While the ongoing Coronavirus pandemic has prevented some archival research I had planned which would have informed much of the STEN series, our good friend Richard at the Vickers Machine Gun Collection and Research Association, has come to our aid and we’re able to cover some of the loading accessories developed for the Sten’s magazines.
As we know the Sten uses a 32-round double stack, single feed magazine which can trace its origins back through the Lanchester Machine Carbine to the Haenel MP28,II’s magazine designed by Hugo Schmeisser [patented in 1931].
The nature of the single feed makes the magazine difficult to load by hand with the last few rounds very hard to insert. So a series of four marks of ‘magazine fillers’ were developed. These are described in the British Army’s official List of Changes in February 1943.
The MkI is described as consisting of “a lever mounted on a short case which conforms to the shape of the magazine. It is hand operated, the loading lever being given a rocking motion during filling. The MKI slipped over the top of a magazine with a rivetted spring tab which indexed into a notch in the front of the Sten mag.
The MkII is very similar but simplified by having the spring catch mounted on the rear instead of the side and engaged a “small rectangular slot on the magazine”. The rear of the spring is turned up slightly to allow the user to remove its from the magazine.
The MkIII, which is possibly the rarest of the fillers, is described as:
“hand operated but of different design from the MkI and MkII. It consists essentially of a spring loaded vertical plunger which is attached externally to a case, the latter to assemble on the magazine. There is no retaining catch. It comprises the following parts:
Case. Is a rectangular shaped steel pressing with a tube of rectangular section welded thereto. The latter, which houses the plunger and spring, has a hole trilled at the lower end to accommodate a pin which restricts the amount of movement of the plunger and acts as a stop for the compressing spring.
Plunger, loading. Is made of two laminated steel strips welded together the top part of which is set to form a handle. The body of the plunger is slotted to accommodate the compression spring. The top part is splayed to form a suitable contact with the cartridge.”
List of Changes, Feb. 1943
The other more common filler is the MkIV. Which is a much simpler design with a loading lever mounted on top of a clip which is attached to the rear of the magazine body and retained by a spring similar to that of the MkII.
Rich has very kindly demonstrated the use of the two most common fillers – the MkII and the simpler MkIV. It takes Rich just under 2 minutes to load that magazine, but he was doing his best to show various angles and unlike a British soldier during the war he hasn’t regularly loaded magazines with one of these fillers either. Despite that the clip gives a good idea of how fast you could load a mag once you’re in the groove.
With the MkIV filler Rich was able to load the mag in about 1 minute 15 seconds, the stability of resting the base of the mag on the table helped with the MkIV’s simpler design.
Also, as a follow on to our previous episode looking at the Sterling Submachine Gun’s magazine Rich has also demonstrated the loading of a Sterling mag to its 34 round capacity. No magazine filler needed with George Patchett’s double-stack, double feed magazine.
Development of the XF-87 began at Curtiss-Wright in 1946, it would eventually be intended to be an all-weather interceptor. The Blackhawk was developed from an earlier ground attack, tactical bomber design, the XA-43. The Blackhawk was a response to the initial specification for a jet-powered night fighter, capable of speeds up to 530 mph, issued by the US Army Air Force in August 1945.
A number of companies responded including Bell Aircraft, Consolidated-Vultee, Douglas Aircraft, Northrop, Goodyear and Curtiss-Wright. The US Army Air Force down-selected Northrop’s design – then known as the N-24 and the Curtiss-Wright design- known as the Model 29A.
The XP-87 had a two-man crew seated side-by-side and was powered by two pairs of Westinghouse XJ34-WE-7 turbojet engines mounted on the wings. In comparison to the sleeker Northrop design, the Blackhawk was a slightly larger, bulkier and heavier aircraft with a straight wing profile. The XJ34-WE-7 turbojets only provided 12,000 lbf and Curtiss-Wright’s test pilot B. Lee Miller described performance in initial tests as sluggish. The Blackhawk’s armament was to consist of four 20mm cannons mounted in a nose turret.
The US Army Air Force designated the Curtiss-Wright jet the XP-87, while Northrop’s N-24 became the XP-89 and full-scale models of both were ordered.
In June 1948 the newly formed US Air Force re-designated fighters from P to F and the XP-87 became the XF-87 when prototypes were ordered. The XF-87 made its first flight in March 1948. During subsequent flight evaluations in October 1948, the Northrop XF-89 was found to be faster than the XF-87 and the US Navy’s XF3D (Douglas F3D Skyknight). While the Blackhawk was a capable and generally satisfactory aircraft it was deemed to be underpowered. It also reportedly suffered from buffeting at relatively slow speeds.
Evaluators disliked the Northrop and reportedly favoured the XF-87, however, one evaluating pilot likened its handling to a medium Bomber. An improved faster and more powerful Blackhawk was planned with J47 engines from General Electric. The fate of a second prototype is unclear and sources conflict. Most sources state that the XF-87 never had its armament fitted, however, photographic evidence clearly shows an aircraft, not with a turret, but with four nose mounted guns. This aircraft may be one of the airworthy prototypes or it could be a full-scale mock up built to show the USAAF during the selection process.
Despite the trials favouring the XF-89, the USAF initially ordered 57 F-87A fighters and 30 RF-87A reconnaissance aircraft from Curtiss-Wright in June 1948. Curtis-Wright and the USAF began a publicity campaign to unveil the new fighter, even appearing on the cover of an August edition of Aviation Week and in numerous other aviation publications, but the orders were abruptly cancelled in October 1948 and the USAF moved forward the development of the Northrop XF-89 instead. Check out our video on the F-89 Scorpion linked above.
The reason for this reversal of the decision is unclear. Only minor faults had been identified during testing and the more powerful J47 engines would have greatly increased the Blackhawk’s speed. The official reason for the cancellation was reportedly a disagreement on the price of a redesigned wing profile. According to his memoir, Walter Tydon, Curtiss-Wright’s chief engineer at the time, believed that some bad blood between Curtiss-Wright’s management and the then-President Harry S. Truman may have led the F-87 contract to be cancelled. Truman was Senator for Missouri from 1935 to 1945 and during that time Tydon believed he had come into conflict with the Curtiss-Wright’s management, perhaps regarding the company’s factory in St. Louis. Without substantial archival research it is difficult to verify either the official reason or Tydon’s theory.
Another potential reason for the cancellation was raised during the Congressional Hearings regarding the B-36 Program, Congressman Charles B. Deane noted that both Curtiss-Wright and Northrop had been informed that “unless they agreed to merge with Consolidated Vultee, business would be bad for them.” The testimony before the hearing notes that Curtiss-Wright were unenthusiastic about a potential merger and this might have been why the F-87 contract was cancelled. The Secretary of the Air Force denied this, however, stating that the cancellation was the result of “operating difficulties with the experimental model of the F-87, plus increasingly satisfactory operating data on competitive all-weather fighters.”
Sadly, the prototype XF-87 Blackhawk’s was reportedly scrapped and photographs and footage of the initial flight testing of the Blackhawk is all we have left. The loss of the interceptor contract to Northrop led to the end of Curtiss-Wright’s aircraft production, with the Blackhawk being their last fighter design.
Special thanks to Mark Lane, the grandson of Walter Tydon, Curtiss-Wright’s chief engineer, for taking the time to discuss the Blackhawk and his grandfather’s role in its design.
The Battle of Palmdale is one of those historic events that could easily spawn clickbait titles: US Navy vs US Air Force, Drone vs Manned Fighter, Runaway WW2 fighter vs Rocket-armed Jet Interceptor. None of these would be a lie!
On 16th August, 1956 a US Navy Grumman F6F-5K Hellcat a target drone went rouge over California and the USAF scrambled a pair of Northrop F-89 Scorpions to shoot it down. The F-89s failed to down the Hellcat but did manage to start a serious wildfire.
A Bridge Too Far (1977) is undoubtedly a classic of the war film genre, massively ambitious it attempts to tell the story of Operation Market Garden. One of the key stories told is that of 2 PARA besieged in Arnhem awaiting relief from XXX Corps.
Perhaps one of the most enduring scenes sees Anthony Hopkins, portraying 2 PARA’s commanding officer Johnny Frost, spot an enemy tank approaching and bark the order: “Bring Up The PIAT!”
The scene itself is actually quite authentic. The PIAT gunner misses, and that isn’t too surprising as despite being a platoon weapon not everyone had a lot of training on them. While the PIAT misses twice – this is because the gunner was firing from an elevated position. This makes judging the range and lead which should be given to an advancing tank all the more difficult. It is something we see in contemporary accounts, including in Arnhem Lift: Diary of a Glider Pilot, by Louis Hagen. Hagen describes firing a PIAT at a self-propelled gun (likely a StuG) from an attic during the fighting in Arnhem: “The direction was perfect, but it fell about twenty yards short.” Similarly, there are accounts from Home Army members fighting in Warsaw during the Uprising which describe exactly the same thing.
While the flash we see in the scene might be excessive the recoil is quite authentic. While writing my book on the PIAT, I did a lot of research into the cultural impact of the PIAT and the numerous films it appeared in since World War Two. I recently wrote an article about the numerous films it has appeared in, you can read that here.
Perhaps the most important and realistic appearance was its first, in the fascinating 1946 film ‘Theirs Is The Glory‘. It’s a unique film that was filmed entirely on location with from veterans of the battle making up most of the cast and help from the British Army’s Army Film and Photographic Unit.
The PIAT appears twice in the film, scene some PARAs are trying to fight through to Arnhem but have been pinned down by what appears to be a French Char B. As a sidenote captured Char B1’s in German service were present in Arnhem).
The PIAT team are seen to move to the flank to get a good shot at Char B. The short scene gives a good indication of how the No.2 would load the PIAT as well as showing the rate of fire possible – a good team could get off five rounds a minute. Theirs Is the Glory also features another brilliant PIAT scene with Corporal Dixon seen knocking out a Panther
I would highly recommend both films as they are both interesting depictions of the battle and both good representations of the PIAT in action.
In this very rare footage we see a Free French Air Force officer, possibly training as a member of the SOE, place a limpet mine on a substantial piece of metal plate.
The mine seen in the footage is clearly much smaller than the Limpets used against ships. The Limpet mine was developed by Military Intelligence (Research) in late 1939-40. Stuart Macrae and Cecil Vandepeer Clarke developed a mine with enough magnetic strength to attach an explosive charge to the hull of a ship. The initial design seen here was quite large but the design was refined as the war went on with various types and marks. Here’s a Type II limpet, a MkIII and here is a Type 6 MkII.
The idea was that divers or saboteurs in small boats could quietly attach the mines to enemy shipping while at anchor. However, the usefulness of magnetic charges was clear and it appears that smaller versions, like that we see in the footage here, were developed for use against armoured vehicles and other substantial armoured targets.
It’s unclear from the film what the explosive charge was, how big it was or how it was laid out inside the mine but from the damaged plate displayed at the end of the footage it may have been a ring of plastic explosive held in place by the four magnets. This would blow the characteristic round hold in the plates.
Interestingly, the limpet mine seen in the film is very similar to a Japanese design, the Type 99 anti-tank mine, however, it has a different fuse design and the four magnets are blocky rather than rounded. Whether the Japanese magnetic mine influenced this design developed by SOE is unknown.
I’ve been unable to find out these mine’s designation, it may not have been given one but it does appear to be fairly well developed. In this photograph we can see that a metal plate carrier has been developed to allow a soldier to carry 4 mines on his back. Perhaps these mines were developed for a specific mission. The magnetic Clam charge, which we have covered in an earlier video, would have done a similar job for smaller task
Sometimes all is not as it seems. That was the case when we examined this Steyr AUG. From the barrel and bipod it appeared to be an AUG in an HBAR or Heavy Barrel configuration but on closer inspection we found that it was in fact a rifle receiver, bolt and bolt assembly and chassis that had been paired with an HBAR barrel assembly.
Ordinarily, the HBAR could be modified to fire from an open, rather than closed, bolt. This example has the standard AUG progressive trigger for semi and full-auto. It does not have the modified bolt carrier, striker or trigger mechanism.
The HBAR has a 4x optic, rather than the rifle’s 1x, while the HBAR-T can be fitted with an optic like a Kahles ZF69 6×42.
Adoption of the AUG HBAR does not appear to have been widespread and Steyr don’t currently list it as an option amongst their upgraded AUGs. For more Steyr we have previously examined a Steyr AUG SMG conversion and a Steyr MPi 81. We’ll take an in depth look at the AUG and AUG HBAR in the future.
Overall Length: 35.5in (90cm)
Barrel Length: 24.4in (62cm)
Weight: 8.6lb (3.9kg)
Action: Gas operated, rotating bolt – the HBAR typically fires from an open bolt, but this rifle-based example fires from a closed bolt.
Capacity: 30 or 42-round box magazines
Destroying railway infrastructure was a key mission for the Resistance groups and SOE agents active in occupied Europe. Numerous methods of damaging or destroying railways were developed, including Exploding Coal, which we have covered earlier in this series. In this 16mm colour footage, believed to have been filmed in 1940, we get an early look at the methods the SOE were developing to destroy track. The ultimate aim was to derail the locomotive and wreck the train with minimal effort and explosive.
In the footage we see two charges have been placed on the piece of track, with detcord attached to both. A soldier, with what appears to be a lever-action Winchester 94, is then seen taking aim. It seems he’s aiming at a striker board attached to ignite the detcord. He fires, we see a puff of smoke and a second later the charges detonate.
The footage then cuts to several men collecting the debris of the shattered piece of track. The track appears to have two large chunks blown out and the top edge, between the two charges, completely blown off.
Later in the war more testing was done and more refined techniques were developed. In their book SOE: The Scientific Secrets Boyce & Everett note that trials of devices and techniques for destroying railway lines carried out at Longmoor where the British Army had extensive sections of track and samples of rails used in different European countries. Trials to find the right quantity and positioning of explosive charges were carried out in late December 1943, these tests would inform later operations.
The SOE’s Descriptive Catalogue of Special Devices and Supplies includes a pair of illustrations demonstrating two methods of laying and detonating these charges. A so-called ‘French’ method with a pair of what the catalogue terms ‘Igniters, Fuze, Fog Signal, MkIA’ ahead of the charges in the direction the train was expected from. The train would crush these Fog Signals firing them and igniting a length of detcord linked to a pair of 3/4lb explosive charges fixed to the track as we see in this film.
The alternative ‘Polish’ method had the same sized and located explosive charges but placed a Fog Signal either side of the charges to ensure that no matter which direction the train came from the charges would be detonated. This method was used on single track stretches of railway. Both of these methods were rated to ‘remove about one metre of rail.’
In this photo we see a member of the French Resistance setting an explosive charge on a railway line. While likely a posed photo we do see the pair of Fog Signals which will stet the charge off. These photographs show a pair of trains reportedly derailed by explosive charges.
Boyce & Everett in their book SOE: The Scientific Secrets suggest that as many as 48,000 ‘Railway charges’, presumable a kit, were produced by the SOE. From the footage we can certainly see this method of destroying rails was effective.
Today, were taking a look at a Winchester prototype developed in the mid-1860s, a period when Winchester was seeking to build on the success of the 1860 Henry Rifle and place the company on a firm financial footing. Oliver Winchester had taken control of the New Haven Arms company before the Civil War and while for a time it had been known as the Henry Repeating Arms Company he eventually sought to put his stamp on the company, renaming it Winchester Arms Company in 1866. At the same time he decided to focus the company’s energies on winning military contracts around the world.
This developmental prototype is in the ‘musket’ configuration: with a longer barrel, a bayonet lug and a wooden forend. The prototype represents one of the many developmental steps towards what would become the Model 1866. It has a number of interesting features – a steel, rather than brass, receiver and a hinged loading port developed by Nelson King, Winchester’s superintendent between 1866 and 1875.
The rifle itself was built by Luke Wheelock, Winchester’s model room mechanic and a designer in his own right who would go onto develop his own rifle designs for Winchester.
The rifle is 54.5 inches long, with a 33.75 inch barrel. Believed to have been built in 1866, it is chambered for a .45 calibre rimfire round. King patented his loading port in May 1866. He described how the port worked:
“Through one of the plates S (preferring that one upon the right-hand side) I form an opening, 0, as denoted by broken lines, Fig. 1, and also seen in section, Fig. 7. This opening is formed so as to communicate through the frame directly to the chamber E in the carrier block, as seen in Fig. 3. Through this opening, and while the carrier-block is down and all parts of the arm in a state of rest, insert the cartridges, point first, through the said opening in the plate S into the chamber E the second cartridge pressing the first into the magazine, and so on with each successive cartridge until the magazine is filled, or until the requisite number has been inserted therein, the follower G being pressed up before the entering cartridges. In the rear of the chamber E2 the frame forms a shoulder to prevent the cartridges from being forced out through the opening in the plate S3 is a cover for closing the opening in the plate S3 and is hinged thereto, as seen in Figs. 1 and 7, the hinge being provided with a spring,a1, the tendency of which is to open the cover C. A spring-catch, d, (see Fig. 1,) secures the cover when closed, so that by pressing upon the said catch the cover will fly open. After the requisite number of cartridges have been placed within the magazine, close the cover, as seen in Figs. 1 and 2.”
To paraphrase: ammunition can be loaded through the opening in one of the receiver side plate when the carrier block is down, insert the cartridges through the opening, pressing the first into the magazine and so on until the magazine is filled… a cover for closing the opening is hinged to the receiver side plate. A spring catch secures the cover when closed.
According to Herbert Houze, King developed the covered loading port design in early January 1866, with a design drawing dating to the 14th January, confirming this.
King altered the design of the rifle’s cartridge carrier so that a cartridge could pass through its lower section straight into the magazine when the action was closed. In theory the aperture could be placed on either side of the receiver, in practice is was placed on the right. Prior to this Winchester had experimented with systems where the tube could slide forward (G.W. Briggs US #58937), a port in the base of the receiver (J.D. Smith US #52934) or a sliding forearm covering a loading port at the rear of the magazine tube (O.F. Winchester UK #3284 [19/12/1865]).
King’s system had the benefit of allowing the rifle to be quickly loaded or topped off without rendering the rifle unusable while loading. Positioning the port in the receiver allowed the magazine tube to be enclosed by a wooden forend.
A cartridge guide was fitted inside the receiver which guided rounds through the cartridge carrier and into the tube magazine. The rounds were prevented from popping out of the magazine, when the carrier was aligned and the cover open, by a shallow shoulder which projected in line with the carrier’s channel to hold cartridges in the tube by their rim.
The hinged cover is held shut by a spring catch mounted on the rear of the cover. When the knurled section on its front is pressed rearwards the cover pops open. The spring catch is actuated when it tensions against the cover’s hinge as it is closed. On the back of the cover there is also a cartridge stop for when the cover is closed.
Another small but interesting feature of the prototype is the catch at the rear of the lever loop, this differs from the manually turned catch seen on the Henry and production 1866. This design appears to be a much better safety feature, simply requiring the user’s hand to depress the catch to unlock it from the stock. It also appears to be a much simpler mechanism than that seen in later models like the Model 1895. The trigger also had an extension protruding from its rear which appears to prevent the trigger from being pulled when the lever isn’t full closed. Neither of these features appear in King’s May 1866 patent.
It appears that the idea of the port with a hinged cover was superseded by what we now recognise as the classic Winchester loading gate in the summer of 1866. King’s new system replaced the hinged cover with a piece of stamped spring steel attached to the inside of the receiver side plate by a screw. The spring steel gate could be pushed in, with the nose of a cartridge, to allow rapid loading. The front face of the gate formed a cartridge guide removing the need for the separate machined guide used in King’s earlier iteration of the system.
King’s revised loading port system required just five, rather than twelve, components: King’s altered cartridge carrier, receiver side plate, spring metal loading gate plate and retaining screws. This simple but elegant design continued to be used for decades on various models of rifle. The company were so pleased with the refinement of the rifle that, according to R.L. Wilson, King was awarded a payment of a $5,000 reward by the company’s board of directors.
Winchester introduced the rifle in 1866, with the first deliveries being made early in 1867, the new rifle was offered in various barrel lengths and patterns including carbine, rifle and ‘musket’. Winchester found some success selling 1866 rifles to the militaries of France and the Ottoman Empire, while many other countries purchased rifles for testing including Britain and Switzerland (whom came close to adopting the Winchester.) The rifles also found success on the civilian market with around 4,500 sold in the first five months.
The Scientific American described the new rifles as “elegant in appearance, compact, strong, and of excellent workmanship. On examination we find its working parts very simple, and not apparently liable to derangement.”
King incrementally developed his loading system before radically simplifying it and this prototype rifle represents an important developmental step in the design of what would become the Model 1866 – one of Winchester’s most important rifles.
Special thanks to the Cody Firearms Museum for allowing us to take a look at this fascinating prototype rifle.
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Winchester Repeating Arms Company, H. Houze (1994)
Winchester: An American Legend, R. L. Wilson (1991)
Today, we’re lucky enough to have some colour footage showing the of testing of a magnetic bomb which could be attached to the petrol tank of vehicles. The footage comes courtesy of the Imperial War Museum.
From the film we can see that the bomb consisted of a small block of plastic explosive, a pair of strip magnets (or possible a horseshoe-shaped magnet) and a Switch No.10 time pencil delay detonator. The explosive block itself looks to be slightly smaller than the SOE’s standard 1.5lb charge.
In the film we see the bomb placed on the boot (or trunk) of a saloon car before various civilians and a corporal experiment with various ways of covertly attaching the bomb to the underside of the car. At one point the corporal allows himself to be dragged along behind the vehicle before making his escape.
Luckily the 16mm footage, filmed by Major Cecil Clarke, also shows us the effect of the explosive charge mounted on a petrol tank full of fuel. According to the details listed for the film by the Imperial War Museum the footage was filmed in 1940, at SOE Station XVII, located at Brickendonbury House in Hertfordshire.
This configuration of the bomb doesn’t appear in the Special Operations Executive’s Descriptive Catalogue of Special Devices and Supplies published in 1944. However, Colonel Leslie Wood, Station XII’s commanding officer, described the demonstration put on during a visit by Brigadier Robert Laycock of the Commandos and William Donovan, the head of the American OSS in June 1942. One of the scheduled demonstrations was the “Effect of small ‘magnet’ charge of explosive on petrol tank of car.”
It appears that this ad hoc magnet charge evolved into ‘the Clam’, which was a smaller, version of the magnetic Limpet mine. The Clam evolved through a number of marks with the MkI having a stamped sheet metal casing and the later MkIII using a bakelite, plastic casing. Both were made up of a plastic explosive charge inside a rectangular, rounded case with a pair of magnets at either end. They were detonated by either a Time Pencil or an L Delay fuse attached to a No.27 detonator. The MkIII had 8oz (226g) of high explosive filler, such as TNT/Tetryl 55/45.
While unlike the larger Limpet they weren’t developed for under water use but the Clam could be mount onto any vaguely flat magnetic surface including engine blocks, fuel tanks, crank cases, cylinder blocks, rail tracks and steel plate.
At just 5.75” x 2.75” x 1.5” they were easily concealable, could be carried in a pocket and were non-descript enough not to draw attention. An estimated 68,000 Clams were made under supervision at Aston House according to Des Turner’s book on Station XII.
We’re lucky enough to have some unique colour footage showing the of testing of some of these explosive devices and in this article we will examine an incendiary-filed case.
In this piece of 16mm colour footage, filmed in 1940 by Captain Cecil V. Clarke, we see what appears to be an attaché case containing three medium-sized bottles, which likely contains a mix of petrol and paraffin or some white phosphorus, prepared for testing at the bomb range at Brickendonbury in Hertfordshire, a Special Operations Executive training and research centre codenamed Station XVII. It’s believed that these films may have been produced as teaching aids for the agents trained at Station XVII and this film may have been shown during a lecture.
While incendiary briefcases, attaché cases and even suitcases are listed in the 1944 SOE Descriptive Catalogue of Special Devices and Supplies they were quite different from this case. They were primarily designed for the quick destruction of documents and items carried inside them. They used sheets of potassium nitrate to burn the case’s contents.
The incendiary case seen in this footage on the other hand appears to be designed to be clandestinely placed and detonated with a delay fuse, to set nearby flammable objects on fire. What was described as a ‘Delayed Action Incendiary’.
In this footage of another separate test we get an idea of the destructive capability of just one of the bottles.
It’s possible that this incendiary case was a proof of concept test for the later cases or perhaps a demonstration of a concealed incendiary device Station XVII were working on. SOE developed a large number of bespoke explosive devices for various missions, so while this device may not have become ‘standard issue’, it may have been developed for a specific purpose.