Below are listed the headings shown in the description of each fuze. The explanatory notes are in earlify the information given under each heading.

Action

This refers to the type of force that causes the fuze to function and the delay with which the fuze functions. (No delay time is given for hydrostatic fuzes. All hydrostatic fuzes fire instantaneously when caused to function by hydrostatic pressure.)

Modification

Under this heading all Mods to date (1 June 1945), with a note concerning the major difference between the Mods.

Status

This indicates availability. Terms used and their meanings are:

Service - The fuze is under current procurement or suitable for procurement if require-ments exist.

Obsolescent - The fuze is becoming obsolete or is being superseded by another de-sign. It is not in production and not suitable for future procurement.

Obsolete - Fuzes are listed as obsolete only when so declared by the Bureau of Ord-nance and so stated in OP 1515, chapter 4. Fuzes may be declared for the following rensons: (1) Present stock is almost exhausted and will not be repelnished. (2) Present stock is in excess of Bureau of Ordnance requirements. (3) The fuze because of safety reasons, is unsuitable for Navy use. Obsolete fuzes may be used, when authorized by the Bureau of Ordnance, for special purpose, such us training.

Restriction on Use

These apply only in Navy usage of good lots of fuzes in the bombs for which the fuzes were intended. Tactical limitations, such as minimum altitude of release, are promulgated by the Chief of Naval Operations. Restrictions on the use of defective lots of fuzes are promulgated in Ordnance Circular Letters and OP 1515. See page 8 for special precau-tions in the use of certain fuzes.

Fuzes for which no restriction are listed are safe for all take-offs and landings any-where, including catapult take-offs and arrested landings.

Air Travel to Arm

This give an average figure (unless otherwise noted) for the air travel, along the tra-jectory of the bomb, required to arm the fuze when installed in bombs for which it is de-signed. The figure given is not to be confused with the minimum safe altitude of release, which depends on other factors.

Indications of Arming

This term refers to the visual evidence of normal arming or partial arming of undamaged fuzes.

Bombs in Which Used

This list includes the bombs for which the fuze was designed and the bombs in which it could be or has been used to give tactical results. See Restriction on Use.