How to size rope

[camaraderie]

KH...Yeah...I think it may be used to prevent chafe on the dockside cleats for boats in long term storage. Makes sense...thanks.

[labatt]

Originally Posted by sailaway21

Cam,
A mooring line parting on a ship will leave the lines imprint in a quarter inch steel bulkhead, or cut a man in two.

Just to get slightly off subject - a TV show - MythBusters - did a test to see if a heavy line or heavy steel cable could actually cut a person in half if it snapped (I'm assuming that this will also apply for nylon or dacron line, since it should be somewhat less lethal than steel cable).

From a summary of the episode:

A 5/8" cable at 30,000 lbs of tension was unable to cut a pig in two (or even cut into it). The MythBusters took the test even further by adding a smaller cable at the end of larger one to create a "whip" effect, and even pre-looped a cable around the pig itself. None of these methods could cut the pig by the pre-tensed cable's inertia alone. The pig was cut in half only when Adam tied a cable around it and then tightened the cable. Also, after making inquiries with almost every safety organization imaginable, the MythBusters were unable to find any concrete evidence of a person being cut in half by a snapped cable.

Just thought people may be interested They did determine, however, that it could break bones or cause internal injuries.

Chris

[btrayfors]

Too bad they didn't use one of the "Myth Busters" TV show producers instead of the pig!

Bill

[Giulietta]

Ahhhh

PIGSLO will be very very upset!!! Used one of his cousins, shame on them....

[camaraderie]

Giu...that's the difference between the chicken and the pig in the traditional "bacon and eggs" breakfast here in the states. The chicken helps out but the pig has committment!

[Giulietta]

One good thing about pigs, too..

In case (and I am saying in case) we ever get occupied by the Islamic, pigs will be safe!!!!!

[sailaway21]

I think we have apples and oranges again here. By cable it appears you are referring to wire rope and it has a stretch factor of 1%. Nylon, on the other hand, has a stretch factor of 40% at breaking strain. 5/8" dia nylon has a breaking strain of approx. 9600 lbs while 5/8" dia wire rope, depending on construction, has a breaking strain of 30,000 lbs or greater. When wire rope parts it basically just falls in the water as it's only stretched 1%. I don't know if I'd trust my pig to almost 5 tons of snap from a nylon line.
Regardless, the lines mentioned earlier are 8-10" mooring lines (2-5/8" to 3-1/4" dia.) with breaking strains from 146,000 - 226,000 lbs. That's over 70 tons, long tons or short, flying back at you and if it hits a pig I think we'll have a new definition of rag-out of pork.
The vessel in question was the SS Thomas Nelson, a Mariner-class freighter, long consigned to razor blades. If, by chance, she's moth-balled somewhere the indentation is in the lazarette aft, starboard side.

The most common line parted is the spring line and it happens when coming alongside and checking the vessel. The old adage is, "strain it but don't part it" as a parted line has no stopping power. Even on a 20,000 lb boat, if you part a spring line, you are going to have 10 tons of force coming back at you. When ships were converting from manila to synthetic it was a common source of death or dismemberment. Seaman today are well educated on this and never stand in the lead of a line. BTW, the most common injury seemed to be amputation of the leg at about knee height.

[khbritten]

Giu -

Have you seen the book, "A Cook's Tour", by Anthony Bourdain? It chronicles vividly the delicious demise of a Portuguese pig. A great read, but be ready to become hungry.

Ken

[pigslo]

I saw that episode of mythbusters. That pig was not harmed at all. He is a family member that is from the acting branch and was paid quite well for that show. He is such a ham though.
pigslo

[yotphix]

Can't speak for the mythbusters but when I worked in film special effects, I saw a small dia. (I think 1/8") 7x19 wire rope break during a tow in car crash scene. The wire shot out faster than the eye could see and neatly severed a 1 1/2" sapling and several smaller branches 15 yards from where it snapped before balling itself all up. Be careful with any tensioned material approaching it's yield strength.