Description
The bomb BLU-3/B is an antimateriel, vane-drag, impact-fired, high-explosive fragmentation bomb.
The bomb body has a pebbled appearance, caused by the steel balls embedded in the body. The bomb fuze is threaded into the base of the body; the cup firing-pin assembly to which the firing pin is mounted, is crimped to the fuze. The bomb stabilizer assembly is attached to the top of the bomb and consists of six spring-loaded drag vanes. In the unarmed condition the drag vane are secured to the sides of the bomb body by the safety strap which, in turn, is held in place by the spring tab. The bomb body is aluminum embedded with steel balls. The vanes are steel. The nester is plastic (bakelite). The spring tab and safety strap are steel. The cup is aluminum alloy. The fuze escapement mechanism is brass, the arming slide is zinc alloy, and the remaining parts of the fuze are steel.
The body of the bomb BLU-3/B is painted yellow and the cup is anodized a gold color. The drag vanes are anodized gold. All markings are in black.
The BLU-3/B is used in the following systems:
CBU-2A (Dispenser, SUU-7/A carrying 360 BLU-3/B)
CBU-2A/A (Dispenser, SUU-7A/A carrying 406 BLU-3/B)
CBU-2B/A (Dispenser, SUU-7B/A carrying 409 BLU-3/B)
CBU-2C/A (Dispenser, SUU-7C/A carrying 409 BLU-3/B)
CBU-14/A (Dispenser, SUU-14/A carrying 114 BLU-3/B)
CBU-14A/A (Dispenser, SUU-14A/A carrying 114 BLU-3/B)
Functioning
Upon release from the dispenser, the spring tab is stripped off by the airstream, releasing the safety strap which is ejected by the drag vanes which are forced open by their springs. Release of the safety strap and the vanes allows the spring-loaded cup to move forward, withdrawing the firing pin from the cavity in the arming slide. In the late model bombs, opening of the vanes allows the spring loaded safety pin to move outward, releasing the arming slide. The drive spring moves the arming slide to aline the detonator, lead charge and firing pin. The bomb is now armed. The escapement mechanism provides a short delay in alining the arming slide. Upon impact, the cup drives the firing pin into the detonator, initiating the explosive train.
Hazardous Components
Bomb BLU-3/B contains approximately 0.4 pound of RDX or cyclotol, a detonator, and a lead cup.
Physical Data
Height, overall - 4 in, 101.6 mm
Diameter - 2.7 in, 68.6 mm
Height, deployed vanes - 6.8 in, 172.7 mm
See Also
Source(s)
TM 9-1385-51, Ammunition (Conventional) for Explosive Ordnance Disposal (1967)
