Meillerwagen
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, 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. The Peenemünde Army Research Center designed the Meillerwagen, and the Gollnow & Son company assembled the Meillerwagen from supplied components. The Meillerwagen was assembled with Italian and Russian 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 half-track launch control vehicle. Launching of V-2s from mobile equipment was studied under code name Regenwurm to replace bunkers such as at the Watten bunker.
Operation
The Meillerwagen A-4/V-2 transport-launcher unit consisted of the following vehicles:- Feuerleitzugmaschine Sd.Kfz. 7/3
- Feuerleitpanzer Sd.Kfz.251
- Hanomag SS-100
- The Meiller-Wagen
- Opel-Blitz T-Stoffwagen
- ''Kesselanhänger für Fl-Sauerstoff''
Transport
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 Clamping collars were used to connect the rocket to the firing stand, and the Meillerwagen was withdrawn less than a meter and the rocket was turned a quarter turn for the fuel connections to face the Meillerwagen platforms, which were lowered into position for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.Fuelling
The hydrogen peroxide tank on the Meillerwagen was filled from a 2120-litre tank truck with its own pump, then the rocket was filled from the Meillerwagen tank. Additional 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 oxygen 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 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.
- T-Stoff: High test peroxide 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 valves 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.
Timeline
- arrival at launch site and dismount rocket; duration 20 minutes from X minus 110 to minus 90 minutes.
- fuelling of B-Stoff and T-Stoff; duration 20 minutes at X minus 55 minutes.
- fuelling of A-Stoff and Z-Stoff; duration 10 minutes at X minus 30 minutes.
- finalise rocket position, couple Meillerwagen to tractor, depart site; duration 5 minutes at X minus 13 minutes.
Structure
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 bogie.
The steerable front truck was fitted with twin duplex wheels, the inner wheels equipped with pneumatic drum brakes. 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 bogie, mounted on bearings so it could swivel and pivot. The bogie 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 bogie 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 bogie. 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-beams, 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 telephones; 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 hard-wiring 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, a hydraulic fluid tank, a control valve group with manometers, and the lifting pistons themselves.The drive motor was a petrol KdF 14 ps engine, adapted for stationary industrial use by the fitting of magneto ignition and a centrifugal governor to the throttle; besides these modifications, the engine was otherwise identical to those found in Volkswagen Beetles, an air-cooled flat-four boxer. The engine was housed in a metal box fixed to the chassis frame. A three-piston eccentric-cam hydraulic pump was coupled to the engine flywheel.
A 70-litre 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, 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 telescopic 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.
All components of the hydraulic system were products of Meiller-Kipper GmbH, except the KdF drive engine from Volkswagen.