Downloaded from https://www.everyspec.com AMCP 706 210 2-5.2 APPLICATION TO FUZE DESIGN PROBLEMS obviously, was not suitable for fruing from a tank. Applying Human Factors Engineering to fuze Fig. 2-3 shows Fuze, MT, XM571, with the design problems reovires that the fuzing mech- setting mechanism redesigned for tank firing anisi be considereu both (1) as a component The design has the following features: of a larger ammunition system, and (2) as a sys- (1) There is no need for time settings be- tem unto itself. In the first instance, the Human yond 10 sec for tank-fired ammunition.
The Factors specialist must consider the entire stock- range of the setting was, therefore, reduced pile-to-target sequence of the ammunition sys- tem and assess the impact of such factors as how and where the system will be used; under what conditions of environment (illumination, weath- er, etc.), by what types of troops, under what limiting conditions. As an example, ammunition designed for rapid salvo firing may preclude mul- tiF',ose fuzing because of the time frame in- volved, or at least, demand that multipurpose settings be made under extremely rapid condi- KNURL tions.
This would imply that such settings re- quire minimum applied torque and positive (visual and auditory) feedback of setting. If fuzes were armed and set at leisure, prior to mission firings, more complicated setting and arming procedures might be permissible. Human Factors studies might be in order to provide feedback data on how many fuzes could be armed or settings be changed per minute under varying conditions. Examining fuze design as a component or system unto itself can be done in a relatively straightforward manner by considering each interaction between man and fuze.
If fuzes contain visual displays (arm-safe marks, posi- tion setting marks, special instructions, etc.), reference should be made to the guidebook data for selection of optimal numeral style, size, color, etc. Choice of control modes-such as rotating bands, selector switches, or screw set- tings--can also be made on the basis of pre- vious study results. The use of mechanical time fuzes in tank-fired ammunition is a good illustration of Human Factors Engineering applied on a system and a component basis, considering not only fuze de- sign but the overall use of the ammunition RELASE system itself.
Previously, a setting wrench was BUTTON used to set the mechanism that was held in posi- tion by the large torque required to move it (100 in.-oz). Because of the wide range (100 sec), each 0.1-sec setting represented a circum- ferential movement of only 0.007 in. Hence, a vernier scale had to be provided. This fuze, Figure 2-3. Setting Mechanism on Fuze, MT, XM571 2-6 .. m =4