the owner of a business manufacturing high-pressure gas compressors, he often used to lead shop floor discussions on the company's high-precision design and welding processes and how these could be used to "knock up a submarine".

After selling his business he had the time to pursue his interest. He travelled extensively, talking to submarine manufacturers, sellers and captains.

He quickly realised that there were real issues with the logistics of launching and retrieving even quite small submarines from other vessels. It was also apparent that once the sub was back on board, moving a suitable mother ship from dive site to dive site was no quick or easy task.

He also soon realised that, to be able to successfully produce a commercially viable submarine it would have to meet some pretty strict criteria.

"The design had to be sexy, easy to launch and retrieve and be trailerable," he says. "The batteries had to be able to be recharged easily and often and safety was obviously paramount."

Fulton quickly decided to ensure the design and construction of the submarine met strict ABS (American Bureau of Shipping) standards and that everything about the design would be as risk-free as possible. This means the sub's controls are logical, easy to learn and similar to an aircraft. An onboard computer controls the 11 electric motors and the two 150hp surface engines.

If, for any reason, the power fails, there are manual controls that ensure the sub is able to surface and radio for assistance.

The Q-Sub is also able to remain underwater for more than 72 hours even after eight hours of recreational diving. This means there is ample time for rescue should the need arise. There are also a number of different ways of getting the sub to the surface. These include jettisoning drop weights, blowing ballast, driving up to the surface with thrusters or pumping the variable tanks dry.

Fulton also benefited from having a wife with a "healthy fear of water". He asked what it would take for her to feel comfortable going beneath the waves. As a result of her reply, Fulton realised he needed to create a design that was as similar as possible to a sports car or two-seater aeroplane, the key being that the pilot and passenger are able to sit side by side in comfortable positions.

He also realised that he had to address the feeling of claustrophobia that many would experience in a tight, enclosed space. His solution was to install large viewing windows.

Although these have been far from easy to create, the benefits they bring are enormous. Not only do they address that closed-in feeling, they also enable the occupants to see the horizon while on the surface (thus dramatically reducing the risk of seasickness). Combined with the Q-Sub's twin forward-facing viewports, they also make it easy to see the bottom and the surrounding sealife, even when visibility is restricted.

To overcome the problems of launching and retrieving from a conventional mothership, Fulton took a two-pronged approach. He designed a submarine able to plane on its own bottom at an impressive 20 knots and ensured it was able to be launched and retrieved using a normal boat ramp.

Like many innovators before him, Fulton was first pleased that no one had thought to do things the way he intended and then realised why.

"The complexities of the design were enormous," he recalls. "For example, the windows are acrylic, have to be 50mm thick and alone cost over $60,000. The rotating stern legs with their associated hydraulic steering, trim cylinders and pressure compensation posed many headaches. Pumps, valves, manifolds, pressure tanks, controls and instrumentation have had thousands of hours of drawings and design put into them. Battery management systems, akin to those found on electric vehicles, all had to be sourced or designed and all the electric motors and battery systems had to be made completely pressure proof."

To ensure the submarine's steel hull would be able to handle the pressure of repeated dives, a large, 1.8-metre-diameter pressure vessel was specially manufactured abroad and brought to New Zealand. The hull was then placed inside and pressurised to 1 times the maximum depth for two consecutive "dives".

"It passed with flying colours," he recalls.

Fulton believes he can market the Q-Sub internationally for less than US$1 million ($1.3 million).

He has also been in detailed talks with the internationally renowned Warwick Yacht Design in Auckland. As a result, WYD has designed an 18m luxury power cat with its own hydraulically operated "garage". This sits between the hulls and is ideal for easily and quickly launching and retrieving the Q-Sub.

Fulton says combining his design with Warwick's means New Zealand can offer a luxury, 18m launch with a world-first planing submarine on board as a second tender for under US$5 million.

He also sees a market for the Q-Sub with police and navy search and recovery missions (with the sub being taken by trailer from one coast to the other or to a lake when required); for navy training (for underwater navigation exercises, control and trimming of submarines and mini war-games); and for fisheries observation, data gathering and water sampling.

Q-Sub

What: Two-person submarine designed and built in NZ, able to dive to over 120m

Surface speed: 20 knots

Weight: Less than 3.5 tonnes including trailer

Power: Fast recharge of batteries in less than 30 minutes

Cost: Less than US$1 million

On display: Hutchwilco New Zealand Boat Show, ASB Showgrounds, Greenlane, Auckland, May 12-15.Large viewing windows are a trademark.

Why Q-Sub?
Named after the sub-hunting Q-Ships in both world wars; shortening of Quick-Sub; young nephews could not pronounce Hugh, called him "Uncle Q".

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