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Gerhard,

This is a pretty good photo of the light 12 pdr except the wheels are the heavier field version. The attached (carriage only) photo has the correct lightweight wheels. "12 Pdr Boat Howitzer Carriage Model(1).bmp.

 

johnhoward

 

12 pdr Boat Howitzer(2).bmp58e67ecfaa67b_12pdrLightBoatHowitzerCarriage(3).thumb.jpg.fde9afc1b12d179dc46744f4944b11fe.jpg12 pdr Boat Howitzer(2).bmp

12 pdr Boat Howitzer Carriage Model(1).bmp

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Johnhoward, Thank you again!

Seems to be this one I found in the meantime by searching at google https://markerhunter.wordpress.com/2011/01/17/dahlgren-12-pdr-small-bh/

As there is a listing of the different measures I will be able to build it correct for the Cairo. Carriage and wheels will be made from brass, the barrel 3D Printed or turned from brass.

Great hint!

 

Regards

Gerhard

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Hi Gerald

 

By watching the photo I posted on the previous page, I`m sure that the CAIRO 12 pounder had the Naval Field Carriage. Thank you for bringing a bit more of clearness to this part of the ship, most useful pictures! All necessary measures can be measured otu from the pics for a good model, so I can start with the smallest Cairo gun too.

 

Best regards

Gerhard

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Gehrhard,

You may want to consider these photos before committing to a field carriage for your 12 pdr. Early in the Civil War the lightweight version like these were used on ships primarily to minimize handling weight. Later they decided the weight savings wasn't so important. We also concluded that it is a 12-pdr lightweight in the Cairo mural photo but couldn't detect much of a wheel rim.

 

By the way, the hurricane deck camber is pretty obvious in the bow casement.

 

johnhoward

12 pdr Boat Howitzer on USS Lehigh.jpg

Boat Howitzer with Farragut.jpg

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Johnhoward

 

When I compare that pics to the photo from the Vicksburg museum entrance, I`m not sure what carriage they used for the 12 pounder. Could be possible too that there was a wodden carriage similar to the sledgelike boat carriage in your post above. Does anyone live near Vicksburg who could take a close look (and photo) from that entrance poster?

Sad that it`s  such a long way from Vienna/Austria/Europe to the museum:default_wallbash:

 

Regards

Gerhard

 

 

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Gerhard,

We live in Missouri which is not, too far from Vicksburg, Mississippi and had been planning a trip there to check out other technical details. We were coordinating with the Cairo Museum curator, Elizabeth Joiner, for assistance getting better access to remains than the pure tourists can get. (They need to protect the Cairo remaining fabric from souvenir hunters) However, Mrs. Joiner is no longer the curator and a replacement or technical contact hasn't been identified so any trip has been delayed indefinitely. Bob Hill and 10 members of the Tampa Bay Ship Modelers visited Vicksburg a few years ago and took a lot of photos which were very helpful but I don't recall any of the mural.

One other factor which leads us to favor the lighter carriage is that the original armament originally allocated to these ironclads while under US Army control was a "mixed bag"of the discarded and obsolete ordnance that nobody really wanted. Inter-service rivalry was alive and well. The Cairo was technically under the command of Gen. George McClellan who was stationed nearly 1000 miles away in Virginia and probably never even cared about its operation. The  Navy field carriage usually included ammo boxes and would be more practical for a land assault by Marines which are part of the US Navy. The lightweight carriage could be easily broken down for  storage aboard ship where space is at a premium and would be easier to handle on the cambered Hurricane deck. I suspect that the carriage recovered with the Cairo was actually still in its crate

I can imagine that both carriage versions were in use on some of the seven "City Class" ironclads and we don't really have any specific information on which was on our "USS St. Louis", but the lighter version looks more interesting.

 

johnhoward

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Hi johnhoward

So I could go with the carriage from post #151 exept the lighter wheels. Measures are good to see in the markerhunters article https://markerhunter.wordpress.com/2011/01/17/dahlgren-12-pdr-small-bh/

Many thanks for your help!

And another request too..............

In the plans from Vicksburg I could see, that there were a Two Cylinder steam engine named " Auxiliary engine". Wher the he..... was this built in:default_wallbash:, location was shown as unknown, whe I followe the plans!

58e8e08f1b253_PlneausHistoricReport-025.thumb.jpg.e63e6a38312f89276feedb71e36bbb71.jpg

 

Regards

Gerhard

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Gerhard,

We have not been able to find any direct evidence of an auxiliary steam engine being recovered with the USS Cairo but the version shone in Ashley's (Bob Hill's source) 1981 NPS drawing depicts a similar engine he apparently found in the US National Archives and a sketch showing it in the lower casement of the hull (perhaps this is where something was recovered in 1963). However the engine in this sketch would be far to large for capstan power as it is even larger than the engines powering the paddle wheel.

We have found several drawings of mid-1800 steam powered capstans which were provided with US Patent applications which provide a more reasonable scale for this engine which would be more integral with the capstan. 

However, the capstan for the USS Cairo is located directly above the centerline coal bin between the Commissary Stores Room and the Fire Room so the gearing and Auxiliary Steam Engine would most likely have been powered by a remote engine and PTO shaft similar to that shown on the 1981 NPS drawing.

Our reconstruction solution therefore was to install a smaller version of the 1981 NPS drawing Auxiliary Engine in the port side lower casement with its PTO shaft leading to the centerline capstan instead of having an engine in the middle of a coal bin. We have installed a box around the below deck bevel & spur  gearing to isolate it from the coal.  So far we have only mocked up the auxiliary engine but it will simply be a reduced scale version of Ashley drawing. I've attached a few photos which I hope will make this description clear.

 

johnhoward

 

capstan patent(1).bmp

Capstan, Steam Powered.jpg

Capstan-Cairo.bmp

20170131_112619-1_resized.jpg

20170223_190050_resized.jpg

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32 minutes ago, johnhoward said:

Gerhard,

We have not been able to find any direct evidence of an auxiliary steam engine being recovered with the USS Cairo but the version shone in Ashley's (Bob Hill's source) 1981 NPS drawing depicts a similar engine he apparently found in the US National Archives and a sketch showing it in the lower casement of the hull (perhaps this is where something was recovered in 1963). However the engine in this sketch would be far to large for capstan power as it is even larger than the engines powering the paddle wheel.

We have found several drawings of mid-1800 steam powered capstans which were provided with US Patent applications which provide a more reasonable scale for this engine which would be more integral with the capstan. 

However, the capstan for the USS Cairo is located directly above the centerline coal bin between the Commissary Stores Room and the Fire Room so the gearing and Auxiliary Steam Engine would most likely have been powered by a remote engine and PTO shaft similar to that shown on the 1981 NPS drawing.

Our reconstruction solution therefore was to install a smaller version of the 1981 NPS drawing Auxiliary Engine in the port side lower casement with its PTO shaft leading to the centerline capstan instead of having an engine in the middle of a coal bin. We have installed a box around the below deck bevel & spur  gearing to isolate it from the coal.  So far we have only mocked up the auxiliary engine but it will simply be a reduced scale version of Ashley drawing. I've attached a few photos which I hope will make this description clear.

 

johnhoward

 

 

 

 

 

Hi johnhoward

 

Thats what I found out by scaling the drawings to same measure. The so called auxiliary engine would have been far larger than the driving engime. I thought, that the auxiliary engine could have driven the capstan and MAYBE the steering, as it was done on different (german) river tugboats, while the Main Auxiliary Engine  "the Doctor", was used for filling the water boiler. If that scond auxiliary engine was used for steering too, this could declare the giant size of it. But in the drawings I did not find any hint for that!

So there is a lot more to find out how they have built the ship, and how they managed to steer it! The fire room did probably not have enough space for an extra engine, so the place of it could have been "around"  the Doctor, or at one side of the vessel in height of the capstan. The plansheet I`ve shown before shows the top view of the engine, there you can see a rod to port side of the engine, but unfortunatly not further parts of it. So we will have to speculate, how the parts we know did work together, and what parts are missing! To illustrate what i mean I`ve made a little sketch fron the auxiliary engine with the Doctor as a simple square set in.

58ea39bb97778_TheauxiliaryEngineTopViewwithDoctor.jpg.5cdd9419d2beddd6c628e27e8b48ed85.jpg

 

Best Regards &Thank you for your worthful help!

Gerhard

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Paddle wheel inlet.bmp

Gerhard,

The "doctor" engine is a whole different story. Unfortunately the Cairo's "Doctor" although originally found, was later lost in the Yazoo River. The version of the "Doctor" shown on Ashley's plan sheet 27(which I assume you have) is pretty good for making a non-functioning model but appears to be a little fancy for the ironclads. Some version of it was carried in almost every later steamboat for boiler safety. Ashley (and Bob Hill) incorrectly show it mounted lengthwise on the paddlewheel feedwater ramp whereas Meagher's reconstruction correctly shows it mounted athwartship in roughly the same location but forward of the ramp and aft of the boilers, between the main engines. (See: Paddlewheel Section attachment). Ashley's sheet 24 Propulsion System Schematic is also full of errors. A functioning "Doctor" would make an interesting model in itself. Some of the attached text helps explain how the doctor really works.

We haven't found any evidence of power assisted steering on the ironclads. Later on some form of hydraulic power rudder assist was implemented on Western river craft. The traditional steering wheel, drum, and chain or cable linking to the tillers seems to have been used, however the tillers were over 100 feet away from the steering wheel so it appears that some system of taking out backlash must have been used. All sternwheeler steamboats would have a similar problem until some of them moved their rudders forward of their paddlewheels closer to the steering wheel. Whatever the case, the lateral control was notoriously ineffective on the ironclads.

 

 

johnhoward

Doctor Engine,Western River(1).jpg

Paddle wheel inlet.bmp

Paddlewheel Section.jpg

Doctor Engine, Arabia(4).jpg

Doctor Specification(2).jpg

Doctor text(1).jpg

Doctor text(2).jpg

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1 hour ago, johnhoward said:

Paddle wheel inlet.bmp

Gerhard,

The "doctor" engine is a whole different story. Unfortunately the Cairo's "Doctor" although originally found, was later lost in the Yazoo River. The version of the "Doctor" shown on Ashley's plan sheet 27(which I assume you have) is pretty good for making a non-functioning model but appears to be a little fancy for the ironclads. Some version of it was carried in almost every later steamboat for boiler safety. Ashley (and Bob Hill) incorrectly show it mounted lengthwise on the paddlewheel feedwater ramp whereas Meagher's reconstruction correctly shows it mounted athwartship in roughly the same location but forward of the ramp and aft of the boilers, between the main engines. (See: Paddlewheel Section attachment). Ashley's sheet 24 Propulsion System Schematic is also full of errors. A functioning "Doctor" would make an interesting model in itself. Some of the attached text helps explain how the doctor really works.

We haven't found any evidence of power assisted steering on the ironclads. Later on some form of hydraulic power rudder assist was implemented on Western river craft. The traditional steering wheel, drum, and chain or cable linking to the tillers seems to have been used, however the tillers were over 100 feet away from the steering wheel so it appears that some system of taking out backlash must have been used. All sternwheeler steamboats would have a similar problem until some of them moved their rudders forward of their paddlewheels closer to the steering wheel. Whatever the case, the lateral control was notoriously ineffective on the ironclads.

 

 

johnhoward

Hi johnhoward

 

Found both books by googlesearch, interesting things to learn for me. As I have learned more in the past few days than in years before! So the doctor should be built in but  turned 90deg. not as Gene Bodnar did show it in his Cairo model: http://www.modelshipbuilder.com/e107_plugins/forum/forum_viewtopic.php?5406.60

When there was no power assisted steering, the other auxiliary engine will have one reason only, to assist the capstan? If we (or you) can find out, where to locate this second auxiliary engine, I will make it too, just for the reason it was there!

 

Regards

Gerhard

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Are you sure that the capstan was steam driven?  With large navy crews could the capstan have been manned by hand.  We're steam driven Capstans used on the rivers in the 1860's?

 

The Smaller caliber Dhalgren boat howitzers were designed to arm boats (especially launches) in support of amphibious operations, a requirement stemming from the earlier Mexican War where the navy was required to land troops and lacked an effective light weight artillery piece.  The idea was to mount the gun in the bow to be able to fire it while approaching the shore and to then quickly dismount it and to remount it on the field carriage that had been carried separately in the boat's stern sheets.  The field carriage was to be wheeled ashore over a ramp formed by extending timbers from the boat's bow.  The "sledge" that you refer to is the mounting for use in arming the boat. Most photos show these boat howitzers on iron field carriages when aboard ship.  My Dixie Gun Works materials which are copies of the original drawings apply to the light 12 pound howitzer and depict a "hybred" field carriage- iron and bronze except the two main wheels which are wooden.  The small tail wheel is iron.

 

The best reference that I can recommend that covers Civil War naval artillery is "Arming the Fleet" by Spencer Tucker.  You can also download a copy of a Civil War US Navy Ordinance Manual    on line from google books.

 

Roger

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Gerhard & Others,

There are several questions in the previous few responses which are very helpful in arriving at the most plausible configuration for the USS Cairo and the other "City Class Ironclads'.

We have been researching this for about 3 years while meanwhile constructing our 1:24 scale model for the Missouri Civil War Museum and I agree we still don't have all the answers.  All of the existing drawings are based on a mixture of actual recovered fragments of the original ironclad, the original written specifications, and reconstructions of the most probable technically plausible configuration. The building of our large scale model has given us better insight for verifying or determining the most likely reconstruction.

Question 1: Are you sure the capstan was steam driven?

Answer: The best proof comes from the NPS Historical Structural Report (HSR) for the USS Cairo under the section on "Auxiliary Equipment" which lists; Steam driven capstan, Steam driven pumps, Hand pumps, and Feedwater steam engine ("Doctor"). The recovered capstan does include release pins to permit manual powering and gearing for two speeds(or mechanical advantage). However, I think steam power would prove most useful for dislodging a 500+ ton ironclad from a sandbar or snag in the shallow US Western Rivers. 

Question 2: ... can we find out the location for this second auxiliary engine?

Answer: Since this engine apparently was not recovered,  I doubt that we will ever find any absolute proof, however as I outlined in a previous response,  our model was used to reconstruct the simplest method of moving the scaled down (Ashley) engine out of the coal bin via a PTO shaft and this is offered for consideration.

Question 3: ... so, the Doctor should be built in but turned 90-degrees,...?

Answer: Yes, however  Gene Bodar actually also located the "Doctor" a little too far aft on top of the paddlewheel feedwater chute which he made flat rather than curving up in front of the wheel. (You may also notice he installed his nicely made boilers backwards) [See: Paddlewheel Inlet attachment]

 

johnhoward

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1 hour ago, johnhoward said:

Gerhard & Others,

...................

 

johnhoward

Hi johnhoward

 

So this all brings me to the conclusion: i will build the doctor close to the boilers as you did show in the Paddlewheel attachment. The auxiliary engine is not to locate, but will be built in too, I will search for the location of this engine, maybe I will make it as you did show earlier, with a connection to the capstan. This WAS steam driven, when I read, what the Vicksburg museum page tells:  https://www.nps.gov/vick/learn/historyculture/capstan.htm

So a lot of open questins are answered in the last few days, Thank YOU Sir!

Even the 12 pounder is now good to locate and to build as a model, so a lot of "extra" work will be made:)

 

Best Regards

Gerhard

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For the sake of speculation... is it possible that the wreck isn't complete in the sense that material has been dredged up or hauled out of the water by salvagers?   When I lived in St. Louis, one of the comments from a gentleman I knew at the Arch Museum was that much has been lost over the years to salvagers and work on the channels.

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1 hour ago, johnhoward said:

Thanks Gerhard,

Good luck with your projects and research. A live steam powered RC ironclad should really be amazing.

 

johnhoward

I`m doing my best, therefore are so many requests I have to make. Still one more, what size did the ships boats have? Soewhere I read about 2 different types of boats, see the pic. I just dont know at the moment where I found this:default_wallbash:

58ebe2d113c09_AllgemeineBeschreibungen-001.thumb.jpg.24a2a69991c98d6c6c2476d78269c01b.jpg

 

1 hour ago, mtaylor said:

For the sake of speculation... is it possible that the wreck isn't complete in the sense that material has been dredged up or hauled out of the water by salvagers?   When I lived in St. Louis, one of the comments from a gentleman I knew at the Arch Museum was that much has been lost over the years to salvagers and work on the channels.

Hi Mark

 

That`s what I`m afraid of, that a lot of things simply disappeared for some reason,  and is lost now maybe forever.

 

Regards& thank you all for stumbling in

Gerhard

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Gerhard,

I've attached the information I have accumulated so far on the Cairo's boats, one launch and three cutters. The photos and outline drawings probably would be enough for a reconstruction but we would prefer an existing detailed drawing.  I haven't yet selected a particular plan for their construction but I've previously read somewhere, possibly Gene Bodar's log, that they were similar to "Bristol Boats". I haven't searched for this yet but it shouldn't be too hard to find.  We plan to display two of them on the starboard side, covered with tarps so only the planform would really be necessary.

One of the others on the port side would be open and contain a bow mounted skid for the 12-pdr boat howitzer but not the barrel so details of this could come from those drawings.

We are hoping to be able to complete our model in about another year so I still have time for research as the boats will be one of the last things to model. 

 

I hope this helps a little,

johnhoward

Cutter beside-USS Cairo.bmp

Cutter plan view.jpg

Cutter profile.jpg

Cutter section.bmp

Cutter,Civil War.bmp

Carondelet(2).bmp

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Hi johnhoward

EVERY hint helps, Thank you!

By studying the sketch above, this could have been a 26ft long cutter. I found one pinnace at the NMM Greenwich collection, wich will be around 16 cm length in 1:50 measure. even the shape comes close to the drawings, but the boat is a bit younger, from 1878. But I expect that there were not so much changes in shape on such boats, so I will go with it. Just the one Launch is still what I wonder about length and shape. By searching for "Bristol Boats" I fell over the Atkin&Co Site, they show a good drawing for a 15ft 6in. boat, even similar to the Cairo drawings.  http://www.atkinboatplans.com/Oar/BruceConklin.html

58ecea215e90f_26ftPinnace.thumb.jpg.47c593a0d9736e29acaa48b84c990ab7.jpg

Best regards

Gerhard

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After all that more theoretical stuff it`s time for smoething real. Today I started with the 12-pounder carriage. This is a really small thing, just about 3,3 cm long without the wheels. The main part is soldered from 4 pieces of 0,5mm brass sheet, still some parts missing, but things go on.

58efaf5c3fe05_12Pfnder001Lafette(1).thumb.JPG.7f6f4f01135e29586581669659e69492.JPG

58efaf895e78f_12Pfnder003.thumb.JPG.216cfdc95103de9dda0b961457e8d804.JPG

58efafbbd9078_12Pfnder004.thumb.JPG.e6e5a18581d80a25f3bd3a3b52268b75.JPG

58efafe252fe5_12Pfnder006.thumb.JPG.f7b675ee96dc639cf23da1dbed3a233f.JPG

 

Best regards, and many thanks for yll your kind likes!

Gerhard

 

 

 

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Very nice work Gerhard,

We'll be starting ours soon, but of course it will be twice the size at our scale and should be a little easier to make.

By the way I've attached another possible version of the capstan steam power system in case you don't like the PTO shaft idea. We originally preferred this idea before we determined it would be in the middle of the coal bin. It does look very similar to the Cairo gearing setup.

 

johnhoward

 

capstan patent(1).bmp

Capstan Patent Explanation(2).bmp

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Hi johnhoward

 

This version of the capstan seems to be too far away from the Cairo`s. It is driven by a single cylinder engine, while the suspected engine should have been a double cylinder engine, when I look at the shape of the machine base parts. The only thing I have to find out is where to place that engine. The gearing setup can be adapted for the capstan, no matter where the engine will take place, time will tell.................

Best regards

Gerhard

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