Subeo: The World's First Under Water Sports Car Oct 24, 2003 – By Barry Zellen
Subeo, a specialist engineering company, has created the World's first
underwater sports car, GEMINI.
GEMINI is a submarine designed as a recreational vehicle and has a depth
range of 50m, even at this depth the pressure on the hatches is about 14
tonnes and the total pressure on the pressure vessel itself is about 125
tonnes. The operating depth is 50m as this is the maximum depth for breathing
normal air which will enable users of the craft to flood the vehicle in the
event of entanglement and escape the vehicle using normal breathing
apparatus. The most interesting viewing is above 50m.
Everything You'd Find In A Large Submarine:
It has all the components of a large submersible namely:- surface buoyancy
tanks, trim tanks, lead trim, lead acid batteries, life support systems,
front and rear hydroplanes, a rudder and a very sophisticated control system
consisting of a PLC (Programmable Logic Controller) and many electrically
operated solenoid valves, pneumatic actuators, stepper motors, encoders and
several electrical power systems. Its estimated forward speed is 4 - 6 knots
and when the surface buoyancy tanks are fully blown will have freeboard of
300 - 400mm. The design and control of the submersible combines just about
every engineering discipline. i.e. structural, electrical, mechanical, life
support, physics, hydrodynamics and naval architecture.
The World's First Recreational Submersible:
There have been several attempts to build recreational submersibles but due
to the complexities of driving these vehicles and being able to carry out the
many sequences of operations it has only been possible with the advent of
modern control systems that these vehicles are a practical proposition. A
modern submersible is more complicated than a small aircraft and is operated
in a much more hostile environment. It also has to carry all necessary life
support as well as resisting huge forces.
SUBEO has developed its 2 man GEMINI sub using up to date technology and
modern materials to create a stunning underwater vehicle for the new
millennium.
Main Features:
The submersible is a two-man craft with an operating depth of 50M and it is
powered by a lead acid battery, 68v 130 amp hour capacity. It has a maximum
speed of approximately 4 knots. The main pressure vessel is of carbon steel,
hot zinc sprayed and finished with polyurethane paint system, the rest of the
structural components are of 316 stainless steel. The fairings stability fins
and surface buoyancy tanks are manufactured from glass reinforced plastic,
the weight of the craft is approximately 3 tonnes in air.
The pressure vessel is torispherical in configuration with a volume of 1500L.
The seating configuration is side by side with the occupants viewing through
acrylic domes which are also the access hatches. When floating on the surface
with the 4 main buoyancy tanks blown the craft has approximately 3OOmm
freeboard below the hatches.
Operation:
The pitch of the craft is altered by a lead trim system which moves a 150kg
weight forward and aft which can pitch the craft by 16 degrees up or down,
front hydroplanes and rear hydroplane in the race of the propeller are also
available for pitch control when the craft is underway. Roll trim is obtained
by pumping water from side to side in the main spherical variable buoyancy
tanks either side of the vessel on the centre of gravity. A high pressure
pump and valve system pumps water into these buoyancy tanks to adjust the
buoyancy of the craft, this pump system is inside the craft in a central pod
between the occupants. All main functions of the craft are controlled through
a programmable logic controller. All valves and actuators are operated by
compressed air, the main control surfaces are moved by stepper motors with
shaft encoders being used to feed back position data to the PLC. The main
surface buoyancy tanks which have a capacity of about 1400L are blown by
compressed air with the vent valves consisting of diaphragm valves also
operated by air.
Motors & Cabin Pressure:
Rotary penetrators are oil filled and pressured to above ambient pressure,
this pressure Is monitored to ensure the integrity of the seals at all times.
The main motor is a 4KW brushed DC motor running at 900 rpm driving a 3
bladed propeller in a kort nozzle which is further surrounded by a large
aluminium duct which carries the rudder and rear hydroplane. Larger brushless
oil cooled motors could be used for higher speeds. The hatches are flanged
hemispherical acrylic fabrications to SME VHO1 they are clamped in a
stainless steel hatch surround which is fixed to a special hinge to allow the
hatch to be clamped by 3 compressed air dogs on each hatch, ensuring the
hatch is sealed on it's 'O' ring seal at shallow depths.
Controls:
All the main control options are on a joystick control, positioned between
the occupants so that both may pilot the craft. The pilots side (port) has
further control switches and a man machine interface MMI where main operating
conditions are displayed, depth, internal pressure, C02, 02 levels, trim
values, lead and main variable buoyancy. Pre-set levels and other criteria
can also be inputted from this touch screen. The main motor direction and
speed control is also situated on the pilots side. Provision is also
available for bow thrusters and vertical thrusters.
Air for the craft is supplied by 4 external air bottles of 232 bar 15L
capacity, this is reduced by a first stage regulator to 15 bar before
entering the vessel. This air is further regulated to 8 bar for operating the
various systems. There is a main system and a reserve system both with their
own regulators, bottles can be pumped by a normal diving compressor.
Life Support:
Life support systems consist of oxygen flask and metering valve sufficient to
keep 2 persons in the craft for 30 hours. C02 is removed by a C02 scrubber
Near the surface the craft may be ventilated by an air inductor which sucks
air into the craft when the small snorkel is above the water surface.
Comfort, cooling, heating and dehumidifier is also incorporated into the
craft. The air bottles and oxygen can be replenished at diving air stations.
All the control functions sensors and actuators are inputted into the PLC
where all their functions are controlled and through the programme resident
in the computer ensure that at all times operations and actions are within
proper parameters and are safe. Manual systems are also available in case of
power failure. Different programmes can be installed for training and special
operations. Full remote control can be achieved by a normal computer
interface.
Gemini Uses:
> Recreational use to view the underwater world safely and to enjoy tbe
wonders of the coral reefs and other clear warm venues.
> By people, for what ever reason, who can't dive conventionally.
> By educational establishments and environmental agencies to monitor
marine ecology.
> In tropical venues there are no small vehicles to carry 2 to 10 persons,
these resort submersibles could be used to carry persons that do not dive to
view the underwater world. Gemini could be purchased by individuals or
leased, for this purpose because the cost of the Gemini is proportional to
large submersibles on a head carrying basis.
> Gemini is an excellent filming platform.
> Military uses could include carrying special operation forces ashore.
> It can be launched from any slipway in a marina and can be launched from
a large yacht 30M plus. With a small floating twin boom pontoon it can be
moored offshore so that people can access the craft safely for trips where
harbour or slipway facilities are not near beach venues.
> Corporate entertainment.
> Patrol of reefs and other underwater reserves.
> Surveying and inspection of shallow water pipelines in venues such as
the Arabian Gulf waters up to 50M deep.
> Robert Leeds is the managing director of Subeo Ltd, a firm based at
Frinton-on-Sea, Essex especially to develop and design small underwater
vehicles. Robert is the designer of the vehicle.
> At present the Gemini craft is a 2-person vehicle which has now been
fully tested and is now operational. The project was kick-started 6 years ago
by a Trade and Industry Innovation grant.
> The craft was built to evaluate sophisticated 'fly by wire' control
systems and side by side seating never used in such a small underwater craft
before. Subeos production model is a 3-person vehicle which has been
developed from market research and sale enquiries in the Middle East and the
south of France.
> At present Subeo is discussing and seeking partnership arrangements with
various European ship builders and looking for suitable venues where
prospective clients can come, see and use the vehicle.
Metri Trials:
Very successful trials were carried out at IFREMER in France under the METRI
programme funded by the European Union (see separate article on IFREMER and
METRI). IFREMER is a French world renowned marine institute that operates the
deep submersible 'Nautile' which discovered the Titanic.
The Ό scale model of the 3-person vehicle and propulsion system was
evaluated. The 3-person production vehicle has a very low drag co-efficient
0.28. Using a 20kw drive train the full size vehicle would achieve velocities
in the region of 7 - 8 knots. The craft will be powered by 'state of the art'
nickel sodium batteries. These batteries are particularly suitable for
submersibles as they do not produce hydrogen gas during the charging process.
They are fully sealed and have excellent energy weight characteristics when
compared to lead acid batteries, the normal energy source for
submersibles/submarines.
The History Of The Submarine:
Normally a submarine is a military vehicle and a submersible is a civil
machine. The first seagoing submarine was built in 1879 by the Reverend
Garett and was called the Resurgent. The first true submersible was probably
the Turtle which was built in 1776 by a David Bushnalls and was used by the
Americans to attack the British fleet in New York harbour. There were
probably previous attempts before 1776 by people trying to make submersibles
but most of the activities prior to this date were using upturned wood or
leather buckets with compressed air being forced down to the divers with
various mechanisms.
First Royal Navy Sub:
The first Royal Navy submarine was the Holland built in 1901 and carried 8
people. Today the present Trident submarines are l 50M long, three times the
height of Nelsons Column and are powered by nuclear energy and have a
displacement of 15000 tonnes. The Polaris submarines of the Royal Navy are
some what smaller but still displace 8500 tonnes and are capable of speeds of
up to 30 knots. To propel a vehicle through the water at this speed takes
tremendous energy. The typical electrical output of a Polaris submarine is
sufficient to power a town.
Subs Today:
Modern day submersibles are very special pieces of machinery and ones that go
to extreme depths to explore the seabed where the Titanic lies are few in
number. There are probably only 3 vehicles today that could reach such
depths. Alvin from Woodshole Institute in the USA is one of them and was the
first vehicle to discover the position and to film the Titanic. There is also
a French vehicle and a Russian vehicle capable of descending 2.5 miles to the
Titanic.
Exploration:
Most underwater exploration and inspection today is carried out by using ROVs
(Remote Operation Vehicles). The risks associated to putting people
underwater are immense and therefore although these vehicles are very
expensive and do get lost occasionally, peoples lives are not put at risk by
these underwater explorations.
Gemini:
GEMINI is a recreational vehicle and has a depth range of 50m, even at this
depth the pressure on the hatches is about 14 tonnes and the total pressure
on the pressure vessel itself is about 125 tonnes. It has all the components
of a large submersible namely:- surface buoyancy tanks, trim tanks, lead
trim, lead acid batteries, life support systems, front and rear hydroplanes,
a rudder and a very sophisticated control system consisting of a PLC
(Programmable Logic Controller) and many electrically operated solenoid
valves, pneumatic actuators, stepper motors, encoders and several electrical
power systems. Its estimated forward speed is 4 - 6 knots and when the
surface buoyancy tanks are fully blown will have freeboard of 300 - 400mm.
The design and control of the submersible combines just about every
engineering discipline. i.e. structural, electrical, mechanical, life
support, physics, hydrodynamics and naval architecture.
There have been several attempts to build recreational submersibles but due
to the complexities of driving these vehicles and being able to carry out the
many sequences of operations it has only been possible with the advent of
modern control systems that these vehicles are a practical proposition. A
modern submersible is more complicated than a small aircraft but is operated
in a much more hostile environment. It also has to carry all necessary life
support as well as resisting huge forces.
SUBEO has developed its 2 man GEMINI sub using up to date technology and
modern materials to create a stunning underwater vehicle for the new
millennium.
Subeo: The World's First Under Water Sports Car
