Sherman Firefly

By 1943 the Western Allies faced a widening gap. The reliable, mass-produced M4 Sherman was the backbone of British and American armoured units, but its 75 mm gun could not defeat the frontal armour of the German Panther and Tiger at normal combat ranges. The American 76 mm gun then entering service was an improvement, yet still not enough, and purpose-built Allied heavy tanks were more than a year away.

The British answer was not a new tank but a new gun in an old one. They took their outstanding Ordnance QF 17-pounder — a 76.2 mm anti-tank gun that could out-shoot almost anything in the German inventory — and forced it into the Sherman’s turret. Driven by engineers including George Witheridge and W. G. K. Kilbourn, the conversion was ready in time for the invasion of Normandy, and it gave Commonwealth regiments genuine tank-killing power at the exact moment they needed it. The result was the Sherman Firefly.

Fitting the huge gun was a feat of improvisation. The 17-pounder was rotated 90° onto its side in a new cradle so its long recoil would clear the cramped turret, the recoil guard was cut down, and a large armoured box was welded to the turret rear to house the radio the breech had displaced. The loader now worked in a space barely big enough for the one-and-a-half-metre shells.

To make room, the hull machine-gunner’s position was deleted and the space packed with ammunition, cutting the crew from five to four. Nothing else changed: the Firefly kept the Sherman’s engine, running gear and armour, so a regiment could absorb it with no new training or spares. It was, deliberately, the least disruptive way to put a war-winning gun into the field.

The gun justified the contortions. Already proven as a towed anti-tank gun in 1943, the 17-pounder firing APCBC punched through about 140 mm of armour at 500 m; with the scarce tungsten-cored APDS round it reached roughly 190 mm at 1,000 m — enough to kill a Panther or Tiger head-on at real battlefield ranges, something no other British or American tank could reliably do in 1944.

The price was conspicuousness. The long barrel and a huge muzzle blast threw up dust and smoke with every shot, marking the Firefly as the dangerous tank in a troop, and German gunners learned to engage it first. At night the flash was fierce enough to briefly blind the gunner. Crews answered by painting the forward half of the barrel in a lighter counter-shade to disguise its length, and by firing from cover and shifting position after a shot. APDS itself was always in short supply and its early accuracy poor, so the deadliest long-range round had to be rationed.

Some 340 Fireflies were ready by D-Day — about one for every troop of four tanks in British and Canadian armoured regiments. Tactics followed the arithmetic: the three 75 mm Shermans laid down high explosive, smoke and volume of fire, while the single Firefly hung back in overwatch as the troop’s only reliable answer to heavy German armour.

Conversion accelerated sharply through 1944, peaking near 400 vehicles a month at the Royal Ordnance factories. By the winter of 1944–45 many troops fielded two Fireflies, and the up-gunned Sherman had become the standard tank-killer of the Commonwealth armoured divisions from Normandy to the German frontier.

The Firefly’s most famous moment came on 8 August 1944 during Operation Totalize, south of Caen. Near Saint-Aignan-de-Cramesnil, a Firefly of the 1st Northamptonshire Yeomanry, gunned by Trooper Joe Ekins — a former shoe-factory hand who had never knocked out a tank before that afternoon — engaged a group of Tigers advancing across open ground and destroyed three of them in about twelve minutes.

One of those Tigers is widely believed to have carried Michael Wittmann, the most celebrated German tank ace of the war, killed with his crew that afternoon — though the exact identity of the tank that fired the fatal round is still debated, with Canadian and Polish units also in action nearby. What is not in doubt is that a single up-gunned Sherman, handled from cover, killed three of Germany’s heaviest tanks in minutes: the clearest vindication the Firefly ever received.

Beyond that one action the Firefly fought everywhere the Western Allies met heavy German armour — through the Low Countries, the Rhineland and into Germany itself — and equipped Polish, Canadian, New Zealand and South African units in Italy as well. Roughly 2,100–2,200 were converted by the war’s end, drawn mainly from the Chrysler-engined Sherman V (M4A4) and the Sherman I (M4) and designated Sherman VC and IC.

It remained strictly an expedient — no new hulls were ever built for it, and its armour stayed the standard Sherman 51–76 mm, leaving it as vulnerable as any other Sherman to a German gun that saw it first. When purpose-designed vehicles like the Comet reached the regiments in 1945, carrying a comparable gun in a properly designed turret, the Firefly’s stop-gap job was finished.

The Sherman Firefly is the textbook war-winning improvisation: not a new tank but a marriage of the best Allied anti-tank gun to the most available Allied hull, fielded fast and in numbers that mattered. For most of a year it was the single most effective tank-killer in the Western Allied arsenal.

Its record rests on that one asset — the gun — bought at the cost of a cramped turret, a deleted machine-gunner and a muzzle blast that drew fire. It was enough. From the hedgerows of Normandy to the Rhine, the Firefly gave Commonwealth crews the one thing the standard Sherman could not: a fair chance against a Tiger at a thousand metres.

• Mark Hayward, Sherman Firefly (Barbarossa Books) — the definitive study.
• David Fletcher, Sherman Firefly (Osprey, New Vanguard).
• Steven J. Zaloga, Sherman Firefly vs Tiger: Normandy 1944 (Osprey, Duel).