Cluster Projectile 270-lb. No. 1 Mk I (Service)

Description: The cluster is a cylindrical metal container consisting of a nose unit, re-cessed to receive the noses of seven 4.5-in. reconnaissance flares, and a fuze adapter, from which radiate seix flash tubes to the fire igniters and three flash channels leading to the explosive pellets in the piston housings. The nose unit is secured to the panel locat-ing plate and the tail plate by the T-section suspension bar and the clamping bars. The clamping bars consists of a bar to which are welded two panels. The clamping bars lo-cate the panels and are secured through the panel locating plates to the tail plate and to the nose unit by spring washers and nuts. The nuts securing the clamping bars to the piston housings are further secured by split pins. The tail tie rod is screwed into the tail plate and the tail unit fastened to ots by a spring washer and nut.

The flares, from which the suspension lugs and domed caps have been removed, are located by the reccesses in the nose unit and panel locating plate. The flares are fuzed with special igniters, consisting of the body and dome portion of the Fuze No. 42 without the percussion cap and striker mechanism, and sealed with primed cambric.

Tail Construction: The Tail No. 69 Mk I consists of a sheet-metal tail cone to which a cylindrical strut is attached by four fins. The tail unit is attached to the tail plate of the cluster by a tie rod, which passes down the center axis of the tail wire.

Functioning: On release from the aircraft, the cluster falls normally until the fuze functions. When the fuze functions, the flash from the magazine passes through the flash tubes to ignite the igniters in the nose of each flare, and through the flash chan-nels to explode the gun-powder pellets in the piston housings. The explosion of the pel-lets forces the pistons out of  their housing, causing the clamping bars to swing out-wards, thus releasing the nose unit, panels, and initiated flares. The flares then function in the normal manner.

Suspension: The cluster is suspended by a single lug secured to a T-section suspen-sion bar, which runs from the nose to the base of the cluster.

Figure 103 - Cluster Projectile 270-lb. No. 1 Mk I