Category Archives: Ordnance

No85 Artillery Fuze

It felt only right and fitting that the souvenir I brought home with me from my recent trip to Flanders was the fuze from a British Empire shrapnel shell. Artillery killed more men on the Western Front than any other weapon and the fuzes form exploded shells are still regularly ploughed up in the fields of Belgium. I am not a collector of relic, but this piece, that I knew had been fired over the trenches of Flanders seemed a very appropriate memento of my trip:imageThis fuze is a No85 and was used on 15 and 18 pounder shrapnel shells. It screwed into the nose of the shell, and the brass ring from the top of the main shell is still attached to the base of the fuze where it blew to pieces, showing up here as a slightly different colour due to the differing metals:imageThe fuze as it was originally manufactured can be seen in this diagram:post-671-0-73288900-1440513383_thumbThe model of fuze and the manufacturer ‘Scovill’ are stamped into the main body:imageScovill were an American manufacturer and this was produced under contract for the British Empire. The ring of the shell that has been left attached is, however, marked up with a Canadian acceptance mark:imageThis fuze is dated, I believe, 1917:imageThe No85 was a time delay fuze and could be set to fire after the shell had completed a certain number of rotations in the air. This occurred at a set rate so it was possible to set the fuze to go off after a certain time in flight, showering the ground beneath with small shrapnel balls. These fuzes were remarkably complicated little components, as can be seen in this cutaway diagram:post-1365-1250688653The following explanation of how the fuze works was given by ‘Max poilu’ on the Great War forum and sets it out far clearer than I could:

The fuze contains a number of overlapping rings burning in sequence. The relationship of each ring to the other determines how long the burning train of powder is. I believe the black powder used in the fuze time trains was a specially selected grade, all black powder is a ‘selected’ grade – but here a particularly fine and stable type.

From the fuze a hollow tube runs inside the shell to a base plate below the shrapnel balls – around 350 lead balls packed in resin in an 18 pounder. Below this plate is a small charge of black powder. The resin holds the balls stable to avoid an affect on flight and burns to give the puff of black smoke for observation. When the timed fuze triggers above the target a small flash is sent from the fuze down the tube igniting the black powder – this ‘explosion’ is a relatively small charge designed just to expel the balls – it is not an explosion in the sense of a HE shell. The shell casing itself is actually quite thin as it does not need to ‘resist’ the detonation as in a HE shell. The fuze is fitted to the shell with shallow threads so that it is separated from the shell casing easily.

This detonation pushes the base outwards ejecting the balls and the fuze head in a wide area over the ground. Think of the shell as a huge shotgun cartridge. The combined velocity of the forward motion of the shell and ejected balls produces an obvious lethal effect.

The shell casings are not designed to fracture. All the component parts; balls, casing, fuse, flash tube and plate are probably the most easily found and numerous objects in the battlefields today.

40mm UGL Practice Grenade

Over the last few years we have covered a number of pouches and a complete bandolier set up to hold 40mm underslung grenade launcher rounds. Tonight however we are looking at one of those 40mm rounds, an L8A1 practice round:imageSadly I do not have the cartridge case for this round, just the projectile but I am sure the missing piece will turn up soon enough. Complete the rounds look like this:l8a140mmAs this is a practice round, the head is blue to indicate that it is safe and free from explosives:imageThe head does contain a coloured powder however to indicate where the round has impacted during training, usually in pink or orange. Whilst this is perfectly safe it is very messy so it is not advised that you try and dismantle a round. A rubber obdurating ring is fitted to the lower part of the round to help create a gas seal with both the cartridge case and the inside of the launcher:imageThe round works by having a small high pressure cup inside the case holding the propellant, when it is fired this cup ruptures and the gas escapes into the rest of the casing where it expands and produces the low velocity needed to launch the grenade itself. The back of the grenade is slightly tapered and there is a circular void in the base which works with this cup to provide the thrust needed to propel it:imageMarkings are printed in white on the outside of the practice round and indicate the size, 40mm calibre and 46mm long, that the round is a practice round with the designation L8A1 and that it was manufactured in February 2011:imageThe size of this round is a common one used by many grenade launchers and is a low velocity round with a typical velocity of just 249 feet per second. These rounds are not hard to find and can be easily found for under £10 but are very attractive and affordable pieces of ordnance for a collection.

Anti-Riot Rubber Baton Round Shell Casing

Rubber bullets were designed to be a non-lethal round for use against crowds of protestors to drive them back when lethal force would be inappropriate. The British Army began to use these rounds extensively in Northern Ireland during the troubles, with their first use in August 1970. The round itself has a metal core surrounded by rubber and this six inch projectile is fired from a metal casing that is slotted into a modified flare gun action in a weapon designated the L67:000000Tonight we are looking at the casing from one of these rounds, and my thanks go to Michael Fletcher who helped me add this one to the collection. The casing is made of aluminium and in shape and size is identical to the CS practice version we looked at here but chemically blackened:

imageStencilled around the outside of the case is ‘ROUND A RIOT 1.5IN BATON LR L3A1’:imageThis then indicates that this is an Anti-riot round, the bore diameter is 1.5 inches and that it is a long range baton round. A second marking indicates that the round was assembled in January 1973:imageThe case itself was manufactured in October 1972, as indicated on the base:image56,000 of these rounds were fired by 1975 and the instructions were for it to be fired at the ground so it ricocheted up into the target as it could cause serious injury and indeed fatalities if fired directly at a person. A safer plastic baton round was introduced in 1972 and slowly replaced this round over the next few years although a small number of fatalities have still arisen. During the troubles 17 people were killed by rubber and plastic baton rounds. Considering that 125,000 of the rounds had been fired that works out to a death rate of 0.0136% so they were a comparatively safe way of dealing with a rioting crowd, especially if used correctly and aimed at the abdomen and legs where they caused great pain but little risk of death, rounds striking the chest or head had the capacity to be fatal and training emphasised how soldiers and police could use the rounds most safely.

20mm Vulcan Cannon Ballast Round

Last year we looked at a 30mm Aden Ballast round here. Since then I have been able to pick up a second ballast round, but this time for a 20mm Vulcan cannon:imageIn appearance this is very much like the other ballast round, being made of a solid piece of cast white metal. The shape is identical to a live Vulcan round with an extractor groove at the bottom:imageAnd the top having the shape of the actual projectile:imageThe weight of the round is identical to that of a real Vulcan round, being used to safely test the weapon and its timing, allowing adjustments to be made on the ground in a controlled environment. Here we see a dismounted Vulcan with a belt of this ammunition:PGU-27-AB-20-102mm-ammunition-m-61-vulcanThe Vulcan is a six barrelled 20mm rotary cannon used on fixed wing aircraft. It was developed in the United States but saw service with the British on aircraft such as the F-4 Phantom. The need for the weapon came out of experience in the Second World War and the realisation that with the speeds jets were becoming capable of, there would only be a split second when rounds would actually connect with their target. This therefore required a weapon with a very high rate of firepower and a round that had enough mass that a few strikes would destroy a plane. 20mm had proved effective in the Second World War and by pairing this with an electrically driven Gatling type of gun extremely high rates of fire could be achieved, in the case of the Vulcan 6,000 rounds a minute. The new cannon was designated the M61 by the US.Vulcan1Each of the cannon’s six barrels fires once in turn during each revolution of the barrel cluster. The multiple barrels provide both a very high rate of fire—around 100 rounds per second—and contribute to prolonged weapon life by minimizing barrel erosion and heat generation. Mean time between jams or failures is in excess of 10,000 rounds, making it an extremely reliable weapon. Most aircraft versions of the M61 are hydraulically driven and electrically primed. The gun rotor, barrel assembly and ammunition feed system are rotated by a hydraulic drive motor through a system of flexible drive shafts. The round is fired by an electric priming system where an electric current from a firing lead passes through the firing pin to the primer as each round is rotated into the firing position.

One RAF Phantom pilot explains the advantages of the cannon over radar guided missiles:

Being unguided, bullets are not susceptible to Electronic Counter Measures (ECM – although the radar used to aim the gun, of course, is) and the gun has no technical minimum range, although there are some practical reasons (e.g. arming of high explosive rounds) why you wouldn’t choose to fire from too close to the target. Also some pilots didn’t like the idea of large aircraft blowing up in their face. In my day, the closer you got to a target, the bigger it looked in the windscreen making it easier to hit! I say ‘A kill’s a kill!!

An RAF Phantom carried 640 rounds for its Vulcan canon and it seems to have been a popular weapon amongst aircrews, combining high rates of fire with impressive hitting abilities. My thanks go to Gary Hancock for his help in identifying this round.

120mm Chieftain HESH Round Transit Tube

It is perhaps unlikely that I will ever have the funds or space to be able to add a tank to my collection (plus I imagine my wife would have a few choice words to say if I did). Small items of militaria related to armour are available though and tonight we are looking at the plastic transit case for a Chieftain 120mm HESH shell:imageThe Chieftain was Britain’s main battle tank throughout much of the Cold War and had a 120mm rifled main gun. Britain used a variety of shells with this gun including HESH, which stands for High Explosive, Squash Head.

HESH rounds are thin metal shells filled with plastic explosive and a delayed-action base fuze. The plastic explosive is “squashed” against the surface of the target on impact and spreads out to form a disc or “pat” of explosive. The base fuze detonates the explosive milliseconds later, creating a shock wave that, owing to its large surface area and direct contact with the target, is transmitted through the material. In the case of the metal armour of a tank, the compression shock wave is conducted through the armour to the point where it reaches the metal/air interface (the hollow crew compartment), where some of the energy is reflected as a tension wave. At the point where the compression and tension waves intersect, a high-stress zone is created in the metal, causing pieces of steel to be projected off the interior wall at high velocity. This fragmentation by blast wave is known as spalling, with the fragments themselves known as spall. The spall travels through the interior of the vehicle at high velocity, killing or injuring the crew, damaging equipment, and/or igniting ammunition and fuel. Unlike high-explosive anti-tank (HEAT) rounds, which are shaped charge ammunition, HESH shells are not specifically designed to perforate the armour of main battle tanks. HESH shells rely instead on the transmission of the shock wave through the solid steel ammunition has good general purpose use, being effective against most targets, though the round is generally used at relatively low velocities because high velocity excessively disperses the pat of explosive. While only effective against tanks without spaced armour or spall liners, the round is still highly favoured for combat demolition purposes. The flattened high-velocity explosive pat is capable of destroying concrete constructions much faster than a HEAT round (which is designed for armour penetration), and without the dangerous fragmentation of a traditional high-explosive (HE) fragmentation round.CR3_thumb_png_1bffb6a288cd7b02814b48cbb0570342These rounds were delivered in individual plastic transit tubes, and two of these were packed inside a metal ammunition box. The plastic container has a screw on lid with a rubber seal to prevent any moisture from entering inside. A wire loop handle is fitted to the top to make them easier to carry:imageSmall holes are fitted around the outside of the lid and main tube to allow a piece of wire to be fitted as a tamper prevention measure:imageThe front of the tube has a pair of labels attached, firstly we have a diamond shaped MOD explosives label, sadly now starting to peel off:imageAnd a large contents label that shows the tube contained a 120mm HESH round, L31A7. The round was manufactured in January 1969, whilst the fuze was produced in December 1968:imageThe tube itself has the date of manufacture moulded into the base, here for 1967:imageThese tubes do appear from time to time, but as they were reused a number of times it is quite nice to get one with labels for as early as 1969, this example was clearly only ever used once and never refilled.Chieftain_Tank_(9628802829)

Jet Engine Starter Cartridge

Early jet engines needed a way to turn the motor over to start the engine going. Many propeller driven aircraft had relied on a man swinging the propeller to turn the engine to kick it into life. This was obviously not an option with a jet engine so a large blank starter cartridge was used. Made of brass, this cartridge looks very much like an artillery shell:imageIt was in effect a large blank cartridge and the gasses from this cartridge expanded and turned the engine over allowing it to start. The top of the case has bent over lips and originally when it was full these would have held a large disc made of a material that would have been consumed by the explosion, such as cardboard:imageThe base of the cartridge is marked up and we can tell this is an Electric Starter Cartridge No9 Mk I and was manufactured in 1952. The ‘K’ indicates it was produced by Kynoch:imageThese cartridges were used on a number of early RAF jets including the Canberra and the Hunter. One American technician who worked on the Canberra bomber recalls using these cartridges:

Tech question: yes, the starter cartridge in the older marks of Canberra was just a huge shotgun shell, albeit without the shot. There was an explosive release of gases which was channelled to the turbine to wind the thing up. The earliest marks B2, T4, TT18 had only 1 fitted per engine, so, after a failed start, it would take several minutes for the area to cool enough for the cartridge to be replaced, often resulting in a delay of 20 minutes or more. 6

The latter (early) marks, PR7, E15, T17, T22 had 3 per engine, 2 as spares. The last mark, PR9, used a really nasty explosive fuel called AVPIN, which was volatile in the extreme. One of our jeeps carrying the stuff through a small town, fortunately in an unpopulated area, caught fire spontaneously, the driver bailed, and the resultant conflagration melted the concrete of the sidewalk. You can imagine the effect this had on the local populous – we were thereafter banned from transporting it through residential areas.

The explosion from the starter cartridge was impressive: 4-foot flames would leap from 3 vents in the engine casing, the whole area would be wreathed in pungent cordite smoke, and pilot and supervising technician would watch the engine and each other nervously in case of engine fire. In 3 years, I only had to evacuate once because of a suspected fire, which turned out to be a false alarm. However, you can imagine that when the plane was fully fuelled, we were out of there in a flash and up and running! untitled
The gas release should take the engine up to about 2000 RPM, which was enough to energize the igniters and allow the engine to work with the start inertia to get it up to normal idling RPM (I forget the figure). The main thing you were watching at this stage was either for an internal fire, in which case the EGT gages would leap off the scale, or compressor surge, usually accompanied by a lot of popping and banging. In both cases, the actions would be the same: throttle closed, HP cock closed, LP pump off; for a fire of course, additional actions would be fire extinguisher shot through the engine (only 1 available) and evacuate (run for the hills!).

Mk V .303 Blank

Happy Empire Day! If you have not already checked out our sister site ‘British Empire Uniforms’ on Facebook please, take a look. There are plenty of period photographs and reconstructions of uniforms from around the Empire in the Interwar and Second World War periods.

Like all countries, the British made extensive use of blank ammunition in training. The .303 round had a number of different types of blank ammunition before settling on the Mk V. in 1894 when cordite was introduced. This round was to remain in service 1957 when the Mk 9 blank was introduced that had a nitrocellulose propellant. Tonight we are taking a closer look at the ubiquitous Mk V cordite blank and we have two different examples:imageThe round on the right is, I believe, a WW1 blank as it came from a WW1 charger of WW1 dated spent rounds so it seems logical to assume it is of that vintage. The round on the left has a 1942 date stamp so is most likely a WW2 blank round. The reason I am being cautious with the dates is that these blanks were often made form cartridge cases that were rejected as not being suitable for ball ammunition, but were still good enough to be converted to blanks. This means the head stamps do not necessarily correspond to the blank itself as they would have been added before the case was relegated to use as a blank. The case heads of these two examples therefore may only tell us when the case itself was manufactured, not when it was converted into a blank:imageThe round on the right is dated 1942 and was manufactured for a Mk VII ball round by Radway Green, that on the left has the ‘K’ for Kynoch. These rounds are Berdan primed rather than having the earlier Boxer primers and the blank itself used 10 grains of sliced cordite. The neck of the case was closed with a rosette crimp:imageBlanks were used extensively for training, and rounds that had been dropped by accident provided great, if dangerous, fun to local children as recalled by Raymond McElvenney:

During the war, these old building were used by the army for training purposes. To make the exercises more realistic, they fired blanks from their guns and there was much banging from large firework things called ‘thunder flashes’…

After the soldiers had gone, we went around the building collecting the spent cartridges up. We also found a number of unfired bullets, so we put them in a crack in the wall. We found a piece of wood with a nail in it; we placed the nail against the bottom of the bullet and hit it with a brick causing the bullet to explode. We thought this was great fun.

In this instance I think the boys actually found unfired blanks, despite the author’s reference to bullets!