Operational shields

Discusses the use of Ammunition Peculiar Equipment (APE) used by the military community to perform various operations on ammunition items. Hays in which operators are protected when using APE are included. Specifically, the design of operational shields to contain effects of an explosion is explained. 

Whenever the operation to be performed involves the potential to cause the initiation of the propellant, explosive or pyrotechnic (PEP) component(s) of a munition item, the APE is either operated by remote control, with the operator behind a protection wall or barrier, or it is enclosed in a protective barricade or operational shield. Barricades or operational shields are designed to protect personnel and assets from the effects of blast overpressures, thermal effects or fireball, and fragments result from the initiation of PEP components, such as the fuze, primer, propelling charge, burster, etc. 

Operational shields are to be designed to conform to the following requirements ... 

SHIELD DESIGN. In the initial approach to operational shield design, the hydrostatic pressure that would result from the MCI in the shield is determined. For a high explosive detonated in a... 

After the design of the shield has satisfied the requirements, and the prototype shield has been fabricated, reference 1 specifies the testing to which it must be subjected. The prototype operational shield must be tested by creating an MCI in a simulated operational environment. 

Documentation of the tests should also be provided by still photography, video camera/recorder systems, and high speed photography. The high speed photography with a minimum speed of 500 frames per second Is necessary to be able to see any flame front exiting a shield. A list of typical Instrumentation used on an operational shield test Is shown on Table II, (see reference A). 

INDUSTRIAL SAFETY PROVISIONS. In the design of the APE and associated operational shield, conventional machine design practices are used to protect operators from hazards associated with moving parts. Proper techniques for guarding of hazardous machine areas are used, including the use of interlocks In the control system to prevent movements until certain conditions are satisfied, or to stop movements In emergency situations... 

SUMMARY. The safety record associated with the use of APE operated remotely or within operational shields is excellent. Operational shields that are properly designed, fabricated, and tested do provide operators with adequate protection, and ensures their safety during hazardous operations. 

Miller, J., APE 1011M6 Operational Shield Tests MK39 Primer In Empty 6 lnch/47 Cartridge Case (1340 Grains Black Powder), Ammunition Equipment Directorate, Tooele Army Depot, Tooele, Utah, D/AE Report 05-82, 22 February 1982. 

Ventilation, fume hoods and bench space are necessary for radiochemical operations. Shielded facihties should be provided for detectors, including those in direct assessment facilities. Access control to all facilities is necessary, both to protect sensitive equipment and to maintain appropriate confidentiality of records. The facility should have an appropriate continuous floor covering (e.g. viryl) to facilitate cleaning and decontamination. 

Are arc welding or cutting operations shielded by flameproof screens or located in bays or booths to protect from direct rays of the arc ... 

Stationary and portable wet type collectors may be placed in the explosives operating bays or cubicles provided the quantity of explosives in the collectors does not exceed five pounds. If placed in separate cubicles, the explosives limits for the collectors may be increased to the amount reflecting the capabilities of the cubicie walls as operational shields. For greater quantities, the location requirements set forth above are applicable. 

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