The ASOC ,
The CPS ,
The Sea Trials ,
The Walk Around
Please keep in mind that this prototype amphibious craft has been built to demonstrate the concept. The craft you are viewing is just a platform, as is the HMMV currently used by the U.S. armed forces. The hull design implemented on this prototype is suited for high speed on rivers, lakes and other relatively calm water. A deeper "V" hull is certainly a possibility for rougher off shore water.
Various application specific configurations can be specified from this basic platform, for example:
- Shore patrol.
- Police.
- Fire.
- Civil defense for flooding and other wet disasters.
- Ship to shore and off shore oil well shuttle.
- Many recreational purposes.
Also, a variety of configurations for seating are possible, for example:
- Seats along the sides with passengers facing inwards.
- Seats in the middle with passengers facing outward.
- Seats parallel to the front seats like a bus.
- Saddle style whereby passengers sit front to back (as requested by the navy).
Furthermore, because this craft is a prototype which has been constructed for the purpose of demonstrating the concept, there is no engine cover, production craft would certainly have an engine cover for heat and sound isolation, personnel protection and the other obvious reasons. And, certainly, a top is a legitimate consideration. The windshield on this craft is merely a windshield off of a motor boat and the production model would need a windshield made with the structural integrity to support a hard-top or a convertible top.
The frame of this prototype runs almost full length, front to rear and is constructed of two pieces of 2" x 4" box steel tubing which run parallel, two feet apart and are joined at appropriate intervals with the same material. Most of this frame is obscured by body construction however some of the support members and some of the cross members are still visible. Also, most of the rear suspension beam is visible from inside the craft; likewise, most of the front suspension beam is visible underneath the dash.
The body of this prototype is constructed of a closed cell foam and fiberglass reinforced plastic sandwich. There was no mold for this body, but, it is intended that this body be used to make a mold. Since there was no mold for this body, the frame was temporarily welded onto a rotisserie about six feet above the shop floor. Then the body was constructed by welding ½" x ½" steel tubing onto the frame in a manner so as produce a shape onto which the closed cell foam could be affixed. Evidence of the ½" x ½" steel tubing is still visible inside the craft on the sides.
At this time, please examine a sample of the closed cell foam used in the construction of this prototype. Attempt to just crush it in your hand; note its resistance. Also note that by virtue of the fact that it is a closed cell foam manufactured at sea level, the further it is pushed below water level, the more buoyant it is. The body is made with ¾" foam base and much of it has additional layers of various thickness of foam. For example, by looking at the bottom, it is obvious where there is a single layer, a double layer and a triple layer of foam. The sides and "hood" also have an additional layer of ½" foam. Furthermore, the floor was filled with a two part foam mixture which is six inches thick by the frame.
To conclude the comments on the body, bullet proofing material is available, a sample of which is available for your examination. The bullet proofing material is also available in a transparent product suitable for windows.
The drive train is comprised of five main elements, the engine, the transmission, the transfer case, the differential, and the jet pump. The engine used for this prototype is a gasoline fueled Ford 351 cu.in. Windsor block which has been built by a company which builds engines for racing boats; this particular engine produces almost 500 horsepower.
The transmission used for this prototype is a Ford C-6 three speed automatic transmission. This transmission has been modified several ways for this application because of the high load induced on the transmission by the jet pump. This load is so great as to prevent a normal automatic transmission from up-shifting through the gears, therefore a manual shift conversion kit installed in order to lock the transmission into high gear while in marine mode. Also the clutches and torque converter have been modified to reduce slippage. These modifications allow this transmission to approach the one-to-one gear ratio needed from the engine to the jet pump. Note that use of a standard transmission would circumvent the need for a modified automatic transmission.
The transfer case is a modified Borgue-Warner product. The patented changes allow it to be installed as seen in this configuration. This member of the drive train can transmit power to either the differential, or to the jet pump, or to both. Transmission of power to both the differential and to the jet pump can be especially useful for water entry/exit or operating in shallow water conditions.
The jet pump is manufactured by Dominator and a variety of impeller blades are available depending on the power, weight and performance criteria. The jet pump is fitted with a "jet-a-vator" for adjusting the height of the jet pump's output for maximum performance. The jet pump is also fitted with a reverse gate which is connected to the brake pedal of the craft. Applying the brake pedal will engage the reverse gate thus redirecting the output of the jet pump to aid in stopping the craft. Sufficient application of the brake pedal will cause the craft to back up. And, stopping and backing up functions can be amplified by simultaneous use of the accelerator pedal.
To conclude the comments on the drive train, please note that there are many manufacturers throughout the U.S. and the world which manufacture the various components used in this drive train. Use of a diesel engine is certainly not out of the question and may even be desirable for fire prevention. Considerations in the selection of drive train elements include but is not limited to the following: price, expected performance, plant location and availability.
By entering the craft now and looking into the rear compartment, one can see the rear round suspension beam which runs transversely through the compartment and into each of the wheel wells. This beam and many outboard suspension parts are made of stainless steel for hostile operating environments, namely, salt water. Notice in the wheel wells, the collar to which the coil suspension springs and shock absorbers are attached. The same collar assembly is used for each of the four wheels. The collar houses a neoprene bushing.
Now, direct your attention to the center of the suspension beam. Notice the two large pneumatic rams attached to the bottom of the beam. These rams are the devices that pull/push the suspension collars to raise/lower the suspension. Also, notice the small ram located in the middle of the beam. This ram is the suspension locking device. This ram is retracted to release the suspension locking bars, also attached to the suspension collars, in order to raise/lower the suspension, and, this ram is engaged to lock the suspension in the up/down position.
Other items of interest in the rear compartment include the following:
- Dual 3700 gallon per hour bilge pumps.
- Jet pump clean out hatch.
- Radiator.
- Mufflers.
- Dual 12 volt batteries.
- Fuel tank.
- Various electrically actuated pneumatic valves.
- Air tank.
The fuel tank in the prototype is a twenty gallon tank which would really be insufficient for a craft which is to spend much time traveling in the water, however, fuel tank may very likely be made integral with the production model's seating and should be more in the neighboor hood of 150 to 200 gallons in capacity. The air tank used in the prototype is an 18 gallon tank and will support five complete full speed up/down cycles of the suspension.
Steering for land vs. water . . . a few words about rack and pinion steering, slide bars, locking and unlocking for the jet pump.
Please stand by for a demonstration of the suspension being cycled . . .
The ASOC ,
The CPS ,
The Sea Trials ,
The Walk Around
Page provided by
's
Monterey Office
(-3).
This page is maintained by RUSSELL HOLDER and
does not represent any views or policies of and is not affiliated
in any way with my employer.
Previous update: 30AUG96 2345HRS
Last update: 07SEP96 2145HRS
Russell@dra.com