Steam rocket

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marksteamnz
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re: Steam rocket

Post by marksteamnz » Tue Aug 16, 2005 9:45 pm

Quote

"High pressure steam can be very dangerous due to it not being visible where a leak might be. In the WW ll era, the techs. working on the catapults on aircraft carriers used to carry a wood stick to sweep around inside any access hatches that they were going to reach into. This was done after a tech. reached into a hatch, and had his hand and forearm severed by an invisible high pressure steam jet caused by a pinhole leak."

Nope Unless the steam is superheated, and steam rockets aren't, you get visible condensation from the saturated steam straight away.
I believe the cut his arm off story is an urban legend. If you can cut your arm off with a pinhole leak from high pressure what ever no one would ever rent you a water blaster / pressure washer. My tiny 2500psi one stings a bit when cleaning the concrete in bare feet.
Doble D2 (800psi steam car) ran for the last few days of a tour I was on with a perforation in a thermocouple pocket. Inefficent, loud hiss and a miserable performance due to the leak, but we were all crowded round the steam genrator working on it during the stops and we all still retain a standard number of digits
Last edited by marksteamnz on Wed Aug 17, 2005 8:31 pm, edited 1 time in total.
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Mark Stacey
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Bruno Ogorelec
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Re: re: Steam rocket

Post by Bruno Ogorelec » Tue Aug 16, 2005 10:39 pm

marksteamnz wrote:Doble D2 (800psi steam car) ran for the last few dys of a tour I was on with a perforation in a thermocouple pocket. Inefficent, loud hiss and a misserable performance but we were all crowded round the steam genrator working on it during the stops and we all still retain a standard number of digits
I presume it was inefficient and performing poorly due to a leak, right?

marksteamnz
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Re: re: Steam rocket

Post by marksteamnz » Wed Aug 17, 2005 8:28 pm

Bruno Ogorelec wrote:
marksteamnz wrote:Doble D2 (800psi steam car) ran for the last few dys of a tour I was on with a perforation in a thermocouple pocket. Inefficent, loud hiss and a misserable performance but we were all crowded round the steam genrator working on it during the stops and we all still retain a standard number of digits
I presume it was inefficient and performing poorly due to a leak, right?
Yes Sorry I dashed the post off in a hurry. D2 had only one weeks running before the tour and was in shake down mode, there just wasn't the time and facilities to get at the pocket and weld up the leak. Doble E11 was also there and it has 1000's of kilometers under it's wheels in the last few years. It runs really well as efficiently for a car of it's generation 1920's. Doble are big bits of kit so you have to compare them to a Rolls Royce or a Packard of the 1930's. Doble was about 10 years ahead of his time perfomance wise.
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Mark Stacey
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Bruno Ogorelec
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Re: re: Steam rocket

Post by Bruno Ogorelec » Wed Aug 17, 2005 8:46 pm

marksteamnz wrote:Yes Sorry I dashed the post off in a hurry. D2 had only one weeks running before the tour and was in shake down mode, there just wasn't the time and facilities to get at the pocket and weld up the leak.
Ah, good. For a moment, I thought you had found Doble a poor machine and was dumbfounded. I've always thought it was one of the finest cars made before WW2.

I've had dreams about a steam car with a propane-fired pulse combustor boiler and a 2-stage Wankel engine. It would probably make for the most compact steamer ever. If a pulsating combustor were used, it would even make engine noises. That's the only thing I have ever held against steam cars -- they don't make a proper noise.

I'd use a low frequency valved pulsejet as combustor, with heavy valves or perhaps with a pre-chamber for valves, like those Japanese designs, to make the thing long-lived. Boy, I'd really like that. A much more interesting way to beat clean exhaust rules than the hybrid Toyotas, I'd say.

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Re: re: Steam rocket

Post by larry cottrill » Wed Aug 17, 2005 9:18 pm

marksteamnz wrote:Nope Unless the steam is superheated, and steam rockets aren't, you get visible condensation from the saturated steam straight away.
I believe the cut his arm off story is an urban legend.
Mark -

I believe that superheated steam is in fact the issue here. I used to work with a land surveyor who was a heavily tattooed ex-Navy man who related a similar story. He worked on a destroyer (I think it was) and supposedly knew a man who was sent to look for a leak that had been heard by several different observers. The Chief Petty Officer told this guy to get a broom from a supply closet and use that to probe for the leak, but he came back with three fingers missing, and supposedly "never bled a drop," because the invisible steam jet had instantly sealed up the severed ends. Obviously, I can't verify the story, but this wasn't a guy prone to making up a lot of tall tales just to impress people, and he claimed to have been there to see it. High pressure superheated steam could certainly do the job, and it would be piped around in the engine areas of most steam-powered ships.

L Cottrill

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Re: re: Steam rocket

Post by xxbgxx » Wed Aug 17, 2005 10:06 pm

Larry Cottrill wrote:
marksteamnz wrote:Nope Unless the steam is superheated, and steam rockets aren't, you get visible condensation from the saturated steam straight away.
I believe the cut his arm off story is an urban legend.
Mark -

I believe that superheated steam is in fact the issue here. I used to work with a land surveyor who was a heavily tattooed ex-Navy man who related a similar story. He worked on a destroyer (I think it was) and supposedly knew a man who was sent to look for a leak that had been heard by several different observers. The Chief Petty Officer told this guy to get a broom from a supply closet and use that to probe for the leak, but he came back with three fingers missing, and supposedly "never bled a drop," because the invisible steam jet had instantly sealed up the severed ends. Obviously, I can't verify the story, but this wasn't a guy prone to making up a lot of tall tales just to impress people, and he claimed to have been there to see it. High pressure superheated steam could certainly do the job, and it would be piped around in the engine areas of most steam-powered ships.

L Cottrill

:shock:

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Re: re: Steam rocket

Post by marksteamnz » Thu Aug 18, 2005 8:23 am

Larry Cottrill wrote:
marksteamnz wrote:Nope Unless the steam is superheated, and steam rockets aren't, you get visible condensation from the saturated steam straight away.
I believe the cut his arm off story is an urban legend.
Mark -

I believe that superheated steam is in fact the issue here. I used to work with a land surveyor who was a heavily tattooed ex-Navy man who related a similar story. He worked on a destroyer (I think it was) and supposedly knew a man who was sent to look for a leak that had been heard by several different observers. The Chief Petty Officer told this guy to get a broom from a supply closet and use that to probe for the leak, but he came back with three fingers missing, and supposedly "never bled a drop," because the invisible steam jet had instantly sealed up the severed ends. Obviously, I can't verify the story, but this wasn't a guy prone to making up a lot of tall tales just to impress people, and he claimed to have been there to see it. High pressure superheated steam could certainly do the job, and it would be piped around in the engine areas of most steam-powered ships.

L Cottrill
One last thing to ponder before I retire from this subject raising the white flag. Why would the GAS (superheated steam) being hot, even very hot, so vastly improve it's cutting ability over a liquid at the same pressure?
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Mark Stacey
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larry cottrill
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Re: re: Steam rocket

Post by larry cottrill » Thu Aug 18, 2005 3:48 pm

marksteamnz wrote:One last thing to ponder before I retire from this subject raising the white flag. Why would the GAS (superheated steam) being hot, even very hot, so vastly improve it's cutting ability over a liquid at the same pressure?
Mark -

Darned if I know. It may just be the vulnerability of animal tissues to that kind of temperature, for example. I certainly can't imagine it cutting through a piece of steel (which CAN be cut, very accurately, by high pressure water, apparently!). If the story is true, there was some experience that led to the chief admonishing the guy to use a broom (presumably, the straw end) to do his probing.

And, as I said, I can't really vouch for the story, just that it didn't come from a totally "wild hare" source, a trustworthy and honourable man who was certifiably completely sober at the time of the telling. He also told us one time how he got so many tattoos: He and his friends on shore leave would come out of a bar, and he would hear the buzz of the little machines coming from the local tattoo parlors - a siren song drawing him inexorably in "just to look at the designs" ... Ha!

L Cottrill

Al Belli
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re: Steam rocket

Post by Al Belli » Thu Aug 18, 2005 4:10 pm

Hi Larry,

Waterjet cutting of steel uses an abrasive slurry. Waterjet cutting of softer materials can use plain water, and is widely used in industry.
The portion pack food plants use waterjet cutting to accurately divide the slabs of product ( like salmon fillets ) into fixed size portions, prior to cryovac sealing. The shape of the bulk product is measured ( in 3D ) by a laser system. The correct integrated portion size is output to the conveyor-based transport system, where the waterjet head cuts the correct size portion from the bulk product. This sounds like an expensive way to separate product into individual pieces, but the savings are excellent due to the elimination of miscuts which relegate the miscut portions to a much lower priced product category.

Al Belli

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re: Steam rocket

Post by marksteamnz » Mon Aug 22, 2005 9:29 pm

OK I lied when I said I was going to leave this alone but no one has pointed out the obvious. Water jets for processing meat etc start at 30,000psi, for cutting hard substrates starting pressures are 40,000psi and as noted you have to inject abrasive into the flow. The presures in ship steam plants are at the most 2500psi. Comparing apples and oranges I feel.
My question still remains. Why is a hot gas at 2500psi so much better at slicing body parts than a water blaster at the same pressure?
As an aside I have seen on video Rod Muller of Strath Steam put a piece of timber into the massively superheated outlet of a 1000psi steam generator. It didn't cut it but it did eventually set it on fire.

Re steam rockets there is also another link worth following showing it isn't instant death assuming proper engineering. http://www.swissrocketman.com/ete02.html
Cheers
Mark Stacey
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larry cottrill
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Re: re: Steam rocket

Post by larry cottrill » Tue Aug 23, 2005 4:14 pm

marksteamnz wrote:Re steam rockets there is also another link worth following showing it isn't instant death assuming proper engineering. http://www.swissrocketman.com/ete02.html
Mark, that is impressive. A nice size, too.

L Cottrill

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Re: re: Steam rocket

Post by xxbgxx » Thu Aug 25, 2005 12:16 am

Larry Cottrill wrote:
marksteamnz wrote:Re steam rockets there is also another link worth following showing it isn't instant death assuming proper engineering. http://www.swissrocketman.com/ete02.html
Mark, that is impressive. A nice size, too.

L Cottrill
THATS WHAT AM TALKING ABOUT
but dam such a steam rocket is hard to build

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