The eighteen pot injector head.
This is the first image blog from Alexsander Savochkin in what we hope will become an expanding resource for those wishing to find out more about the design and construction of the A4/V2 missile. The precise 3D CAD model imagery is based exclusively on original drawings produced in Germany from 1940 to 1945. When enough material has been uploaded we will create a fixed menu item called ‘Anatomy of the V2‘ where we hope to be able to offer coverage of the entire missile in detailed 3D models like the ones shown here – Robert J. Dalby, editor in chief, V2 Rocket History.com
Click the above video to see an animation of the diffuser cup inner core (the animation may take a few seconds to show at maximum resolution).
The image gallery below has all the above pictures in higher resolution, some with additional text, as well as additional pictures not included in this post.
A schematic drawing of the Askania rudder servo 'Rudermaschine LRM 3'showing the critical compact dimentions of the device making it ideal for retro fit projects for smaller aircraft.
Photo shows cast aluminium thrust ring with electro-hydraulic servos in position. Note different crank lever shapes (pale green arm on servo) for fins 1/3 and 2/4 This excellent restoration is the work of Horst Beck. Photo copyright: The Horst Beck Collection
Photo shows a unique display at the Horst Beck Collection (HBC). Over many years Mr Horst Beck has painstakingly acquired and restored many A4-V2 missile parts - and in some cases, reassembled them into complete sub-assemblies. Shown here is part of the collection's hydraulic servos and trim motor parts display. In the foreground we see four hydraulic servos, and behind them their A frame mounting 'chairs'. The top shelf, from left to right, shows a servo with motor removed (and placed on its right). In the middle, two trim motors and chain sprocket gear-boxes for the aerodynamic trim surfaces on the trailing edge tips of fins 2 and 4. Next the pale green crank levers, the first longer one is for the hydraulic servo that controls the jet vanes and trimmers on fins 1 and 3. The shorter version minus the top horn, is used on the servos for fins 2 and 4. The last, silver coloured item,os a servo stabiliser (all the servos shown have one already fitted). Photo copyright: The Horst Beck Collection
Wreckage of hydraulic servo from fin 2 or 4 of V2 missile that fell on a farm in Essex in March 1945. The motor has been removed and we can see details of the oil gear pump and valve control gear. The 3 position electromagnetic relay switch is visible at the 7 to 8 o'clock position within the open aperture. The push rod that connects the relay to the gear pump valves is also visible as a short brown coloured rod with a fine wire connector at each end, running in towards the gear-valves from the 9 o'clock position. The point that provides electrical current for the motor (which runs all the time and in one direction only) can be seen at the three o'clock position. The black housing has two sets of brass tongues that receive the matching brass spades mounted on the base of the motor for power input. The motor drive shaft has a female square socket coupling to connect the motor to the middle drive gear of the gear pump. A small portion of the square drive shaft of the central gear can just be seen in the photo - in the centre of the valve control block.
This collection of parts were all found in vicinity of the Nordhausen manufacturing facility. parts include servo crankcase caps -top left, electro-magnetic switch installation plate - middle top, crank bearing covers - top right, gear pump blocks with base - centre, and crank-shaft, piston rod, and hydraulic piston - btm left. The deep recess on the piston circumference is for a rubber seal and is an interesting variation in ring seal design (at least 4 variations of piston design were employed, with three designs flown on combat missiles). A valve tilt seat is visible a little to the right of the piston. A broken servo mount stabiliser is shown - middle right. The cast piston rod, top right, has not been drilled and milled - the part is 'raw' as supplied by the manufacturer before machining has been completed. Normally the manufacturer's details are machined off the metalwork - but not in this rare case. The three letter code gfa is clearly visible on the part and stands for the firm of Otto Fuchs Metallwerke.
Two Askania (designed) hydraulic gear pumps - the examples shown here have two ceramic insulators with with Nichrome wire type heating elements. The heaters are located at each end of the pump on the long axis. The pump on the right still has its power supply wires attached and was easily repaired and restored to full function in our workshop.This type of pump (with heaters) seem to be rare among the debris of European combat impact sites but fairly common in debris collections emanating from research flights in Peenemünde and parts of Poland. An explanation maybe that the oil could be warmed up sufficiently simply by starting all four hydraulic gear pumps sooner in the pre-launch sequence. The only downside being that the already noisey missile would be making yet more noise in the risky period leading up to launch.
Close-up of Askania gear pump relic with oil heaters. This picture shows an unusual feature on the otherwise normal cast aluminium base of this gear pump. The knurled knob positioned between the oil flow balance adjusters has a purpose that is unknown to us. The two oil-flow balance adjuster valves visible in the picture have slot head adjuster screws and you can also see the knurled circumference on each screw. This parallel knurling is engaged by a crease formed in the facing surface of the copper spring strips. The function of these strips is to create tactile feedback that the technician making the adjustment can feel in the handle of the screwdriver. This was done because the gear pump needed to be adjusted in a dark and narrowly confined space.
Gear pump showing flow adjusters (two slot head screws nearest bottom of picture) and ceramic heater elements situated at each end of the block. The square drive shaft coupler (corroded but still identifiable) has been highlighted in red paint. The open holes either side are the main control valve guides. The copper spring strips visible on each oil flow adjuster provide locking and tactile feed-back for the adjusting process. This relic was recovered from Usedom island.
Hydraulic gear pump with close up detail showing ceramic heater element insulators with flat, possibly nichome, metal strip element threaded through them. This oil heating system was designed to maintain a specific viscosity of the oil regardless of environmental temperature, to better maintain oil flow rates and thus pump efficiency. The heating system is found only rarely on surviving relics.
Photo shows a flown graphite jet vane complete with mounting plate and fasteners as well as pre-flight centre index tip. V2 relic from the Horst Beck Collection (HBC). Photo copyright: The Horst Beck Collection
Photo shows four restored graphite jet vane support blocks and bearing housings. The round plates we can see here act as heat sinks and allow heat to radiate away from the support block and bearing to help prevent expansion due to relatively rapid and uneven temperature distribution accumulation. The graphite vanes were quite brittle and cracking caused by rapid and uneven expansion could cause the vane to disintegrate. The area around the graphite vanes was exposed to the accumulation of heat not merely as a result of duration of the motor burn time but temperature was also increased at higher rates as the jet plume expanded with the decreasing atmospheric pressure as the missile gained altitude. This excellent restoration is the work of Horst Beck. Photo copyright: The Horst Beck Collection
Photo shows restored air-rudder and fin detail. The grey painted barrel-strainers are both adjusted independently to reduce slack in the drive chain and avoid introducing a deflection bias in the air rudder. The 1.9kg counterbalance weight normally located at the top of the trim fin (or air rudder) is missing in this presentation. This excellent restoration is the work of Horst Beck. Photo copyright: The Horst Beck Collection
Photo shows partially restored air-rudder and fin detail. The image on the left shows the relationship of the trim motor to the air rudder drive shaft on fins 2 and 4. A chain similar in gauge to the type used on a push-bike and yet, at the other end of the shaft, the chain transmitting the torque of the trim motor to the air-rudder drive sprocket has a heavy gauge chain similar to that found on a 1000CC motor-cycle! This excellent restoration is the work of Horst Beck. Photo copyright: The Horst Beck Collection