With the development of the Saturn launch vehicle, it became mandatory to develop a system for restraining the vehicle until after all checks and engine thrust buildup were completed. The basic Saturn I holddown arm constrains the vehicle by clamping it between a fixed support and a movable jaw. The jaw is on a link pinned to rotate sufficiently to release the vehicle. There are three links in the jaw (restraining) system arranged so that with a small force provided by a pneumatic separator mechanism, the large loads of the vehicle can be restrained. Design details discussed are the link system, the separator, adjustments, and the energy absorber. The function of preloading is discussed. The secondary release system is described. Finally, the design differences between the Saturn I and the Saturn V arm are described
