Post War Mound City, Illinois: Union Monitors Laid Up

Joined
May 12, 2018
neoshofrontshot_opt.jpg

Hopefully this picture works. The caption may be hard to read and omits some details, so here's my analysis, going right to left, foreground to background:

Mound City, Ill., USN Reserve Fleet ca 1868:

Right Row:
USS. Neosho (Osage class)
USS. Marietta (Marietta class)
USS. Sandusky (Marietta class)

Left Row:
USS. Yuma (Casco II class)
USS. Shiloh (Casco II class)
USS. Klamath (Casco II class)
USS. Etlah (Casco II class)
USS. Umpqua (Casco II class)

USS. Yuma & Shiloh appear to be moored outboard of the USS. Neosho, the Klamath & what I presume to be Etlah are moored along side what I think is the USS. Marietta, while the what should be the USS. Umpqua is moored to the USS. Sandusky. I based my ordering on the visible named ships (Neosho, Yuma, Kalmath), the captions claims (Shiloh), and then assumed the remaining ships were added to the row based on when they completed (Etlah, Umpaqua, Marietta, and Sandusky). That to me is logical, although of course there is no way to know from the photo and so often logical means wrong in these sorts of endeavors.

I also called the Casco's "Casco II" as they represent the result of Ericsson fixing the design and were completed as monitors , rather than those completed as torpedo boats. If you count the original design, the as completed unseaworthy, and the torpedo boat and monitor refits I suppose you could say it's actually "Casco IV" or "Casco III". AFAIK I'm the only one who cares to differentiate but honestly one could argue the two in service variants were entirely separate classes altogether.

If you don't know, the class was built incorrectly after one of Ericssons rivals in the Monitor Board got a hold of them, decided to add more armor and ballast tanks to them and didn't do the math meaning they were in sea worthy, and it was a major scandal. Fortunately the war ended before any of the flawed ships saw much action.

This apparently is the only photo of the Marietta class ships (the twin stacked monitors in the background), and we might be able to glean some details from it. For one, although the navy excepted them they were never commissioned, and so I think we can assume them to be in "as built" states. So they definitely look a bit like the USS. Ozark as everybody likes to say, but I do see key differences. The taller cone roofs atop the turrets whilst in ordinary to me suggests that they might have pilot houses atop their turrets... but I see some super structure on the Sandusky that might be a Pilothouse behind the turret too? The turrets are definitely farther forward than the Ozark's was, it seems the designers intended to balance the engines and the turret weight against one another as in the Canonnicus class of coastal monitors. Allegedly these ships were going to have a pre-refit USS Monitor style pyramid pilot house forward of the turret but if so that idea in my mind likely didn't leave the paper as these ships seem to have more influence from later classes of monitors in regards to superstructure. They seem to have a lot less superstructure than the Ozark, too, with only a small cabin aft of the twin smokestacks. Possibly they had a canopy that would cover the deck up to the turret as in the Neosho.

Bet you'd never guess Battleship Row would be in a river in Illinois, eh?
 
Excellent detective work! Obviously this is a labor love for you and so informative for me and many others.
Regards
David
 
Depended on the ship, and also ones definition of seaworthiness! The designers of Monitors were well aware of the trade offs in seaworthiness they were making by using the low freeboard design, but were willing to make the trade to reduce the amount of the ship that needed armoring and also be able to support the very heavy turrets.

Seaworthiness got better as designs improved and by the end of the war there were a few truly ocean going monitors as well as many coastal and a few river ones. Neosho & her gaggle above were river boats.

The level of seaworthiness varied greatly between class, and also what seas the ships contended with. Even ocean going monitors tended to be towed, mainly to save wear on the then not 100% reliable engines and also saved on coal consumption. Although going out to sea on a later monitor designed for the task was certainly feasible, it wasn’t very comfortable for crews. It was often a fight to keep monitors from shipping water in after waves broke across their decks, and things were pretty miserable to be aboard at times of rough weather.

In terms of the Casco class... well as first launched they had major problems with not sinking right off the bat due to bad math which was eventually fixed by having their decks raised by 2ft which by Monitor standards is just madness! Even then they weren’t very good, and I’d almost blame them for causing a lot of the post war navy’s issues as their existence on paper kind of distorts the size & power of the Navy on top of not being very good ships.
 
The Casco class were designed by Alban C. Stimers originally with a "turtleback" deck. Design changes are usually blamed for the failures of the ships. Legend has it that he was assigned to one, and was shortly afterwards found with hammer and chisel trying to remove his name from the ships plaque !
 
Depended on the ship, and also ones definition of seaworthiness!
I'd actually say it would be a very unusual monitor that could fight at sea. There were a few that could traverse the sea without too much danger, but for a monitor to be able to fight it needs the turret to be in one of two states:

1) Turret locked and aligned with the ammunition passage in the turret floor matching the one in the hull roof, which IIRC means the turret points straight ahead.
2) Turret jacked up and able to rotate into ammunition passage position when needed.

In the second case then there is a path for shipping large amounts of water, because the turret is jacked up, and no monitor could endure that for any length of time unless the sea was particularly calm.

That leaves the first case, which means giving up many of the advantages of a monitor in the first place. Any pitching up and down is going to ruin your accuracy, and it's the long axis of the ship moving which you need to worry about not the short (as with a broadside) so the waves will impact performance much more than with a broadside-firing vessel.
 
I've always been amazed anyone designed one that could float at all. That's a crazy amount of metal. No matter how many times it's been explained I still find it astonishing.
Well, it's always a matter of bouyancy. The reason monitors were so difficult is because they wanted as small an amount of reserve bouyancy as possible to keep them right down near the level of the water, which is what led to the Casco debacle as even a quite small maths error ruined them. A comparable maths error on a regular warship of similar size would have been barely noticed.


One thing I've sometimes found interesting is to consider whether the "Monitor" design was even a good idea on the face of it. As far as I can tell it's a better solution if your limiting factors involve gun numbers (or power) and armour-quality iron, but not if your limiting factors involve engines and you want each individual combatant to be quite capable.

As best I can determine the 1850s broadside ironclads of the Crimean War and their 1856 derivatives would have been superior in a one-on-one fight to a Monitor or a Passaic, because the better quality armour on the Aetnas and Erebuses gave them much the same protective power and the high velocity 68 pounders gave them a similar anti-armour punch. It's an open question whether the US could actually have built an Aetna though because they had trouble with producing thick single plate wrought iron armour, and the Monitor could be seen as an attempt to produce a good ironclad that can successfully fight despite using the much heavier "laminate" armour for the same protective qualities.*


* The USN did have a high velocity 64 pounder gun, but didn't identify it as a good anti-armour gun.
 
Well, it's always a matter of bouyancy. The reason monitors were so difficult is because they wanted as small an amount of reserve bouyancy as possible to keep them right down near the level of the water, which is what led to the Casco debacle as even a quite small maths error ruined them. A comparable maths error on a regular warship of similar size would have been barely noticed.


It's this. Fortunately I lack the math skills to be anything but amazed- following engineers around this war always flattens me anyway. I don't know. For some reason there seems to be an idea how kinda backwards and primitive things were 150 years ago. Especially for non-engineers ( that'd be me ), things like who on earth figured out how much metal could float has created what amounts to hero worship. I've never been a big fan of magic shows. It's very nice, but conjuring up miracles like floating hunks of metal is what gets me.

Curious- were monitors a good idea?
 
Well, it's always a matter of bouyancy. The reason monitors were so difficult is because they wanted as small an amount of reserve bouyancy as possible to keep them right down near the level of the water, which is what led to the Casco debacle as even a quite small maths error ruined them. A comparable maths error on a regular warship of similar size would have been barely noticed.


One thing I've sometimes found interesting is to consider whether the "Monitor" design was even a good idea on the face of it. As far as I can tell it's a better solution if your limiting factors involve gun numbers (or power) and armour-quality iron, but not if your limiting factors involve engines and you want each individual combatant to be quite capable.

As best I can determine the 1850s broadside ironclads of the Crimean War and their 1856 derivatives would have been superior in a one-on-one fight to a Monitor or a Passaic, because the better quality armour on the Aetnas and Erebuses gave them much the same protective power and the high velocity 68 pounders gave them a similar anti-armour punch. It's an open question whether the US could actually have built an Aetna though because they had trouble with producing thick single plate wrought iron armour, and the Monitor could be seen as an attempt to produce a good ironclad that can successfully fight despite using the much heavier "laminate" armour for the same protective qualities.*


* The USN did have a high velocity 64 pounder gun, but didn't identify it as a good anti-armour gun.
I have always thought the Keokuk design with proper armour ( which means a bigger vessel as her captain suggested should be constructed) would have been a better option.
The CSN was too hung up on Brooke's system and the USN on Dahlgrens bottles to pay heed to the fact they already had the 64pdr, little inferior to the 68pdr 95cwt as an anti armour weapon. It would have sufficed for at least two years if not longer, while more powerful weapons were developed.
 
It's this. Fortunately I lack the math skills to be anything but amazed- following engineers around this war always flattens me anyway. I don't know. For some reason there seems to be an idea how kinda backwards and primitive things were 150 years ago. Especially for non-engineers ( that'd be me ), things like who on earth figured out how much metal could float has created what amounts to hero worship. I've never been a big fan of magic shows. It's very nice, but conjuring up miracles like floating hunks of metal is what gets me.
Well, they'd had wooden ships for thousands of years, and it just requires realizing there's nothing special about wood - which was a realization that had to be made for anything more developed than a dugout canoe.
It's literally just "a ship sinks into the water until it's displaced an amount of water equal to the weight of the ship".

Curious- were monitors a good idea?
They were probably a good solution to the manufacturing constraints the Union faced, but absent those constraints Civil War monitors were not a good idea. They also missed several features that would have made them notably better for small weight penalty and had some serious design compromises.

Still, Some Ironclad is better than No Ironclad. But I beg leave to doubt that a monitor could actually have beaten a balanced squadron of, say, 1x 51-gun frigate and 3x gunboats.
 
I have always thought the Keokuk design with proper armour ( which means a bigger vessel as her captain suggested should be constructed) would have been a better option.
"Proper armour" - aye, there's the rub! I wouldn't want to see how big Keokuk would need to get to be properly armoured with multiple 1" laminate...
 
I also called the Casco's "Casco II" as they represent the result of Ericsson fixing the design and were completed as monitors , rather than those completed as torpedo boats.

I was not aware of that. I see these were the ones built on the rivers; were they the extent of the Casco IIs? Were they basically Ericsson's original design? Able to carry the intended armament and armor? Thanks.
 
I was not aware of that. I see these were the ones built on the rivers; were they the extent of the Casco IIs? Were they basically Ericsson's original design? Able to carry the intended armament and armor? Thanks.
My understanding is that the Casco design was so altered (by Stimer IIRC?) that Ericsson refused to sign off on them. The two key changes though were:

1) The weight calculations were for seasoned wood, but green wood was used instead because seasoned wood could not be had. This impacted the bouyancy.
2) The one-inch iron plates used in the calculations were "40 lb plate" (i.e. 40 lb per square foot) which was a standard boiler plate thickness, 15/16 of an inch instead of one inch. However the "whole inch" was demanded because someone (Stimer?) thought that the 15/16 inch plates were cheating the government out of some of the iron they'd paid for with their "one inch plates". The result was that the armour weighed 1/15 more than it should, so about a 6.7% increase.

Neither would have mattered much on a ship that wasn't deliberately built to be as low to the water as possible. Both together meant the Casco's calculated freeboard once stored and turret fitted was negative.

A few of them were caught early enough that they could be altered to increase draft, but the rest just had the turret removed and were turned into The World's Worst Torpedo Boats.
 
It's actually worth considering the other properties of the Monitors, because they're often misrepresented. In this case I'll be using three ships to compare them to - the Warrior, the Aetna (i.e. a typical 1850s coastal ironclad) and a generic wooden heavy frigate.


I'll be considering draft, turning circle, speed, cost and rate of fire.


Draft.

The Warrior was very deep, with a draft of about 27 feet, and this made her a seagoing warship only. She was incapable of littoral operations but could of course get involved in action anywhere with deep water (such as the main channel of Hampton Roads, in fact).
The draft of the Aetna was very shallow, about six feet (though her sisters went as deep as 8.5). She could conduct littoral operations.
A typical wooden heavy frigate would have a draft between 18 and 22 feet.
The Monitor's draft was 10.5 feet, and so she's not as good for littoral operations as the Aetna.

Turning circle.

The turning circle of the Warrior was measured at full speed at about 700 yards (in deep water), and would be less at a lower speed.
Most wooden frigates were 350-400 yards at full speed.
The Monitor herself was never measured, but the Passaics were ca. 350 yards and the Canonicuses were ca. 300. Hydro modelling suggests the Monitor would be ca. 500 yards in shallow water and ca. 350 in deep.
I have no data for the Aetnas.

Speed.

The Warrior was very fast, 14 knots under steam alone and could be faster with sail.
The Aetnas were very slow, ca. 4 knots under power for Aetna herself and her sisters went up to 5.5.
A typical heavy frigate would be ca. 11-12 and some went up to 14.
The monitors were generally 5-6 knots, though a few of the late war ones eased up to nine. The Cascos actually completed as monitors hit about four.
(This affects the turning time, much like the turning circle does. So oddly enough Warrior could do a full circle in less time than Monitor, because her circle is twice as big and she gets around it about three times quicker.)

Cost (using period conversion rates of £1 = $5.)

The Warrior was very expensive and cost £377,292 (about $1.9 million).
The Aetnas were very cheap, with a cost for all five of less than £300,000 (so each one was about $300,000).
The Shannon (a typical heavy frigate) cost £127,000 (so about $635,000)
The Monitor was $275,000, and the costs of later monitors rose quickly; the Passaic was $400,000 and the Cascos were estimated at $395,000 (but there were cost overruns and I've seen a figure of "half a million dollars apiece").


Rate of fire.

The Monitor herself fired at ca. one round every 7-8 minutes per gun (41 rounds fired in 3 hours 20 minutes from two guns, including a 20 minute pause to resupply the turret) and later monitors fired less often because the 15" guns took much longer to reload - the turret needed to be locked in the ammunition resupply position while it was done.
As for the British ships used in comparison, a rate of fire of greater than one round per minute was possible for many of them but I'll simply use the number for the 7"-8" guns of various types as this is the slowest (at one round per minute).
Based on this metric the scale of broadside fire rate is:
Monitor: 0.3 rounds per minute (2 guns, ROF 7-8 minutes per)
Aetna 8 rounds per minute (8 guns on broadside, ROF 1 per minute)
Warrior 20 rounds per minute (20 guns on broadside)
Typical heavy frigate 26 rounds per minute (but actually higher because of lighter guns).


The interesting thing to contemplate about some of these is how little information there was in the US about them, in particular the cost. Ericsson thought that the Warrior cost "three and a half millions", about double the true value, and may not have been aware of (or mentioned) the low cost of the Aetnas.
 
So barely any larger? Colour me surprised - I was picturing trying to fit on 8" or so of laminate iron for the same protective value as a Monitor turret...
Koekuk: 159ft 6ins x 36ft x 8ft 6ins, 697tons
Columbia: 216ft x 48ft x 14ft, 2.074 tons.
are you thinking of 8" overall or just over the gunhouses?
 
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