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| Model Walrus class boat at sea. |
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| Model Walrus class boat at sea. |
| On this page, a boat made by Harry Grapperhaus
is presented. Harry has been building model submarines for over fifteen
years and has constructed an American nuclear sub and three Dutch boats:
Dolfijn, Zwaardvis and Walrus class. In this page the building of a Walrus
class boat is treated. The boat is approximately 1.6 m long and weighs
about 30 kg. The boat dives using compressed air and has an onboard air
compressor.
All pictures on this page were taken by
Harry Grapperhaus.
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| Class | Walrus |
| Build | |
| Length | 1.6 m |
| Width | |
| Weight | 30 kg |
| Transmitter | |
| Balast system | Compressed air balast tank |
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| The bulkheads being cut-out in balsa wood. |
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| The bulkheads are fitted on a wooden broomstick. In this way the complete model can be rotated, very handy. |
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| The model cut open, approximately at the water line. In the bottom part, all of the balsa bulkhead have been removed. Aluminum bars were glued in to keep the hull into shape. |
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| The receiver, a switch, and two multiswitch units in the back. |
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| Pressure gas bottle (blue, 1.5 L, 7 bar) and compressor in the back. |
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| The electric motor and shaft to the screw. On both sides two rods to control each of the four cross planes. |
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| The beautiful brass screw and the cross planes. |
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| The sail of the Walrus model. |
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| Details of the sail showing the periscopes and masts. |
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| Schematics of the pressurized air system Harry uses in his boat. The system consists an air compressor, pressure tank, and 13 (!!) solenoid valves that are used for dive control and to operate the masts and torpedo tubes. |
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| Block diagram of the fail-safe system Harry has designed. The system operates the emergency buoy, the air compressor, vent and blow valves and a safety venting system. For example, (1) the compressor automatically starts if the boat is surfaced and the system pressure is too low and (2) if the signal from the receiver is lost, a emergency gas valve is opened and the buoy is released. |
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| Details of the fail-safe system. Above: electronic schematics Below: (left) the separate prints (right) the assembled prints sticking out of the submarine. |
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| Harry explaining Sytse how to build a submarine at the U-Boot meeting in Koln, September 2000. |
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| A proud Harry Grapperhaus and his Walrus. |
| The above pictures show the outstanding
quality of Harry's work. The model looks great and the inside is packed
with fancy technical stuff. But does it also work? It may
be not a surprise that the answer is yes.
In a documentary about the Dutch Royal Navy submarine force, the TV crew was not allowed to make video recordings of a submerged Walrus class boat. They solved this problem by using Harry's quality model instead. The video footage below was ripped from this documentary.
If you are impressed by Harry's work, and you should be, say hello to him with an E-mail: |
