When discussing artillery ammunition, the subject of ‘hot shot’ rarely, if ever, comes up. Looking into the matter somewhat, it can be found that both land artillery and naval artillery used ‘red bullets’ though it was not a popular round to be fired because of the threat of an early detonation if the procedures for firing the round were not followed.
Regarding firing hot shot from a naval platform, a good place to begin would be Arming the Fleet: US Navy Ordnance in the Muzzle-Loading Era by Spencer Tucker, pages 93-94:
'Hot shot were also employed at sea, for wooden sailing ships were especially vulnerable to it. The shot was heated red-hot (white heat might turn it too brittle). The powder charge, contained in a strong flannel cartridge with no holes, was loaded, and then a tight, dry wad of hay 1 caliber in length was put in. This was followed by a tight clay wad or a wet hay wad with the water squeezed out. The hot shot was then loaded by means of a carrier, and the gun was fired. If it was to be fired depressed, another tight wet wad was rammed in to hold the shot in place. If two wads were used-one dry and the other damp-there was no danger of the shot causing ignition and the gun could be pointed [aimed] before it was fired.'
'The gun could also be double-shotted, that is, fired with an ordinary shot followed by a hot shot. Hot shot required a reduced powder charge, usually one-quarter to one-sixth the weight of the ball. This enabled it to penetrate the enemy hull 10 to 12 inches (if it penetrated farther, there would not be sufficient air for burning).
Excellent primary source material for firing red hot shot, or as the French called them 'red bullets', can be found in Volume II of Louis de Tousard's American Artillerist's Companion, pages 253-258.
1.The round shot would be heated on an iron grate over a 'well-kindled coal fire' and it usually took three-quarters of an hour to properly heat the shot for firing.
2.The powder charge is smaller than that for regular firing, a fourth or a fifth of the shot's weight. And the roundshot have to be carefully chosen as the heat will cause the shot to expand and then it won't fit in the bore.
3.The powder cartridge should be serge or flannel with no holes so that the powder does not 'leak' into the tube when rammed.
4.A 'good dry wad' is first used with the powder cartridge and then a damp one and then the hot shot is placed and then the entire round is rammed, then fired.
Here is an excerpt from John Elting's Swords Around a Throne in Chapter XXIV, pages 486-487 regarding 'hot shot':
'Hot shot,' the most efficient incindiary projectile, was simply a solid shot, heated in the middle of a good fire. (Coast defense forts often had special reverberatory furnaces with racks for heating large numbers of shot at one time. Captain Napoleon Bonaparte built a good many excellent ones along the Mediterranean coast in 1793.) The guns were laid on their target and carefully cleaned beforehand so no loose powder grains remained in their tubes; the powder charge was then loaded, followed by a sabot and one or more wads of woven hay, the outer one slightly dampened. That completed, the glowing hot shot was inserted in the tube and rammed down and the gun immediately fired. This could be a ticklish business, though it looked far more dangerous than it actually was; artillerymen, especially home guard types like the canoniers garde-cotes, did not like to handle 'red bullets.' In November 1810 Napoleon ordered a detailed manual printed on the use of hot shot and intensified training.'
Follow-up to above: I checked James' "Naval History of Great Britain" and it is clear that the forecastle guns using hot shot were on shore, not
on board the ship, a fact that I had missed in reading Rainier's letter.
Do you have a reference for that action and the use of red bullets by Chiffrone?
It seems to me that the discussion here and on TMP has fallen victim to that regular problem of loose language - people with legal training are often accused of being pedantic, but there is a good reason for it.
in this case, we have “'Hot shot were also employed at sea, for wooden sailing ships were especially vulnerable to it.” In one way, this is true - coastal batteries fired out to sea and wooden ships full of flammable materials like rope, wood, sailcloth, grease etc. made great targets, which were both large and much higher than land military units. However, while there certainly seem to have been some whacko ideas about furnaces at sea, the idea is just crazy - look up what happened to the RN first rate Queen Charlotte in 1800, when she caught light. carrying furnaces was outright lunacy, which is why no contemporary account has appeared.
So, a bit of precision language cures it all - all the theorists of the time talk about siege guns and coastal fortresses employing heated rounds, the latter using ships for target practice. That was the full extent of it.
History of heated shot. Nice picture of a British furnace from around our era
Here are two more sources on the subject:
From The Line of Battle: The Sailing Warship 1650-1840 edited by Robert Gardner, 158:
‘Red-hot shot had been tried at sea from time to time but again the dangers seemed to outweigh any advantages. A furnace was required and a gun had to be run out and fired very quickly after the shot was loaded; the shot needed to lodge in the target ship’s timbers to stand a chance of setting the ship alight and even in these circumstances the fire was often quickly extinguished. Conventional wisdom confined the use of hot shot to coast defense fortifications.’
From Roundshot and Rammers: An Introduction to Muzzle Loading Land Artillery in the United States by Harold Peterson, 64:
‘One special firing technique that came to the fore during this era was the red-hot shot designed to set fire to an enemy ship or building. These incindiery projectiles could be fired from gun, howitzer, or mortar with equal facility, and they were effective. It was red-hot shot from the American siege battery at Yorktown which set the British frigate Charon afire and sank her in 1781, and there are numerous other examples of their effectiveness. To fire hot shot, the gun crew first prepared a hole in the ground about six feet in diameter and four feet deep. In this they built a hot fire, then placed the balls on top. Then they prepared the artillery piece with a load of powder, a wad, and either a wooden disc the exact size of the bore or a thick piece of sod to keep the hot ball from igniting the powder when it was seated. They tried to have everything ready so that the shot could be fired as soon as they placed the ball in position. Otherwise the shot would cool and lose its effectiveness. It was, after all, a dangerous and tedious technique, and there was no sense in doing it if the shot was going to arrive at its target too cool to set a fire.’
The Prussian Carl von Decker in ‘Die Artillerie fuer alle Waffen’ (1816) p.205 says the next calibre down of round should be chosen due to the expansion under heating (which can take up to an hour). The cannon should loaded as usual and then some damp hay put down the barrel. The barrel should be elevated to help the ball roll down and the cannon then fired immediately. At shorter ranges and in the mountains a smaller charge should be preferred. https://books.google.com/books/about/Die_Artillerie_für_alle_Waffen_oder_Leh.html?id=0rdRAAAAcAAJ
Smola doesn’t say much, limiting the round to siege and coastal battery use. He describes how to build a heating oven with one per three pieces. I suppose with smaller calibration balls, the windage would be significantly greater and thus such rounds would be less accurate.
On TMP there is a discussion going on whether hot shot was actually use by ships as well as against them. to clarify I found this on the site of the US Constitution Museum (by Matthew Brenckle):
As the Royal Navy tightened its blockade of the American coast during 1813, U.S. Navy captains searched for innovative ways to give American warships an advantage against superior numbers. In Boston, Captain Charles Stewart, a life-long tinkerer, conceived of a portable furnace capable of quickly heating cannonballs to between 1,200 and 1,500 degrees Fahrenheit. The red-hot balls might be fired at a pursuing warship; if they stuck in its timbers, they could quickly ignite dry, tarry, painted wood. On December 5, 1813, Stewart outlined his concept for the Secretary of the Navy William Jones:
According to Stewart, nothing could be more effective at extricating a ship from a tight spot than a few hot shot fired from the ship’s stern chasers. His idea was not wholly original. Shore batteries often employed this tactic during the period, but the process was generally considered too dangerous for shipboard use. The problems of heating and transporting super-heated shot from furnace to gun, and then loading the gun without the powder charge going off prematurely, speak for themselves. Nevertheless, Secretary Jones seemed intrigued by the idea, and 20 days later Stewart forwarded a model of his invention to Washington:
By this point, the full-scale prototype had already been installed on board USS Constitution. On December 18, Navy Agent Amos Binney paid $294.34 to George Darracott of Boston. The bill enumerates the items purchased: “1 Furnace for heating Shot 467lbs,” “Grates and Frame,” “1 p[ai]r Shot Tongs,” “1 Shot Ladle,” and “30 lbs Sheet Iron.”
So far, we’ve never found evidence of Constitution or other American ships using the furnaces in combat. The British were well aware of them, however. A Dutch informant in New London, Connecticut told Captain Nash of HMS Saturn that it was “generally understood in the United States all the American Ships of War are now fitted with furnaces for heating Shot; and…the same person knows it to be the case with the Frigate Constitution.”
Interesting, thanks for this Kevin. It gives a whole new meaning to the phrase 'playing with fire'. I'm curious, do we have any accounts of its use/going wrong?