ferro-cement submarine versus conventional concrete

RWATSON--thank you!! finally someone understands what im trying to go for-

this has exactly been my philosophy of submarine design since day one--i never wanted to deep dive---i just want a cruising sub that runs more on the surface.. you have hit the nail on the head!! 100 ft is perfect or maybe a little bit more around 120. or about 4 atms
--since systems over(under water)120 ft become much more complicated--
btw i do love yachting and sailing

diving under weather though --thats probably the biggest point i like about a sub--when cruising --you just dive under water during the storms. hopefully the batts are charged enought to outlast the storm...i did think of putting a sail on the sub in case of engine failure. it wont win the america's cup but heck itll get me out of a jam if needed. so i just posted a new thread to discuss surface running characteristics..and--which is why steel has peaked my interest-
what i was thinking was--since i would ahve about 20-25 ft of the overall length of the sub as actual usable space...(the rest is ballast etc) i could look at a smaller but much stronger steel pressure hull- then build an exo-shell around the pressure vessel. this was done by Gibsons marine with a 30 ft sub called the needlefish--ill post the address if anyone wants to check out the intire building process--its really enlightening!
anyway a 20 ft x 8 ft steel pressure vessel is the same as a 50 ft concrete pressure vessel..with about the same space--problem is--if you build for surface running you really have to chnage the design characteristics. u-boat designs are the best- but they are very challenging deisgns to build and design. as you probably know there are tradeoffs to any design...

Good to talk to you again Mr Watson!..if i didnt love subs--i would build me a trimaran--or a cat. I did design on paper- a couple planing tri designs...im not a monohull guy..but i used a stepped hull design for a cat hull. someday ill post it. thought a wave piercing design is almost like the idea of a sub--have you seen the "earth race" type vessels??? these are wave peircing designs almost like a surface sub hybrid.
but great insight!..kudo's

 

one other thing--just to inform others--i have been looking at building a 30 ft tugboat in place of a sub--so right now im on the fence--

sigh..having to redesign my sub hull leaves me a bit discouraged--im not one to back away from a bit of frustration-- but this really seems like a setback.. so its still a 50 50 chance ill go with a sub vs a powerboat--the pros are--for sub more range and i can cross an ocean-- for a tug i am limited. the sub goes under weather - the tug sits in a harbour-- but the tug is much more easily built and i may even make a few bucks doing some under the table work here and there...etc...i could go on but people get the idea- there are -for me- pros and cons for both//most would say go with the tug but im not ready to let that dream go just yet...

 

A couple of remarks..
Under 100ft waves you need alot more than 50 to 100ft down where you still get some acceleration. To get rid of the 10ft wave motion you defineatly need to go 50ft down. Actually it's more related to wave length how deep is the impact.
In the oceans there's good visibility to 200ft..

BR Teddy

 

teddydiver- so if i am understaning you correctly--i would need a vessel that could go to 200 ft--which means that my safety factor should withstand maybe 300 -400 ft safely?

i do understand that the trough on a 100 ft wave would bring the sub to the surface. so i have considered that issue as well as the "what if" my batts run out before a major storm is over.then im bobbing like a cork on the surface rechargeing my batts.
but
also i plan to run in the great leakes 80% of the vessels life. the waves are a different motion--they break sooner and crest faster.

thanks Teddy.

 

destruction depth of concrete tubular structures

Paper Number 3011-MS
Title OCEAN IMPLOSION TEST OF CONCRETE (SEACON) CYLINDRICAL STRUCTURE
Authors Roy S. Highberg and Harvey H. Haynes, Civil Engineering Laboratory
Source

Offshore Technology Conference, 2-5 May , Houston, Texas
Copyright 1977. Offshore Technology Conference
Language English
Preview ABSTRACT

An ocean implosion test was conducted on a pressure-resistant concrete cylindrical structure to obtain the depth at implosion. The structure was a reinforced concrete cylinder with hemispherical end caps, twenty feet (6.1 m) in overall length, ten feet (3.05 m) in outside diameter, and 9.5 inches (241 mm) in wall thickness. The structure was near-neutrally buoyant having a positive buoyancy of 12,000 pounds (5.4 Mg) for a hull displacement of 85,000 pounds (38.5 Mg). The implosion depth of the cylinder was 4700 feet (1430 m). A predicted implosion depth, using an empirical design equation based upon past test results, was 16 percent less than the actual implosion depth.

INTRODUCTION

A pressure-resistant, reinforced concrete hull was constructed in 1971 as part of a Seafloor Construction Experiment, SEACON I. The structure was placed on the seafloor at a depth of 600 feet (180 m) for 10 months. Figure 1 shows the SEACON I hull prior to its ocean emplacement. Since its retrieval in 1972, it has been located in the open air about 150 ft. (50 m) from the ocean. In the summer of 1976, the structure was returned to the ocean for an ultimate load test, that is, the structure was lowered into the ocean until implosion.

SPECIMEN DESCRIPTION

The cylindrical structure was assembled from three precast, reinforced concrete sections. The straight cylinder section, 10.1 feet (3080 mm) in outside diameter by 10 feet (3050 mm) in length by 9.5 inches (241 mm) in wall thickness, was fabricated by United Concrete Pipe Corporation. The concrete hemisphere end-closures, 10.1 feet (3080 mm) in outside diameter by 9.5 inches (241 mm) in wall thickness, were fabricated in-house. Tolerances on the sections conformed to concrete pipe standards of not to exceed to ±0.75 inch (19 mm) for the inside diameter or minus 0.5 inch (13 mm) for the wall thickness.

Steel reinforcement in the amount of 0.70% by area was used in both the axial and hoop direction. Reinforcing bars of 0.6 inch (15 mm) diameter were employed throughout the structure. A double circular reinforcement cage was fabricated for each precast section; the concrete cover on the outside and inside reinforcing cage was 1 inch (25 mm). For the cylinder section, hoop rebars had a spacing of 27.25 inches (692 nm) and 31.25 inches (794 mm) for the inside and outside cages respectively.

The hemispherical end-closures were bonded to the cylinder section with an epoxy adhesive, no other attachment besides the epoxy bond was employed (Figure 2). The gap between the mating surfaces of the hemisphere and the cylinder was less than 0.13 inch (3 mm) for 75% of the contact area. Prior to epoxy bonding, the concrete surfaces were prepared by sandblasting and washing with acetone.

Source: http://www.onepetro.org/mslib/servlet/onepetropreview?id=OTC-3011-MS&soc=OTC

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contribution by wil
concretesubmarine.com



Concrete Submarine Yacht 200 ton / 18m - video overview inside outside - a submarine yacht is not dark inside...

http://www.youtube.com/user/wilfriedellmer#p/a/u/0/BehlL9ssHzI

 

Why aren´t you in Jail mate?

 

You know is like an herpes, it always come back. Even jail don't want him. He likes too much the rear interaction between cell mate.
Ignore him.
Daniel

 

Very interesting bit of info there Welmer. Please excuse the two professional insulters - they stomp all over every half interesting post as soon as someone else dares post anything on this site.

Of course, the question that will spring to mind from your post is the relevance of such a small object in comparison to the much larger structure you have built.

I guess we still have to hold our breath to see if your ediface works as there has been next to no engineering info available to us.

Can you extrapolate a launch date yet ?

 

Thanks for that *******!

Support this drug dealer, and feel fine.

 

No doubt building a Submarine in Columbia is a bit suspicious. Even if you were above board anytime you got remotely near a legitimate marina the coast guard would be on your **** so fast it wouldn't even be funny.

 

At least the portholes will allow you to watch the depth charges going off.

 

As you said Richard!
http://www.reuters.com/article/idUSTRE6631UV20100704
Anyway it looks like the one above..

 

I have no doubt Teddy, that we have been on the right track from the very first reply on Wellmers idiotic approach!

Richard

 

Oh sure - thats why he is building it in the navy dockyard - to be secretive. You guys crack me up big time

 

The navy dockyard:




....is in fact Mr. Ellmers backyard.

But support him further, for which reason so ever......................