Army mortars v screw galleys

JeffEngel wrote:

Theemile wrote:
Sadly, this has me thinking about a hedgehog launcher - a WWII weapon which was essentially a few dozen mortars mounted together to create a pattern of destruction wherever they are aimed - the shipborne issues would be compounded - except for the accuracy bit, since a hedge hog is an aim-over-there-ish weapon.

The hedgehog was used for depth charge distribution against a submarine that wasn't localized beyond over-there-ish - you got "accuracy" under those conditions just by hosing down an area with pain. Surface fighting wouldn't have that kind of need except in case of fighting in the dark or thick fog, but the sub could be put out of action or driven off by underwater detonations that may not do much good against a ship when they go off in air.

If the idea is just to rip up sails and rigging, you're in better shape. That said, I've got no idea how bad sheer concussion is on sails or rigging, or how well these charges are going to spread jagged bits of metal to rip them up.

If you don't mind ripping through ammo and you do want to get things done in a hurry, you could use something hedgehog-like - a cluster of mortars firing shells in a narrow fan. While the army can do very good things with mortar accuracy and well-timed fuses for air burst, a ship has to worry about the sea under it pitching it in ways that the army only needs to fear if it takes to fighting during earthquakes.

But in the spirit of varying the exercise some, rockets with timed fuses for air bursts may be another source of indirect fire. I don't think I'd care to try them on any ships with any sails or rigging though.

The British used the Hale rockets on their bombardment ships in the war of 1812 (and Napoleonic wars), and those ships were rigged. I think one of the previous posters was correct, you'd probably need a ship with the appropriate (Ketch) type sail plan for either ordinance type, but I believe the Hale's were used widely in the British fleet for a number of years on most vessels.

Theemile wrote:Sadly, this has me thinking about a hedgehog launcher - a WWII weapon which was essentially a few dozen mortars mounted together to create a pattern of destruction wherever they are aimed - the shipborne issues would be compounded - except for the accuracy bit, since a hedge hog is an aim-over-there-ish weapon.

This was my thought too. A hedgehog or katyusha-type weapon (although I would not want to be the one firing rockets from aboard any wooden ship) firing shells/warheads with incendiary "shrapnel" might be effective.

Keep in mind that the US Army, when considering coastal defense requirements at the end of the 19th century, considered the smallest number of coastal defense mortars (12" mortars, pre-sighted, fixed fortified positions, fixed aiming points, invulnerable to all incoming fire except mortar fire) to be 4 mortars in a diamond formation. And even that was half a battery. Most coast defense installations built at the time included at a minimum 16 mortars per position to bracket the enemy warship with as many shells as possible. This should give you some idea of the challenges of aiming these mortars from dry land. Add in a ship pitching and yawing every which way? No way. Not with the minimal number of mortars you'd be able to fit on a galleon (i.e. one or two at most). Again, the Army's Coast Defense Artillery expected 16 mortars firing at once from fixed positions at pre-sighted coordinates to be effective at taking out an enemy battleship.

Darman wrote:

Theemile wrote:Sadly, this has me thinking about a hedgehog launcher - a WWII weapon which was essentially a few dozen mortars mounted together to create a pattern of destruction wherever they are aimed - the shipborne issues would be compounded - except for the accuracy bit, since a hedge hog is an aim-over-there-ish weapon.

This was my thought too. A hedgehog or katyusha-type weapon (although I would not want to be the one firing rockets from aboard any wooden ship) firing shells/warheads with incendiary "shrapnel" might be effective.

Keep in mind that the US Army, when considering coastal defense requirements at the end of the 19th century, considered the smallest number of coastal defense mortars (12" mortars, pre-sighted, fixed fortified positions, fixed aiming points, invulnerable to all incoming fire except mortar fire) to be 4 mortars in a diamond formation. And even that was half a battery. Most coast defense installations built at the time included at a minimum 16 mortars per position to bracket the enemy warship with as many shells as possible. This should give you some idea of the challenges of aiming these mortars from dry land. Add in a ship pitching and yawing every which way? No way. Not with the minimal number of mortars you'd be able to fit on a galleon (i.e. one or two at most). Again, the Army's Coast Defense Artillery expected 16 mortars firing at once from fixed positions at pre-sighted coordinates to be effective at taking out an enemy battleship.

Note though that they were at that point worried about well-armored steam vessels. Charis faces sailing ships and screw galleys with armor almost solely on the front face, so some shrapnel falling from the sky can do effective work without needing solid hits by powerful munitions like those coastal defense batteries needed.

On the other hand, it's informative that Earth's wet navies using mortars - bomb vessels, bomb ketches - used them solely for coastal bombardment. A quick look showed no instance of their use against another ship, even those at anchor (e.g., Battle of Copenhagen). Maybe a longer look could be more informative, and maybe someone else knows more than I've got.

n7axw wrote:Actually, the aiming issue might not be as bad as you think.
Regular cannon have to get direct hits to do their thing. Imagine mortar shells with proimity timed fuses set to go off about 200 feet above the galley. Not only would you raise the dickens with personnel, you would also shed the rigging. And the shrapnel would spread out allowing for a bit of leeway with the aim.

There is always going to be a certain amount of artistry at aimimg any kind of cannon from shipboard at a moving target. It just doesn't seem to me that the difficulty level here should be much worse than an ordinary cannon once everything is factored in.

Don

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Shrapnel will do sod all to a ship and the crew unless on the exposed upper deck, Even a light wooden splinter deck would completely protect the gun crews. As for damaging rigging again shrapnel will be fairly pitiful just look at how bad it was at cutting barbed wire on the Somme. For that sort of work you need either HE or preferably chain/bar shot.

As to the aiming difficulty with a cannon at realistic ranges (50 - 100 yards) you may have say 15 degrees of roll which will hit the target (counting sails/masts/rigging as hits. With a mortar or plunging fire you have maybe 1 degree of roll variance that will still hit the target. It is telling that during the battleship era on earth they didn't really try to get plunging fire until after the dreadnought revolution and electronic/pneumatic stabilization on ships with very large mass and low roll rate.

The thing that got me thinking about the idea was the bombardment ships. So why not a mortar with shells set for airburst at 100 to 200 ft up with shrapnel spread at a radius of, say, 100 feet... You might need to modify the galleon's ssil plan a bit or make other adjustments, but I doubt that they would be major adjustments. The thing should be doable.

Don

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n7axw wrote:The thing that got me thinking about the idea was the bombardment ships. So why not a mortar with shells set for airburst at 100 to 200 ft up with shrapnel spread at a radius of, say, 100 feet... You might need to modify the galleon's ssil plan a bit or make other adjustments, but I doubt that they would be major adjustments. The thing should be doable.

Don

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The technology isn't there for that kind of airburst quality, I know RFC has used them on land but I feel that he is pushing Black Powder fuses further than history tells us is possible. Also he is firing them at massive infantry positions where missing 50+ feet in any direction doesn't matter much and even then digging in negates them to a massive degree which he has correctly demonstrated in text.

Shrapnel is in my opinion one of the most over-rated projectiles in the history of artillery. It has it's place but that place is against large dense infantry formation usually fired direct trajectory by cannon. Mortars in the BP age were universally high angle ground exploding shells due to the unreliability of fuzes.

For more on Shrapnel and what it can and can't do see Wikipedia. https://en.wikipedia.org/wiki/Shrapnel_shell it is very clear that it is not really suited to mortar style rounds.

Silverwall wrote:

n7axw wrote:Actually, the aiming issue might not be as bad as you think.
Regular cannon have to get direct hits to do their thing. Imagine mortar shells with proimity timed fuses set to go off about 200 feet above the galley. Not only would you raise the dickens with personnel, you would also shed the rigging. And the shrapnel would spread out allowing for a bit of leeway with the aim.

There is always going to be a certain amount of artistry at aimimg any kind of cannon from shipboard at a moving target. It just doesn't seem to me that the difficulty level here should be much worse than an ordinary cannon once everything is factored in.

Don

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Shrapnel will do sod all to a ship and the crew unless on the exposed upper deck, Even a light wooden splinter deck would completely protect the gun crews. As for damaging rigging again shrapnel will be fairly pitiful just look at how bad it was at cutting barbed wire on the Somme. For that sort of work you need either HE or preferably chain/bar shot.

As to the aiming difficulty with a cannon at realistic ranges (50 - 100 yards) you may have say 15 degrees of roll which will hit the target (counting sails/masts/rigging as hits. With a mortar or plunging fire you have maybe 1 degree of roll variance that will still hit the target. It is telling that during the battleship era on earth they didn't really try to get plunging fire until after the dreadnought revolution and electronic/pneumatic stabilization on ships with very large mass and low roll rate.

With those screw galleys, the guns are on the upper deck. The lower deck is where they have the cranks for the screws.

As for the sails, they are made out of cloth, not barb wire. Of course shapnel will shred them.

With aiming, lobing the shell adds a layer of complexity, but you not need the same level of accuracy as with regular cannon. So yes, there is some difficulty here, but probably not that different than with regular cannon. An experienced gun captain would handle it just fine, especially under the conditions you would be engaging the screw galleys.

Don

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n7axw wrote:As for the sails, they are made out of cloth, not barb wire. Of course shapnel will shred them.

With aiming, lobing the shell adds a layer of complexity, but you not need the same level of accuracy as with regular cannon. So yes, there is some difficulty here, but probably not that different than with regular cannon. An experienced gun captain would handle it just fine, especially under the conditions you would be engaging the screw galleys.

Don

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Accuracy of mortars from ships is historically known to be complete shit. Read about the bombardment of the forts protecting New Orleans during the civil war. Firing on a massive immobile target from a moored flat bottomed craft specifically designed as a mortar platform they missed something like 75% of the shots. The complexities of dropping trajectories is massively more complex than you assume, literally a single degree of roll can cause you to miss your target by several hundred feet.

The other issue is that for accurate mortar fire you need very consistently burning and consistently sized propellant charges, something that is not really doable with black powder.

As for your idea of using shrapnel from above on crew it will work once maybe and then just putting some light 1" or less timbers or plyboard above the heads of the gun crews will negate all effectiveness as shrapnel from a mortar will only be falling at terminal velocity + a small amount from the bursting charge. A lot of what made Napoleonic shrapnel powerful was the horizontal velocity of being fired from a long barreled cannon.

Finally with all due respect shredding the sails is not actually that important in a sea fight, The real aim is to cut the rigging that controls them and or the masts/spars so the sails loose all power.

cutting one halyard or stay has the same effect as punching hundreds of holes into the body of the sail. Also with the projectiles coming almost straight down there will be very few sail hits as the sails are oriented parallel with the direction of travel. Again you would get better results with shrapnel fired horizontally from a long gun perpendicular to the sail.

Silverwall wrote:Finally with all due respect shredding the sails is not actually that important in a sea fight, The real aim is to cut the rigging that controls them and or the masts/spars so the sails loose all power.

cutting one halyard or stay has the same effect as punching hundreds of holes into the body of the sail. Also with the projectiles coming almost straight down there will be very few sail hits as the sails are oriented parallel with the direction of travel. Again you would get better results with shrapnel fired horizontally from a long gun perpendicular to the sail.

And don't forget that for Screw Galleys, sails are a secondary source of motive power, largely used to give the people manning the cranks a rest between battles. DURING battle, the screw galleys aren't supposed to use sails at all!

evilauthor wrote:
And don't forget that for Screw Galleys, sails are a secondary source of motive power, largely used to give the people manning the cranks a rest between battles. DURING battle, the screw galleys aren't supposed to use sails at all!

Congrats on taking the wind out of Don's sails EA!