Smooth Bore against Ironclads

[DaveBrt]

2/3/63 Genl Whiting states: "I prefer the 10 inch (Columbiad) smooth bore, to rifle guns as against ironclads. We can use the 120 lb bolt in them with effect."

Found in National Archives, Letters of the Department of the Cape Fear, Chap. 2, Vol. 334.

Thoughts about this choice?

 

[AndyHall]

Smoothbores he had at hand could fire a heavier shot than rifles, perhaps?

Would Whiting be looking to "rack" the ironclads' armor (i.e., loosen and knock it apart), rather than penetrate it directly?

 

[Ironclader]

What I have read about the ordnance tests by both US Navy and Royal Engineers (Shoeburyness) from about 1864-1867 (against 3- to 6-inch naval armor) indicates that the most potent projectile against wood-backed armor was the chilled steel (Palliser) bolt, followed by the chilled iron round shot. By September 7 & 14, 1866, The Mechanic's Magazine could report that chilled steel shells of Palliser's design were completely penetrating the thickest (i.e. 6-inch) target armor before exploding in the wood backing.

I'm pretty sure that by 1863 the lighter-armored USN river gunboats had already suffered badly from bolts fired from Whitworth rifles, even though horse-drawn calibers were small.

On Google Books, there are tons of contemporary reports (in advocate-printed books, military journals, and engineering/scientific periodicals) on armor testing and resulting debates, but until about 1864 it seems to be focused mostly on the various guns and armor designs than upon projectiles. Europe-centric British experts did not get around to testing against the much thicker monitor armor for some years. And their 1867 analysis of the 15-inch Rodman (aka Dahlgren) smoothbore seems biased against finding results that would upset British digestion. (This is an early example of the institutional bias in some modern US military procurement programs.) Even the newspaper accounts hint that the tests stopped short of finding bad news:

"THE RODMAN GUN -October 19, 1867, The London Illustrated News.
THE Engraving on our front page represents the huge "Rodman" gun, so called from the name of its inventor, which has lately been tried with success against the Warrior target at Shoeburyness. Guns of this description are now carried by some [in fact, ALL] of the monitors and other turret-ships of the American navy. The one at Shoeburyness is of gigantic size, made of cast iron, at Pittsburg, we believe, weighing nineteen tons, and having a bore 15 in. in diameter. It is not rifled or grooved, but is a smooth-bore, and carries a round shot of 453 lb., with a charge of 100 lb. of American powder. This ponderous shot, having a velocity of 1500 ft. a second, easily pierced the 3-in. plates of the Warrior target in two places at the trial a fortnight ago, but it is the opinion of many English artillerists that it could not pierce the Hercules target. There can be no doubt of its tremendous power at short distances. At a long range of course the Armstrong or any rifled gun would be more effective."

All opinions are from my amateur reading of the reports. Search "Shoeburyness" and check it out yourselves...

 

[7th Mississippi Infantry]

Smoothbores he had at hand could fire a heavier shot than rifles, perhaps?

Would Whiting be looking to "rack" the ironclads' armor (i.e., loosen and knock it apart), rather than penetrate it directly?

That was my first thought as well.

I seem to recall in Myron J. Smith's The CSS Arkansas: A Confederate Ironclad on Western Waters , "loosening the iron" was very effective.

I can only imagine the number of ruptured eardrums among crew on the receiving end of a 120 lb bolt.

 

[rebelatsea]

In the early 1860s, at ranges up to around 500 yards there was little difference between smoothbore and rifles in terms of actual damage inflicted - provided you could actually hit a moving target ,given the primitive sighting and fire control systems of the time. Projectiles fired from rifled guns held on to their velocity so that at longer ranges they could penetrate where smoothbore projectiles velocity would drop off rapidly, especially large calibres.
I have said this elsewhere, but it must be borne in mind that accepted battle range in most European navies until around 1866 - 7 when the new Krupp and French rifles began to be introduced.
Incidentally, an elongated bolt fired from a smoothbore will tumble in flight.

 

[georgew]

In the early 1860s, at ranges up to around 500 yards there was little difference between smoothbore and rifles in terms of actual damage inflicted - provided you could actually hit a moving target ,given the primitive sighting and fire control systems of the time. Projectiles fired from rifled guns held on to their velocity so that at longer ranges they could penetrate where smoothbore projectiles velocity would drop off rapidly, especially large calibres.
I have said this elsewhere, but it must be borne in mind that accepted battle range in most European navies until around 1866 - 7 when the new Krupp and French rifles began to be introduced.
Incidentally, an elongated bolt fired from a smoothbore will tumble in flight.

Hi Rebel. I agree with your conclusion about the small difference between rifles and smooth bores at close ranges. What you're describing was the basis for the classic argument between the proponents of smaller, faster loading guns versus the all big gun lovers. I think the beginnings of this debate also had something to do with the Glatton trials, substituting heavy broadside carronades for long guns. It was assumed that you couldn't accurately target anything at long range, so lets close in and hammer them. The all big gun approach just wasn't viable until fire control caught up with ballistics. There were a number of armoring approaches tried out during the CW. Keokuk, Galena and Arkansas come to mind. In my opinion the Arkansas case is not useful for generalizations. She had a sort of composite "armor" peculiar to the Confederates in this time frame. Sort of an "M & M" approach. Hardened outer shell (iron and timber), softer inside (pressed cotton) and another layer of timber. For rounds 9-inch or below, it actually worked. The problem was that the cotton layer, which retained splinters from the outer timber layer, was vulnerable to the heat from the incoming round with a possibility of fire. Another factor here is the use of T-rail. It had somewhat different properties than plate. The bulb/base with intermediate sheer webs of this rail made its resistance a function of the angle of the impact. Reversing the outer rail was actually a very good idea. Stabilizing the outer rail with concrete or metal filings had another interesting property, it allowed the rail to take a hit and deform. Classic armor functions by stopping the round. The T-rail, when properly fastened would deform, helping to dissipate the kinetic energy of the round. It can be argued that the biggest problem with Arkansas' shield was insufficient backing for the iron. But consider the sheer volume of fire concentrated on Arkansas during her run past the Union fleet. The T-rail approach was a viable alternative if you didn't have the ability to roll or transport plate. But you had to realize that changing out deformed rail after an action was inevitable. In the case of smooth bore versus rifled rounds, the issue is the size of the round and the distance from the target. Because even Union ironing tended to be laminated (think Monitor turrets), the classic ironing approach wasn't actually an issue. Mass x velocity x number of hits results in damage. Based upon the demonstrated resistance of Confederate laminated ironing and the difficulty in producing large bore rifles safely, the smooth bore with chilled bolt was probably the preferred weapon for the period. It didn't hurt Union gunners that the average CSN ironed vessel was slow usually giving the Yankee vessel the option of engaging or breaking off during actions.

 

[DixieRifles]

My 2 cents . . . . . .

A rifled shot that hits its mark is better than any large caliber shot that misses.

Rifled ordnance of all types---rifles, pistols, artillery---are much more accurate than smooth bores.

 

[rebelatsea]

Georgew. That is very good indeed, very well written and clear. Better than I could have done I think.
Arkansas presents a dilemma in that her protection performed better than modern calculations, both Nathan Okun's PENETRA program and my own gun tables indicate that it should not have stood up under the punishment it did.
The under layer or rail armour wasn't actually fastened to the backing thoroughly, Brown complained about not being able to obtain the correct amount of fastenings, and the top layer although reversed and driven into the gaps between the railheads, was only held on by a sort of strapping, as in William Geogehans drawing in a previous post. There was also no cementation between layers. Had these two things been carried out, the ship may well have survived in much better condition than she actually did.
CSS Louisiana, although a seriously flawed concept had a shield properly secured and we both believe, infilled with cement and iron filings mix. No penetration whatsoever was achieved at point blank range.

 

[rebelatsea]

My 2 cents . . . . . .

A rifled shot that hits its mark is better than any large caliber shot that misses.

Rifled ordnance of all types---rifles, pistols, artillery---are much more accurate than smooth bores.

The first point is a no brainer, but you have to be able to get a hit in the first place. The second point depends on range and how "true" the casting of the projectile and driving mechanism that rides the rifling is.

 

[DaveBrt]

Gen. Whiting wrote many, detailed letters regarding his plans for defending Wilmington in late '62 and early '63. The OP quote is from one of those letters.

In early '63, he received 2 10" Columbiads, sending one for Fort Caswell and one to Fort Fisher. Whiting was convinced that the USN would attempt to run ironclads past the forts so that Fort Fisher could be destroyed from the river side. To prevent running past, he wanted the 10" guns and "submarine mortars" and he ordered the river side of Fort Fisher's guns to be protected.

The OR Atlas shows that at the early '65 battles, Battery Buchanan, the southern protection against an ironclad charge around Fort Fisher, had 2 10" and 2 11" smothbores. Fort Fisher had 7 10" Columbiads. Unfortunately, for our question, all were facing east (seaward), while the monitors were placed in close above the NE corner of the fort -- where no 10" was likely to be able to bear on them.

 

[AndyHall]

In early '63, he received 2 10" Columbiads, sending one for Fort Caswell and one to Fort Fisher. Whiting was convinced that the USN would attempt to run ironclads past the forts so that Fort Fisher could be destroyed from the river side.

With good reason -- that's similar to what DuPont was trying at the same time at Charleston, although it might actually have worked better at Wilmington.

 

[Dilandu]

Thoughts about this choice?

Well, against the sloped sides of Confederacy ironclads he may be right. It seems that the shots from the rifled guns of this era tended to deflect on such armor too much.

 

[rebelatsea]

Well, against the sloped sides of Confederacy ironclads he may be right. It seems that the shots from the rifled guns of this era tended to deflect on such armor too much.

Manufacturing techniques could not yet get the tightness off fit between projectile and rifling it required. Brookes came close, certainly better than the Woolwich shunt rifling where the studded projectiles tended to wobble in the bore. The best was the Whitworth hexagonal bore but that required very high tolerances to match twist in rifling and projectile.

 

[georgew]

Manufacturing techniques could not yet get the tightness off fit between projectile and rifling it required. Brookes came close, certainly better than the Woolwich shunt rifling where the studded projectiles tended to wobble in the bore. The best was the Whitworth hexagonal bore but that required very high tolerances to match twist in rifling and projectile.

Rebel, I seem to remember reading that a pair of Whitworth rifles were donated by blockade runners for use at Fort Fisher. Apparently they were horse-drawn and pulled down the beach to an area where a runner came ashore to give cover to the crew, passengers and portable cargo for unloading on the beach. They were breech-loaders and I think of 5 or 6 inch bore. I don't find them in the index of Fonvielle's "The Wilmington Campaign" so I may have seen it in a book on the fort called "Goliath". I've often wondered why similar guns were not mounted in a turret. Admittedly, the rounds were expensive and more difficult to acquire, but they would have been reasonably accurate and with breech-loading could be provided with decent protection for the gun crew.

 

[rebelatsea]

Rebel, I seem to remember reading that a pair of Whitworth rifles were donated by blockade runners for use at Fort Fisher. Apparently they were horse-drawn and pulled down the beach to an area where a runner came ashore to give cover to the crew, passengers and portable cargo for unloading on the beach. They were breech-loaders and I think of 5 or 6 inch bore. I don't find them in the index of Fonvielle's "The Wilmington Campaign" so I may have seen it in a book on the fort called "Goliath". I've often wondered why similar guns were not mounted in a turret. Admittedly, the rounds were expensive and more difficult to acquire, but they would have been reasonably accurate and with breech-loading could be provided with decent protection for the gun crew.

Georgew that's new info to me, I will have to look into that .Cdr Robbins has researched the guns at Wilmington and fort Fisher extensively, that 's how we discovered by a process of elimination that the guns of CSS Wilmington would have been a pair of 11" Brooke SB. On the face of it ,mounting a pair of breechloaders in a turret was more than possible .Cole's turret in Trusty mounted a pair of 7" Armstrong BLR.

 

[DaveBrt]

Rebel, I seem to remember reading that a pair of Whitworth rifles were donated by blockade runners for use at Fort Fisher. Apparently they were horse-drawn and pulled down the beach to an area where a runner came ashore to give cover to the crew, passengers and portable cargo for unloading on the beach. They were breech-loaders and I think of 5 or 6 inch bore. I don't find them in the index of Fonvielle's "The Wilmington Campaign" so I may have seen it in a book on the fort called "Goliath". I've often wondered why similar guns were not mounted in a turret. Admittedly, the rounds were expensive and more difficult to acquire, but they would have been reasonably accurate and with breech-loading could be provided with decent protection for the gun crew.

The Ft. Fisher Whitworths were a regular field battery of 4 3" guns, kept by Whiting when his people rescued them from a stranded blockade runner. Their main value to the blockade running community was the ability to move them quickly to cover a stranded ship (in fact, 2 were stationed on the beach, north of the fort) and the ability to fire very accurately. While the guns could not seriously damage a blockader, they could destroy boarding party boats and could hit the blockade ships repeatedly if they stayed close enough to hit the stranded ship with their own, shorter range guns.

 

[georgew]

The Ft. Fisher Whitworths were a regular field battery of 4 3" guns, kept by Whiting when his people rescued them from a stranded blockade runner. Their main value to the blockade running community was the ability to move them quickly to cover a stranded ship (in fact, 2 were stationed on the beach, north of the fort) and the ability to fire very accurately. While the guns could not seriously damage a blockader, they could destroy boarding party boats and could hit the blockade ships repeatedly if they stayed close enough to hit the stranded ship with their own, shorter range guns.

Thanks for the clarification, Dave. I need to find that photo.

The Ft. Fisher Whitworths were a regular field battery of 4 3" guns, kept by Whiting when his people rescued them from a stranded blockade runner. Their main value to the blockade running community was the ability to move them quickly to cover a stranded ship (in fact, 2 were stationed on the beach, north of the fort) and the ability to fire very accurately. While the guns could not seriously damage a blockader, they could destroy boarding party boats and could hit the blockade ships repeatedly if they stayed close enough to hit the stranded ship with their own, shorter range guns.

Ah a bit more on the subject: ref Blockade - The Civil War at Sea by Robert Carse, pg 43. "While the champagne cocktails were poured and drunk aboard the Banshee, Taylor made a mental note that became a very private communication to his employers. It was that they send out to Colonel Lamb a field battery of six rifled long-range Whitworth guns, along with ammunition for the pieces and caissons and gun-team harness. He would make the delivery in the Banshee and the colonel was sure to appreciate the nature of the gift..." pg 71 "...the Hebe, a contraband -runner out of Bermuda, banged onto the beach...The Niphon...sent a boat to capture her and hold her. Lamb's cavalry was already on the beach...Lamb had brought down two of his mule-drawn Whitworth guns, the gifts of Tom Taylor, supercargo of the Banshee...The gunners were a bit off target...A few days later, in better weather, the large vessels of the squadron closed with the shore. They put salvos into Lamb's lunettes and smashed them and the battery crews had to crawl to stay alive. Landing parties reached the beach. There was a short bayonet, sword and cutlass fight. Then the fine Whitworth guns were loaded aboard the boats and taken off as prizes..." pg 110 "The British steamer Modern Greece had tried to run the bar...she had pile onto the beach. Lamb went out to her with a part of his soldiers...she still held in her hold four modern twelve-pound Whitworth rifles and ammunition for them. Lamb rigged tackles. He got the guns,then the ammunition on deck...(he) send the lot safely through the surf...The Whitworth guns were put in shape at the fort. They had the longest carry of any gun then constructed, could throw a shell five miles at an elevation of twenty-five degrees..." Unfortunately, the ref on pg 43 and 71 doesn't specify caliber or number of guns actually delivered. You get the impression it was only two versus the requested six. Getting them off a beach into surf boats implies that they were field guns, not heavier armament.

 

[DaveBrt]

Thanks for the clarification, Dave. I need to find that photo.

Ah a bit more on the subject: ref Blockade - The Civil War at Sea by Robert Carse, pg 43. "While the champagne cocktails were poured and drunk aboard the Banshee, Taylor made a mental note that became a very private communication to his employers. It was that they send out to Colonel Lamb a field battery of six rifled long-range Whitworth guns, along with ammunition for the pieces and caissons and gun-team harness. He would make the delivery in the Banshee and the colonel was sure to appreciate the nature of the gift..." pg 71 "...the Hebe, a contraband -runner out of Bermuda, banged onto the beach...The Niphon...sent a boat to capture her and hold her. Lamb's cavalry was already on the beach...Lamb had brought down two of his mule-drawn Whitworth guns, the gifts of Tom Taylor, supercargo of the Banshee...The gunners were a bit off target...A few days later, in better weather, the large vessels of the squadron closed with the shore. They put salvos into Lamb's lunettes and smashed them and the battery crews had to crawl to stay alive. Landing parties reached the beach. There was a short bayonet, sword and cutlass fight. Then the fine Whitworth guns were loaded aboard the boats and taken off as prizes..." pg 110 "The British steamer Modern Greece had tried to run the bar...she had pile onto the beach. Lamb went out to her with a part of his soldiers...she still held in her hold four modern twelve-pound Whitworth rifles and ammunition for them. Lamb rigged tackles. He got the guns,then the ammunition on deck...(he) send the lot safely through the surf...The Whitworth guns were put in shape at the fort. They had the longest carry of any gun then constructed, could throw a shell five miles at an elevation of twenty-five degrees..." Unfortunately, the ref on pg 43 and 71 doesn't specify caliber or number of guns actually delivered. You get the impression it was only two versus the requested six. Getting them off a beach into surf boats implies that they were field guns, not heavier armament.

Trotter, Ironclads and Columbiads (The CW in NC; The Coast) says there were 4 2.75" guns, brought in on Modern Greece.

 

[georgew]

Trotter, Ironclads and Columbiads (The CW in NC; The Coast) says there were 4 2.75" guns, brought in on Modern Greece.

This from Rod Gragg's "Confederate Goliath", pg80 re Whitworths emplaced at Battery Gatlin. In command was a Col. Read. "...The gunners manning a 12-pounder Whitworth stood firm under the barrage...so did some of the other field artillery crews, but the gun crews working the 32-pounder and a 6-pounder Whitworth cowered under the hail of enemy fire and refused to man their guns...The Whitworth's lieutenant went down and so did Read..." So it appears that there were at least 3 groups of Whitworth's at Fort Fisher during its career. We still don't know the caliber of the guns brought in by Taylor on the Banshee.

 

[georgew]

Georgew. That is very good indeed, very well written and clear. Better than I could have done I think.
Arkansas presents a dilemma in that her protection performed better than modern calculations, both Nathan Okun's PENETRA program and my own gun tables indicate that it should not have stood up under the punishment it did.
The under layer or rail armour wasn't actually fastened to the backing thoroughly, Brown complained about not being able to obtain the correct amount of fastenings, and the top layer although reversed and driven into the gaps between the railheads, was only held on by a sort of strapping, as in William Geogehans drawing in a previous post. There was also no cementation between layers. Had these two things been carried out, the ship may well have survived in much better condition than she actually did.
CSS Louisiana, although a seriously flawed concept had a shield properly secured and we both believe, infilled with cement and iron filings mix. No penetration whatsoever was achieved at point blank range.

Hi Rebel. I think there is evidence that the cement/metal filings technique originated in construction of the shield for the Georgia. Sections of her ironing with samples of the cement/filings were recovered from the wreck years ago. Cotton cladding is one of those things you'd almost have to do experimental work on to get any answers. Western pressed cotton bales of that era ran about 435-460 lbs/bale. If you rely only on the weight of the bale to hold it in place, the kinetic energy of any complete round of almost any caliber will displace the bale. The Confederates realized this and tended to pile their cotton two or three bales deep and two or three high at a minimum. The cumulative weight of the bales made them less likely to be displaced. This apparently worked well against small arms, shell fragments and small caliber field artillery. The obvious improvement is to bulkhead the cotton with wood. You've put an empirical formula on this board at one time approximating 16 inches of wood with one inch of ironing. This is a reasonable simplification, but subject to two major variables: green wood and/or a wood/cotton/wood sandwich construction. A number of Confederate boats were well known for using green timber, subject to drying out, leaks and rot. Green wood can, however, also be more pliable for a period of time. It is possible, but difficult to demonstrate, that heavy planking and timbering with green wood allowed more deflection of any iron facing with a slight improvement in dispersing the kinetic energy of the incoming round. The sandwich construction case is a whole other animal. Your handy rule of thumb for iron/wood combinations works fine, but iron/wood/cotton/wood again with endless possible combinations of thickness and percent moisture in the wood appears to be one of those things that are unique to each construction. In particular, can you add the thickness of the two wood layers and divide by sixteen? What if any value do you put on the cotton? Do you have to count each wood layer separately? How much residual energy is left after the strike on the outer ironing and wood panel? I think the account of the modifications to the shield of the Arkansas at Vicksburg may give us a clue. They added cotton bales behind the existing wood bulkheads at Vicksburg. I believe this was to minimize the kind of splintering experienced as she ran through the Union fleet above the city. The question of whether she was cotton-clad at all before Vicksburg arises. The only report I've seen that indicates she might have been concerns her catching fire and her executive officer, Lt. Stevens, seizing a fire hose to put out the blaze.