No. 69 grenade
Encyclopedia
The British No 69 was an offensive (as opposed to defensive) hand grenade
developed and used during World War II
. 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 their own grenade.
The shell of the No 69 grenade was composed entirely of the hard plastic, Bakelite, 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 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in flight and the grenade exploded on impact; and like the Gammon grenade, which used the same fuze design, it was withdrawn from service soon after the Second World War ended.
, the No 73 Thermos bomb
and the No 77 smoke grenade
. The "Allways" fuze
is an impact-only fuze. The term "Allways" refers to the fact that all of the possible ways in which the grenade could hit a target were guaranteed to trigger detonation
. 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
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
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
from the fuze. With the pin removed the striker and detonator would be free to come into contact, which would the 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
. 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.
Hand grenade
A hand grenade is any small bomb that can be thrown by hand. Hand grenades are classified into three categories, explosive grenades, chemical and gas grenades. Explosive grenades are the most commonly used in modern warfare, and are designed to detonate after impact or after a set amount of time...
developed and used during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. It was adopted into service due to the need for a grenade with smaller destructive radius than the No 36M "Mills bomb"
Mills bomb
Mills bomb is the popular name for a series of prominent British hand grenades. They were the first modern fragmentation grenades in the world.-Overview:...
. 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 their own grenade.
The shell of the No 69 grenade was composed entirely of the hard plastic, Bakelite, 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 fuze
Fuze
Fuze Beverage, commercially referred to as just Fuze , is a manufacturer of teas and non-carbonated fruit drinks enriched with vitamins. Currently the brand consists of five vitamin-infused lines: Slenderize, Refresh, Tea, Defensify, and Vitalize...
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 Second World War 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 bombGammon bomb
The Gammon bomb, officially known as the No. 82 grenade was a British hand grenade used during World War II.-Overview:Designed by Capt. R.S. Gammon MC of the 1st Parachute Regiment, the Gammon bomb was developed as a replacement for the temperamental and highly dangerous "sticky bomb" grenade...
, the No 73 Thermos bomb
No. 73 Grenade
The No. 73 grenade, also known as the Thermos or Woolworth bomb, was a British anti-tank grenade used during the Second World War. It got its nickname from the resemblance to a Thermos flask.-Development:...
and the No 77 smoke grenade
No 77 grenade
The No. 77 Grenade was a British white phosphorus grenade used during the Second World War. The No. 77 was introduced in 1943 and consisted of 8 ounces of white phosphorus, an impact fuse and a tin casing. It was intended for laying down smoke screens and as a signalling device...
. The "Allways" fuze
Fuze
Fuze Beverage, commercially referred to as just Fuze , is a manufacturer of teas and non-carbonated fruit drinks enriched with vitamins. Currently the brand consists of five vitamin-infused lines: Slenderize, Refresh, Tea, Defensify, and Vitalize...
is an impact-only fuze. The term "Allways" refers to the fact that all of the possible ways in which the grenade could hit a target were guaranteed to trigger detonation
Detonation
Detonation involves a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations are observed in both conventional solid and liquid explosives, as well as in reactive gases...
. 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
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 by using at least two races to contain the balls and transmit...
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
Firing pin
A firing pin or striker is part of the firing mechanism used in a firearm or explosive device e.g. an M14 landmine or bomb fuze. Firing pins may take many forms, though the types used in landmines, bombs, grenade fuzes or other single-use devices generally have a sharpened point...
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
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
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
Safety pin
A safety pin is a simple fastening device, a variation of the regular pin which includes a simple spring mechanism and a clasp. The clasp serves two purposes: to form a closed loop thereby properly fastening the pin to whatever it is applied to, and to cover the end of the pin to protect the user...
from the fuze. With the pin removed the striker and detonator would be free to come into contact, which would the 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
Shrapnel shells were anti-personnel artillery munitions which carried a large number of individual bullets close to the target and then ejected them to allow them to continue along the shell's trajectory and strike the target individually. They relied almost entirely on the shell's velocity for...
. 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.
