Cluster Projectile 1,000-lb. No. 16 Mk II (Service)

Description: This cluster consists of three fagots of 4-lb. incendiary bombs. The bombs in each fagot are arranged nose-to-tail with their safety plungers inward so that they are all depressed. The bombs are held in place by a front end plate, a rear end plate, a top and bottom beam, four wooden slats, tensioning straps, and a retaining bar. The retaining bar has a series of lateral pins which engage tabs on the tensioning straps. A shear wire passes through a bridge and the retaining bar at a position near the front end plate. A channel secured to rear end plate supports a fuze adapter, the outer end of which is closed by transit plug fitted with a leather washer. Inside the adapter is a pis-ton, through which a pin is passed, arranged to engage the lower end of a pivoted lever. The fuze adpater and the piston are slotted to receive the lever. The upper end of the lever is forked and is connected to the retaining bar. A nose cover is fitted to the front end plate to decrease the drag of the cluster. The tail unit is attached to a spring-load-ed rod extending through the center of the cluster. The tail is held compressed against the sping by an arming wire arrangement.

Tail Construction: The Tail No. 48 Mk II and III is of the telescopic type and is supp-lied fitted to the cluster in the closed position. It consists of five fairings, forming a shortened cone, carried by the rear end plate of the cluster, and a strut mounted on supports, carried by an inner tube which slides in an intermediate tube. The intermediate tube extends through the whole length of the outer tube, which is secured to the end plate of the cluster. The intermediate tube replaces the central bomb of the middle and tailend fagot of the cluster.

A spring is housed in the inner tube, with one end bearing against a stop in the tube and the other end bearing against a cap which closes the inner end of the intermediate tube. The spring, which is under compression, tends to slide the inner tube out of the intermediate tube to extend the tail. This movement is limited by a ferrule on the inner tube, which engages a ferrule in the intermediate tuben when the tail is fully extended.

The inner and intermediate tubes have holes provided in them, which register when the tail is closed. A safety wire is threaded through the holes to retain the tail in its closed position against the action of the spring. A 4-ft. fuzing lanyard is attached to the eye of the safety wire by a shackle, and a similar shackle is provided at the free end of the lanyard.

Functioning: When a fuzed cluster projectile is released from the plane, the arming wire is withdrawn, starting the delay of the fuze and releasing the tail unit, which then springs out on its rod to be fully extended position. When the fuze functions, the fuze magazine charge is fired and the pressure of the gases forces the piston in the fuze adapter against the lower end of the pivoted lever. The lever is thus rocked about on its pivot and exerts a pull on the retaining bar of the cluster. This causes the retaining bar to break its shear wire and to be moved so that the pins on the bar disengage theresel-ves from the tabs of the tensioning straps. The straps then fly outward, and the cluster disintegrates, scattering the bombs, which fall away separately. The individual incendiary bombs function on impact.

Suspension: A British type suspension lug is fitted to the top beam, and tapped holes in the beam are provided for fitting American type lugs.

Remarks: The fagot at the nose end of the cluster contains 79 bombs. The central end tail fagot contains 78 bombs each, the central bomb of each of these fagots being removed to allow insertion of the outer tube, which accommodates the stem of the tail and is secured to the rear end plate of the cluster.

Figure 112 - Cluster Projectile 1,000-lb. No. 16 Mk II

Figure 113 – Tail Unit No. 488 Mk II for Cluster Projectile No. 16 Mk II

Figure 114 – Nose assembly details of Cluster Projectile No. 16 Mk II