Water Tank Repairs 4

[artfarmartfarm]

I am repairing my water tank that was damaged during the a recent earthquake. QUESTION:
My tank is made of 4'by 8' 5/8th inch plywood & 4"x4" verticles with a plastic liner & sits on gravel. I want to replace the rusted three bands of 1/2" steel rod stock with stainless steel cable.
The round tank is 13,000 gallons,4 ft high,& 24 ft diameter. What I want to know is; what minimum tensile strength cable do I need to hold it all together? I will be putting three or four seperate loops around the tank. Ballpark figures would be be OK.

 

[MikeHalloran]

Because of stainless steel's lower yield point, I'd be inclined to use a larger net section of cable.

Or paint the steel.

Related question: Steel bands on wooden pipe and tanks are normally threaded on both ends, and 'crossed' in a cast fitting that sits between the nuts, so you can tension the bands. How will you tension the cable?






Mike Halloran
Pembroke Pines, FL, USA

 

[vonlueke]

artfarmartfarm: Tensile yield strength of typical stainless steel is Sy = 210 MPa; and a factor of safety of FS = 2 isn't uncommon. I'm currently getting D = {(FS)(50914 N)(2n+0.5)/[(Sy)(n+1)^2]}^0.5, where n = number of cables, Sy = cable tensile yield strength (MPa), and D = unstranded cable diameter (mm). E.g., if n = 3, FS = 2, and Sy = 210 MPa, this gives D = 14.04 mm. If the cable is stranded, then the total cross-sectional area of the strands would need to equal the above unstranded cross-sectional area.

 

[metengr]

You can also order 301, 302 or 304 stainless steel wire product form in full hard, 3/4 or 1/2 hard conditions from cold working to increase yield and tensile strengths for this application.

 

[unclesyd]

Here is one of many sites that carry Stainless Steel wire rope. You might want to look at hot dipped galvanized wire rope.
This page if for non-flexible wire rope that requires special terminal ends. If you use a more flexible construction there will be a lot more termination possibilities but at a cost.

http://www.loosco.com/