A bit more information
NOMENCLATURE: Grenade, Hand, No.74, Anti Tank (S.T. or Sticky Bomb)
SERVICE: Land
DESIGN/PART NO:
TYPE: Anti Tank, Hand, Blast
FILLED WEIGHT: 2.25 lbs
EXPLOSIVE CONTENT AND WT OF EXPLOSIVE: 1.25 lbs Nobel's 823 (Nitroglycerin)
PRINCIPAL DESIGN FEATURES: A sperical glass flask covered in stockinette impregnated with an adhesive. A screwed neck to the flask accepts a handle containing a striker mechanism based on that of the No.36m grenade. The detonator assembly of the cap has a 5 second delay fuse and detonator. There are two metal hemispheres clampled around the flask in transit to protect the adhesive.
MARKING: The hemispheres are buff with a red filling band. The handle is black.
Grenade, Hand, No. 74, Anti tank, Mark 1
This grenade was, originally known as the grenade S.T. and may be referred to as the "sticky bomb". It is a H.E. hand grenade with a time delay designed to be thrown at or placed on an A.F.V. and to stick there until it detonates.
The body consists of a spherical glass flask enclosed in a sock of woollen material which has been treated with a Viscous adhesive, and having a short neck, which is screw threaded externally. Fitting inside the neck and projecting some way into the body is a thin aluminium cup which holds the detonator assembly when this is inserted. In transport and storage the mouth of the flask is closed by a plug, either a flat wooden disc held in place by a plastic plug shaped to fit screwed moulded plastic ring, or a hollow moulded plastic plug shaped to fit the interior of the aluminium cup and secured by a cork or cork substitute disc and a flat topped screw cap which is, protected from accidental removal by a strip of adhesive tape.
The filling is about 1-1/2 lb. of Nobel's Explosive No. 823 which is a nitroglycerine explosive of a consistency similar to that of vaseline, with a life of two years in temperate climates and one year in hot.
To protect the glass flask till the grenade is ready for use, it is enclosed in a metal casing which consists of two hemispheres held together at the base by a spring hinge. This casing springs apart when the metal tape around its neck is removed. A number of small rubber studs project from the inside of the casing to ensure that the adhesive does not prevent the casing opening. For protection in transport the joint in the casing is covered by a strip of adhesive tape, in the earlier models. This tape must be removed before the grenade can be used.
The handle, of moulded plastic, is carried separately from the body in storage. The striker is carried in the handle and has a striker spring acting between a perforated diaphragm at the top of the handle and the Range of the striker head. A "Mills" type striker lever fits under a nut at the top of the striker and lies against the side of the throwing handle, being held in position by, a safety pin which also blocks any downward movement of the striker. The safety pin carries a label with the legend, "Danger. Do not remove this pin until the grenade is to be thrown." The handle is attached to the glass flask when preparing for use by a moulded plastic screwed ring.
The detonator assembly, also packed separately, consists of a 0.410 inch cartridge head fitted on to a brass sleeve which is crimped on to a length of white safety fuze. The other end of the safety fuze is crimped into an A.S.A./C.E. detonator. This assembly is housed in a bakelite holder and the projecting part of the detonator fits into a perforated C.E. pellet. The C.E. pellet and holder are secured together by a length of adhesive tape. Two rubber bands are placed round the bakelite holder to centre the detonator assembly. Should these be wrongly placed or not spaced properly, a blind may result due to incorrect positioning of the cap. A delay of 5 seconds is obtained with this assembly.
This grenade has proved rather too fragile for Service conditions, since breakages occur in transport, and leakages have been rather frequent because insufficient air space is allowed for expansion of the viscous explosive in warm conditions and there is no positive sealing of the rifling. A weak point in the detonator assembly is the necessity for correct positioning of the rubber bands. Prematures have been caused by the striker nut working loose, thus releasing the striker, which, on the safety pin being withdrawn, can then drive down on to the cap without the thrower being aware of the fact. This difficulty has been overcome.
Weight of grenade, 2 1/4 lb.
Action. The plug is removed from the mouth of the grenade, the detonator assembly inserted, care being taken that the rubber bands are corrcctly positioned on the bakelite holder, and also that the cap does not project above the rim of the holder. In the latter event there is a danger of the rim of the cap forming a gas seal which will not allow the gases from the burning safety fuze to escape and premature detonation will occur. The handle is screwed in position and the casing removed by pulling off the metal tape securing it. Immediately before throwing, the safety pin is withdrawn and the grenade thrown or placed on the target with sufficient force to break the glass flask. The hand must be removed from the handle quickly as otherwise the action of the striker may be too sluggish to fire the cap. After a delay of 5 seconds the detonator will initiate the C.E. pellet which sets off the main filling. From trials it is considered that over 1 inch of armour plate is required to give protection against this grenade.
Marking. The outer casing is painted buff with a red filling ring on the upper part just below the neck. The following stencilling is in black:
74 A.T.I .. .. .. Grenade number, type, and mark
823 .. .. .. .. Explosive filling followed by the filler's
initials and date of filling.
Packing. Five grenades are packed in a steel case, each flask being held in a claw type spring fitting closed, with a spring ring. Five handles wrapped in corrugated paper are also packed in this case. Five detonator assemblies are carried in a cardboard tube attached to the lid of the case by spring clips.
Dimensions of case .. .. 18 in. x 11 in. x 6 in.
Weight filled .. .. .. 22 lb.
Three of these cases are packed in a wooden crate of the following dimensions:
21 1/4 in. x 20 1/2 in. x 13 1/2 in.
Filled weight .. .. .. 84 lb.
Grenade, Hand, No. 74, Anti tank, Mark 2
This grenade is used for the same purposes as the Mark I above, but is a much more satisfactory design.
The body is a bakelite moulding in two parts with a short neck which is screw threaded internally, and has two holes diametrically opposite to take two projections in the metal casing, so positioning it. The woollen cover, treated with adhesive, is also used. The filling is about 1 1/4 lb. of Nobel's Explosive No. 823, the small reduction in content being due to the provision of an adequate air space to allow for expansion of the filling. Resting on a flange inside the body is an aluminium primer tube, which is held in position by a rubber sealing ring and a bakelite sealing plug. A perforated C.E. pellet is carried at the base of the primer tube and is protected by a sponge rubber washer with a thin rubber grip washer above it. A thin cardboard cover, with becket, keeps dust out of the sealing plug.
The metal casing is similar to that used with the Mark I, except that the neck is closed by a spring clip and there is a metal loop on the spring hinge which can be used to carry the grenade on the webbing equipment.
The main differences between the handles for the Marks I and II are the sharp point of the striker to enable it to fire the detonator in the igniter assembly, and the fact that the handle screws direct into the top of the body, thus making a stronger union than was possible with the Mark I method. The possibility of prematures due to the striker nut unscrewing has been overcome by spinning over the end of the striker, while accidental removal of the trigger with the safety pin still in position is prevented by a projection between the arms of the fork at the top of the trigger.
The detonator assembly (see Fig. 7) has also been modified. A 1.5 gr. "B" mixture detonator is held in a metal cap carrier, which is secured to a brass sleeve wrapped with paper. This sleeve has four vent holes, the gases from the safety fuze escaping through them into the flutes in the sealing plug. The sleeve is crimped to a length of safety fuze with a plug of priming composition on top
to help ignition. An A.S.A./C.E. detonator is crimped to the safety fuze, and the complete assembly gives a delay of about 5 seconds.
This detonator is being replaced by the Mark III, as the 1.5 gr. "B" mixture detonator is too powerful, the flash from it tending to blow down the outside of the safety fuze and so ignite the A.S.A./C.E. detonator prematurely. The Mark III uses the cartridge head cap of the Mark I grenade.
Action. The action of the Mark II is generally similar to the Mark I. The cardboard cover is removed and a detonator assembly pushed into the hole, provided for it in the sealing plug, when it is prevented from dropping out by the thin rubber grip washer. The handle is screwed on and the casing removed. Thereafter the action is as for Mark I, but in this case there is no need for the sudden release of the handle which is necessary with the Mark 1.
Marking. The metal casing is painted buff with a red filling ring around the upper part and the number, type, and mark of grenade are stencilled in black. Also stencilled on the casing are the number of the filling 823 the filler's initials and the date of filling.
Packing. Four grenades are packed in individual shock proof compartments in a steel case or wood box G.112. In the centre compartment are four handles, a holder containing the four detonator assemblies, and four clips with which the grenades can be attached to the webbing equipment.
Dimensions of case .. .. .. 13 in. x 13 in. x 7 in.
Weight filled .. .. .. .. 35 lb.
Tony. 
