Naval Shell Fire: Why Not?

Factual Questions
1

Explosive artillery shells, as opposed to solid shot or canister or grape shot , were know and used during the wars of the French Revolution, the Napoleonic Wars, the American Revolution and before. It was shell fire that set fire to the Chateau of Hugomont at the Battle of Waterloo in 1815. Shell fire was horribly destructive of wooden ships as demonstrated by the engagement between the Kersarge and the Alabama off Cherbourg in the American Civil War. Yet, until well after the end of the Napoleonic Wars navies did not use explosive shells. At Trafalgar in 1805 the British, French and Spanish fleets pounded away exclusively with solid shot, grape and canister. Not a single shell was fired. A simple question: why?

One explanation is that it was too dangerous to keep gunpowder filled shells on wooden ships. That doesn’t work because those same ships kept tons of gunpowder on board in kegs and in made up cloth cartridges. If the danger presented by large quantities of gunpowder could be managed surely the danger of accidental explosion of shells could be managed as well.

It could not have been from a sense of propriety and fair play. Hand grenades were used. The Bonhomme Richard’s victory over the Serapis during the American Revolution was secured when a hand grenade thrown from the BHR’s yardarm fell in a stack of ready cartridges on the British ship’s gun deck, burning and scorching a fair part of the crew. If the combatants’ were willing to hurl infernal anarchists bombs at each other they surely would not hesitate from shooting them out of cannons.

It wasn’t the technology of naval cannons. Shells were fired from special short gun tubes using a reduced powder charge (so as not to rupture the shell before its fuse burnt out). The British navy had a similar gun called a Carronade or a Smasher used to throw huge solid shot over a short distance. Nelson’s Victory carried two of them at the bow of the ship. Either could throw a 68 pound shot out to 250 yards or a similar weight of grape or canister. Sometimes, as when the Victory broke the line at Trafalgar, a charge of grape/canister was loaded on top of a round shot for a truly destructive blast.

So, why did Navies not use a weapon that could have made a huge difference in the outcome of any number of 17th, 18th and 19th Century engagements? Imagine the effect on the history of Europe if the French-Spanish fleets at Trafalgar had met Nelson’s tactics with shell fire.

2

:smack: If a Mod would shift this over to General Questions it would be appreciated. SG

3

No percussion detonators - they weren’t invented for a few more years IIRC. HE shells were fired from mortars and had a separate fuse that was manually lit before the propellant charge was fired. But mortars were short-barrelled enough for the fuse to be accessible.

4

[QUOTE=Malacandra]
No percussion detonators - they weren’t invented for a few more years IIRC.
[/QUOTE]
To expand upon this:

You need time for the fuse to burn down, hence the need to fire the shell in a high arc. A fuse short enough to detonate at the proper time with a straight-line shot will be so short that there’s a danger of it detonating in the gun.

On land the inaccuracy of a high arcing shot is acceptable. Troop formations are more spread out, cities and forts are big targets, and if you don’t get the fuse length quite right the shell can still go off after it hits the ground.

At sea the targets are smaller and if you miss or cut your fuse too long the shell sinks and is wasted. Mortars are not an effective weapon at sea. (Unless you’re using them to bombard land-based fortifications, of course. Ship-based mortars fired from British bomb ships at Fort McHenry were the “bombs bursting in air” in the U.S. national anthem.)

5

What he said.

Naval ships of the Napoleonic/American Civil War period carried shells (filled with explosives) and corpses (filled with incindiary stuff). They were used for example by the Royal Navy both times they burned down Coppenhagged (1807 and the other time). Doctrine simply faovred solid shot for anti-ship work.

6

[QUOTE=Spavined Gelding]
It wasn’t the technology of naval cannons. Shells were fired from special short gun tubes using a reduced powder charge (so as not to rupture the shell before its fuse burnt out). The British navy had a similar gun called a Carronade or a Smasher used to throw huge solid shot over a short distance.
[/QUOTE]
Shells were fired explicitly from mortars. While a carronade has a shorter barrel than a “long gun”, it was still longer than a mortar and it was acually designed to fire a very fast ball.

The mortars, with their extremely high trajectories and long burn times, were ideal for siege work against stationary targets such as cities, but they could not be aimed (or even loaded with the appropriate care) in the heat of battle. A carronade was very nearly a point blank weapon, something of which the mortar is the exact opposite.

The French Admiral Paixhans began writing theoretical works on the topic of exploding shells in the 1800s and his ideas were not successfully tested until 1824. After that, it was a matter of developing the appropriate cannon to deliver the shells. The natural conservatism of the 19th century military combined with a lack of large-scale ongoing wars probably delayed their acceptance, as well. (For one thing, the earliest cannon developed to handle the new fuzed shot were pretty massive, limiting their use to capital ships.)
Note that while the Wikipedia article notes guns being placed aboard ships in the 1840s, their actual opportunity for use was quite a bit later–1849 and 1853.

It was not until the U.S. Civil War that more guns carrying smaller weapons could be built and tried out in numbers.

After Paixhans’s experiments, the best timed fuze that was developed in the 19th century was the Bormann fuze. Bormann was a Belgian officer, the fuze was kept a military secret, and Belgium did not get into any wars, so that delayed its use in smaller cannon for several years.

Captain Splingard, also, I believe, a Belgian, seems to have developed the first fuze that could be exploded on contact rather than being ignited by firing the gun and then burning through to the charge. His was a concussion fuze rather than a percussion fuze, intended to be placed in a ball rather than in a cylinder type shell. His weapon was developed in the 1850s.

7

I had completely forgotten about mortars and bomb ketches. Clearly they were used during the period (…and the bombs burst in air…). There was an incident in one of the Hornblower stories about this and they were used at Copenhagen and, of course, Fort McHenry. Apparently their use depended on very precise observation of the bomb’s fall and minute adjustments of the powder charge, since 19th Century mortars could not be adjusted for elevation.

It is not likely that fuses were a big problem. The earliest bomb fuses were simply wooden plugs with a hole bored through and filled with a combustible like quick match. The fuse was adjusted by sawing of increments with a special saw. The fuse was then driven into a hole in the shell and loaded into the gun tube. The fuse didn’t need to be separately lit. It was ignited by the propellent charge. All you had to do was make sure the fuse was facing away from the propellent charge.

Once you got the shell into the body of a ship all you wanted was for it to burst. You didn’t much care if the shell burst was simultaneous with the impact or an instant later as long as there was fire and flying fragments inside the enemy’s ship. This may hint at the reason. Ships of the line of the Napoleonic period had sides of from 18 inches to two feet thick. Were the howitzer shells and mortar bombs of the period too fragile to punch through two feet of seasoned oak planking and ribs? A shell that broke up on impact or bounced off didn’t do much good. A shell that lodged on the exterior of a ship was likely to disperse its explosive force and fragments in the wrong direction. These were not modern high explosives, after all.

On reading all for your comments (for which I thank you) I’m inclined to think that the reasons were a combination of things, including the development of a sufficiently robust shell with a useful explosive charge and a reliable fuse, and a gun that would throw the shell with enough force achieve penetration. Until all those things happened a naval shell was just not reliable enough a ship killer to bother with.

8

It would have been a greatly increased storage problem. Gunpowder was a fairly small item and could be confined in one special area for relatively safe storage (and naval officers of the era were very aware of the dangers of carrying explosives on board). Cannonballs were a safe item and could be stacked up anywhere on a ship. It would have been very difficult to have tried to store explosive shells with the same care that could be given to gunpowder.

9

[QUOTE=Spavined Gelding]
I had completely forgotten about mortars and bomb ketches. Clearly they were used during the period (…and the bombs burst in air…). There was an incident in one of the Hornblower stories about this and they were used at Copenhagen and, of course, Fort McHenry. Apparently their use depended on very precise observation of the bomb’s fall and minute adjustments of the powder charge, since 19th Century mortars could not be adjusted for elevation.
[/QUOTE]

And I think that may be the key. If I remember the Hornblower story correctly (and assuming the technique described was accurate) the bomb ketches were securely anchored close to shore, and adjustments to the aim were made by varying the length of the anchor cables and precise trimming of the fuse. Obviously this worked well when firing on a large immobile land-based target (eg Copenhagen), but in a naval engagement both the vessel firing and the target would be moving with the sea and in relation to each other, making any adjustments based on the fall of the previous shot worthless.

Just a guess of course – the question’s not one that had ever occurred to me before.

10

There’s also an incident in one of the Hornblower stories where Hornblower has tiume to extinguish the fuse on an unexploded mortar shell, preventing its detonation.

I have a feeling this is one of those things Forester himself wondered about, reading all those back issues of the Naval Gazette that he never actually saw reported (like his question – why didn’t a crew under the decks of a captured ship simply surrender, instead of fighting back bu cutting the ropes to the ship’s wheel and steering it from below, and firing through the decks?) I suspect that, whenever he found such an unanswered question, he worked it into a story. The “crew below decks” made its way intio the unfinished “Hornblower During the Crisis”, and “Why didn’t anyone ever extinguish a mortar shell” into “Commodore Hornblower”.

11

I’ve read more Ramage than Hornblower, and one book (The Ramage Touch) has Ramage capturing a couple of French bomb ketches, spending some time finding out how they work, and then deploying them against their former owners. The subject of putting out a mortar fuse is touched on briefly; they’re supposed to be inextinguishable by smothering or inundating. And, as stated, naval mortars were aimed by pivoting the anchored ship, which was easier to accomplish than traversing the weapon itself.

12

One other point may simply have been that naval ships (and their guns) had very very long lives which added a lot of inertia to planning. If your fleet is composed of dozens and dozens of ships ranging from bradn-new to forty years old, all carrying 18, 24 or 32 pounders cannon, and you have a choice of spending your years procurement budget on:
[ol]
[li]half a dozen similar but improved ships with essentially the same armament[/li][li]four new ships with brand-new guns with incompatible ammunition that most seamen would not know how to use[/li][li]no new ships, but equipping twenty old ones with guns with incompatible ammunition that most seamen would not know how to use[/li][/ol]
which would you go with? Bearing in mind you are always either in a war, or have a piddly peace-time budget.

There are a usually a formidable range of reasons NOT to adopt innovative new weapons and techniques in war, right up until the point where some nutcase finally does it, at which point everyone else has to do it in a rush or get massacred by Mr Annoying Radical-Innovator.

I think something similar happened with rifles generally, and then bolt-action rifles. Lots of experimentation, then someone takes the plunge and is rapidly followed.

13

[QUOTE=Paul in Saudi]
…corpses (filled with incindiary stuff).
[/QUOTE]
Carcass. Not corpse.

The ability to make a proper carcass was one of the marks of a master gunner. It was an iron strapwork sphere filled with incendiary material, and rather tricky to assemble. They were rarely used, as they were much more effort to make that their effect warranted, but every now and again, a master gunner would assemble one for educational purposes, and for tradition’s sake.

Shells and shrapnel of the Napoleanic and pre-Napoleanic era were, by and large, anti-personnel in nature, with incendiary side effects. For ship-to-ship action in that era, you want penetration, not fragmentation. Shells have much lower sectional density than shot, and so do not penetrate nearly so well. When you’re trying to punch through upwards of two feet of oak (in places), you can’t be bothered with second-best.

If you want incendiary effects, you use heated solid shot instead - this was done moderately often, though it was dangerous - you had to heat the shot in a furnace until red-hot. whilst that was happening, the gun crew would charge their gun, then ram a wad of clay down on top of the charge. The heated shot would be brought to the gun ins a stretcher, and carefully loaded. If, at any point, the shot were dropped, you ran a serious risk of fire or explosion, but if you did everything right, you had the penetration of shot, with the inceniary effect of an 18 or 24lbm red-hot hunk o’ iron as well. Nasty.

If you wanted anti-personnel fire from your guns, in a naval battle, grape, canister, and lagrange were all available - for the distances the naval fights took place at, those were plenty deadly enough.

14

Forester describes the use of heated shot, in Lieutenant Hornblower, but he bnotably has it fired from a land fort rather than a ship. Considering the difficulties he describes with that land-based effort, I find it hard to imagine carrying out such an operation on a naval vessel that :

1.) Is pitching and rolling

2.) Is itself highly incendiary

3.) Is carrying its own gunpowder for its guns on the same deck where you have to be heating shot.

15

It was done. Two examples:

Battle of Lake champlain - both sides, the British notabley from their ship, the Confidence.
Hampton Roads

People did a LOT of risky things back then, that more modern, risk-adverse people wouldn’t or couldn’t imagine - they had balls as big as their shot.

16

I don’t doubt it was done. I just wouldn’t want to be around.
Heck, I’m amazed they could go aloft on a stormy night and reef the topsails without lights or safety lines. Or that Mark Twain could pilot a boat down the Mississippi on a dark night without sonar.

17

Skills that are lost, by-and-large, and just as well, I’m thinking. Life was a damn-sight cheaper back then.