Episode 62: Killer Cable Snaps

Air Date: October 11, 2006

If a cable snaps, it can cut a person in two.

busted

A 5/8" cable at 30,000 lbs of tension was unable to cut a pig in two (or even cut into it), but did cause potentially lethal injuries. 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.

Sounds can be recovered from old pottery.

busted

The MythBusters were unable to recover any recognizable sound from the pot using a record player with a glass needle (to prevent scratching the clay). Even with professional audio enhancement and the most advanced sound systems available, they were unable to recover any discernible sounds from the straw-made grooves on the pots.

61 Comments

  1. Jon says:

    In response to “If a cable snaps, it can cut a person in two” it obviously can happen. It just did. http://thelede.blogs.nytimes.com/2007/06/22/amusement-park-accident-severs-girls-feet/

    A teenage girls shins were severed when she got hit by a cable on an amusement ride. Sad, but true.

    • Argh Science Pirate says:

      Technically it cut her into 3, then, right?

  2. Lynn says:

    There’s a lot more mass with a torso of a human or a pig than a girl’s ankles.

  3. Andrew C. says:

    In training films for Merchant Mariners, most high strength cable (10+tons) simply parts and drops to the deck. However, Synthetic mooring lines are capable of cutting a man in two at the hips, as demostrated in a famous Navy training film and many recorded incidents.

  4. Chris says:

    I think the recent events at Six Flags in Kentucky shows a revisit might be needed, of course they should somehow show some sensitivity to the issue. Even if it can’t be reproduced we all know it can happen, at least in relation to the legs/feet.

  5. Scott says:

    The girl at Six Flags was not cut in two. Only her feet were severed.

  6. Brian says:

    Regarding the girl at six flags. The cable might have wrapped around the girl’s feet, and then the ride dropped, severing the feet. We will know when the investigation is complete. Just a possibility.

    -Brian

  7. Frank says:

    The Cable At six flags would have cut thru the girls body just as quick as it did her ankles its a combination of tension and the speed the cable is moving as was shown in another episode a playing card can cut you if it is moving fast enough

  8. Ray says:

    Don’t pre-stress concrete cables have the same possibility of cutting one in half, as they unravel violently? I presume this would be before setting of the concrete, but I remember my uncle talking about some of the injuries he has seen.

  9. rich says:

    I hate to contradict your findings and I LOVE your show. BUT….
    I am an off-road enthusiast and an SAR volunteer.
    My land cruiser has a 12K pound winch on the front and an 8k in the rear.
    I have seen winch cables snap with very violent results! I have seen grilles and windshields shattered! When we winch, we keep all people away at a ratio of twice the length of the cable. The operator of the winch stays below the dash or farther away if the remote cable allows. We try to place blankets on the cable to slow the flow of the break just in case. I have seen fabric go everywhere but, because we demand such safety measures, No one has been killed. Look into The Fremont Hills OffRoad people in Hollister. I believe it can happen but it has to be because of user ignorance.

    Just my two cents.

    Peace brothers!

  10. Brad says:

    I guess I won’t be telling my dead 2nd cousin that the snapped cable, while loading an oil drilling rig for movement, shouldn’t have taken the rear of his skull off.
    I would have thought that similar forces placed mid-torsoe on the body could sever a torsoe in half as well. From what I saw, I think there was something wrong with the design of the experiment. I didn’t see a test that would mimic my cousin’s accident. Although I concede, it would be very hard to duplicate precisely on any given attempt.

  11. Ben says:

    Just not enough tension. 30000 lbs seems like a lot, but compared to the ratings on really heavy cables- it honestly isn’t that much. I also agree with Andrew that a synthetic line might be a better choice to check though. Think about it like getting burnt- it’s not the temperature of the liquid, it’s how much energy is in it. A more elastic line stores a heck of a lot more energy before it snaps than one that is brittle.

  12. Ben says:

    Also, I think we need to keep ‘rich’ away from high tension wire and fast: “We try to place blankets on the cable to slow the flow of the break just in case.”

    With my favorite line: ” I have seen fabric go everywhere but, because we demand such safety measures …”

    Such demanding safety measures as… (gasp) blankets! I for one, am SHOCKED to see a man go to such lengths as to see BLANKETS used by a civilian purely for safety. Haha- well, Linus felt better with one at least.

  13. PA Taco says:

    Ben, obviously you don’t wheel and do not know the safety measures we take during a recovery. I understand that it sounds silly to you. The blanket absorbs some of the energy when a winch rope breaks thus lessening the damaging/lethal force. This is a common knowledge safety precaution in our hobby.

    This experiment was to only determine the plausability of a snapped cable cutting a person in two. A cable snapping is still a deadly force and can still cause much damage to a person or property.

  14. Vengeful says:

    Ben…you sir are a moron.

    I’d like to see you survive a winch cable snapping at 30,000lbs of tension without a counterweight. ARB specifically sells a product to weigh down the winch line just for this purpose. Are you going to call ARB stupid, too?

  15. TJ says:

    MANY of Myth Buster’s attempts at busting are flawed, deeply….so that myths are failed to be busted that should have, and that some “Busted” issues should be confirmed rather than busted, etc.

    Some are ok…but…you have to take them with a grain or three of salt.

    In THIS case, I think there’s confusion between a 5/8″ cable, and the diameters used in commercial settings…and the injuries caused by flying hooks and so forth, vs the injuries specific to the cable whipping.

    The real whipping danger is the unravelling cable acting as a giant weed whacker..the strands, not the entire cable…are what cut.

  16. shawn says:

    I have operated tow truck for 10 years, its very simple to settle this, the cable needs to be overstressed. snap the cable,don’t cut it. the cop car rear axle myth is a perfect example. snap the cable in one clean jerk.

  17. danny says:

    i have two remarks on this test firstly being a farmer i know that a pigs torso is much stonger becouse there is less of an area where there are no ribs in a human there is about a 6 inch area where the only bone that would be broken would be the spine and secondly a 30 k lb tension is not very much why dont you try something more like heavey machinery cables that are about twice that

  18. Matt says:

    Ray is correct. Prestress cables for pre-cast concrete piles start around 30,000 psi. Do they snap and kill people? Yes, for an example, see the OSHA website for a fatality investigation (www.osha.gov/dts/shib/shib060204.html). The fatality described involved a strand stressed to 166,000 psi. When the restraint failed, the cable sprung losse and killed a worker. It hit him in the head, so who knows what it would have done to his torso? (Besides, precisely whose sex life depends on whether it would just kill someone, or cut them clean in two? Consider Scott’s comment above: The girl on the amusement park ride ONLY lost her feet and ankles. Dude, get a life!)

    Look around the web at pictures where the boom of a crane fails. The energy of the impact allows latticed tube steel to conform to the topography of what it falls along or across. Sometimes the cable snaps, under tension. It’s difficult to believe 200′ of 1 1/2″ diameter wire rope(at about 2.5 pounds per foot) coming at you sharp like the business end of a bull whip couldn’t cut a pig in half.

  19. owen says:

    although highly unlikely to happen to be there u did not test cheese or barbed wire

  20. Michael says:

    I think that you guys went the wrong direction with the “whip effect. My neighbor had half of her face taken off when the clevis pin broke sending the cable and clevis back at her. Just something to think about. It doesn’t have to cut someone in half to be very deadly. Also a 3/4″ cable will need much more then 30,000lbs to break, and most accidents of this nature that i have heard of were 3/4″ or larger.

  21. matt says:

    I know this is a little old, but I am overseas deployed with the U.S. Navy. Did you try the Navy Safety center web site. Although it has only happened twice that I know of in the last couple of years, the arresting cable on an Aircraft Carrier has snapped killing people. This is a 1 and 7/16 inch cable with a sheer strength og 215,000 psi. something to look into

  22. Ben says:

    The BUSTED rating is flawed. In physics and engineering a cable is accurately approximated as a spring. The energy stored in a spring follows the simple equation E=kx^2. That is, the amount of energy is equal to the “spring constant” multiplied by the length of the spring’s extension. The spring constant is the same for any length of the same material. But a longer length of cable will allow a longer extension. To increase the speed of the broken cable rocketing back, the MythBusters should have used a longer cable in addition to higher tension. They only used less than 100 yards… try the length of a big suspension bridge cable. That might cut a man (or pig) in half.

  23. Tim says:

    I was in the navy, I still don’t why but while we were mooring after we got the lines across, to the dock somebody messed up. and turned on the engine of the ship the lines stared, creaking, then smoking, all the wile we were running, on the stern or back of ship the lines did not snap, the bow or front was not so lucky it snaped breaking a friends arm in three places. and it barly touched him. Mythbusters did a few things

  24. Tim says:

    mythbuster did a few things wrong, first of all it won’t slice you in half but it would take off your head ,hands and legs anywere that has joint. also use a nylon mooring line for better results.

  25. T Stewart says:

    In 1996 while having the winch and cables on our work 4X4′s checked, the technitian who was carrying out the tests showed me a cable from one of the dock cranes in Durban harbour. It had snapped and almost completely cut one of the dock workers in half. Judging by the blood, fragments of tissue and fabric he had been hit by the end of the snapped cable. They were trying to figuer out why the cable snapped.

  26. kenth says:

    I don’t recall seeing the episode, but one difference is that they use pig flesh to simulate human.

    There are a couple of potential problems with that. First, is the thickness and toughness of the skin of pigs. It appears to be very thick and tough compared to our own. The second potential problem with simulating human flesh is the temperature. Pig flesh is going to be harder due to, well, being dead. The fat and other components are harder and more inelastic due to being at whatever temperature the surrounding environment is; or harder still if it has been refrigerated.

  27. GEORGE says:

    Here is the real problem. The pig was not anchored like a human would be. The weight of the pig was not on its legs, like a human would be, and therefore, the body of the pig “gave” when the cable hit.

  28. Smart Mike says:

    The test was flawed. Pulling stopped in just a few feet. Look at moving the Trump condo sales office in Toronto in Jan. 08. Huge steel I beam cut. R.Y. Mike

  29. tm says:

    A friend of mine used to work as a sailer on one of the largest tug boats in the world and he witnessed a colleague get cut in half when in a storm the tow line connected to a tanker they were towing snapped like a piece of string. These are huge cables, but mother nature was stronger. He quit not too long after that.

  30. Matt C> says:

    There have been many instaces of arrester cables in the navy severing body parts. I am sure that if one of those struck the torso of a human it would cut him in two.
    There were several major limbs lost during the vietnam era. And even the Nvy has guidelines on where to stand on a carrier flight deck to avoid just such injuries.

  31. Paul says:

    Big difference between a dinky ass cable like they used and a 3″ mooring line.
    Check navy safety films for the guy that lost a leg. Or as Matt C pointed out arresting wire on aircraft carriers. I did tours on CV 63, 64 and short stints on a couple others. If an arresting wire can snap and flip a huffer. it can kill and has killed flightdeck personnel

  32. Tim E says:

    I spent 8 good years in the service of my beloved U.S.Coast Guard and as any seaman will attest, there is a significant difference between the “snap-back” of a metal cable and a nylon hauser.
    Coast Guard (as well as Navy and Merchant Marine) training films showing the results of a 5 inch double braidled mooring line snap-back is unforgettable. It will absolutly cut a man in half.
    Granted, this nylon line was not cut while under strain. Instead, a load was applied until it failed. A very large load, like a battleship underway.
    Remember, every action has an equal opposite reaction. Energy cannot be lost, only transfered or converted.

  33. leon says:

    I use winches and cable just about every day ranging from towing to retrieval and yes demolition I have used cable to pull and cut when I demolish trailer houses, small home’s and garages cable makes a great saw.
    The flaw that I think in your test was the barrel that was welded to the floor, (remember the sparks?)
    If you put the pig near the middle and hook the other end and hit the winch. It might work out better.

  34. bukster says:

    The pottery recording story got a boost today from the BBC news website. In 1860, an inventor Edouard-Leon Scott de Martinville tried etching sound into soot covered paper using a device he called a phonautograph. There was no way to play the sound back. He was just interested in the patterns the sound made into the paper. However using modern analysis, it is now possible to try to replicate the sound.

    Here’s the BBC website link. You can hear the sound. The recording quality is terrible. However, it is now the oldest voice recorded ever.

    http://news.bbc.co.uk/2/hi/technology/7318180.stm

  35. Andrew says:

    I agree with Andrew C. After attending the Marine Institute of St. John’s NL. I have learned that using some synthetic rope of any size would have a deadly outcome.

  36. Ian from Scotland says:

    First of all…LOVE…the show.
    Anyhoo…..Many moons ago, early sixties I think, there was an incident that made news in the “Kyles of Bute”, part of the River Clyde estuary. A steamer called “Queen Mary ll” (no…not the big new one)was moored at the pier at “Tighnabruaich”. One of the mooring cables snapped and lashed across the pier, severing a woman`s leg. Nasty!!
    So, the myth of the killer cable must be at least plausible….Hmmm?

  37. Greg says:

    I was in the Navy in the late 80′s and have seen training films showing a CDP (cross deck pendant, AKA arresting gear cable) snap and sever a flight deck worker’s body just above the waist. Completely in two pieces, guts hanging and the whole thing. They showed us this film at least 5 times while at A school, and I saw it several more times throughout my 6 year enlistment. I don’t recall the name, but it was always shown with “The man from LOX” and the forrestal flight deck fire film. Surely there are some former ABH’s out there that have seen these films!

  38. Doug says:

    Id love to see the wire rope myth revisted. Never seen it happen, but im sure the force of a 1 1/4 cable breaking would do a lot more damage than 5/8. As others stated, nylon or synthetics can have even more force.

  39. Stan says:

    1 1/8 cable used on rig moving trucks in the oil patch make one hell of a mess when they snap.
    There is a reason the headache racks on the back of the winch trucks are built so sturdily.
    Same with dozers, the heavy 1/2″ wire mesh on the back of the ROPS is there for when the winch cable breaks.
    The 4WD poster above is right, stay back at least the length of the cable.

  40. Wes McIntyre says:

    come to Whistler Blackcomb and retest your tests on our winchcats (snowcats in a bog mountain environment on cables)

  41. Sailor says:

    The major concern I have with how they busted this myth is the fact that they used a release to allow the wire to snap back. if the wire had parted under the stresses imposed on it, it would have been because it was stretched past it’s limit. It would have parted and contracted, causing an elastic reaction. The wire hadn’t reached it’s stretch limit because they released it remotely before it got there. In the Navy, as mentioned earlier, we use videos to teach this. I have seen lines part and the results are not pretty. Synthetic line is more dangerous usually but some lines are designed to simply drop in place when they part. (Kevlar is one of them) A training film I once saw shows a mooring line parting and snapping back to COMPLETELY SWEVER THE DECK HOUSE!!! If it can slice off a steel structure I see no reason why it wouldn’t slice through a human.

  42. Brian says:

    The pottery recording in from the X-File’s the Lazarus Bowl

  43. NICK says:

    cables when they break fray at there ends, and from experence are very sharp what if you were hit by the frayed ends of a broken steel or some other cable i have feeling you would not end up to well.

  44. Daniël says:

    As i work in the port of Antwerp, i have seen what steel cables can do with persons and cars. The tention thats on some of those cables is more than u can pull with your tests. maybe u can do those tests again but with some added tension.

  45. Larry says:

    I was a tramp linemen all my life…Building high lines and transmission lines “high voltage lines across country “…In the 34 years I DID see the hard line brake 5 different times… “hard line”…”The winch cable to pull in the large heavy wire” One of the pullers were powered by a V12 Detroit…49,600 feet of 1-1/8 inch all steel cable …Under a very hard pull one day…IT SNAPPED…It took out 3 arms off 3 different towers and twisted 3 more then bent 2 before it got stopped…Another time a 7/8 inch all steel cable broke and tore a H frame steel pole down and took the tops out of 7 large pine trees…Working on a 515 foot 500KV river crossing tower 1966 …when a 5/8 cable got loose and ran free up the tower with the long 515 feet tail pulling it down…The tail snapped 2 peaces of angle iron off like butter…We had a 1 inch all steel cable run free off a 38,000 foot winch…” Like a back latish on a fishing reel…There were all kinds of twists in the cable…We could not un-twist the cable , 6 men and an oak 4×4 8 foot long …So I but a board on the cable, drove a ford 3/4 ton PU on the board and cut the cable…When it was cut and got loose it tore the front fender and the whole grill off the truck…

    I worked for T.D.Bross Line Co …

    We did anything and everything that every one would not and could not do…

    This was back when Linemen were wild and crazy, and there was not word as {{{CAN,T}}} …I.B.E.W. 1249

  46. keith colbourne says:

    at work we had to watch a video of a tuck pulling out another truck , they had 2 short pieces of nylon rope joined with a clevis, the rope broke sent the clevis flying into the truck hit him in the head and killing him .
    keith
    ibew 424

  47. Tom says:

    I was on board a tanker aground on a sandbar and a large rescue tug was trying to pull us off during heavy winds. They were using about 1.5″ cable and it was payed out about 400 feet. My ship was small as tankers go, 40,000 tons, but I’m sure the tension was 100,000 lbs. A BM2 suffered an amputated leg, a GMG1 had a broken ankle and a SN had a dislocated shoulder. Four or five had shrapnel wounds. Pieces of wire flying all over the place.

  48. Dave says:

    The only time I have heard of someone getting cut in half by a snapping cable was an industerial accident. It was not the snapping cable that did it, it was the touque of the drilling rig when it hit rock and yes a person was cut in half. It happened in Colorado 25 years ago. But a snapping cable, busted.

  49. Needa says:

    Frank, you do realise that the playing card, even with Jamie’s super card throwing rig, just bearly drew blood?

  50. mik says:

    well it looks like you guys need to redo this one!!

  51. Anonymous says:

    Maybe not at your torso, but cables are fully capable of decapitation or cutting limbs off. A friend of a friend of mine was decapitated by a cable.

  52. Ami d'un Ami d'un Ami d'un... says:

    Pff, how many urban legends start with “A friend of a friend of a friend of a friend of…”

  53. Brian says:

    This was possibly one of the worst episodes – sorry guys I love the show but this one was seriously flawed

    The puny hydraulic ram and thin cables that were cut was not an accurate representation of the forces involved.

    Jamie even said they were pulling the weight of 10 cars. This is nothing compared to the weight of a ship and a hawser wrapped around a capstan that applies enough force to stretch the cable to snapping point. It needs redoing using a ships capstan.

    As for the acoustic pot

  54. Bill says:

    Mooring lines are much larger

    140000 Lb B/S and snap from nylon is enormous compared to wire

  55. Jack H says:

    A cable simply breaking and perhaps whipping, is one thing. But a cable broken and playing out under load will slice you in two

  56. Steve says:

    In 1967 I worked at my uncle’s prestressed concrete manufacturing facility. The cables in this operation where 400 feet long and where tensioned by a steam powered system of some kind. One day the cables were making a strange singing noise. As my uncle, a civil engineer specializing in prestressed concrete construction stepped over one of the cables to examine it, his foreman followed. As the foreman stepped over the cable the device that held the cable failed and sliced the foreman almost in half. The cable sliced upward through the groin detaching the hip and one leg and threw the rest 400 feet in the opposite direction. The episode that tested this “myth” did not recreate the kind of instantaneous release of energy that a failure of this kind can create.

  57. danR says:

    Sounds from the later comments that Mythbusters’ test here has been busted.

    Obviously people can be cut in half under the right circumstances and Mythbusters haven’t even come close to the right circumstances.

  58. Doug says:

    After seeing how much flawed testing is done on this show, I think they should renamed the show and call it “Myth Makers “.

  59. Martin Wilson says:

    The Mythbusters really need to re-visit this one. The issue here is energy, and its storage and release. A wire rope in tension stores energy as a spring. The amount of stored energy is given by Energy=1/2*k*x^2. The energy is stored in the length of the cable. They used only 15 or 20 feet of cable. If they did exactly the same thing, but went to the aircraft runway and used 1,000 or so feet, they could easily demonstrate cutting a pig in half. A rough calculation, using the 5/8 cable (assuming 6 x 19 Class Heavy Duty IWRC Rope) and 20 feet long tensioned to 30,000 lb.s, stores about 3,000 ft. lb.s of energy. It the cable was 1,000 feet long to start with, and tensioned to the same 30,000 lb.s it would store 166,000 ft. lb.s of energy. If that energy were released in one second, it would generate over 300 horsepower, plenty of power to cut a pig in half. If you really want to be impressive, make the cable 2,000 feet long (doubles the energy stored and the power generated).You could cut several pigs in half with that.

    • Bruce Weidenhamer says:

      There is an additional situation that has not yet been discussed. In the early days of stream powered donkey engines the winch was stationary so the cables were run through many pulleys to get to the work site. These pulleys were often anchored by long cables. When the pulley cable snapped under load the energy stored in the winch cable was released laterally. Image standing in the bend of a drawn bowstring when it is released.

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