CSS Atlanta question

[andy19k10]

Did Porter have anything to do with the design of the conversion of Fingal into an ironclad ram or was it all the Tift brothers?

 

[Mark F. Jenkins]

I believe it was an all-Tift show, but I'll wait for a few others to chime in... I can't completely rule Porter out, but I don't recall that he had much of a role in Atlanta.

 

[rebelatsea]

Mark is indeed right, she was built as far as practicable after the plan of CSS Mississippi by the Tifts. The hull proportions were different obviously, and the casemate had to accommodate the top of Fingals engine which protruded through the new gundeck.
Bil Ragan suggests that the plan was in fact the one that Pierce drew up for the two small Mississippi class vessels.
There are two unanswered questions :
Why was the inner layer of armour alternate strips of timber and 2" iron plate instead of all plate as designed, as this effectively reduced her armour to 2" thickness instead of the 4" always quoted?
Who drilled all the holes in her sponsons so that she leaked lie a sieve until they were plugged?

 

[andy19k10]

She certainly looked as if she had alot of the "Mississippi" in her. I'v read that she was the most uncomfortable ironclad to be on, but that could be wrong. Its a shame really, so much was expected of her and a very......ambitious (to say the least) sortie was planned..........but, history happens. I wonder how she would have done at sea had those monitors not been there?
I cant find much on her in Union service, but I wonder what the USN's opinion of her was?

 

[georgew]

Mark is indeed right, she was built as far as practicable after the plan of CSS Mississippi by the Tifts. The hull proportions were different obviously, and the casemate had to accommodate the top of Fingals engine which protruded through the new gundeck.
Bil Ragan suggests that the plan was in fact the one that Pierce drew up for the two small Mississippi class vessels.
There are two unanswered questions :
Why was the inner layer of armour alternate strips of timber and 2" iron plate instead of all plate as designed, as this effectively reduced her armour to 2" thickness instead of the 4" always quoted?
Who drilled all the holes in her sponsons so that she leaked lie a sieve until they were plugged?

Were her sponsons actually ironed? If so 2 inch?

 

[georgew]

Mark is indeed right, she was built as far as practicable after the plan of CSS Mississippi by the Tifts. The hull proportions were different obviously, and the casemate had to accommodate the top of Fingals engine which protruded through the new gundeck.
Bil Ragan suggests that the plan was in fact the one that Pierce drew up for the two small Mississippi class vessels.
There are two unanswered questions :
Why was the inner layer of armour alternate strips of timber and 2" iron plate instead of all plate as designed, as this effectively reduced her armour to 2" thickness instead of the 4" always quoted?
Who drilled all the holes in her sponsons so that she leaked lie a sieve until they were plugged?[/quote
Trying to place a wooded superstructure on a metal hull with the join area submerged is just asking for trouble with leaks. The Confederates probably used only partially cured wood which doesn't help when you're trying to keep seams tight. You wonder whether the reduced ironing was due to lack of availability of iron or a need to keep weight down to reduce her draft. You also wonder, if examining the well known photos of her hull in dry dock where her vertical center of gravity would be when loaded? The knuckles make her much wider and more resistant to rolling, but as you pointed out her engine had a higher c of g because of a vertical orientation. Do we know how wide the strips of timber were between the 2" iron on the inner layer of the shield?

 

[Mark F. Jenkins]

I cant find much on her in Union service, but I wonder what the USN's opinion of her was?

Well, here's a start: ORN I:14, pp. 273-6, part of the survey conducted on Atlanta just after her capture.

U. S. S. WABASH,
Port Royal Harbor, June 22, 1863.​

SIR: In obedience to your order, dated 20th instant, we have held a strict and careful survey on the late Confederate ironclad steamer Atlanta, and have the honor to submit the following report:

1st. We find that this vessel was originally an iron merchant steamer called the Fingal. She has been cut down so as to leave the deck about 2 feet above the water with her present draft. A casemate rises from this deck sufficiently large to accommodate four guns, the sides and ends of which are inclined at an angle of about 29 degrees with the horizon. The top is flat, and the roof of the pilot house extends above it pyramidally to a height of about 3 feet. The deck overlaps the original iron hull 6 feet on each side, tapering toward the ends of the vessel and projecting beyond them. The sides are protected by timber running from a point several feet below the water line to the edge of the deck, forming a heavy, solid overhang of wood and armor.

The armor, 4 inches in thickness, is composed of two layers of 2-inch roller-iron plates 7 inches wide, the inner of which runs horizontally and the outer vertically. They are secured to a backing of oak 3 inches thick and of pine 15 inches thick, by bolts 1¼ inches in diameter, countersunk on the outside of the armor and drawn up on the inside of the vessel by nuts and washers. Wherever the bolts pass through a space is left between the horizontal plates, which is fitted in with oak plank to avoid the expense and trouble of drilling through more than one layer, as we suppose.

The bow terminates in an iron beak or ram, which forms a part of the stem. A wooden pole connected with an iron lever, capable of being lowered below the water and raised again at pleasure, projects beyond the ram and carries at its end a percussion torpedo.

There are three portholes on each side and one at each end. The bow and stern guns are pivoted so as to work at the end or at either of the nearest broadside portholes. The broadside guns are not opposite to each other. Each porthole is defended by an iron shutter, made in the same manner as the armor of the vessel, except that the two layers of plates are strongly riveted together. The shutters are hung upon a pivot in one of the upper corners, and may be raised by a chain from one of the lower corners, passing through the side and attached to a tackle on the inside of the vessel. When the tackle is let go the shutter will fall into its place by its own weight and close the porthole.

The dimensions are as follows: Extreme length, 204 feet; extreme breadth, 41 feet; draft of water, 15 feet 9 inches.

The battery deck is of great strength. It appears to be of solid timber 17 inches thick, resting on beams 10 inches thick.

2d. The machinery consists of two cylinders 39 inches in diameter and 30 inches stroke. The engines are vertical and direct acting, with a surface condenser. There is one flue-tubular boiler, having four furnaces, two at each end of the boiler. There are also one auxiliary boiler, three steam pumps, a blowing engine and pans. The engines were built by James and George Thomas, of Glasgow, in 1861.

3d. The armament is composed of two 7-inch and two 6.4-inch rifled guns of the Brooke pattern, and they all bear the marks-of the Tredegar foundry.

The rifling consists of seven grooves, each of which is formed by a curved cut starting from the bore, running below it to a depth of about 0.10 inch and then returning to-the bore upon an increased curve. The next groove commences where the last terminates.

The following are some of the principal dimensions:

7-inch. 6.4-inch.
Extreme length inches 147.00 142.00
Length from base ring to muzzle do. 124.25 121.00
Length from base ring to end of cascabel do. 22.75 21.00
Diameter of cylinder do. 31.30 24.65
Diameter at rim bases do. 31.40 24.75
Diameter at muzzle do. 14.15 10.79
Thickness of wrought-iron sleeve do. 2.00 2.00
Length of wrought-iron sleeve do. 30.25 30.00
Weight of wrought-iron sleeve pounds 15,300 9,200

The chambers of the guns are conical. The guns are not turned. Their exteriors are in the condition in which they left the mold. There is no chipping about the rim bases, but the metal runs from their faces in a curve to the proper diameter on the vertical plane between them.

The elevating screws are similar to those in use on board our own ships.

The breech sights are described on the ordnance invoice as of the Brooke pattern. The bar slides through the box with an angle in front. The graduation is in yards on one side and in degrees on the other.

The locks correspond nearly with those in use on the modern navy guns.

The 7-inch guns are mounted on pivot carriages, resembling our own very nearly. They traverse on iron circles.

The 6.4-inch guns are mounted on Marsilly carriages, differing in some trifling particulars from our own standard.

The portholes are so small as to admit of very slight lateral training, and of an elevation not to exceed from 5 degrees to 7 degrees.

4th. Owing to the extreme heat and foul air prevailing in the ship, but a slight examination could be made of the ammunition. It will be necessary to remove it before it can be safely overhauled. It is estimated, however, that the quantity will not vary far from 125 to 150 rounds. The powder is stowed in wooden tanks and consists of 8, 10, 12, 14, and 16 pound charges. There are two magazines, one forward and the other abaft.

We find on board various classes of projectiles for the guns--solid shot, shells with percussion and time fuzes, shells marked "Robbins' fluid shells" for 7-inch rifles, and a quantity of grape and canister for the 6.4-inch rifles. The following are the weights and lengths of the shot and shell:

Kind of projectile. 7-inch. 6.4-inch.
Length. Weight. Length. Weight.
Inches. Pounds. Inches. Pounds.
Shell 16 100 13½ 68
Wrought-iron shot:
Long 15¼ 133 12 94
Short 12 114
Case shot 14 123 10½ 76

The shot, shells, and small-arms ammunition are so scattered about the vessel, and some of those articles are in such insecure places that no exact report or even satisfactory examination of them can be made until they are collected and classified.

The same remark applies equally to small arms, locks, sights, gun implements, etc., which are scattered promiscuously about the vessel.

5th. For the reasons assigned in the preceding section of this report we would respectfully recommend that the ship be thoroughly broken out, and all stores in every department be collected where they can be examined and an accurate account be taken of them. At present any report upon them must necessarily be very imperfect and unsatisfactory.

6th. The ship requires thorough cleaning. At present she is in great disorder. It is impossible that anyone could remain below the battery deck for any length of time without serious inconvenience, if not danger, on account of the foul air prevailing there. The officers' apartments, as well as the berth deck, are very imperfectly ventilated, rendering them almost uninhabitable in hot weather; the heat upon the latter is almost insupportable, owing to the galley being placed there. Before employing this vessel in our own service we would strongly recommend that measures be taken to provide light and air below.

7th. The machinery generally is in good condition and requires but slight repairs to fit it for service. There are marks of four shot upon the hull. One XV-inch struck the side of the casemate on a line with the portholes; it broke the armor completely through, although its course was somewhat oblique; the wooden backing was much splintered and several bolts were drawn from their places. It has left a large hole entirely through the armor and backing, though the shot itself did not pass through.

Another shot struck the midship port shutter on the starboard side, breaking both layers of plates and indenting the armor beneath. The course of this shot was more oblique than that of the former.

A third shot struck the top of the pilot house, broke the heavy iron casting that framed it, and displaced several plates below it, breaking and indenting them.

A fourth shot struck the edge of the overhang about amidships on the starboard side; it broke and displaced several plates, but did not penetrate them. The direction of this shot was very oblique.

The smokestack has a hole through it, caused by a splinter from the port shutter.

All necessary repairs to the hull can be made in a few days, with but trifling expense.

8th. One feature in this vessel is particularly noticeable, and that is the roughness of all the work about her. No expense has been incurred for finish or ornament. The comfort of the crew and its sanitary condition appear to have been totally disregarded. Efficiency in battle seems to have been the sole point aimed at.

9th. The armor appears to have been made of English railroad iron, rolled into its present shape. In some of the fractures it has broken off almost as short as if it had been cast iron. The pine backing, it is probable, does not possess the best qualities for resistance, being very brittle, and in consequence dangerous to those inside of the casemate.

10th. As chronometers and other nautical instruments were found on board, there is reason to suppose that this vessel was intended for sea purposes.

11th. Drawings accompany this report, which will show the general appearance of the ship and some of her arrangements.

We are, sir, very respectfully, your obedient servants,

WM. RODGERS TAYLOR,
Captain, U. S. Navy.
C. R. P. RODGERS,
Commander.
ROBERT DANBY,
Fleet Engineer, U. S. Navy.
A. S. MACKENZIE,
Lieutenant, U. S. Navy.​

Rear-Admiral S. F. DU PONT,
Comdg. South Atlantic Blockading Squadron, Port Royal, S. C.

NOTE.--The backing of the armor is composed of three layers of wood. The outer one, of oak, runs vertically; the next, of pine, runs horizontally, and the third, also of pine, runs vertically.

 

[7th Mississippi Infantry]

No expense has been incurred for finish or ornament. The comfort of the crew and its sanitary condition appear to have been totally disregarded. Efficiency in battle seems to have been the sole point aimed at.

Interesting contrast to Ericsson insisting the Monitor have brass doorknobs and such

 

[Mark F. Jenkins]

There seems to be little in the ORNs directly about what was thought of the Atlanta in Federal service, apart from one place in a private letter from Admiral Lee to Assistant Secretary Fox, where Lee called her "a horrid thing to live in." She seemed to be regarded as serviceable; she was in active service from January 1864 through the end of the war, mostly in Hampton Roads and up the James River, where her 15-16' draft hampered her a bit. She shelled Confederate cavalry near Fort Powhatan on May 21, 1864, driving them off; this may have been the only time she fired her guns in anger for the Union.

Notes I took in my quick look-through:
____________________
It looks like the Atlanta was ready for service in the US Navy by January 1864. On Jan 18, she was ordered from Philadelphia to Hampton Roads under the command of Acting Volunteer Lt. Thomas J. Woodward. On January 29, Admiral Lee requests a monitor, as the Atlanta's draft (15-16') is too deep to pass Harrison's Bar below City Point. The Atlanta arrived at Hampton Roads on February 14.

In a private letter to Assistant Secretary Fox, Lee called the Atlanta "a horrid thing to live in."

Steam tugs guarded the Atlanta as well as other large Union Navy ships against possible torpedo attack.

Apparently the Atlanta could indeed pass Harrison's Bar, at least with assistance, as she is later reported above City Point.

She shelled Confederate cavalry operating near Fort Powhatan on the James River on May 21, driving them off.

On July 11, the Atlanta was ordered to Washington, arriving on July 14. She left again for the James River the following day.

On July 31st, she was reported repairing at Norfolk (and had been since July 18).

Woodward was still in command on 1 November. and 1 Jan, at Hampton Roads.

24 Jan she was ordered up James River in reaction to the appearance of the Confederate ironclads at Trent's Reach. She arrived above City Point on Jan 26, grounding briefly.

Remained in James River through the end of the war. Ordered to Norfolk May 29 1865. Woodward replaced by Lt. Cmdr. B. Wilson as of June 1.
___________________________________

 

[andy19k10]

It would be interesting to see what modifications were made to he befor she commisioned as USS Atlanta. Very good account!

 

[Mark F. Jenkins]

I believe she was re-armed with Parrott rifles; ORN II:1 p. 40 gives her armament as two 150-pounder rifles on pivots and two 100-pounder rifles in broadside. Other than that, I'm not certain. Most of the information about her in the books is from her stint in the Confederate Navy... even though it could be argued that she served in the Federal Navy for a longer time.

 

[rebelatsea]

Well, here's a start: ORN I:14, pp. 273-6, part of the survey conducted on Atlanta just after her capture.

U. S. S. WABASH,
Port Royal Harbor, June 22, 1863.​

SIR: In obedience to your order, dated 20th instant, we have held a strict and careful survey on the late Confederate ironclad steamer Atlanta, and have the honor to submit the following report:

1st. We find that this vessel was originally an iron merchant steamer called the Fingal. She has been cut down so as to leave the deck about 2 feet above the water with her present draft. A casemate rises from this deck sufficiently large to accommodate four guns, the sides and ends of which are inclined at an angle of about 29 degrees with the horizon. The top is flat, and the roof of the pilot house extends above it pyramidally to a height of about 3 feet. The deck overlaps the original iron hull 6 feet on each side, tapering toward the ends of the vessel and projecting beyond them. The sides are protected by timber running from a point several feet below the water line to the edge of the deck, forming a heavy, solid overhang of wood and armor.

The armor, 4 inches in thickness, is composed of two layers of 2-inch roller-iron plates 7 inches wide, the inner of which runs horizontally and the outer vertically. They are secured to a backing of oak 3 inches thick and of pine 15 inches thick, by bolts 1¼ inches in diameter, countersunk on the outside of the armor and drawn up on the inside of the vessel by nuts and washers. Wherever the bolts pass through a space is left between the horizontal plates, which is fitted in with oak plank to avoid the expense and trouble of drilling through more than one layer, as we suppose.

The bow terminates in an iron beak or ram, which forms a part of the stem. A wooden pole connected with an iron lever, capable of being lowered below the water and raised again at pleasure, projects beyond the ram and carries at its end a percussion torpedo.

There are three portholes on each side and one at each end. The bow and stern guns are pivoted so as to work at the end or at either of the nearest broadside portholes. The broadside guns are not opposite to each other. Each porthole is defended by an iron shutter, made in the same manner as the armor of the vessel, except that the two layers of plates are strongly riveted together. The shutters are hung upon a pivot in one of the upper corners, and may be raised by a chain from one of the lower corners, passing through the side and attached to a tackle on the inside of the vessel. When the tackle is let go the shutter will fall into its place by its own weight and close the porthole.

The dimensions are as follows: Extreme length, 204 feet; extreme breadth, 41 feet; draft of water, 15 feet 9 inches.

The battery deck is of great strength. It appears to be of solid timber 17 inches thick, resting on beams 10 inches thick.

2d. The machinery consists of two cylinders 39 inches in diameter and 30 inches stroke. The engines are vertical and direct acting, with a surface condenser. There is one flue-tubular boiler, having four furnaces, two at each end of the boiler. There are also one auxiliary boiler, three steam pumps, a blowing engine and pans. The engines were built by James and George Thomas, of Glasgow, in 1861.

3d. The armament is composed of two 7-inch and two 6.4-inch rifled guns of the Brooke pattern, and they all bear the marks-of the Tredegar foundry.

The rifling consists of seven grooves, each of which is formed by a curved cut starting from the bore, running below it to a depth of about 0.10 inch and then returning to-the bore upon an increased curve. The next groove commences where the last terminates.

The following are some of the principal dimensions:

7-inch. 6.4-inch.
Extreme length inches 147.00 142.00
Length from base ring to muzzle do. 124.25 121.00
Length from base ring to end of cascabel do. 22.75 21.00
Diameter of cylinder do. 31.30 24.65
Diameter at rim bases do. 31.40 24.75
Diameter at muzzle do. 14.15 10.79
Thickness of wrought-iron sleeve do. 2.00 2.00
Length of wrought-iron sleeve do. 30.25 30.00
Weight of wrought-iron sleeve pounds 15,300 9,200

The chambers of the guns are conical. The guns are not turned. Their exteriors are in the condition in which they left the mold. There is no chipping about the rim bases, but the metal runs from their faces in a curve to the proper diameter on the vertical plane between them.

The elevating screws are similar to those in use on board our own ships.

The breech sights are described on the ordnance invoice as of the Brooke pattern. The bar slides through the box with an angle in front. The graduation is in yards on one side and in degrees on the other.

The locks correspond nearly with those in use on the modern navy guns.

The 7-inch guns are mounted on pivot carriages, resembling our own very nearly. They traverse on iron circles.

The 6.4-inch guns are mounted on Marsilly carriages, differing in some trifling particulars from our own standard.

The portholes are so small as to admit of very slight lateral training, and of an elevation not to exceed from 5 degrees to 7 degrees.

4th. Owing to the extreme heat and foul air prevailing in the ship, but a slight examination could be made of the ammunition. It will be necessary to remove it before it can be safely overhauled. It is estimated, however, that the quantity will not vary far from 125 to 150 rounds. The powder is stowed in wooden tanks and consists of 8, 10, 12, 14, and 16 pound charges. There are two magazines, one forward and the other abaft.

We find on board various classes of projectiles for the guns--solid shot, shells with percussion and time fuzes, shells marked "Robbins' fluid shells" for 7-inch rifles, and a quantity of grape and canister for the 6.4-inch rifles. The following are the weights and lengths of the shot and shell:

Kind of projectile. 7-inch. 6.4-inch.
Length. Weight. Length. Weight.
Inches. Pounds. Inches. Pounds.
Shell 16 100 13½ 68
Wrought-iron shot:
Long 15¼ 133 12 94
Short 12 114
Case shot 14 123 10½ 76

The shot, shells, and small-arms ammunition are so scattered about the vessel, and some of those articles are in such insecure places that no exact report or even satisfactory examination of them can be made until they are collected and classified.

The same remark applies equally to small arms, locks, sights, gun implements, etc., which are scattered promiscuously about the vessel.

5th. For the reasons assigned in the preceding section of this report we would respectfully recommend that the ship be thoroughly broken out, and all stores in every department be collected where they can be examined and an accurate account be taken of them. At present any report upon them must necessarily be very imperfect and unsatisfactory.

6th. The ship requires thorough cleaning. At present she is in great disorder. It is impossible that anyone could remain below the battery deck for any length of time without serious inconvenience, if not danger, on account of the foul air prevailing there. The officers' apartments, as well as the berth deck, are very imperfectly ventilated, rendering them almost uninhabitable in hot weather; the heat upon the latter is almost insupportable, owing to the galley being placed there. Before employing this vessel in our own service we would strongly recommend that measures be taken to provide light and air below.

7th. The machinery generally is in good condition and requires but slight repairs to fit it for service. There are marks of four shot upon the hull. One XV-inch struck the side of the casemate on a line with the portholes; it broke the armor completely through, although its course was somewhat oblique; the wooden backing was much splintered and several bolts were drawn from their places. It has left a large hole entirely through the armor and backing, though the shot itself did not pass through.

Another shot struck the midship port shutter on the starboard side, breaking both layers of plates and indenting the armor beneath. The course of this shot was more oblique than that of the former.

A third shot struck the top of the pilot house, broke the heavy iron casting that framed it, and displaced several plates below it, breaking and indenting them.

A fourth shot struck the edge of the overhang about amidships on the starboard side; it broke and displaced several plates, but did not penetrate them. The direction of this shot was very oblique.

The smokestack has a hole through it, caused by a splinter from the port shutter.

All necessary repairs to the hull can be made in a few days, with but trifling expense.

8th. One feature in this vessel is particularly noticeable, and that is the roughness of all the work about her. No expense has been incurred for finish or ornament. The comfort of the crew and its sanitary condition appear to have been totally disregarded. Efficiency in battle seems to have been the sole point aimed at.

9th. The armor appears to have been made of English railroad iron, rolled into its present shape. In some of the fractures it has broken off almost as short as if it had been cast iron. The pine backing, it is probable, does not possess the best qualities for resistance, being very brittle, and in consequence dangerous to those inside of the casemate.

10th. As chronometers and other nautical instruments were found on board, there is reason to suppose that this vessel was intended for sea purposes.

11th. Drawings accompany this report, which will show the general appearance of the ship and some of her arrangements.

We are, sir, very respectfully, your obedient servants,

WM. RODGERS TAYLOR,
Captain, U. S. Navy.
C. R. P. RODGERS,
Commander.
ROBERT DANBY,
Fleet Engineer, U. S. Navy.
A. S. MACKENZIE,
Lieutenant, U. S. Navy.​

Rear-Admiral S. F. DU PONT,
Comdg. South Atlantic Blockading Squadron, Port Royal, S. C.

NOTE.--The backing of the armor is composed of three layers of wood. The outer one, of oak, runs vertically; the next, of pine, runs horizontally, and the third, also of pine, runs vertically.

Well, here's a start: ORN I:14, pp. 273-6, part of the survey conducted on Atlanta just after her capture.

U. S. S. WABASH,
Port Royal Harbor, June 22, 1863.​

SIR: In obedience to your order, dated 20th instant, we have held a strict and careful survey on the late Confederate ironclad steamer Atlanta, and have the honor to submit the following report:

1st. We find that this vessel was originally an iron merchant steamer called the Fingal. She has been cut down so as to leave the deck about 2 feet above the water with her present draft. A casemate rises from this deck sufficiently large to accommodate four guns, the sides and ends of which are inclined at an angle of about 29 degrees with the horizon. The top is flat, and the roof of the pilot house extends above it pyramidally to a height of about 3 feet. The deck overlaps the original iron hull 6 feet on each side, tapering toward the ends of the vessel and projecting beyond them. The sides are protected by timber running from a point several feet below the water line to the edge of the deck, forming a heavy, solid overhang of wood and armor.

The armor, 4 inches in thickness, is composed of two layers of 2-inch roller-iron plates 7 inches wide, the inner of which runs horizontally and the outer vertically. They are secured to a backing of oak 3 inches thick and of pine 15 inches thick, by bolts 1¼ inches in diameter, countersunk on the outside of the armor and drawn up on the inside of the vessel by nuts and washers. Wherever the bolts pass through a space is left between the horizontal plates, which is fitted in with oak plank to avoid the expense and trouble of drilling through more than one layer, as we suppose.

The bow terminates in an iron beak or ram, which forms a part of the stem. A wooden pole connected with an iron lever, capable of being lowered below the water and raised again at pleasure, projects beyond the ram and carries at its end a percussion torpedo.

There are three portholes on each side and one at each end. The bow and stern guns are pivoted so as to work at the end or at either of the nearest broadside portholes. The broadside guns are not opposite to each other. Each porthole is defended by an iron shutter, made in the same manner as the armor of the vessel, except that the two layers of plates are strongly riveted together. The shutters are hung upon a pivot in one of the upper corners, and may be raised by a chain from one of the lower corners, passing through the side and attached to a tackle on the inside of the vessel. When the tackle is let go the shutter will fall into its place by its own weight and close the porthole.

The dimensions are as follows: Extreme length, 204 feet; extreme breadth, 41 feet; draft of water, 15 feet 9 inches.

The battery deck is of great strength. It appears to be of solid timber 17 inches thick, resting on beams 10 inches thick.

2d. The machinery consists of two cylinders 39 inches in diameter and 30 inches stroke. The engines are vertical and direct acting, with a surface condenser. There is one flue-tubular boiler, having four furnaces, two at each end of the boiler. There are also one auxiliary boiler, three steam pumps, a blowing engine and pans. The engines were built by James and George Thomas, of Glasgow, in 1861.

3d. The armament is composed of two 7-inch and two 6.4-inch rifled guns of the Brooke pattern, and they all bear the marks-of the Tredegar foundry.

The rifling consists of seven grooves, each of which is formed by a curved cut starting from the bore, running below it to a depth of about 0.10 inch and then returning to-the bore upon an increased curve. The next groove commences where the last terminates.

The following are some of the principal dimensions:

7-inch. 6.4-inch.
Extreme length inches 147.00 142.00
Length from base ring to muzzle do. 124.25 121.00
Length from base ring to end of cascabel do. 22.75 21.00
Diameter of cylinder do. 31.30 24.65
Diameter at rim bases do. 31.40 24.75
Diameter at muzzle do. 14.15 10.79
Thickness of wrought-iron sleeve do. 2.00 2.00
Length of wrought-iron sleeve do. 30.25 30.00
Weight of wrought-iron sleeve pounds 15,300 9,200

The chambers of the guns are conical. The guns are not turned. Their exteriors are in the condition in which they left the mold. There is no chipping about the rim bases, but the metal runs from their faces in a curve to the proper diameter on the vertical plane between them.

The elevating screws are similar to those in use on board our own ships.

The breech sights are described on the ordnance invoice as of the Brooke pattern. The bar slides through the box with an angle in front. The graduation is in yards on one side and in degrees on the other.

The locks correspond nearly with those in use on the modern navy guns.

The 7-inch guns are mounted on pivot carriages, resembling our own very nearly. They traverse on iron circles.

The 6.4-inch guns are mounted on Marsilly carriages, differing in some trifling particulars from our own standard.

The portholes are so small as to admit of very slight lateral training, and of an elevation not to exceed from 5 degrees to 7 degrees.

4th. Owing to the extreme heat and foul air prevailing in the ship, but a slight examination could be made of the ammunition. It will be necessary to remove it before it can be safely overhauled. It is estimated, however, that the quantity will not vary far from 125 to 150 rounds. The powder is stowed in wooden tanks and consists of 8, 10, 12, 14, and 16 pound charges. There are two magazines, one forward and the other abaft.

We find on board various classes of projectiles for the guns--solid shot, shells with percussion and time fuzes, shells marked "Robbins' fluid shells" for 7-inch rifles, and a quantity of grape and canister for the 6.4-inch rifles. The following are the weights and lengths of the shot and shell:

Kind of projectile. 7-inch. 6.4-inch.
Length. Weight. Length. Weight.
Inches. Pounds. Inches. Pounds.
Shell 16 100 13½ 68
Wrought-iron shot:
Long 15¼ 133 12 94
Short 12 114
Case shot 14 123 10½ 76

The shot, shells, and small-arms ammunition are so scattered about the vessel, and some of those articles are in such insecure places that no exact report or even satisfactory examination of them can be made until they are collected and classified.

The same remark applies equally to small arms, locks, sights, gun implements, etc., which are scattered promiscuously about the vessel.

5th. For the reasons assigned in the preceding section of this report we would respectfully recommend that the ship be thoroughly broken out, and all stores in every department be collected where they can be examined and an accurate account be taken of them. At present any report upon them must necessarily be very imperfect and unsatisfactory.

6th. The ship requires thorough cleaning. At present she is in great disorder. It is impossible that anyone could remain below the battery deck for any length of time without serious inconvenience, if not danger, on account of the foul air prevailing there. The officers' apartments, as well as the berth deck, are very imperfectly ventilated, rendering them almost uninhabitable in hot weather; the heat upon the latter is almost insupportable, owing to the galley being placed there. Before employing this vessel in our own service we would strongly recommend that measures be taken to provide light and air below.

7th. The machinery generally is in good condition and requires but slight repairs to fit it for service. There are marks of four shot upon the hull. One XV-inch struck the side of the casemate on a line with the portholes; it broke the armor completely through, although its course was somewhat oblique; the wooden backing was much splintered and several bolts were drawn from their places. It has left a large hole entirely through the armor and backing, though the shot itself did not pass through.

Another shot struck the midship port shutter on the starboard side, breaking both layers of plates and indenting the armor beneath. The course of this shot was more oblique than that of the former.

A third shot struck the top of the pilot house, broke the heavy iron casting that framed it, and displaced several plates below it, breaking and indenting them.

A fourth shot struck the edge of the overhang about amidships on the starboard side; it broke and displaced several plates, but did not penetrate them. The direction of this shot was very oblique.

The smokestack has a hole through it, caused by a splinter from the port shutter.

All necessary repairs to the hull can be made in a few days, with but trifling expense.

8th. One feature in this vessel is particularly noticeable, and that is the roughness of all the work about her. No expense has been incurred for finish or ornament. The comfort of the crew and its sanitary condition appear to have been totally disregarded. Efficiency in battle seems to have been the sole point aimed at.

9th. The armor appears to have been made of English railroad iron, rolled into its present shape. In some of the fractures it has broken off almost as short as if it had been cast iron. The pine backing, it is probable, does not possess the best qualities for resistance, being very brittle, and in consequence dangerous to those inside of the casemate.

10th. As chronometers and other nautical instruments were found on board, there is reason to suppose that this vessel was intended for sea purposes.

11th. Drawings accompany this report, which will show the general appearance of the ship and some of her arrangements.

We are, sir, very respectfully, your obedient servants,

WM. RODGERS TAYLOR,
Captain, U. S. Navy.
C. R. P. RODGERS,
Commander.
ROBERT DANBY,
Fleet Engineer, U. S. Navy.
A. S. MACKENZIE,
Lieutenant, U. S. Navy.​

Rear-Admiral S. F. DU PONT,
Comdg. South Atlantic Blockading Squadron, Port Royal, S. C.

NOTE.--The backing of the armor is composed of three layers of wood. The outer one, of oak, runs vertically; the next, of pine, runs horizontally, and the third, also of pine, runs vertically.

Had Atlanta not run aground ,I think she could have run past the two monitors. This is where the problem of slow firing guns when aimed at a moving target would become apparent. In this engagement as with the action at Mobile Bay and at Trents Reach, the CS ironclads were stationary or almost so and the range ridiculously close. English solid plate would not have stood up to the 15" at effectively point blank.

 

[rebelatsea]

Were her sponsons actually ironed? If so 2 inch?

George, 1 layer of plate extended some 4ft below the waterline, according to the drawings made in Philadelphia Navy Yard.

 

[andy19k10]

Had Atlanta not run aground ,I think she could have run past the two monitors. This is where the problem of slow firing guns when aimed at a moving target would become apparent. In this engagement as with the action at Mobile Bay and at Trents Reach, the CS ironclads were stationary or almost so and the range ridiculously close. English solid plate would not have stood up to the 15" at effectively point blank.

I completely agree! Southern armor plate was (probably) of very poor quality and laminate in nature. I understand the thickest that could be rolled was 2 inch thicknesses? I'm not sure if other Union ships had the same type, but the Monitor's turret was made up of 1 inch layers (eight in all) which was much lesss effective than one solid sheet.
BTW would anyone happen to know the thickness of armor plate the North and GB were capable of rolling at the time?

 

[andy19k10]

I would hope that befor she was commisioned into the US Navy something would have been done to improve Atlanta's ventilation..........

 

[Mark F. Jenkins]

Had Atlanta not run aground ,I think she could have run past the two monitors. This is where the problem of slow firing guns when aimed at a moving target would become apparent. In this engagement as with the action at Mobile Bay and at Trents Reach, the CS ironclads were stationary or almost so and the range ridiculously close. English solid plate would not have stood up to the 15" at effectively point blank.

Problem is, Webb was not planning to "run past" the monitors; he was planning to engage them.

 

[gary]

Don't know about how thick

BTW would anyone happen to know the thickness of armor plate the North and GB were capable of rolling at the time?

Darn good question. That should be posted at the International Naval Research Organization's membership or even SteelNavy.com

I do remember reading about the T-34 tank and how the Russians found that sloping armor at 30 degrees makes it the equivalent of being 200% thicker. So, 2" at 30 degrees would be like 4".

 

[rebelatsea]

I completely agree! Southern armor plate was (probably) of very poor quality and laminate in nature. I understand the thickest that could be rolled was 2 inch thicknesses? I'm not sure if other Union ships had the same type, but the Monitor's turret was made up of 1 inch layers (eight in all) which was much lesss effective than one solid sheet.
BTW would anyone happen to know the thickness of armor plate the North and GB were capable of rolling at the time?

WE could roll 6" by 1863, the problem was designing ships to carry it !
The quality of CS 2" plate was very variable, Tredegar and Schofield and Markham could and roll quality armour, If they could have rolled it in plates rather than strips it would have much better. Selma was experimenting with 4 and 5 inch plate in 1864.
The union appeared satisfied with 1" rolled plate, but it was comparitively brittle unless used in great thickness. New Ironsides had I think 4" solid plate, but what it's resistance was I don't know.
The other major factor of course is adequate support and backing, to increase the protective resilience.

 

[rebelatsea]

Problem is, Webb was not planning to "run past" the monitors; he was planning to engage them.

Yes he was, I think he was hoping to get one with the spar and ram the other ! I bit contrary to his instruction to get his ship to sea, but then Webb was a bit of a glory hunter, and had he succeeded in sinking the monitors and getting to sea, he would certainly have achieved that !

 

[Mark F. Jenkins]

Webb's communication to Mallory just before the battle indicates otherwise. From ORN I:14, p. 287:

C.S.S. ATLANTA,
Wassaw River, [Ga.,] June 15, 1863​

SIR: I learned yesterday that two ironclads are inside of Wassaw Sound and are still there. I will leave to-morrow morning to attack them, but do not intend to take the vessel outside.

After I make this attack I shall return to the obstructions below Thunderbolt and wait for the cooperation of the Savannah to carry out my views in accordance with your suggestions, expressed in my letter to you of the 10th instant.

I have the honor to be, very respectfully, your obedient servant,

W. A. WEBB,
Commanding Naval Squadron.​

HON. S. R. MALLORY,
Secretary of the Navy, Richmond, Va.