british

The M4 Sherman, Part 2

In this post, I am going to discuss the British Sherman Firefly. And to tell you about that, first I need to tell you some things about some other tanks, the Crusader, the Panzer IV, and the M3 Lee/Grant.

A Panzer IV E of the Afrika Korps. Later models would feature an upgraded, larger 75mm cannon with superior performance. The short 75 was still a powerful gun, however.

A Panzer IV E of the Afrika Korps. Later models would feature an upgraded, larger 75mm cannon with superior performance. The short 75 was still a powerful gun, however.

 

The Crusader was an excellent tank, certainly, but it was unprepared to face off against Germany’s new main battle tank, the Panzer IV. The Panzer IV had better armor, better performance, and an armament that had a drastically superior effective range against the Crusader than the Crusader’s main gun did against the Panzer IV. Even the later models of the Crusader, which mounted a much more powerful cannon, still stood little chance against an aggressive and aware Panzer.

A Crusader Mk III, with 57mm cannon.

A Crusader Mk III, with 57mm cannon.

The M3 Lee and Grant tanks were some of the first to mount a cannon which could reliably engage Panzers. There is little practical difference between the “Lee” and “Grant” variations, and mostly consisted of slightly different turret construction.

The M3 Lee. My understanding is that the commander's cupola on top of the 37mm turret could rotate independent of the turret, to an extent. Also note the cast, rather than welded or bolted hull.

The M3 Lee. My understanding is that the commander's cupola on top of the 37mm turret could rotate independent of the turret, to an extent. Also note the cast, rather than welded or bolted hull.

They were somewhat unusual tanks, featuring a full range 37mm light cannon turret on top of the hull like a normal tank (though this was the time at which engineers were settling on what the future would even call a “normal” tank.) However, mounted on the front of the hull and off to the side was a much larger cannon. Interestingly, while they did not have similar ammunition, this new gun shared a round diameter of 75mm with the main gun of the Panzer IV. The M3 was far better armored than the Crusader, and the hull cannon could engage a Panzer IV reliably at the same distances a Panzer IV could engage the M3.

The M3 Grant. Note the heavier top turret with no command cupola. Note the different hull construction. Some Lee variants had this hull, as well.

The M3 Grant. Note the heavier top turret with no command cupola. Note the different hull construction. Some Lee variants had this hull, as well.

The Grant/Lee, however, was only in production for a short time, as they were intended to be an intermediary measure leading up to the M4 Sherman. After the introduction of more capable British and American tanks, most M3s were moved to the Pacific front to act as infantry support tanks.

The British used a slightly different nomenclature for the base Sherman variants. The M4 was the Sherman Mk. I. The M4A1 was the Mk II, the A2 was the Mk III, and so on and so forth.

This brings us to the Sherman Firefly. By 1943, the North African front was plagued by Germany’s feared, respected final boss of the battlefield, the Panzer VI Tiger. The Tiger outgunned anything the allies could throw its way, and was heavily armored enough to easily survive most tank-on-tank engagements.

Tiger 131. It was captured by the British in North Africa and brought back to England in secret. Nowadays, it stars in movies.

Tiger 131. It was captured by the British in North Africa and brought back to England in secret. Nowadays, it stars in movies.

The Tiger was not completely invulnerable, however. The British responded to it with the 76.2mm 17-Pounder cannon. This heavy gun could penetrate even the thick front armor of the Tiger, from over a kilometer away.

Vaguely phallic, highly effective.

Vaguely phallic, highly effective.

The next issue, of course, was mounting the massive thing on a tank. The Cromwell, Britain’s main tank in 1943, simply couldn’t fit it, so they turned to the Sherman.

Cromwell, I charge thee. Cast away ambition. Aww... don't be sad. We love you anyways, even if you can't carry the 17-pounder.

Cromwell, I charge thee. Cast away ambition. Aww... don't be sad. We love you anyways, even if you can't carry the 17-pounder.

Even then, few involved in the project were convinced that the Sherman could mount the 17-Pounder, any more than the Cromwell. An engineer by the excellent name of Kilbourn, who worked for Vickers, managed this difficult feat, and spectacularly. He designed a breech and recoil system that would let the massive gun be mounted on a Sherman turret, possibly with the assistance of black magic. Of course, to make the design work, he had to remove a crewmember position entirely, and rearrange most of the secondary equipment such as the radio, to fit even his condensed 17-pounder turret.

Once again, all of these in-profile renditions are brought to you by http://www.tanks-encyclopedia.com

Once again, all of these in-profile renditions are brought to you by http://www.tanks-encyclopedia.com

 

Once fielded, the Firefly became just the monster needed to fight the Tiger and Panther tanks. It could engage and destroy both from over a kilometer. Once a Firefly started putting rounds out, German armor had little opportunity to retaliate.

The Firefly had problems, of course. Some of them are very Britishly summarized by Ken Tout of the 1st Northamptonshire Yeomanry:

“The Firefly tank is an ordinary Sherman but, in order to accommodate the immense breech of the 17-pounder and to store its massive shells, the co-driver has been eliminated and his little den has been used as storage space. ... The flash is so brilliant that both gunner and commander need to blink at the moment of firing. Otherwise they will be blinded for so long that they will not see the shot hit the target. The muzzle flash spurts out so much flame that, after a shot or two, the hedge or undergrowth in front of the tank is likely to start burning. When moving, the gun's overlap in front or, if traversed, to the side is so long that driver, gunner and commander have to be constantly alert to avoid wrapping the barrel around some apparently distant tree, defenceless lamp-post or inoffensive house.”

Ken Tout, author of numerous works, including A Fine Night for Tanks.

Ken Tout, author of numerous works, including A Fine Night for Tanks.

 

German units quickly made any Firefly tanks their priority targets. An interesting way of disguising a Firefly among other Shermans was devised because of this. The front half of the cannon was painted with a wavy pale pattern on the lower part of the cannon, which masked the distinctive appearance of the 17-pounder cannon to distant observers.

Thanks to the camouflaged barrel, not even this man and his kids realize the impending danger to their Panzer division.

Thanks to the camouflaged barrel, not even this man and his kids realize the impending danger to their Panzer division.

We’ll see the Firefly again in a later post, when I discuss the different types of ammo used by tanks in WWII (and present day).

From here, we will move on to the more irregular applications of the Sherman.

Nazis hate her: Single woman entrepreneur improves Merlin engine with this odd, simple fix.

During the days of the Blitz, the RAF relied on two primary aircraft for routing the Luftwaffe. these were the Spitfire and the Hawker Hurricane. 

Hurricane (top) with Spitfire (bottom) 

Hurricane (top) with Spitfire (bottom) 

Both of these aircraft were surprisingly capable of holding their own against the Luftwaffe's Bf-109E series fighters. The Spitfire in particular went on to become one of the most effective and important aircraft of the war.  Both of these planes' early variants were powered by the Rolls-Royce "Merlin" engine. 

 

What a British looking piece of equipment.  

What a British looking piece of equipment.  

Though a fine engine, the Merlin suffered from a very major drawback. When pulling negative G-force (nosing down to enter a sharp dive quickly, in particular), the carburettor  would flood with fuel, stalling the engine.  

As the Bf-109 utilized injection type engines, they did not suffer from this same issue, and thus could perform evasive maneuvers that the Spitfire and Hurricane could not match.  

Enter: Beatrice Shilling. 

 

Here she is, looking cooler than you ever will in your life.  

Here she is, looking cooler than you ever will in your life.  

Shilling had an interest in engineering (and motorcycles) her whole life. By 1936, she had a reputation as a tinkerer, motorcycle racer, and genius. When she wasn't tuning up her bike and dominating the Brooklands race-track, she enjoyed a long engineering carreer with the Royal Aircraft Establishment.  As promised by my headline, Shilling's fix for the "negative G" issue was simple, and odd in its simplicity. 

The component itself is shown in the lower left of this diagram. That's all there was to it.  

The component itself is shown in the lower left of this diagram. That's all there was to it.  

The RAE Restrictor would manage the flow of fuel during negative G conditions, preventing the carburettor from flooding, and letting RAF pilots match a diving Nazi fighter with confidence. The component was also referred to as "Miss Shilling's Oriface" which sounds remarkably dirty to anyone who isn't British.  

By 1941, every plane powered by a Merlin engine had this component installed, and later engines utilized injection like their Luftwaffe counterparts, or integrated Shilling's design.  Still, this simple but brilliant fix made a huge difference in the RAF's ability to combat the Luftwaffe's assault on England, as well as their ability to push the offensive later in the war. 

The Semi-Automatic Conversion Kit for Allied Rifles in WWI

The Pederson Device (named after its designer) was a (somewhat) modular attachment for the British Enfield and American Springfield 1903  rifles. It consisted of a special device that would be installed into the bolt and receiver of the rifle, allowing it to fire small (but very high power for their size) cartridges in sequence without having to operate the bolt between shots. A semi-automatic conversion kit. These devices were developed in the utmost secrecy, and were referred to as a "Springfield .30 caliber M1918 pistol".  Of course, it had been less than a decade since the US had adopted the M1911 .45 semi-automatic handgun to replace their old service revolver. Since the 1911 (which is still used in the US military today) was designed by John Browning himself, and the Central Powers were aware of this, I question the effectiveness of the Pederson's mock designation.

This ugly yet elegant bastard here.

Ideally, the Pederson device could be used to great effect in clearing trenches and laying down fire on the move, two things made difficult by the need to operate a bolt after every shot on normal rifles. The specialty rounds designed for it were not as powerful as the ones normally loaded into their parent firearm, but still maintained effectiveness at just over the anticipated engagement distances.

Using the device was as simple as using the rifle it was meant to go in. The operator needed to remove the standard bolt (something they'd learn in the first few minutes of weapon training, more or less), then slide the Pederson device in place. From there, they could fire from the  40 (!) round magazine as needed.

Thanks to the fine people at odcmp.co for this convenient diagram

Thanks to the fine people at odcmp.co for this convenient diagram

As of the time of me writing this, I am not entirely sure what the specifics of magazine removal and jam clearing were. Apparently, though, the magazines could be removed and replaced with one hand, so I assume they used a simple latch or spring that could be undone by pulling at the right angle. I don't even have a guess as to how/if you needed to chamber a new round or otherwise operate the bolt to clear a jam.

While the springfield Pederson devices have been common amongst private collectors since the end of the war, the other variants are far more uncommon, and information about them was scarce until very recently. I do know of a collector near to me that has the only non-replica British Enfield variant Pederson device known to still exist. Perhaps it's time I paid them a visit.