When test fittings are not in use, they should be:

When test fittings are not in use, it is essential to store them under lock and key in a central location to maintain safety and security. This practice minimizes the risk of unauthorized access and potential accidents that could arise from improper handling or storage of these fittings, which may be related to explosive materials or equipment.

Storing them securely ensures compliance with safety regulations and protocols that govern the handling of explosives on shipboard environments. A centralized location helps to keep the inventory organized and readily available for when they are required again, promoting efficiency in operations.

Other storage methods, such as leaving them outdoors for ventilation or placing them in the nearest magazine, do not provide the same level of security or appropriate environmental control needed for test fittings. Additionally, reporting them to the commanding officer may be necessary in certain situations but is not a method of storage. Thus, the practice of secure storage is vital for both safety and operational effectiveness.