Breaking Strains

[j.sabourn]

I have suddenly had figures appearing in my memory when talking about Breaking Strains etc. Can someone please confirm or reject that 2, 3 and 3.25 times the circ. squared was the SWL of 12, 24, 36 wires to a strand of wire. Obviously wires of more modern construction will more than likely have different values now. Cheers John Sabourn

[Doc Vernon]

I like this JS
But honestly know sweet fanny adams about it haha!
Sure you will get some replies! I am all tied up! LOL
Cheers



http://www.google.com.au/url?sa=t&rc...58187178,d.dGI

[j.sabourn]

Is that with 12 24 or 37 strands. I am probably thinking of rope. However when you are talking to someone ashore don't want to say the wrong thing, or they think you are a bit of a romancer in whatever you say. They are usually clueless any way as regards shipping and think all sailors wear bellbottoms and dance funny jigs. Cheers John S

[Doc Vernon]

As said JS
Not a bleedin clue on this! Just found that on the Net!
Cheers

[happy daze john in oz]

For years I wondered what SWL on a crane meant now I know.

But recall a chef who had a strain weight load, told me he had to strain to have a crap and very often the only load he got rid of was a fart.

[Ivan Cloherty]

I have suddenly had figures appearing in my memory when talking about Breaking Strains etc. Can someone please confirm or reject that 2, 3 and 3.25 times the circ. squared was the SWL of 12, 24, 36 wires to a strand of wire. Obviously wires of more modern construction will more than likely have different values now. Cheers John Sabourn

Hmmm may need to research my old books but Mr Bullivant says that a breaking strain of 6 x 12- 2.5" circ with a weight of 4.19 lbs per fathom has a guaranteed breaking strain of 12 tons whereas a 6 x 24 - 2.5" circ with a weight of 5.31 lbs per fathom has a guaranteed breaking strain of 18.55 tons.

Hope this helps you with your theory John, could work it out backwards but a bit too early in the morning for me

Happy Daze- some people still think that SWL means Swing with Leisure

[j.sabourn]

Sounds like I should have said B.S. not SWL. However it was the 12, 24 and 36 strands I was wondering about if correct. Believe the SWL was one third or something of the BS. Nearly right. A Landlubber wouldn't notice I suppose. Cheers John S.

[robpage]

Swl =bs/6

[Ivan Cloherty]

Sounds like I should have said B.S. not SWL. However it was the 12, 24 and 36 strands I was wondering about if correct. Believe the SWL was one third or something of the BS. Nearly right. A Landlubber wouldn't notice I suppose. Cheers John S.

John you did say B S also checked with the Boatswains Manual as a rough guide for shipboard use 'square the circumference and multiply by 2' so if you use that on a 6 x 12 you're certainly going to be on the right said using that formula on a 24 and 37,

actual figures are for 24 are circ-squared x3 37 circ-squared x 3.25

all above are for flexible steel ropes. Standing rigging have different figures those above 4.24" circ x 2.25

the SWL is normally considered to be one-sixth of the breaking strain given by the makers or shipboard practice circ-squared x 0.4

Construction and crane wires have different formulae although with more ships having cranes these would be applicable seawise also, the Ontario Rigging Manual has 53 pages of formula and wire descriptions but the only words I recognise are 'Liverpool Splice' and 'Flemish Splice' but had to use this book as a bible when dealing with cranes when running my company. Had an Amercan Standards book as well, but seems to have gone walkies.

Think I'll go back to bed !!

[j.sabourn]

#6... Nothing gells to todays standards Ivan. As wire is now measured by diameter and not circumference. Pity the mate who orders a 2 and a half inch wire thinking of circumference. Cheers John S