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The Swedish Military Argus V1 crash report from 1944
The Nosecone was of course the most damaged part, and a complete reconstruction has been impossible. It consists of a cover of light metal which is bolted to the front of the fuselage. Most certainly was there a compass located inside the nose cone, because there has been findings of the remains of the suspension and a couple of copper discs, which have been identified as the damping discs from a Askaniacompass. From the nose cone comes several electrical cables and a pressure line, most certainly for the autopilot.
The middle part of the fuselage is built with sturdy steel plates. The first part acts as the fuel tank, and in the rocket that landed in Karlskrona was a smaller ammount of fuel found. The fuel tank holds ~600 litre. Behind the tank there is 2 spherical containers containing compressed air or some other compressable gas. The containers are wrapped with many layers of piano-string, if this is made to increase the strenght of the containers or because of any other reason is not known. In the Karlskoga-rocket the containers were cylindrical instead of spherical but besides that they were contructed similar and had the same size.
The tail is also made from steel plates. At the upper left side of the tails front is a large inspection hatch located, and inside it is the auto pilot mounted at a frame made of steel tubing which is coupled with springs to the tail shell. At the rear of the tail is the tail-fin, side rudders, stabilizer and the height rudder located. The area of the rudders is rectangular and remarkably small. The fixed parts of the rudders and the tail-fin are constructed from steel plates with steel girders, everything spot welded. The side- and height rudders is made from riveted light metal.
The main parts of the fuselage is connected by sturdy rivets, so the rocket can be assembled or dismantled quickly.
The wing is built from spars. They are mounted in pairs beside each other, the first one is connected to the wing´s top plate and the second one connects to the wing´s bottom plate. Through all of the spars runs a very sturdy steel tube. The top and bottom plating is made of steel and almost everything is spot welded. The steel tube runs through the both of the wings and also through the fuel tank.
Closest to the fuselage is a rear supporting rod mounted and connected to the fuselage through a ball joint. This rod is built from formed steel profiles.
The wing lacks rudders and are recangular without any arrow shape of any kind. The profile is ordinary and not a high speed one.
One of the gyros, the main gyro (1), acts as both steering and horizontal gyro. It is completely free suspended and the gyros rotation axle is set 70° from vertical and parallell to the lenght of the rocket. The gyro is stabilized in this position with 70° angeled air ventiles (2) similar to the ones on a regular gyro horizon. The main gyro is equipped with supporting magnets (3), which probably were connected to a compass for correction of the by the gyro set course. The main gyro affects both the side- and the height rudders servo engines.
The Aneroidbarometer with servo is used to give the rocket a certain altitude of flight. It consists of two serie coupled aneroid boxes in a aneroid housing (6), a turn knob (7) and a servo (8). The servo affects a cradle (9), at which the main gyro is located. The cradle can turn 20°. Altering the flight altitude is done with the turning knob, which is graded in mBar from 730 to 1000mBar. 730mBar is equal to an altitude of ~2500m at normal atmosphere. When starting the rocket the cradle is set to give the rocket an elevation of 20°. When it reaches an altitude that is 800m below flight altitude the aneroid servo affects the crade so the elevation decreases until it becomes 0 at the chosen flight altitude. The aneroid servo is very sensitive and reacts at a pressure difference at 1 mBar (10m).
The compass is a normal, double-working Askania-compass with a pneumatic pick-up. From the compressed air tanks comes a tube to the compass. A small device behind the compass converts the pneumatic energy from the compass pick-up into electromagnetic energy. The devise is simply a pressure box with a membrane. To each side of the membrane is a pressure tube connected from the compass. The membrane has electrical triggers, one at each side of the membrane. When the rocket loses its course, compressed air from the compass forces the membrane to the other side, and electrical connection occurs in the trigger. These triggers are serie-connected with the main gyro and causes the steering servos to manouver the rocket into its course again. Again, this method is very simple and therefore reliable and cheap.
Compressed air enters the upper part of the fuel tank from the two compressed air containers through a reducing valve. The pressure in the containers is probably 150 bar. The fuel is drawn from the bottom of the tank in a fuel line to the back of the fuselage. This line is connected to a filter consisting of a pack of perforated discs inside a cylindrical container. At the outside of the filter is a label that says that the filter has been tested with 15 bar, so the fuel pressure is not likely to be above 10 bar.
After the fuel has passed through the first valve it then enters a spring-loaded membrane, which is connected to a second valve. The spring tries to open this valve and the fuel pressure to close it. The purpose of this valve is not known.
After the second valve the fuel can lift a needle valve and enter the main fuel line, which leads to the nine fuel nozzles. A small line connected to the main fuel line goes to the fuselage and has an endcap to it. This line is probably used for testing. The needle valve movement and therefore the ammount of fuel entering the engine at each pulse is restricted by a screw at a linked rod. On top of this rod is a damping device in form of a flat spring, which is affected by the end of a piston inside a cylinder. The cylinder is connected to the main line going to those three pressure-sensing nozzles.
An increase in pressure pushes the rod and decreases the fuel injected. The pressure on this rod is limited by a small spring. One side the rod is connected to a spring-loaded membrane, and the other side of the membrane connects to the open air so a drop in pressure decreases the ammount of fuel inected at each pulse. The other side of the rod is affected by a spring which is affected by a piston. One side of the piston is by a line connected to a pitot-tube outside the fuselage. In that way the spring pressure increases with increasing ram-pressure and therefore also the ammount of fuel injected.
The pressure-sensing nozzles are also connected to a line, in which compressed air can be injected in order to start the engine.
Stockholm the 26 aug 1944
Bo Lundberg / Erik Lindkvist
