Potential and upgraded ironclad designs

[gunlock_wolg]

A thread where we discuss what ironclads may have looked like in terms of shape, armament, gun placement (turret or broadside), and armor.

 

[gunlock_wolg]

So a major question to start out this thread: if the war had continued until let's say 1870 and rifling was common practice on naval cannons, which would be more effective a turret or broadside, or would it be a combination of the two such as with later ships like H.M.S. Dreadnaught having secondaries in her hull but a main caliber in her turrets?

 

[JohnDLittlefield]

In the time of the ACW, ammunition was also advancing quickly, as shown by the 200 & 300 lbers. Mines and torpedoes were advancing. Armor was advancing. Gun production methods were being improved. The science of guns and fuel were each rapidly advancing. So, it might be difficult to make guesses about a single technological chance, since many aspects of weaponry were being advanced together (and many were being made obsolete every year), and in a very intertwined and symbiotic manner.
However, we may look to Europe to see how these changes were being addressed. For example, the self-propelled torpedo was under development, steel was being applied to ship's hulls, and metallurgy was rapidly advancing allowing for thicker armor.
I love the ACW period for the technology, but I really love the advances that were made in the next two decades, foreign and domestic (since there was little that strictly one of the other).
Just a thought.

 

[gunlock_wolg]

In the time of the ACW, ammunition was also advancing quickly, as shown by the 200 & 300 lbers. Mines and torpedoes were advancing. Armor was advancing. Gun production methods were being improved. The science of guns and fuel were each rapidly advancing. So, it might be difficult to make guesses about a single technological chance, since many aspects of weaponry were being advanced together (and many were being made obsolete every year), and in a very intertwined and symbiotic manner.
However, we may look to Europe to see how these changes were being addressed. For example, the self-propelled torpedo was under development, steel was being applied to ship's hulls, and metallurgy was rapidly advancing allowing for thicker armor.
I love the ACW period for the technology, but I really love the advances that were made in the next two decades, foreign and domestic (since there was little that strictly one of the other).
Just a thought.

I was meaning if the war had continued for let's say 5-10 years longer what would be some of the advancements on ironclads and how would they look, And how would these advancements effect what system of aiming there guns.

 

[Carronade]

So a major question to start out this thread: if the war had continued until let's say 1870 and rifling was common practice on naval cannons, which would be more effective a turret or broadside, or would it be a combination of the two such as with later ships like H.M.S. Dreadnaught having secondaries in her hull but a main caliber in her turrets?

Welcome aboard!

I would consider turret vs. broadside in terms of the main battery; secondary and lighter guns are almost always on the broadside. Can we think of examples of ships with their heavy guns in a mix of turrets and broadside mounts? The few that come to my mind are cruisers from a later time like the Scharnhorst or Edgar Quinet classes of the early 1900s.

Getting back on topic, as long as the US Navy was focused on fighting the Civil War, I expect they would continue to use turrets. The main drawback of turrets was the low freeboard of turreted ships, an issue for ocean-going ironclads.

 

[gunlock_wolg]

I know it's a bit primitive but here is a concept I have for a broadside and turreted monitor which I call "U.S.S. Ogre."
Scratch that I can't seem to get my photo to load

 

[Carronade]

Interesting, sixteen guns, able to fire ten on the broadside, not bad. The corner guns in the casemate might also be able to fire directly forward/aft, or on a 45-degree angle if the casemate was faceted like CSS Neuse or Albemarle. Nice work!

 

[gunlock_wolg]

Interesting, sixteen guns, able to fire ten on the broadside, not bad. The corner guns in the casemate might also be able to fire directly forward/aft, or on a 45-degree angle if the casemate was faceted like CSS Neuse or Albemarle. Nice work!

Thank you. I was gonna put the corner guns of the casemate onto a inlaid turret able to fire forward/aft, depending on direction, and be part of the broadside.

 

[gunlock_wolg]

Ok so now that I have a few potential ideas thought up I have a question. Could a pre dreadnaught monitor have an a b y turret configuration? If so how would it even keep from flipping if firing a full broadside?

 

[Carronade]

I'm not aware of any ship being capsized by the recoil of her own guns. It was suggested that HMS Agincourt, which had the largest centerline battery of any battleship, fourteen 12" in seven twin turrets, would capsize if she fired full broadsides, so her gunnery officer did precisely that at Jutland to show that it wasn't so.

I assume you're considering a superfiring arrangement, raising B turret over A? The concern in putting any weight higher up in a ship is general stability - heeling, rolling, listing - and the solution is simply to have the hull large enough and particularly wide enough to accommodate it. A ship with a raised B turret needs to be a bit larger than one with three turrets all on one level. I'm not sure how far the science of making these calculations had advanced in the 1860s.

There would not seem to be any physical reason why superfiring turrets could not be used, but it was not actually thought of until the South Carolina class was designed around 1903. One concern was that the blast of the guns in the upper turret might damage the lower turret or injure personnel inside, but USN tests disproved this, as long as the turret roof was solid. Monitor turrets often just had gratings on top, for lighting and ventilation, and some 1900s turrets had spotting hoods for the turret officers in the roof, so some ships with superfiring turrets could not fire them within say 20 degrees of directly forward or aft. This still allowed them to use all guns on the broadside, so there was still an advantage over non-superfiring arrangements.

Getting back to the 1860-70s, turret ships generally had the turrets sitting directly on top of the armored hull or armored citadel, hence relatively low freeboard. Then navies developed barbettes, circular armored structures which raised the guns higher. In early barbette ships, the guns were uncovered, but they soon began putting armored structures over them which came to be called turrets.

 

[unionblue]

Very interesting thread! Looking forward to seeing other designs!

Unionblue

 

[rebelatsea]

I expect someone was waiting for me to insert an oar - or a piston !
We know how the European ironclads developed, and we know what the Union were doing with the monitor design, drawings also exist for the completion of the "Steven's battery" ( several different ones !). The only question is or should be what would the Confederate States Navy have done if a measure of independence had been gained, and this entirely depends on when hostilities are assumed to cease.

 

[Bil R]

Hello Gentlemen,

This is an interesting thread and a great 'what if' scenario. With the passage of time and the benefit of hindsight most of us would conclude that the ideal arrangement for gunned vessels would be turrets on the ends arranged fore and aft. However, we tend to take innovation and technology for granted and assume that any advancement is inevitable. Consider if the turret had never been invented or proposed. Imagine a 20th century Iowa class battleship fitted with long range heavy guns mounted in a long casemate. Such an evolution is not impossible. The Spanish were surprised that the Mayans could calculate celestial events precisely thousands of years into the future and yet did not use the wheel. Why? Perhaps they had no need for it. Perhaps their transportation needs were met satisfactorily by other means. Regardless, an obvious invention that had served mankind for thousands of years elsewhere was not commonplace in the New World. It took awhile for the turret to catch on.

If we assume the ACW lasted until 1870 what would the ironclad trends have been on either side? In my proposal I am assuming some basic conditions: 1) A basic stalemate on land existed as conditions were in June 1864 > Confederate control of Atlanta, Mobile, Galveston, Charleston, Wilmington and Richmond 2) The Confederate economy is functional and relatively stable 3) The blockade restricts but does not eliminate imports 4) The Union continues to apply political pressure on European powers to prevent the importation of warships. Under these conditions what would have resulted? This is my reasonable speculation.

USN -

The USN was committed to the turret as the primary feature of future construction. It was within the capabilities of industry, it was a remarkable innovation and it was battle proven. Even so, D. Porter still wanted to convert a Kalamazoo to a 10 gun broadside ironclad. This view was not shared by all, especially the primary naval powers of the era, Britain and France. Despite the success of the Thunderer, Devastation and Dreadnought, neither nation would adapt the turreted battleship as the primary capital ship for another two decades. While broadside ironclads fell out of favor the debacle of the Captain set back turret development for years. Central battery ironclads became the trend of the 1870s and 1880s. Barbette ships were built and eventually both powers returned to turret ships by the early 1890s.

Returning to the USN I think the Kalamazoo class would have been completed in the latter part of 1865 and early 1866. The Dunderburg and Puritan (with 2 turrets) would have also been commissioned by this time. Combined with the Dictator and New Ironsides these would have formed the essential, deep draft seagoing ironclads to face any potential European adversary. Had the US felt truly threatened I think they would have built a follow-on class of Kalamazoos with iron hulls, higher freeboard and armed with four 20" SBs. I think too they would have reconsidered the Steven's Battery and rebuilt her with a higher freeboard and twin turrets. She probably would be fitted with four 15" SBs in turrets located nearer midship due to her fine fore and aft lines. Her last known design was with a large single turret fitted with 20" SBs. By this time the USN really appreciated the benefits of twin turrets and would have altered that. The US seemed to be committed to the smashing power of large SBs rather than the piercing power of RFs.

For inshore operations I can see a follow-on twin turret version of the Tecumsehs being built. The Cascos were a disaster and would be replaced by more Milwaukees. As these became commissioned many of the tinclads and other early war conversions would have been phased out. I think a certain number of tinclads would have been retained for smaller river operations. For merchant protection, more Wampanoags would have been built and commissioned. I think too, the USN would try to match Confederate innovations in torpedo boat construction and use. None of these suggestions reveal any dramatic change from the existing trends. I don't see superfiring turrets adopted yet or the embrace of steel over iron construction. Those would come but it would be years later.

CSN -

Given the assumptions above I am suggesting that the Confederacy could import a limited amount of machinery, iron plate and guns. Had the war continued the Columbus Naval Works along with Tredegar would have built more reliable and robust machinery. By 1866-67 they should have been able to engine all of their domestic construction with far better machinery than that of the early war. Iron plate construction would have continued but been limited by iron supplies. Rifled Brookes and perhaps some large SBs would be available for armament. Torpedo construction would be far advanced over the Union but self propulsion would still not be available. Torpedo boat tactics would rapidly evolve and become a possible game changer within 2 to 3 years. Foreign acquisition of warships would still be possible but on a more clandestine basis. Those are all possible trends suggested by prior events. Now let's consider more precise speculation.

By 1863 there were numerous concerns and complaints expressed regarding the utility of first generation Confederate ironclads. This resulted in multiple meetings and discussions in early 1864. While these issue were addressed, the resulting designs had to account for the domestic industrial capacity and the tactical situation of the time. What emerged were more seaworthy hull designs, smaller, more heavily armored casemates and heavier (but fewer) weapons. The second generation of Confederate ironclad designs were laid down later that year and would have been commissioned by mid-late 1865. This includes the Milledgeville, Wilmington and Petersburg classes (Graves double ender). In addition, Warner had been authorized to build his monitor proposal. I imagine it would have been a single turret design on a Milledgeville type hull. As experience with these were obtained I think Warner's monitor design would be the most favored for future development. Perhaps by 1868-69 larger twin turret Warner monitors would have been laid down. These would have become the primary harbor and off shore ironclads of the CSN.

For inland and river operations, a heavier Albemarle design would be still be useful. Easy to construct, ideal for shallow water and more potent than all but the larger USN monitors, it was a battle worthy design. One with a shorter, thicker casemate and heavier weapons would be capable well into the 1870s. I also think all CSN ironclads would be fitted with spar torpedoes. This is where the Confederates had a opportunity to level the field. The development of seaworthy, off shore torpedo boats operating in massed night time raids could have sunk a number of blockaders. The USN would have responded by moving their vessels further off shore which would have made the blockade less effective. Moreover, when a Union vessel was hit, others would leave station and come to her aid. This would have again offered opportunities for runners to enter and exit port. I do not see the CSN obtaining heavy sea going ironclads able to contest USN sea going ironclads on a one to one basis. Despite their appearance the Stonewalls were very limited.

That being said, the CSN still could have obtained a number of cruisers and gunboats, as they always did, appearing as merchant vessels (i.e., Waccamaw, Texas, Hercules, Ajax, etc.). The commerce war would have continued with 4 to 8 cruisers active at any time. In mid 1864 the CSN had started construction of four 'Alabama' type cruisers at Mobile. This trend probably would have continued. Another possibility is that the CSN could have obtained lighter, sea-going ironclads in the form of converted blockade runners. They could not have faced a Kalamazoo but could have handled just about anything less. Such a conversion actually occurred in 1865-66. By early 1865 Dudgeon was building a number of blockade runners when the market crashed. One of these runners, I believe the Mary Augusta, was converted by them into the central battery ironclad Bolivar and sold to Venezuela (see Transactions RINA, vol. IX, 1868). She was considered a success, being fast, seaworthy and well armed.

In conclusion, I think the CSN of 1870 would have been a mixture of 2nd and 3rd generation (mostly monitor) ironclads, numerous torpedo boats, a dozen cruisers and perhaps a few light seagoing ironclads. This of course, is all speculation.

All the best,
Bil

As an aside, I believe the French get credit for superfiring turrets. The first appeared with the battleship Henri IV which was designed in 1895-96. Being French and very methodical the upper turret was first test fired with only sheep occupying the lower turret. When opened, the lower turret contained all dead sheep that apparently died from shock. The officers were concerned about this but noted that the medium caliber barrel of the upper gun did not extend past the sighting hood of the lower turret. It would be another few classes of warships before this arrangement was repeated.

 

[rebelatsea]

Hello Gentlemen,

This is an interesting thread and a great 'what if' scenario. With the passage of time and the benefit of hindsight most of us would conclude that the ideal arrangement for gunned vessels would be turrets on the ends arranged fore and aft. However, we tend to take innovation and technology for granted and assume that any advancement is inevitable. Consider if the turret had never been invented or proposed. Imagine a 20th century Iowa class battleship fitted with long range heavy guns mounted in a long casemate. Such an evolution is not impossible. The Spanish were surprised that the Mayans could calculate celestial events precisely thousands of years into the future and yet did not use the wheel. Why? Perhaps they had no need for it. Perhaps their transportation needs were met satisfactorily by other means. Regardless, an obvious invention that had served mankind for thousands of years elsewhere was not commonplace in the New World. It took awhile for the turret to catch on.

If we assume the ACW lasted until 1870 what would the ironclad trends have been on either side? In my proposal I am assuming some basic conditions: 1) A basic stalemate on land existed as conditions were in June 1864 > Confederate control of Atlanta, Mobile, Galveston, Charleston, Wilmington and Richmond 2) The Confederate economy is functional and relatively stable 3) The blockade restricts but does not eliminate imports 4) The Union continues to apply political pressure on European powers to prevent the importation of warships. Under these conditions what would have resulted? This is my reasonable speculation.

USN -

The USN was committed to the turret as the primary feature of future construction. It was within the capabilities of industry, it was a remarkable innovation and it was battle proven. Even so, D. Porter still wanted to convert a Kalamazoo to a 10 gun broadside ironclad. This view was not shared by all, especially the primary naval powers of the era, Britain and France. Despite the success of the Thunderer, Devastation and Dreadnought, neither nation would adapt the turreted battleship as the primary capital ship for another two decades. While broadside ironclads fell out of favor the debacle of the Captain set back turret development for years. Central battery ironclads became the trend of the 1870s and 1880s. Barbette ships were built and eventually both powers returned to turret ships by the early 1890s.

Returning to the USN I think the Kalamazoo class would have been completed in the latter part of 1865 and early 1866. The Dunderburg and Puritan (with 2 turrets) would have also been commissioned by this time. Combined with the Dictator and New Ironsides these would have formed the essential, deep draft seagoing ironclads to face any potential European adversary. Had the US felt truly threatened I think they would have built a follow-on class of Kalamazoos with iron hulls, higher freeboard and armed with four 20" SBs. I think too they would have reconsidered the Steven's Battery and rebuilt her with a higher freeboard and twin turrets. She probably would be fitted with four 15" SBs in turrets located nearer midship due to her fine fore and aft lines. Her last known design was with a large single turret fitted with 20" SBs. By this time the USN really appreciated the benefits of twin turrets and would have altered that. The US seemed to be committed to the smashing power of large SBs rather than the piercing power of RFs.

For inshore operations I can see a follow-on twin turret version of the Tecumsehs being built. The Cascos were a disaster and would be replaced by more Milwaukees. As these became commissioned many of the tinclads and other early war conversions would have been phased out. I think a certain number of tinclads would have been retained for smaller river operations. For merchant protection, more Wampanoags would have been built and commissioned. I think too, the USN would try to match Confederate innovations in torpedo boat construction and use. None of these suggestions reveal any dramatic change from the existing trends. I don't see superfiring turrets adopted yet or the embrace of steel over iron construction. Those would come but it would be years later.

CSN -

Given the assumptions above I am suggesting that the Confederacy could import a limited amount of machinery, iron plate and guns. Had the war continued the Columbus Naval Works along with Tredegar would have built more reliable and robust machinery. By 1866-67 they should have been able to engine all of their domestic construction with far better machinery than that of the early war. Iron plate construction would have continued but been limited by iron supplies. Rifled Brookes and perhaps some large SBs would be available for armament. Torpedo construction would be far advanced over the Union but self propulsion would still not be available. Torpedo boat tactics would rapidly evolve and become a possible game changer within 2 to 3 years. Foreign acquisition of warships would still be possible but on a more clandestine basis. Those are all possible trends suggested by prior events. Now let's consider more precise speculation.

By 1863 there were numerous concerns and complaints expressed regarding the utility of first generation Confederate ironclads. This resulted in multiple meetings and discussions in early 1864. While these issue were addressed, the resulting designs had to account for the domestic industrial capacity and the tactical situation of the time. What emerged were more seaworthy hull designs, smaller, more heavily armored casemates and heavier (but fewer) weapons. The second generation of Confederate ironclad designs were laid down later that year and would have been commissioned by mid-late 1865. This includes the Milledgeville, Wilmington and Petersburg classes (Graves double ender). In addition, Warner had been authorized to build his monitor proposal. I imagine it would have been a single turret design on a Milledgeville type hull. As experience with these were obtained I think Warner's monitor design would be the most favored for future development. Perhaps by 1868-69 larger twin turret Warner monitors would have been laid down. These would have become the primary harbor and off shore ironclads of the CSN.

For inland and river operations, a heavier Albemarle design would be still be useful. Easy to construct, ideal for shallow water and more potent than all but the larger USN monitors, it was a battle worthy design. One with a shorter, thicker casemate and heavier weapons would be capable well into the 1870s. I also think all CSN ironclads would be fitted with spar torpedoes. This is where the Confederates had a opportunity to level the field. The development of seaworthy, off shore torpedo boats operating in massed night time raids could have sunk a number of blockaders. The USN would have responded by moving their vessels further off shore which would have made the blockade less effective. Moreover, when a Union vessel was hit, others would leave station and come to her aid. This would have again offered opportunities for runners to enter and exit port. I do not see the CSN obtaining heavy sea going ironclads able to contest USN sea going ironclads on a one to one basis. Despite their appearance the Stonewalls were very limited.

That being said, the CSN still could have obtained a number of cruisers and gunboats, as they always did, appearing as merchant vessels (i.e., Waccamaw, Texas, Hercules, Ajax, etc.). The commerce war would have continued with 4 to 8 cruisers active at any time. In mid 1864 the CSN had started construction of four 'Alabama' type cruisers at Mobile. This trend probably would have continued. Another possibility is that the CSN could have obtained lighter, sea-going ironclads in the form of converted blockade runners. They could not have faced a Kalamazoo but could have handled just about anything less. Such a conversion actually occurred in 1865-66. By early 1865 Dudgeon was building a number of blockade runners when the market crashed. One of these runners, I believe the Mary Augusta, was converted by them into the central battery ironclad Bolivar and sold to Venezuela (see Transactions RINA, vol. IX, 1868). She was considered a success, being fast, seaworthy and well armed.

In conclusion, I think the CSN of 1870 would have been a mixture of 2nd and 3rd generation (mostly monitor) ironclads, numerous torpedo boats, a dozen cruisers and perhaps a few light seagoing ironclads. This of course, is all speculation.

All the best,
Bil

As an aside, I believe the French get credit for superfiring turrets. The first appeared with the battleship Henri IV which was designed in 1895-96. Being French and very methodical the upper turret was first test fired with only sheep occupying the lower turret. When opened, the lower turret contained all dead sheep that apparently died from shock. The officers were concerned about this but noted that the medium caliber barrel of the upper gun did not extend past the sighting hood of the lower turret. It would be another few classes of warships before this arrangement was repeated.

Excellent summary Bil. You are right about the guns for the CSN. John M Brooke had drawn up plans for 13" smoothbores and rifles (for some reason the rifle was referred to as a 12.75" - maybe this was the measurement across the lands). John L Porter had planned and begun construction of a 250ft vessel to carry two of these weapons, but Brooke advised that the casemate - singular - so it wasn't another "Wilmington", be altered to carry 4 guns. The ship was fired and found still burning when the Union entered Richmond. I think Porter would have continued development of the double citadel design for the principal coast defence vessel. However the design of Jackson is a puzzle as it has features which do not resemble previous or current ICs, and a further development of this should not be discounted, as should an updated Columbia. William Grave's peculiar double ended aberration would not be repeated BTW I like your designation of Petersburg for it. I think you are right about the Albemarle design, which of course had already developed a "son" in Porter's improved Albemarle. James H Warner would probably be allowed to continue development of his monitor which seems to have been a turreted Jackson, although his focus would be on machinery at least initially.
What would you do about the Mississippi?

In terms of European involvement, The RN would be quick to unload the Laird vessels back to their original owners together with any other odds they didn't want which might be of use the new navy. There were also speculative builds in various dockyards which conceivably the CSN might look at. Nevertheless I am with you in that the priority would armour for domestic construction together with some machinery initially.

 

[gunlock_wolg]

Now that I'm finally able to read my thread I have a question that's really off topic. But were there any naval battles in the state of West Virginia?

 

[DaveBrt]

If we assume the ACW lasted until 1870 what would the ironclad trends have been on either side? In my proposal I am assuming some basic conditions: 1) A basic stalemate on land existed as conditions were in June 1864 > Confederate control of Atlanta, Mobile, Galveston, Charleston, Wilmington and Richmond 2) The Confederate economy is functional and relatively stable 3) The blockade restricts but does not eliminate imports 4) The Union continues to apply political pressure on European powers to prevent the importation of warships. Under these conditions what would have resulted?
*****
Given the assumptions above I am suggesting that the Confederacy could import a limited amount of machinery, iron plate and guns. Had the war continued the Columbus Naval Works along with Tredegar would have built more reliable and robust machinery. By 1866-67 they should have been able to engine all of their domestic construction with far better machinery than that of the early war. Iron plate construction would have continued but been limited by iron supplies./QUOTE]
Bil,
I hate to be contentious, but I cannot wrap my head around the stalemate in place in June 1864, the siege of Petersburg began in mid-June. Richmond could not be retained for 5 more years in that condition for about a dozen reasons. This requires a reason for the Union armies to stop operations through the Cis-Mississippi.

The only thing that I can reasonably(?) believe would stop the war in June '64 would be the death of Lincoln and the filling of the Presidency with someone not willing to finish the war. I have no idea who that would be or what mechanism would get him to office until March of '65, but this is the ONLY way the South could have lasted 5 more years. The new President would have had to get an armistice or peace treaty signed. For the Confederacy to survive 5 more years, the Union army would have had to leave central Virginia, along with the cessation of hostilities.

So, if the war is stopped by a peace treaty that no one expects to survive for long, then the blockade would be lifted. Now the South has to face internal reconstruction, war plant expansion, and importation at a level that it could pay for. But with no blockade, the sky's the limit for Confederate shipbuilders. Would they have adopted the turret (since they could now get the machinery they could not otherwise build)?

 

[USS ALASKA]

I know it's a bit primitive but here is a concept I have for a broadside and turreted monitor which I call "U.S.S. Ogre."

This looks like a turreted / armored citadel ship as did evolve after the ACW and continued until before WWII.

upload.wikimedia.org/wikipedia/commons/d/df/Victoria_Class_Battleship_Starboard_elevation_and_Deck_plan.jpg
282

Cheers,
USS ALASKA

 

[Hussar Yeomanry]

Nice thread

May I recommend Warrior to Dreadnought - Warship Development from 1860 to 1905 by D K Brown

It's a decent sized and very detailed book that is very well illustrated with much technical detail (some of which I will admit went over my head) that looks mainly but not exclusively at how the Royal Navy attempted to deal with the challenges that the fast pace of technological developments of the period provided.

It also points out something that is too often ignored in all these things. Politics. Faction A likes Technological Solution A. Faction B likes Technological Solution B. Are they going to go with the better solution or the one backed by the Faction with more influence...

(Deep Sigh)

 

[USS ALASKA]

May I recommend Warrior to Dreadnought - Warship Development from 1860 to 1905 by D K Brown

It's a decent sized and very detailed book that is very well illustrated with much technical detail (some of which I will admit went over my head) that looks mainly but not exclusively at how the Royal Navy attempted to deal with the challenges that the fast pace of technological developments of the period provided

Great book!

Cheers,
USS ALASKA

 

[USS ALASKA]

In early barbette ships, the guns were uncovered, but they soon began putting armored structures over them which came to be called turrets.

upload.wikimedia.org/wikipedia/commons/3/3f/HMS_Benbow_Starboard_elevation_and_Deck_plan.jpg

Cheers,
USS ALASKA