Meillerwagen
Encyclopedia
The Meillerwagen was a German
World War II
trailer used to transport a V-2 rocket from the 'transloading point' of the Technical Troop Area to the 'launching point', to erect the missile on the Brennstand (firing stand), and to act as the service gantry for fuelling and launch preparation. The unofficial 'Meillerwagen' name was often used in official documents and refers to a parts supplier for the trailer, Meiller-Kipper GmbH of Munich
, Germany (founded 1850). The Army Research Center Peenemünde designed the Meillerwagen, and the Gollnow & Son company assembled the Meillerwagen from supplied components. The Meillerwagen was assembled with Italian
and Russia
n prisoner laborers of the Lager Rebstock
. The Meillerwagen was vehicle code number 102 of several vehicles in a V-2 launching battery, which included an 8 ton launch control vehicle. Launching of V-2s from mobile equipment was studied under code name
Regenwurm ("Earthworm") to replace bunkers such as at the Watten bunker.
Transport
After completing the process of fitting the warhead
to the V-2 rocket, the Technical Troop used a strabo crane at the transloading point to transfer the missile from the Vidalwagen to the Meillerwagen for transport to the launching point. Typically a Hanomag
SS-100 tractor pulled the Meillerwagen up to 45 km/h (28 mph) forward with the rocket travelling tail-first – the maximum speed in reverse was 15 km/h since the Meillerwagen's pneumatic brakes
could not be coupled to the tractor when being pulled backward.
Setup
After the Meillerwagen was close to the launch point, the Firing Platoon Truck Section took charge and removed the rocket's camouflage
cover and rudder protection. The control compartment batteries, alcohol-filling connection, tools, and other equipment were loaded into a box on a strut at the top of the Meillerwagen's lift frame. The Meillerwagen was moved via hand winches to the firing stand and then levelled via the two extendable outriggers with end-jacks.
Lift
The rocket was raised via the Meillerwagen lift frame and hydraulics
. When vertical, the rocket was suspended above the firing stand, which was raised to touch the rocket fins. Clamping collars were used to connect the rocket to the firing stand, and the Meillerwagen was withdrawn less than a meter and the rocket was turned a quarter turn for the fuel connections to face the Meillerwagen platforms, which were lowered into position for standing. A separate three-section extendable ladder, the Magirus
ladder, was used for areas of an erected rocket not accessible via the Meillerwagen.
Fueling
The hydrogen peroxide
tank on the Meillerwagen (126 litres) was filled from a 2120-litre tank truck with its own pump, then the rocket was filled from the Meillerwagen tank. Additionally Meillerwagen piping included the following:
, and the hydraulic lifting frame.
The trailer chassis
was a lattice frame of tubular members. It comprised a transverse trunnion
box member at the front, from which six longitudinal tube members ran aftward and converged into one large main central tube at the rear; the six longitudinal members were braced vertically and horizontally by smaller-gauge tubes. The rear central tube member supported a large horizontal-plane turntable. A steerable front truck was installed just behind the trunnion box member, while the turntable surmounted a two-axle rear bogey.
The steerable front truck was fitted with twin duplex wheels (four tyres), the inner wheels equipped with pneumatic drum brake
s. The duplex wheels rode on swinging wishbone axles with transverse semi-elliptical leaf spring suspension. A steering lock was included for use during rear towing.
A turntable at the rear of the chassis frame supported a bogey, mounted on bearings so it could swivel and pivot. The bogey was fitted with two axles, a fixed middle axle and a steerable rear axle, both of the swinging wishbone type with transverse semi-elliptical leaf spring suspension. The middle axle was fitted with pneumatic brakes, while the rear axle was unbraked. A feedback steering system was included in the design, so that any change in direction by the rear bogey (and fixed middle axle) was duplicated by the steerable rear axle, but to twice the extent. The linkage for the feedback system was for used front towing, and was disengaged during rear towing.
The towing arm could be fitted to the front truck, or the steerable rear axle of the rear bogey. The towing arm was fitted with a sprung force stem, contrived so that the tow arm 'floated' horizontally at zero relative weight.
Each front corner of the chassis was fitted with a swing-out A-frame
boom equipped with a screw jack and foot plate. The booms enlarged the Meillerwagen footprint to stabilise it during erection of the rocket, and provided a means of adjusting the Meillerwagen transverse level. The booms deployed outward and forward of the lifting frame trunnion axis to prevent it toppling forward or to either side.
The lifting frame was constructed of two formed I-beam
s, with tubular and box transverse braces. The lifting frame was fitted with plumbing for fuelling the rocket; wiring for powering and monitoring the rocket and for field telephone
s; accommodations for carrying and dismounting the rocket; and folding platforms to service the rocket with rungs to access them.
Electrics
The lifting frame was fitted with outlet sockets and wiring for field telephones. A main connection from the armoured launch vehicle switchboard to inlet sockets on the lifting frame provided circuits for four field-phone stations at the Meillerwagen – one each at the upper and lower folding work platforms and two at the launch table.
An early configuration of the Meillerwagen included hardwiring of two electrical power circuits and two FLAK-plug circuits for the power and control needs of the rocket. The system included four sockets at the upper and at the lower end of the lifting frame, and the connective wiring fixed along the starboard beam. The four circuits were connected to two Stotz ejecting plugs, stowed with their cables along the side of the lifting frame. All of this wiring had become redundant by the time the rocket attacks began, but was not removed from the Meillerwagen.
The Meillerwagen chassis was fitted with a Notek tail light at the rear, its patch plug at the front, and the connective wiring in a conduit along the chassis frame.
Hydraulics
The lifting frame erected the rocket from horizontal to vertical, using hydraulic power. The hydraulic lifting equipment consisted of a hydraulic pump and its drive motor, an oil reservoir tank, a control valve group with manometers, and the lifting pistons themselves.
The drive motor was a petrol KdF (Volkswagen) 14 ps (hp) motor, adapted for stationary industrial use by the fitting of magneto ignition
and a centrifugal governor
as throttle; besides these modifications, the motor was otherwise identical to those found in VW Beetles
, an air-cooled flat-four boxer
. The motor was housed in a metal box fixed to the chassis frame. A three-piston eccentric
-cam
hydraulic pump was coupled to the drive motor flywheel
. (Meillerwagens at Operation Backfire
were fitted with electric motors as hydraulic drive in place of the petrol motor.)
A 70-litre (15 gal) oil tank was fixed to the chassis frame as hydraulic fluid
reservoir.
Oil under pressure flowed from the hydraulic pump to the control valve group consisting of three valves in a common housing, manipulated via one large cross-handle and two small hand taps. The large cross-handle regulated the speed of raising or lowering the lifting frame. One hand tap selected direction to either raise or lower the lifting frame. The second hand tap controlled oil flow to the lowering piston (see below), to begin lowering of the lifting frame from its vertical position.
The two hydraulic lifting pistons each consisted of one stationary cylinder and four extending cylinders. The largest extending cylinder included a flange
halfway along its length, against which hydraulic pressure could be selectively applied from either above or below; it was used during raising to delay its extension until all other cylinders had extended, and also to begin the lowering process when the lifting frame was vertical (once lowering had thus been initiated, gravity finished the job).
All components of the hydraulic system were products of Meiller-Kipper GmbH, except the KdF drive motor from Volkswagen.
Platforms
Acting as gantry, the lifting frame included a number of work platforms from which crewmen serviced the rocket. Three (later two) platforms folded flat against the lifting frame, and could be folded out from the elevated lifting frame with the use of a hand winch. Each folding platform included a safety rail of folding posts and chains.
Two side platforms or catwalks were inserted into holders for deployment on each side of the lifting frame, otherwise stowed together on brackets near the turntable. A rotating platform could be suspended from the rocket nose, to provide access to the rocket control compartments on the far side of the rocket.
The port beam of the lifting frame was fitted with around 40 rungs along its full length, with which crewmen climbed to the working platforms.
Accommodations
The lifting frame included two accommodations for the rocket, a nose clamp around the warhead and a pivoting clamp around the rocket midsection. Both accommodations included a saddle, and various mechanisms to assist dismount of the rocket onto its launch table. The mechanisms were operated with two drive shafts running up the port lifting frame beam. The drive shafts ran within the integral rungs, and were operated by a crewman with a ratchet hand tool.
The two drive shafts comprised a short shaft and a long shaft; both starting at the trunnion end of the lifting frame, one running half the length of the lifting frame while the other ran the full length.
The short drive shaft operated the pivot clamp around the rocket mid section, which could move the rocket 28 mm (~1") forward or backward along its centreline. The rocket midsection was fitted with a band which included trunnion pins placed in opposition; the pivot clamp held the rocket by the trunnion pins. The pivot clamp was able to rock on a transverse shaft, thus causing the rocket to move along its centreline. After erection of the rocket to a vertical position, it was held suspended above the launch table; by use of the pivot clamp, the weight of the rocket could be gently lowered onto the launch table until fully taken up, allowing the rocket to be unsecured from the lifting frame, thus dismounting it from the Meillerwagen.
The short drive shaft operated a screw sleeve, which extended to work a bell crank
. The bell crank turned a transverse shaft fitted with an eccentric cam, which would push or pull the pivot clamp, thus moving the rocket forward or aftward along its centreline.
The long drive shaft ran along the full length of the port beam of the lifting frame. It entered a worm gear at the pivot clamp, then continued to the nose clamp where it entered another worm gear. A shift lever at the nose clamp disengaged the drive shaft to allow either simultaneous or independent operation of the two worm gears. The worm gear at the pivot clamp operated a pair of scissor arms, one on each side of the lifting frame to insert or extract the trunnion pins from the rocket. The worm gear at the nose clamp operated the jaws of the nose clamp to either open or close, thus enclosing or releasing the rocket.
drum brakes, installed on the front and middle axles. The middle axle brakes could also be applied mechanically with a hand-operated cable, to act as a parking brake.
The Meillerwagen’s pneumatic brakes drew air pressure from the towing vehicle, and were operated by the tractor driver as an extension of his vehicle’s brake circuit. A control valve handle on the Meillerwagen regulated the braking force it drew from the tractor, depending on whether the Meillerwagen was laden with a rocket or unladen.
The Meillerwagen was equipped with two compressed air reservoirs, filled from the towing vehicle. These allowed the Meillerwagen to use its pneumatic brakes when it was unhitched from the tractor. In the unhitched mode, the Meillerwagen brakes were operated from the control valve handle, to provide braking ability during winching and hand-manoeuvring around the launch site.
The brake control and regulator system were supplied by Graubremse GmbH. The compressed air reservoirs, pneumatic brake cylinders and drum brakes were supplied by Knorr Bremse GmbH.
(permanganate) flask.
The rocket was provided with ejecting umbilical connectors, although their precise deployment evolved. Initially these 'Stotz plugs' travelled as Meillerwagen accessories, stowed on the lifting frame along with their cables. Later, the Stotz plugs were stowed in the cable box, and a ten metre cable mast was stowed on the lifting frame for ultimate erection on the launch table at the launch site.
Australian War Memorial. Treloar Center. Canberra, Australia.
(Operation Backfire
emeritus, unrestored, serno 5628)
Cosford RAF Museum, Cosford UK.
(Operation Backfire emeritus, restored, serno unrecorded)
USAF Museum, Wright/Paterson AFB, Ohio, USA.
(A4b experimental unit, restored, serno 7364)
Unknown number taken east in 1945, all or none of which may still exist in former USSR.
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
trailer used to transport a V-2 rocket from the 'transloading point' of the Technical Troop Area to the 'launching point', to erect the missile on the Brennstand (firing stand), and to act as the service gantry for fuelling and launch preparation. The unofficial 'Meillerwagen' name was often used in official documents and refers to a parts supplier for the trailer, Meiller-Kipper GmbH of Munich
Munich
Munich The city's motto is "" . Before 2006, it was "Weltstadt mit Herz" . Its native name, , is derived from the Old High German Munichen, meaning "by the monks' place". The city's name derives from the monks of the Benedictine order who founded the city; hence the monk depicted on the city's coat...
, Germany (founded 1850). The Army Research Center Peenemünde designed the Meillerwagen, and the Gollnow & Son company assembled the Meillerwagen from supplied components. The Meillerwagen was assembled with Italian
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
and Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
n prisoner laborers of the Lager Rebstock
Government bunker (Germany)
The Government Bunker in Germany, officially named Ausweichsitz der Verfassungsorgane des Bundes im Krisen- und Verteidigungsfall zur Wahrung von deren Funktionstüchtigkeit , in English: Emergency Seat of the Federal Constitutional Organs for the State of Crisis or State of Defence to Maintain...
. The Meillerwagen was vehicle code number 102 of several vehicles in a V-2 launching battery, which included an 8 ton launch control vehicle. Launching of V-2s from mobile equipment was studied under code name
Code name
A code name or cryptonym is a word or name used clandestinely to refer to another name or word. Code names are often used for military purposes, or in espionage...
Regenwurm ("Earthworm") to replace bunkers such as at the Watten bunker.
Operation
The Meillerwagen A-4/V-2 transport-launcher device as conformed by next vehicles:- Feuerleitzugmaschine Sd.Kfz. 7/3 (command vehicle)
- Feuerleitpanzer Sd.Kfz.251 (command vehicle)
- Hanomag SS-100 (tractor vehicle)
- Meiler-Wagen (V-2 mobile wagon-launcher)
- Opel-Blitz T-Stoffwagen (fuel car-tanker)
- Kesselanhänger für Fl-Sauerstoff (liquid oxygen wagon-tanker)
Transport
After completing the process of fitting the warhead
Warhead
The term warhead refers to the explosive material and detonator that is delivered by a missile, rocket, or torpedo.- Etymology :During the early development of naval torpedoes, they could be equipped with an inert payload that was intended for use during training, test firing and exercises. This...
to the V-2 rocket, the Technical Troop used a strabo crane at the transloading point to transfer the missile from the Vidalwagen to the Meillerwagen for transport to the launching point. Typically a Hanomag
Hanomag
Hanomag was a German producer of steam locomotives, tractors, trucks and military vehicles. Hanomag first achieved international fame by delivering a large number of steam locomotives to Romania and Bulgaria before World War I....
SS-100 tractor pulled the Meillerwagen up to 45 km/h (28 mph) forward with the rocket travelling tail-first – the maximum speed in reverse was 15 km/h since the Meillerwagen's pneumatic brakes
Air brake (road vehicle)
Air brakes are used in trucks, buses, trailers, and semi-trailers. George Westinghouse first developed air brakes for use in railway service. He patented a safer air brake on March 5, 1872. Originally designed and built for use on railroad train application, air brakes remain the exclusive systems...
could not be coupled to the tractor when being pulled backward.
Setup
After the Meillerwagen was close to the launch point, the Firing Platoon Truck Section took charge and removed the rocket's camouflage
Camouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
cover and rudder protection. The control compartment batteries, alcohol-filling connection, tools, and other equipment were loaded into a box on a strut at the top of the Meillerwagen's lift frame. The Meillerwagen was moved via hand winches to the firing stand and then levelled via the two extendable outriggers with end-jacks.
Lift
The rocket was raised via the Meillerwagen lift frame and hydraulics
Hydraulics
Hydraulics is a topic in applied science and engineering dealing with the mechanical properties of liquids. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. In fluid power, hydraulics is used for the generation, control,...
. When vertical, the rocket was suspended above the firing stand, which was raised to touch the rocket fins. Clamping collars were used to connect the rocket to the firing stand, and the Meillerwagen was withdrawn less than a meter and the rocket was turned a quarter turn for the fuel connections to face the Meillerwagen platforms, which were lowered into position for standing. A separate three-section extendable ladder, the Magirus
Magirus
Iveco Magirus AG is a truck manufacturer based in Ulm, Germany, founded by Conrad Dietrich Magirus . The company began manufacturing fire-fighting vehicles in 1864. In the late 1910s, it started the production of trucks and buses...
ladder, was used for areas of an erected rocket not accessible via the Meillerwagen.
Fueling
The hydrogen peroxide
Hydrogen peroxide
Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...
tank on the Meillerwagen (126 litres) was filled from a 2120-litre tank truck with its own pump, then the rocket was filled from the Meillerwagen tank. Additionally Meillerwagen piping included the following:
- Fuel Pipes
- :The elevated lifting frame was fitted with piping to fuel the rocket with A, B, P, and T-stoff
- A-stoff: Liquid oxygenLiquid oxygenLiquid oxygen — abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries — is one of the physical forms of elemental oxygen.-Physical properties:...
equipment consists of a pipe, which follows a circuitous route along the centreline of the lifting frame’s lower half. The pipe is fixed on the lifting frame by brackets, and closed at each end by cast ramp-and-claw seals.
- B-stoff: Ethyl alcohol equipment consists of a pipe which runs along the full length of the starboard beam of the lifting frame. The pipe is slung from the underside on straps, and closed at each end by threaded seals.
- P-stoff: Compressed nitrogen (or compressed airCompressed airCompressed air is air which is kept under a certain pressure, usually greater than that of the atmosphere. In Europe, 10 percent of all electricity used by industry is used to produce compressed air, amounting to 80 terawatt hours consumption per year....
) equipment to service the rocket consists of several batteries of compressed air tanks carried on the chassis frame, and a pipe fixed to the full length of the starboard beam of the lifting frame. The P-stoff batteries consist of one bank of six fixed tanks, and two banks of two removable tanks. (compressed air for the Meillerwagen pneumatic brakes was sourced from a separate set of two tanks across the front of the chassis frame)
- T-stoffT-StoffT-Stoff was the oxidizer part of a bipropellant rocket fuel combination used in Germany during World War II. It is a stabilized high test peroxide...
: Hydrogen peroxideHydrogen peroxideHydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...
equipment consists of a pipe which runs along the starboard beam of the lifting frame from the trunnion end to the halfway point. The pipe is fitted at the upper end to the triple valve assembly, consisting of two flow valvesFlow control valveA flow control valve regulates the flow or pressure of a fluid. Control valves normally respond to signals generated by independent devices such as flow meters or temperature gauges.Control valves are normally fitted with actuators and positioners...
and a three-way valve. The triple valve assembly connects to two tanks, a large measuring tank and a smaller overflow tank. The measuring tank can be filled to the rocket's required amount of T-stoff, after which any excess flows down a stand pipe to the overflow tank. The measuring tank is fitted with a ventilation stud, which vents displaced air as the tank is filled. The ventilation stud includes a ball cock fixed to a frustum stopper, which blocks the vent stud in case of accidental overfilling so that T-stoff does not spray from the air vent. Both T-stoff tanks are fitted with an inspection window.
Structure
The structure of the Meillerwagen consisted of the wheeled trailer chassisChassis
A chassis consists of an internal framework that supports a man-made object. It is analogous to an animal's skeleton. An example of a chassis is the underpart of a motor vehicle, consisting of the frame with the wheels and machinery.- Vehicles :In the case of vehicles, the term chassis means the...
, and the hydraulic lifting frame.
The trailer chassis
Chassis
A chassis consists of an internal framework that supports a man-made object. It is analogous to an animal's skeleton. An example of a chassis is the underpart of a motor vehicle, consisting of the frame with the wheels and machinery.- Vehicles :In the case of vehicles, the term chassis means the...
was a lattice frame of tubular members. It comprised a transverse trunnion
Trunnion
A trunnion is a cylindrical protrusion used as a mounting and/or pivoting point. In a cannon, the trunnions are two projections cast just forward of the centre of mass of the cannon and fixed to a two-wheeled movable gun carriage...
box member at the front, from which six longitudinal tube members ran aftward and converged into one large main central tube at the rear; the six longitudinal members were braced vertically and horizontally by smaller-gauge tubes. The rear central tube member supported a large horizontal-plane turntable. A steerable front truck was installed just behind the trunnion box member, while the turntable surmounted a two-axle rear bogey.
The steerable front truck was fitted with twin duplex wheels (four tyres), the inner wheels equipped with pneumatic drum brake
Drum brake
A drum brake is a brake in which the friction is caused by a set of shoes or pads that press against a rotating drum-shaped part called a brake drum....
s. The duplex wheels rode on swinging wishbone axles with transverse semi-elliptical leaf spring suspension. A steering lock was included for use during rear towing.
A turntable at the rear of the chassis frame supported a bogey, mounted on bearings so it could swivel and pivot. The bogey was fitted with two axles, a fixed middle axle and a steerable rear axle, both of the swinging wishbone type with transverse semi-elliptical leaf spring suspension. The middle axle was fitted with pneumatic brakes, while the rear axle was unbraked. A feedback steering system was included in the design, so that any change in direction by the rear bogey (and fixed middle axle) was duplicated by the steerable rear axle, but to twice the extent. The linkage for the feedback system was for used front towing, and was disengaged during rear towing.
The towing arm could be fitted to the front truck, or the steerable rear axle of the rear bogey. The towing arm was fitted with a sprung force stem, contrived so that the tow arm 'floated' horizontally at zero relative weight.
Each front corner of the chassis was fitted with a swing-out A-frame
A-Frame
An A-frame is a basic structure designed to bear a load in a lightweight economical manner. The simplest form of an A-frame is two similarly sized beams, arranged in a 45-degree or greater angle, attached at the top...
boom equipped with a screw jack and foot plate. The booms enlarged the Meillerwagen footprint to stabilise it during erection of the rocket, and provided a means of adjusting the Meillerwagen transverse level. The booms deployed outward and forward of the lifting frame trunnion axis to prevent it toppling forward or to either side.
The lifting frame was constructed of two formed I-beam
I-beam
-beams, also known as H-beams, W-beams , rolled steel joist , or double-T are beams with an - or H-shaped cross-section. The horizontal elements of the "" are flanges, while the vertical element is the web...
s, with tubular and box transverse braces. The lifting frame was fitted with plumbing for fuelling the rocket; wiring for powering and monitoring the rocket and for field telephone
Field telephone
Field telephones are mobile telephones intended for military use, designed to withstand wartime conditions. They can draw power from their own battery, from a telephone exchange , or from an external power source. Some need no battery, being sound-powered telephones.Field telephones were first used...
s; accommodations for carrying and dismounting the rocket; and folding platforms to service the rocket with rungs to access them.
Electrics
The lifting frame was fitted with outlet sockets and wiring for field telephones. A main connection from the armoured launch vehicle switchboard to inlet sockets on the lifting frame provided circuits for four field-phone stations at the Meillerwagen – one each at the upper and lower folding work platforms and two at the launch table.
An early configuration of the Meillerwagen included hardwiring of two electrical power circuits and two FLAK-plug circuits for the power and control needs of the rocket. The system included four sockets at the upper and at the lower end of the lifting frame, and the connective wiring fixed along the starboard beam. The four circuits were connected to two Stotz ejecting plugs, stowed with their cables along the side of the lifting frame. All of this wiring had become redundant by the time the rocket attacks began, but was not removed from the Meillerwagen.
The Meillerwagen chassis was fitted with a Notek tail light at the rear, its patch plug at the front, and the connective wiring in a conduit along the chassis frame.
Hydraulics
The lifting frame erected the rocket from horizontal to vertical, using hydraulic power. The hydraulic lifting equipment consisted of a hydraulic pump and its drive motor, an oil reservoir tank, a control valve group with manometers, and the lifting pistons themselves.
The drive motor was a petrol KdF (Volkswagen) 14 ps (hp) motor, adapted for stationary industrial use by the fitting of magneto ignition
Magneto (electrical)
A magneto is an electrical generator that uses permanent magnets to produce alternating current.Magnetos adapted to produce pulses of high voltage are used in the ignition systems of some gasoline-powered internal combustion engines to provide power to the spark plugs...
and a centrifugal governor
Centrifugal governor
A centrifugal governor is a specific type of governor that controls the speed of an engine by regulating the amount of fuel admitted, so as to maintain a near constant speed whatever the load or fuel supply conditions...
as throttle; besides these modifications, the motor was otherwise identical to those found in VW Beetles
Volkswagen Beetle
The Volkswagen Type 1, widely known as the Volkswagen Beetle or Volkswagen Bug, is an economy car produced by the German auto maker Volkswagen from 1938 until 2003...
, an air-cooled flat-four boxer
Flat engine
A flat engine is an internal combustion engine with multiple pistons that move in a horizontal plane. Typically, the layout has cylinders arranged in two banks on either side of a single crankshaft and is sometimes known as the boxer, or horizontally opposed engine. The concept was patented in 1896...
. The motor was housed in a metal box fixed to the chassis frame. A three-piston eccentric
Eccentric (mechanism)
In mechanical engineering, an eccentric is a circular disk solidly fixed to a rotating axle with its centre offset from that of the axle ....
-cam
Cam
A cam is a rotating or sliding piece in a mechanical linkage used especially in transforming rotary motion into linear motion or vice-versa. It is often a part of a rotating wheel or shaft that strikes a lever at one or more points on its circular path...
hydraulic pump was coupled to the drive motor flywheel
Flywheel
A flywheel is a rotating mechanical device that is used to store rotational energy. Flywheels have a significant moment of inertia, and thus resist changes in rotational speed. The amount of energy stored in a flywheel is proportional to the square of its rotational speed...
. (Meillerwagens at Operation Backfire
Operation Backfire (WWII)
Operation Backfire was a military scientific operation during and after World War II, which was performed mainly by British staff. It was part of the Allies' scramble to loot as much German technology as they could....
were fitted with electric motors as hydraulic drive in place of the petrol motor.)
A 70-litre (15 gal) oil tank was fixed to the chassis frame as hydraulic fluid
Hydraulic fluid
Hydraulic fluids, also called hydraulic liquids, are the medium by which power is transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil or water...
reservoir.
Oil under pressure flowed from the hydraulic pump to the control valve group consisting of three valves in a common housing, manipulated via one large cross-handle and two small hand taps. The large cross-handle regulated the speed of raising or lowering the lifting frame. One hand tap selected direction to either raise or lower the lifting frame. The second hand tap controlled oil flow to the lowering piston (see below), to begin lowering of the lifting frame from its vertical position.
The two hydraulic lifting pistons each consisted of one stationary cylinder and four extending cylinders. The largest extending cylinder included a flange
Flange
A flange is an external or internal ridge, or rim , for strength, as the flange of an iron beam such as an I-beam or a T-beam; or for attachment to another object, as the flange on the end of a pipe, steam cylinder, etc., or on the lens mount of a camera; or for a flange of a rail car or tram wheel...
halfway along its length, against which hydraulic pressure could be selectively applied from either above or below; it was used during raising to delay its extension until all other cylinders had extended, and also to begin the lowering process when the lifting frame was vertical (once lowering had thus been initiated, gravity finished the job).
All components of the hydraulic system were products of Meiller-Kipper GmbH, except the KdF drive motor from Volkswagen.
Platforms
Acting as gantry, the lifting frame included a number of work platforms from which crewmen serviced the rocket. Three (later two) platforms folded flat against the lifting frame, and could be folded out from the elevated lifting frame with the use of a hand winch. Each folding platform included a safety rail of folding posts and chains.
Two side platforms or catwalks were inserted into holders for deployment on each side of the lifting frame, otherwise stowed together on brackets near the turntable. A rotating platform could be suspended from the rocket nose, to provide access to the rocket control compartments on the far side of the rocket.
The port beam of the lifting frame was fitted with around 40 rungs along its full length, with which crewmen climbed to the working platforms.
Accommodations
The lifting frame included two accommodations for the rocket, a nose clamp around the warhead and a pivoting clamp around the rocket midsection. Both accommodations included a saddle, and various mechanisms to assist dismount of the rocket onto its launch table. The mechanisms were operated with two drive shafts running up the port lifting frame beam. The drive shafts ran within the integral rungs, and were operated by a crewman with a ratchet hand tool.
The two drive shafts comprised a short shaft and a long shaft; both starting at the trunnion end of the lifting frame, one running half the length of the lifting frame while the other ran the full length.
The short drive shaft operated the pivot clamp around the rocket mid section, which could move the rocket 28 mm (~1") forward or backward along its centreline. The rocket midsection was fitted with a band which included trunnion pins placed in opposition; the pivot clamp held the rocket by the trunnion pins. The pivot clamp was able to rock on a transverse shaft, thus causing the rocket to move along its centreline. After erection of the rocket to a vertical position, it was held suspended above the launch table; by use of the pivot clamp, the weight of the rocket could be gently lowered onto the launch table until fully taken up, allowing the rocket to be unsecured from the lifting frame, thus dismounting it from the Meillerwagen.
The short drive shaft operated a screw sleeve, which extended to work a bell crank
Bell crank
A bell crank is a type of crank that changes motion through an angle. The angle can be any angle from 0 to 360 degrees, although 90 degrees and 180 degrees are common....
. The bell crank turned a transverse shaft fitted with an eccentric cam, which would push or pull the pivot clamp, thus moving the rocket forward or aftward along its centreline.
The long drive shaft ran along the full length of the port beam of the lifting frame. It entered a worm gear at the pivot clamp, then continued to the nose clamp where it entered another worm gear. A shift lever at the nose clamp disengaged the drive shaft to allow either simultaneous or independent operation of the two worm gears. The worm gear at the pivot clamp operated a pair of scissor arms, one on each side of the lifting frame to insert or extract the trunnion pins from the rocket. The worm gear at the nose clamp operated the jaws of the nose clamp to either open or close, thus enclosing or releasing the rocket.
Brakes
The Meillerwagen was equipped with pneumaticAir brake (road vehicle)
Air brakes are used in trucks, buses, trailers, and semi-trailers. George Westinghouse first developed air brakes for use in railway service. He patented a safer air brake on March 5, 1872. Originally designed and built for use on railroad train application, air brakes remain the exclusive systems...
drum brakes, installed on the front and middle axles. The middle axle brakes could also be applied mechanically with a hand-operated cable, to act as a parking brake.
The Meillerwagen’s pneumatic brakes drew air pressure from the towing vehicle, and were operated by the tractor driver as an extension of his vehicle’s brake circuit. A control valve handle on the Meillerwagen regulated the braking force it drew from the tractor, depending on whether the Meillerwagen was laden with a rocket or unladen.
The Meillerwagen was equipped with two compressed air reservoirs, filled from the towing vehicle. These allowed the Meillerwagen to use its pneumatic brakes when it was unhitched from the tractor. In the unhitched mode, the Meillerwagen brakes were operated from the control valve handle, to provide braking ability during winching and hand-manoeuvring around the launch site.
The brake control and regulator system were supplied by Graubremse GmbH. The compressed air reservoirs, pneumatic brake cylinders and drum brakes were supplied by Knorr Bremse GmbH.
Accessories
The Meillerwagen carried a number of accessories on the chassis and lifting frame, both for itself and the rocket. A toolbox fixed on the chassis carried snow chains, a tyre pump, and assorted tools for the Meillerwagen and KdF motor. The chassis was equipped with a pair of blast shields, entrenching tools, a hand-steering A-frame, two jacks, a spare tyre and a folding ladder. Special trays were fixed on the chassis to carry the transport cases which held various rocket accessories such as the graphite steering vanes, the nose fuse, and the Z-stoffZ-Stoff
Z-Stoff was a name for calcium permanganate or potassium permanganate mixed in water. It was normally used as a catalyst for T-Stoff in military rocket programs by Nazi Germany during World War II....
(permanganate) flask.
The rocket was provided with ejecting umbilical connectors, although their precise deployment evolved. Initially these 'Stotz plugs' travelled as Meillerwagen accessories, stowed on the lifting frame along with their cables. Later, the Stotz plugs were stowed in the cable box, and a ten metre cable mast was stowed on the lifting frame for ultimate erection on the launch table at the launch site.
Specifications
'Laden' refers to carriage of an unfuelled rocket with warhead fitted. 'Camouflage frame' is a tube-frame box assembled around the rocket and covered with tarps, rarely used during combat launches.- Total length: With towing arm – Unladen without Camouflage frame, 14700 mm; Laden with Camouflage frame, 16665 mm. Without towing arm – Unladen without Camouflage frame, 12610 mm.
- Shipping class: S (for the unladen vehicle)
- Total width: Unladen without camouflage frame, 2800 mm. Laden with camouflage frame, 2870 mm.
- Total height: Unladen without camouflage frame, 3270 mm. Laden with camouflage frame, 4200 mm.
- Total weight: Laden, 15476 kg. Unladen, 11300 kg.
- Axle loads: Front axle – laden, 7010 kg; unladen, 5860 kg. Middle and rear axle – laden, 4385 kg; unladen, 2720 kg.
- Turning circle radius: 10700 mm. Clearance: 350 mm.
- Maximum towing speed: forwards, 45 km/h; backwards, 15 km/h.
- Brakes: Type – Knorr single-acting pneumatic cylinders and internal-shoe drums.
- Front axle wheels: Brake cylinders, 125/140 mm; drum brake shoes, 400 x 140 mm; Pneumatic. Middle axle wheels: Brake cylinders, 80/110 mm; drum brake shoes, 400 x 120 mm; Pneumatic or cable. Pneumatic brake lines: Steel pipes, 15 mm, diam x 1.5 mm; rubber hose lines, 24.5 mm, diam x 1.3 mm. Pneumatic storage: two tanks, each of 40 litres capacity at 6 kg per cm2.
- Wheels: Type – split rim. Rim size: 8" x 20.
- Tyres: Type – Pneumatic tyres, front axle duplex tyres, middle and rear axle single tyres. Size, 270-20. Air pressure – Front axle, 4,8 atm.; Middle and rear axle, 5,8 atm.
- Wheelbase: Overall, 9800 mm; trailing rear truck, 2600 mm. Track width: Front axle, 1250 mm (central distance between duplex tyres); middle and rear axle, 2000 mm.
- Hose connectors: B-material line – steel tube of 70 mm ID; upper and lower connectors, M 90 x 2 mm; tank drain valve, M 45 x 1.5 mm. T-material line – aluminium pipe of 32 mm ID; upper and lower connectors, R 1 3/4. A-material line – light alloy pipe of 70 mm ID; Upper and lower connectors claw clutch size, NW 70 mm. P-material line – steel tube of 10 mm; 6 compressed gas bottles, 230 atm.; filling pressure with a volume of 58 L each; filling and emptying connecting pieces, AM 14 x 1,5 mm.
- Hydraulic lifting system:
- Oil pump: Design – Meiller-Kipper single-action three-piston high-pressure pump. Reservoir capacity, 70 litres; acid-free spindle oil.
- Drive engine: Design – Stationary KdF engine (from VolkswagenVolkswagenVolkswagen is a German automobile manufacturer and is the original and biggest-selling marque of the Volkswagen Group, which now also owns the Audi, Bentley, Bugatti, Lamborghini, SEAT, and Škoda marques and the truck manufacturer Scania.Volkswagen means "people's car" in German, where it is...
) type 120/15. Working type – Four-stroke petrol Otto engine. Fuel – 74 oct gasoline; Coldstart fuel, ether. Stroke, 64 mm. Bore, 75 mm. Number of cylinders, 4. Capacity, 1131 cm³. Compression ratio, 1:5,8. Working number of revolutions, 1470–1500 rpm. Continuous operation, 14 hp. Fuel consumption under full load, ~5.4 L/hr. Lubricating oil consumption, about 20 cm³/hr.- Tools for the VW Motor: 1 starting crank, coldstart fuel (ether) in canister.
- Hydraulic presses: Number, 2. Design – 1 cylinder + 4 extending pistons (3 pressure pistons and 1 combined pressure and lowering piston).
- Accessories: hand steering pole, 2 blast shields, Stotz plugs and cables, catching net for the Stotz plugs, entrenching tools (1 pick, 1 spade), tool hoist, camouflage frame and tarps, 2 jacks, 2 side platforms. Cable Mast.
- Toolbox with contents: Cable kit, 1 Wheel-brace, 4 Snow chains, 2 Tubular extensions (for boom cranks), 2 ratchet keys (for drive shafts), Tommy bar (for frame brace turnbuckles), 1 spirit level, 1 x 4 m patch cable (for tail light), 1 crank handle (for platform winch), repair kit for catching net, Tool kit.
- Tool kit: 1 Hand pump with hose, 1 Combination pliers, 1 Mechanics hammer, 2 Tyre levers.
Survivors
Of a reported production run of 200 units, three are confirmed survivors.Australian War Memorial. Treloar Center. Canberra, Australia.
(Operation Backfire
Operation Backfire (WWII)
Operation Backfire was a military scientific operation during and after World War II, which was performed mainly by British staff. It was part of the Allies' scramble to loot as much German technology as they could....
emeritus, unrestored, serno 5628)
Cosford RAF Museum, Cosford UK.
(Operation Backfire emeritus, restored, serno unrecorded)
USAF Museum, Wright/Paterson AFB, Ohio, USA.
(A4b experimental unit, restored, serno 7364)
Unknown number taken east in 1945, all or none of which may still exist in former USSR.