Continuing my short series about shrapnel ammunition, prompted by finding a First World War shrapnel ball in a field in France.
This is part two of a three-part article. Links to the previous and next parts can be found at the foot of the article.
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In the 1780s an officer in the Royal Artillery of the British Army had an idea that would overcome the ineffectiveness of common shell as an artillery ammunition. Common shell was the only ammunition of the era that exploded as a modern shell does – the other types were either one large
solid iron ball or many small ones. The problem was that when common shell exploded the case tended to split only into a few large chunks, limiting the number of enemy soldiers who could be hit by the fragments.This officer realised that if the common shell was filled not just with gunpowder but with small metal balls packed in gunpowder then these balls would be blasted out when the shell exploded, increasing greatly the number of flying lumps of metal available to injure the enemy.
After many years of experimenting, the result was a shell that the British Army adopted in 1803 and used with good effect through the latter half of the Napoleonic Wars – in the Peninsular War and at Waterloo. It was at first named ‘spherical case’ but was soon renamed after the officer who had invented it: shrapnel, from Henry Shrapnel’s surname.
Spherical case or shrapnel shells were fired with the aim of exploding them as an air burst in front of enemy troops (see diagram linked to in the footer of this article). The gunpowder charge within the shell was just enough to burst the case and form a cloud of shrapnel balls. The forward momentum of the shell would then carry this cloud of balls down onto the enemy.
These early forms of shrapnel shell were fairly effective but suffered from several problems. They used the same type of time fuse as the common shell, so were very difficult to set precisely enough to get the air burst in the right place to shower the enemy with the shrapnel balls. Some models also had a tendency
to explode prematurely because friction between the balls, the gunpowder and the case caused sparks.The second half of the 19th century saw the adoption of rifled cannon firing the modern shape of shell – a cylinder with a pointed end – rather than the old spherical shells. Along with that came several other innovations that transformed the shrapnel shell from merely useful to almost universal.
One key innovation was the invention of nose-cone timed fuses which were set by turning rings that made up the cone and were far more precise and reliable than a simple tube of gunpowder. They still contained a track of gunpowder that burned down at a known rate but this was now internal and manufactured to much better tolerances. Twisting the rings short-circuited parts of the track of gunpowder, allowing the required time delay to be set for the distance to the target.
Another change was moving the bursting charge that broke open the shell to release the balls from being around the balls themselves to being near the base of the shell. The bursting charge now sat below a disk and the shrapnel balls sat above it. When the bursting charge ignited it hurled the disk forward, pushing out the shrapnel balls like a piston. This separation of balls and bursting charge made the shells much less likely to go off prematurely.
The shrapnel shell had now reached the form in which it would enter the First World War and I will cover the role of shrapnel in that conflict in the next part of this article.
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Diagram of 19th century shrapnel shell airburst
Previous part (part one) of this mini-series
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