BEACH LAUNCH METHODOLOGY - How do you launch a 45x17 meter boat (147.5 x 55 foot) trimaran from a sloping shoreline without any kind of special preparations to the beach? The answer is with quite a bit of forward planning in design. A wheel and bearing recovery system requires a lot less effort from any winch system. This is far more efficient than using grease on the underside of a hull or logs as rollers. The Ancient Egyptians were the first to move large objects with rollers, when they built their Pyramids.
RECOVERY - Three special bogies are designed to cradle the pontoon twin hulls and central hull. The front bogies are designed to be self aligning on approach to the shore and to float at the correct height to aid the aim of the operator, who simply snags the overhead straps.* The rear bogie is submerged until the front bogies are under the front pontoons, when flotation tanks are blown and it comes up to cradle the central hull.
LAUNCH - Is much easier than recovery, the support tractor vehicle simply pushes the trailer into the surf and floods the flotation tanks - allowing the SeaVax to float gently off, into the sea. Once launched, the SeaVax powers away from the trailer, which is then pulled backwards out of the water and parked - until it is needed to recover another SeaVax for servicing. *In autonomous mode, the SeaVax unit is guided in with infra-red beacons or other equivalent.
BEACH LAUNCHING - Thousands of boats are beach launched and recovered every year, but our boat is somewhat larger that your typical power or fishing boat. This of course means making our own custom built rig. We are likely to enter the famous Guinness Book and other World Record databases such as the FIA or UIM, when launching the biggest beach launched vessel from the biggest ever boat trailer. We are looking into this.
DESIGN - Our custom rig has to be able to handle smooth sand and irregular ridged sloping shingle beaches. It will also double up as a handy platform for servicing a SeaVax, for cleaning of the hull and solar panels - although the solar wings can be cleaned while the vessel is at sea.
NEW ZEALAND - In a little fishing town called Ngawi, they routinely use trailers with extra long drawbars, that couple to a bulldozer, caterpillar tracked vehicle.
SUITABLE LAUNCH PLATFORMS - The BELL and CAT 6x6 all wheel drive earth moving dumper trucks, or the equivalent, may prove to be ideal launch and recovery vehicles. The tipper bucket/body would be removed and replaced with a suitable coupling. During launch the driver would need to be well rehearsed in reversing.
TRACTOR LAUNCH - We are going to need a launch vehicle with bags of power and grip to match. The Bell 50D could be an platform to modify to that end. The Bell 50D uses a 16 liter Mercedes Benz OM 502LA V8 turbocharged and intercooled, four-stroke, diesel engine with direct injection to give 380kW (510hp) output, driving through an Allison 4600PR ORS transmission with 6 forward gears and 1 reverse. The fuel tank holds 575 litres (152 US gallons). The tyres are Radial Earthmover: 875/65 R29s. Volvo and John Dere also produce equivalent 6x6 earth movers.
SWAN NECK COUPLING - This Volvo is hauling a K-Tec sand scraper. The coupling to the tractor unit is similar to that we have in mind for our trailer.
GETTING A GRIP - Tyre technology has come on in leaps and bounds in recent years. More earth moving and agricultural vehicles are being fitted with rubber that spreads the load and so reduces rolling resistance.
FLOATATION TYRES - Wide tyres spread the load preventing soil compaction and decreasing rolling resistance, so reducing the power required to simply move a large trailer. Nearly half of all modern agricultural and earth moving equipment is now fitted with floatation tyres as standard, compared to around 10% 5 years ago. Don't forget the basics, a larger wheel offers less rolling resistance and tends to iron out the bumps.
FLOATATION TIRE SIZES CHART HANDY REFERENCE FOR DESIGNERS
ROYAL MARINES - The RE/RLC Combat Support Boat (CBS) is launched using a specialist trailer. The unladen weight is 4.75 tonnes, length 8.8m, beam 2.77m and draught 0.65m. The CSB trailer from Oldbury adds another 6.1 tonnes, and is 10m long. At over 11 tonnes, the CSB and trailer is not a small load and so it is usually towed by large logistics vehicles, as the image above shows. Together, the total length of the trailer and truck will be just short of the 20m of a C17 Hercules (or Globemaster) cargo deck.
LOW LOADER - A Specialized XL 110 HDG (hydraulic detachable gooseneck) lowboy trailer. This 53′ x 102″ lowboy boasts a 110,000 lb overall capacity and features air ride suspension, ride height control and aluminum wheels.
TRAILER - The BCG53-183 is a 53', 18,000lb GVWR Combination Aluminum and Steel Gooseneck boat trailer that is custom built for an Outerlimits 42' Legacy.
[LEFT] - Munich-based truck maker F.X. Meiller has seen the future of construction hauling,
as this sleek all-wheel drive tipper capable of dumping in all four directions. Chinese transportation designer Haishan Deng created a series of concept drawings depicting what Meiller's new super tipper truck in action that won him a 2007 red dot award.
LINKS & REFERENCE