The British No. 69 was a

hand grenade A grenade is an explosive weapon typically thrown by hand (also called hand grenade), but can also refer to a shell (explosive projectile) shot from the muzzle of a rifle (as a rifle grenade) or a grenade launcher. A modern hand grenade ...

developed and used during the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

. It was adopted into service due to the need for a grenade with smaller destructive radius than the No. 36M "Mills bomb". This allowed the thrower to use a grenade even when there was little in the way of defensive cover. In contrast, the much greater destructive radius of the Mills bomb than its throwing range forced users to choose their throwing point carefully, in order to ensure that they would not be wounded by the shrapnel explosion of their own grenade. No 69 grenade diagram

The shell of the No. 69 grenade was composed entirely of the hard plastic,

Bakelite Polyoxybenzylmethylenglycolanhydride, better known as Bakelite ( ), is a thermosetting phenol formaldehyde resin, formed from a condensation reaction of phenol with formaldehyde. The first plastic made from synthetic components, it was developed ...

, which shattered without producing fragments like a metal bodied grenade. Metal fragmenting sleeves were available to increase the grenade's lethality. Using the No. 69 bomb was very simple: the screw-off cap was removed and discarded, and the grenade was then thrown. When the grenade was thrown, a linen tape with a curved lead weight on the end automatically unwrapped in flight, freeing a ball-bearing inside the fuze. In this manner the "all ways" action impact

fuze In military munitions, a fuze (sometimes fuse) is the part of the device that initiates function. In some applications, such as torpedoes, a fuze may be identified by function as the exploder. The relative complexity of even the earliest fuze ...

was armed in flight and the grenade exploded on impact; and like the Gammon grenade, which used the same fuze design, it was withdrawn from service soon after the

ended.

All-ways fuze

The No. 69 was the first British device to make use of the "all-ways fuze" later seen in the No. 82 Gammon bomb, the No. 73 Thermos bomb and the No. 77 smoke grenade. The "all-ways"

is an impact-only fuze. The term "all-ways" refers to the fact that all of the possible ways in which the grenade could hit a target were guaranteed to trigger

detonation Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with s ...

. Normally, impact-detonated munitions must hit the target with a particular point of impact (i.e. perpendicular to the fuze mechanism) in order to detonate. In contrast, no matter which way the No. 69 grenade hit the target (e.g. landing on its base, or sideways or upside down) it would still explode. The all-ways fuze was composed of a free-floating striker and detonator combination held apart by a weak spring. On top of this assembly was a steel

ball bearing A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races. The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this ...

pressed against a conical housing by the striker. Any impact in the vertical axis would impart acceleration to either the striker or the detonator, causing the

firing pin A firing pin or striker is a part of the firing mechanism of a firearm that impacts the primer in the base of a cartridge and causes it to fire. In firearms terminology, a striker is a particular type of firing pin where a compressed spring ...

to contact and ignite the detonator. Any impact in the horizontal axis would cause the ball bearing to follow the slope of the conical housing converting the horizontal acceleration into a vertical one, touching off the detonator as before. The fuze was worked by the user first unscrewing a plastic cap to expose a long, narrow cloth streamer with a curved lead weight attached to the end. Upon release from the hand or projector the weighted streamer, would catch the air and quickly unwind from the top of the grenade, eventually withdrawing a loose

safety pin The safety pin is a variation of the regular pin which includes a simple spring mechanism and a clasp. The clasp forms a closed loop to properly fasten the pin to whatever it is applied to and covers the end of the pin to protect the user from t ...

from the fuze. With the pin removed the striker and detonator would be free to come into contact, which would happen due to the force of impact when the grenade struck a hard surface. The all-ways fuze had a minor design defect in that the hard steel ball bearing would be propelled away from the explosion as a piece of

shrapnel Shrapnel may refer to: Military * Shrapnel shell, explosive artillery munitions, generally for anti-personnel use * Shrapnel (fragment), a hard loose material Popular culture * ''Shrapnel'' (Radical Comics) * ''Shrapnel'', a game by Adam C ...

. When used in an "offensive" application such as the No. 69 grenade, where the user was not required to take cover before throwing, there was a chance that the user could be struck and injured by the fast-moving ball bearing. According to military author Ian V. Hogg, this problem led to restrictions in the use of the grenade as practice ordnance.Hogg, Ian (1974). ''Grenades & Mortars''. Ballantine Books, p. 47?.

Markings

* A ring of red "X" in the top half between the safety cap and middle indicated that it has a filling suitable for tropical use (humidity). *A green band just under the middle ring indicated an

Amatol Amatol is a highly explosive material made from a mixture of TNT and ammonium nitrate. The British name originates from the words ammonium and toluene (the precursor of TNT). Similar mixtures (one part dinitronaphthalene and seven parts ammoniu ...

80/20 filling. *The white letters "BAR" on the green band indicated a

Baratol Baratol is an explosive made of a mixture of TNT and barium nitrate, with a small quantity (about 1%) of paraffin wax used as a phlegmatizing agent. TNT typically makes up 25% to 33% of the mixture. Because of the high density of barium nitrate, ...

20/80 filling. *The white letters "LYD" on the green band indicated a

Lyddite Picric acid is an organic compound with the formula (O2N)3C6H2OH. Its IUPAC name is 2,4,6-trinitrophenol (TNP). The name "picric" comes from el, πικρός (''pikros''), meaning "bitter", due to its bitter taste. It is one of the most acidic ...

filling.

References

External links

Photo of No 69 grenade

Sectional view showing "all-ways" fuze

Another sectional view of a No 69 grenade
{{Authority control World War II grenades of the United Kingdom Concussion grenades Hand grenades of the United Kingdom Weapons and ammunition introduced in 1942