valve is in this position. This position should be used to stop stanchions during raising or lowering or to hold the stanchions either up or down. CAUTION The control valve lever must never be held or left in any position between 1 and 2 or 2 and 3, since this allows fluid to drain from the accumulator, through the system, to the gravity tank. The power package accumulator does not contain sufficient fluid to raise and lower the stanchions more than three times without the pump operating. Approximately 20 minutes is required for the pump to replenish fluid to the operating level in the accumulator, if stanchions are cycled three times without the pump operating. The READY CONDITION for normal operation specifies 1,500 psi accumulator pressure; however, stanchions will raise and lower, taking a longer period of time with a lower pressure, as is experienced if stanchions are cycled without the pump operating. Pressure at the start of the third cycle will be approximately 850 psi without the pump operating. NOTE If the stanchions are cycled more than three times without the pump operating, air will enter the piping and cylinders, and fluid will overflow the gravity tank. It is then necessary to fill, vent, and charge the system as specified in the applicable operating manual. During the READY and SECURE conditions, the following checks are to be made: During the READY condition at 1-hour internals, check the accumulator pressure, accumulator and gravity tank liquid levels, controller switch for AUTOMATIC setting, and make sure the pump is not operating when accumulator pressure is 1,500 psi or above. During the SECURE condition, make a daily check of the accumulator pressure, accumulator and gravity tank liquid level, valves for position (open or closed), and controller switch for OFF setting. The system must be operated WEEKLY to raise and lower the stanchions, to vent air from both ends of the hydraulic cylinders, and to check the operations of the system. It is not necessary to attach the barricade webbing during this exercise. MAINTENANCE PROCEDURES Arresting gear must be kept ready for instant use. There is only one way such a condition may be effected; that is, by constant inspection, repair, and maintenance. Preoperational and postoperational inspection of all components is a necessity and mandatory, as directed by the applicable MRC. Every section, topside, below deck, engine areas, and ready stowage must be prepared to function on command. Maintenance can be divided into two broad categories: preventive maintenance and corrective maintenance. Preventive maintenance consists of routine shipboard procedures designed to increase the effective life of equipment or to forewarn of impending troubles. Corrective maintenance includes procedures designed to analyze and correct material defects and troubles. The main objective of shipboard preventive maintenance is the prevention of breakdown, deterioration, and malfunction of equipment. If, however, this objective is not reached, the alternative objective of repairing or replacing failed equipment-corrective maintenance—must be accomplished. Maintenance by the arresting gear crew must go beyond a wipedown and periodic lubrication. The arresting gear personnel must be instructed to alert the officer in charge to any signs of malfunction, wear, looseness, leakage, damage, or any other irregular conditions in the arresting gear equipment. They should also learn the physical location of all operating parts, cable runs, air supply lines, valves, electrical supply lines, switches, fuse boxes, tools, and spare parts. Engine inspection should be visual, mechanical, and operational. The following general notes apply to maintenance throughout the arresting gear equipment: Mechanical inspection is performed while the engine is at rest. It consists of a security check, exercising the engine, and manipulating the controls. This inspection is a check for looseness, excessive play, improper operation of hidden parts, lack of lubrication, or any abnormal resistance to motion. 3-46