Can high-pressure steam cut a body in half?

[What Exit?]

http://www.straightdope.com/columns/060804.html

Concerning the final paragraph:
Some industry sources speculate that using a broom to search for leaks may have started aboard ships with steam boilers, where tight quarters and noisy conditions may have made it difficult to find leaks quickly without some direct evidence. It may even have been recommended as a way to survive a steam leak, using the broom to check that the route to safety was clear. Then again, most shipboard steam isn't at high enough pressure to slice through wood (although it could cut the bristles). Personally I'm guessing the broomstick thing is part of the informal neophyte training process familiar to anyone who's worked in industry: "Did they tell you about high-pressure steam leaks? Cut you right in half. Better wave this broom."

I was on the USS Ranger CV61 from 1985 to 1989. The Ranger is now retired.
...The Steam used on the ship in various applications was 1200 PSI, 600 PSI, 300PSI an 150 PSI. In the machine spaces, 1200 PSI was piped to many locations. It was used to drive the 4 main shafts, to power the eight primary electrical generators and IRC to operate the Flash/Evaporator water distillers. I think 1200-PSI steam was used for the steam catapults. I am sure I am forgetting applications, as I was an Electrician Mate and not a Boiler Tech. We had training concerning the threat of 1200-PSI steam and the broom handle was never mentioned.
...A very small steam leak from a valve was noisy enough to hear over the ear protection and machine noises and quickly created a cloud of steam that was easily seen. I am grateful I never witness a major leak but one chief had his arm very badly burned in a 1200-PSI leak his other arm broken by the Petty officer that grabbed the Chief’s arm and dragged him hard and quick out of the area of the leak. The Chief, who was a Grizzle old Vietnam small boats veteran, said he was never more afraid in his life.
...Anyway, all of this was to make the point that we did have 1200-PSI steam, it was considered very dangerous and we were never told anything about using a broom to test for leaks.

Jim

[Dinsdale]

Just wanted to observe that perhaps we may need a new appellation for una. Member, assistant, staff, may be insufficient. I propose that we hereafter afford una her due and properly refer to her as primary source! ;)

[kaylasdad99]

We might also benefit from a pronunciation guide. OO-NAH, or YOU-NAH?

I usually pronounce it Oo-nah in my head.

[What Exit?]

We might also benefit from a pronunciation guide. OO-NAH, or YOU-NAH?

I usually pronounce it Oo-nah in my head.
Hardly a guide, but I went to High School with a girl name Una and she pronounced it Oo-nah.

[Daithi Lacha]

A pal's older brother did a stint in the Merchant Marines out of NY. He told us about the whole broom-handle thing, checking for leaks. He said they would even fine you if you whistled below decks, as it would put everyone on the alert for escaping steam. I don't know if he was ribbing us, or if he was the rib-ee.

[Cervaise]

I usually pronounce it Oo-nah in my head.Oo-nah, Oh-prah. Oh-prah, Oo-nah.

[Lemur866]

Another shipment of kudos for Una. Do you ever get tired of our adulation?

[Una Persson]

I pronounce it "oo-nah", if you all really are curious...
Another shipment of kudos for Una. Do you ever get tired of our adulation?
No adulation needed; I'm not worth it. All I want to do is help people out on science and engineering topics where I can.

[robby]

I served on submarines from the late 80s to mid-90s. Our main steam was at about 600 psi. I heard the broom thing numerous times. There was no question that you would hear the leak; the broom was supposed to help keep operators from blundering in front of a small, invisible jet of steam while the leak was being isolated.

[robby]

I pronounce it "oo-nah", if you all really are curious...

No adulation needed; I'm not worth it. All I want to do is help people out on science and engineering topics where I can.
P.S. I was pretty impressed myself to see you immortalized in an actual column of Cecil's, Una.

[Rhubarb]

My 2¢ worth on the broom story. I served aboard a destroyer in the 70's with a 1200 psi superheated steam plant and I witnessed (and repaired) a fair number of small steam leaks. It is the noise that alerts you to their existence. Finding them by sound is a different matter. Since there may be a number of possible sources in a relatively small area, and you need to know exactly what is leaking and where, the recommended method for locating small steam leaks was to use an inspection mirror. Droplets of water would condense on the mirror when it encountered the steam. You could then decide whether it could be repaired immediately, usually not the case, or simply roped off until you returned to port.

As far as using a broom, that story was widespread in the Navy. I first heard it in "A" school. On one occasion we got the opportunity to see if it was true. There was a leak in the main steam strainer (immediately above my head where I stood Throttle Watch). The EOOW (Engineering Officer of the Watch) had one of the messengers fetch a broom and tried to cut it in half with the steam. While it didn't cut it in half, the handle got pretty severely charred and the bristles actually caught fire. Every one in the engine room was suitably impressed and none of us EVER tried to find a steam leak with just our hands.

[Malienation]

I saw a show on (TLC?) a couple of years ago in which fairly intricate designs were cut using a tiny hi-pressure water jet in 1" thick glass. And I saw a show on the Food network a few months ago in which they show a hi-pressure water jet used to cut sandwiches in a sandwich factory.

[Una Persson]

I saw a show on (TLC?) a couple of years ago in which fairly intricate designs were cut using a tiny hi-pressure water jet in 1" thick glass. And I saw a show on the Food network a few months ago in which they show a hi-pressure water jet used to cut sandwiches in a sandwich factory.
True - you're thinking of water jets. But those use quite a bit higher pressure - on the order of tens of thousands of psi.

Here's a quick link I Googled that talks a bit about that: http://www.flowcorp.com/waterjet-resources.cfm?id=335

[chorpler]

Yeah, my brother's friend owns his own water jet thingamajig that he uses to cut thick sheets of metal and glass into intricate computer-controlled designs. We had him carve a logo for my dad's company out of aluminum and stainless steel. But as Una said, it operates at like 20,000 psi, and he said it also uses grains of sand when cutting metal, although he may have been making that up.

I'll tell you what, though -- that thing would have no trouble slicing a broom handle in half.

[chorpler]

Yeah, my brother's friend owns his own water jet thingamajig that he uses to cut thick sheets of metal and glass into intricate computer-controlled designs. We had him carve a logo for my dad's company out of aluminum and stainless steel. But as Una said, it operates at like 20,000 psi, and he said it also uses grains of sand when cutting metal, although he may have been making that up.

Huh. According to Una's link, he wasn't making it up; they do add abrasives when cutting things that are very hard, like metal.

[Lizard]

True - you're thinking of water jets. But those use quite a bit higher pressure - on the order of tens of thousands of psi.

Here's a quick link I Googled that talks a bit about that: http://www.flowcorp.com/waterjet-resources.cfm?id=335

That is an incredibly fascinating website. This technology has been around for several decades but I've never heard of it before. According to the site linked, streams of water .004 to .1 inch are used to cut materials from plastic diapers to concrete. The water stream is traveling at Mach 3 when under 60,000 p.s.i., and the pressure also heats the water up to 170-180 degrees Fahrenheit.

Clearly, these machines are not to be messed with. But they sound way cool! I wonder what it would be like to see the concrete-blaster in action. Given how hot the water is, would everyone have to keep their distance?

[Lizard]

And I should add that maybe a steam leak on a ship couldn't cut a body in half, but the the devices mentioned in that leak sure could!

[Lizard]

Oops. :smack: "Link," not "leak."

[Northern Piper]

I may be misremembering here, but I seem to recall reading the broom thing in one of Heinlein's short stories. If confirmed, that could be the source of it - alternatively, it could be that as a Navy man, he was incorporating what he'd heard in the service.

a very inconclusive post.

[Exgineer]

I have absolutely nothing to add to the steam discussion unless somebody asks a more specific question, but even then Una would get to it with a more concsise, complete, better written, and more accessible answer than I could ever come up with. And I have a Master's in power systems.

She rocks, I suck.

[TimeIsRight]

I was a Machinist Mate (MM) in the US Navy, stationed on a steam powered Destroyer in the early 70s. The speed (US ships of that era) was controlled in the engine room. The MMs do this by turning a large wheel that opens or closes the main steam valve to the turbine engines. The steam was superheated and was used to power generators/pumps/turbines located in the engine room. We were told to use a broom stick to find steam leaks. Thankfully no one I know of ever had to do it.

[myronpeek]

Just to add to the volume already in the link, I served in the Navy from the 70's thru the 90's as a Machinist Mate in the engine room. We were taught to check for steam leaks with a broom ( or other relatively "soft" object) to protect ourselves from verifying this particular question. Hope this helps.

[What Exit?]

Great, so none of the MMs & BTs bothered to tell the EMs how to avoid getting par boiled by a steam leak. Nice guys, I thought we were all fellow snipes. ;)

Jim

[Rhubarb]

Great, so none of the MMs & BTs bothered to tell the EMs how to avoid getting par boiled by a steam leak. Nice guys, I thought we were all fellow snipes. ;)

Jim
Sorry, unless you got "greased", you're a mere fresh air snipe. Important information such as this is reserved for us hole snipes.
OTOH, if you did get greased, welcome to the brotherhood, and where the hell were you on the How not to get the shit burned out of yourself in the engineroom class day? Probably off replacing the batteries in the sound-powered phones. :p




Rhubarb - Charter member of Fraternal Order of Packing Pullers, Local #OU812. Motto - "A packing puller in the hand is worth two in the valve." :D

[What Exit?]

Sorry, unless you got "greased", you're a mere fresh air snipe. Important information such as this is reserved for us hole snipes.
OTOH, if you did get greased, welcome to the brotherhood, and where the hell were you on the How not to get the shit burned out of yourself in the engineroom class day? Probably off replacing the batteries in the sound-powered phones. :p




Rhubarb - Charter member of Fraternal Order of Packing Pullers, Local #OU812. Motto - "A packing puller in the hand is worth two in the valve." :D
No, I looking for some Gig Line to lower a bucket of steam down to the Bowling alleys. We let the IT boots change the batteries in the sound-powered phones.

I never got greased, so despite my work in the main space, I was definitely a Fresh-Air Snipe.

Jim {EM3}

[windydink]

This leak detection proceedure was told to me by a WWII vetrean engine room seaman who served in the south pacific aboard vessels utilizing superheated steam for power and propultion. One story related was that at that time his responsibilities was "Oil Can". His captain even introduced him to General McCarthur for his successful efforts to keep the ship stabilized by transfering fuels and ballast after the ship was hit by a torpedo. He eventually became a chemist and US Air Force Fuels Operations Officer. This friend is now approximately 80.

As mentioned, the primary hazard was scalding burns from sudden steam leaks in enclosed spaces. The intent of utilizing the boom handle was to locate the leak without causing damage to human limbs. He never stated the leaking steam would actually cut the broom handle. As one commenter previously noted, in one test, the wood handle was not cut but severly burned.

Regarding the use of using water jets to cut steel, I worked with this gentleman and his terminal engineers and managers. I was not present but a contractor in the early 1990s used the method to cut a 36" diamater "Manway Hole" into the side of a 1980 vintage steel gasoline tank. The steel was between 3/8 " and 7/16" thick. Only water was used as the fire hazard was high due to gasoline stored in adjoning tanks and we did not want sand to contaminate the interior of the tank being cut..