Truck-mounted Helical Rail Guided Missile Launcher M398.
The M398 is seen from the right rear with the launching rail elevated and without the missile loaded. Ladders are stowed on each side of the launcher rail. (Picture from TM 9-500 C3 Data Sheets for Ordnance Type Materiel.)
The driver's compartment of the base chassis truck is detailed in this image. A. Windshield wiper motor. B. Rear view mirror. C. Clamping screw. D. Instruction data plate. E. Ammeter. F. Speedometer. G. Fuel gage. H. Instrument cluster light. J. Truck nameplate. K. Windshield locking handle. L. Servicing and publication data plate. M. Instrument panel compartment. N. Cowl ventilator. P. Responsible agency data plate. Q. Primer pump control knob. R. Auxiliary power receptacle. S. Crankcase ventilation shutoff valve control. T. Choke control knob. U. Crankcase ventilation shutoff data plate. V. Oil pressure gage. W. Air pressure gage. X. Water temperature gage. Y. Headlight beam indicator. Z. Ignition switch. AA. Low air pressure warning data plate. BB. Throttle control knob. CC. Light switch. DD. Windshield wiper switch. EE. Dimmer switch. FF. Horn button. GG. Starter pedal. HH. Accelerator pedal. JJ. Transmission gearshift lever. LL. Service brake pedal. MM. Clutch pedal. (Picture from TM 9-2320-209-10 C11.)
The installed valve-in-head, wet-sleeve engine is viewed from the left. Bore and stroke were each 4⅛" (10.48cm) for a displacement of 331in³ (5.42L). Firing order was 1-5-3-6-2-4. (Picture from TM 9-2320-209-20 C3.)
The opposite side of the engine is labeled. Compression ratio was 6.73:1, and the engine weighed 872lb (395kg). The air compressor could be a Bendix-Westinghouse 2-UE-7-1/4-VW that was cooled with engine coolant, or, as shown here, a Midland Ross Co. 5400B air-cooled type. Both were 2-cylinder units that used engine lubrication and displaced 7¼ft³ (.205m³) per minute at 1,250rpm. Replacing the water cooled compressor with an air cooled model required installing a new air filter manifold assembly. (Picture from TM 9-2320-209-20 C3.)
The 5-speed manual transmission is shown dismounted from the vehicle. In addition, a 2-speed double-sprag Wisconsin Axle T-136-10 transfer was controlled from the cab. It was geared to drive the front axle slightly slower than the rear axles. An overrunning double-sprag clutch in the transfer drive to the front axle automatically eliminated power delivery to the front wheels until the rear wheels slipped ~8%. A 2-speed transfer with an air-actuated positive lock-up mechanism could also be used, which allowed the driver to engage the front axle on command. (Picture from TM 9-2320-209-20 C3.)
The Michiana Products Corp. MPC-D9633 fuel tank was mounted under the right front corner of the body, supported by two brackets and secured by two straps. (Picture from TM 9-2320-209-20 C3.)
Two Delco-Remy 6TN23 12-volt lead-acid batteries were connected in series for the 24-volt electrical system. The battery box was on the right side of the cab between the running board and cab door. (Picture from TM 9-2320-209-20 C3.)
The front suspension and steering gear components are labeled in this image. (Picture from TM 9-2320-209-20 C3.)
The Timken SFD-75-H-X2 bevel-drive, top-mounted, double-reduction, single-speed front axle is shown installed. (Picture from TM 9-2320-209-20 C3.)
The rear springs were inverted with slipper-type ends. Driving and braking forces were transmitted to the chassis by torque rods that were arranged to maintain the vertical position of the rear axle drives regardless of the evenness of the road surface. The left side of the vehicle had both upper and lower torque rods, while the right side had lower rods only. (Picture from TM 9-2320-209-20 C3.)
Two Timken SFD-75-H-X2 bevel-drive, top-mounted, double-reduction, single-speed axles were mounted in tandem at the rear of the vehicle. Power was transmitted from the transfer to the forward rear-axle differential and from there to the rear rear-axle differential by another propeller shaft. Three torque rods were attached to each axle. (Picture from TM 9-2320-209-20 C3.)
The interior of a service brake is revealed in this image. The service brakes were an air-operated hydraulic system, and a Timken Duo-Grip handbrake was mounted on the rear output shaft of the transfer. The air compressor kept the two air reservoirs filled to a pressure of 100-105psi (7.03-7.38kg/cm²). (Picture from TM 9-2320-209-20 C3.)
The Lacrosse missile was delivered to the assembly area in two containers, one for the warhead and the other for the main assemblage and rocket motor. The large wings were fixed, with steering done by the smaller rear fins. The complete missile weighed 2,360lb (1,070kg), was 230" (584cm) long, and was 20½" (52.1cm) in diameter. Tip to tip, the fins spanned 56⅜" (143.19cm) and the wings spanned 81" (205cm). The solid-fueled rocket motor was 102" (259cm) long, 16" (41cm) in diameter, weighed 832lb (377kg), and could propel the missile 12 miles (19km). (Picture from TM 9-500 C3 Data Sheets for Ordnance Type Materiel.)
Though there are differences in this launcher vehicle, this image serves to illustrate the size of the missile. (Picture available from Redstone Arsenal Historical Information.)
