Over-all length: 3 7/8 inches.

Maximum diameter: 2 1/8 inches.

Threaded length: 3/8 inch.

Number of threads: 4, right-hand.

Construction: This fuze is made of brass and consists of a nose cap, a central spindle, and four powder time rings. Of the four powder rings surrounding the spindle, the first and third are fixed. The second and fourth rings are movable and keyed so that they move as one unit. Housed in the base of the central spindle is a firing pin which is sepa-rated from the movable primer by a small coiled spring. The base plate contains a flash charge of black powder.

Operation: This fuze may be set for any time between 0 and 30 seconds is increments of 1/5 second. On set-back the primer moves down onto the fixed firing pin, sending a flash up through the central spindle to the upper time ring. As the last powder time ring burns, the flash is transmitted to a black-powder magazine and thence to an auxiliary detonating fuze which is used in conjunction with this fuze and is threaded into the fuze pocket separately.

Remarks: This fuze is also used in Navy 8-cm antiaircraft projectiles.

Figure 330 – Type 89 Powder Time Fuze.