Is This The Fastest Manmade Object Ever?

Hiya…Kara here. Since Gunther didn’t have much to say about our ongoing winter stop here in North Fort Myers I figgered I should try to edumacate ya’ll just a bit. Besides…I wuz bored.

Let’s ponder the question of “What’s the fastest manmade object ever?”

Like many of you…I had long thought based on reading it both on the web and in other credible media sources that the fastest objects ever created by mankind was Voyager I which was launched way back in 1977…it’s now past the outer reaches of the solar system in interstellar space and is traveling at 38,610 mph. This was just something I’ve known for a long time it seems like. Then out of the blue…into my email pops a reference to an article about a nuclear powered manhole cover…so I read the reference article and sure enough…it claims that the story is true and that it went down like this.

Back in the early days of nuclear warhead testing…everything was tested above ground…which as you know leaves a lot to be desired as it allows the immediate radiation of the blast to go out and do radiation things to nearby people and/or wildlife. In addition there’s that whole pesky radioactive fallout problem. Short tangential note…most people think that radiation and contamination are the same thing but they are two distinctive things. Radiation is stuff like gamma rays, neutrons, and alpha particles and contamination or fallout is normal stuff that is penetrated by the radiation…this results in what nuclear scientists call activation where the normally non radioactive dirt sucks up a gamma or neutron and gets turned into something that will decay radioactively. It’s a poor analogy…but think of it like poo and smell…the smell is similar to the radiation and the poo is the stuff that sticks to your shoe when you walk through the cow pasture.

Anyway…due to the radiation and fallout problems those smart scientists wondered if they could do underground testing instead…thereby keeping the radiation from getting out as it’s attenuated by the dirt and the radioactivity from getting out as it’s buried…well, last least as long as the blast doesn’t open up the surface which is usually the case. The problem is that back in the early days they set off lots of warheads to study how they went off, what sort of particles they produced and other weapons related topics…so they weren’t sure how their instrumentation would work for underground tests or if they needed to build something different. Being good engineers…they decided to conduct some tests…and came up with a series of tests under an operation called Plumbbob. Two thirds or so through the 29 warhead testing series they had a warhead named Pascal-A where they bored a 4 foot diameter 500 foot deep hole and put a small nuclear warhead (well, it was small as nukes go but in real terms was pretty darned big at a yield of 55 tons of TNT). Leaving the hole open they backed away and set it off…resulting in the world’s largest Roman Candle as blue flames rushed out of the open hole. Their instrumentation seemed to work OK though…so they went on and built a larger 300 ton warhead (or so they thought) named Pascal-B.

For Pascal-B they decided to cap the hole since some of the radiation and radioactive fallout came out the shaft…see the world’s largest Roman Candle above. So they lowered the warhead to the bottom of their 500 foot deep shaft, plugged the shaft with a 5 foot thick concrete plug, and welded a steel plate 4 feet in diameter and 4 inches thick to the top of the shaft…the plate weighed about 1,900 pounds. They weren’t sure whether the cap would stay on so they aimed a 160 frame per second movie camera at the plate with a vertical field of view at the plate of about 1/4 of a mile or 1,320 feet. Backing further away than they did for Pascal-A…they again set it off. Just a small amount of smoke and debris were visible coming out of the shaft so they declared the test a success…and went back to the lab to review the film.

Unfortunately…on review of the film it turned out that it showed them exactly nothing. In one frame the cover is there, intact, and no visible evidence of the detonation at the surface is visible…in the next frame 1/160 of a second later the plate is just gone…analysis of the top of the shaft later revealed that the plate was gone. No trace of the plate or the concrete plug which was about 10 feet from the warhead was ever found.

So think about this…what you have here is a nuclear powered potato gun. A 500 foot long 4 foot diameter barrel aiming straight up and set off 300 tons equivalent (it was actually more depending on which scientific analysis of the test you read on the web…it’s a deep rathole:-) of TNT at the bottom. The temperature and immediate radiation of the blast vaporizes the concrete into plasma (really hot gas) which then expands up the barrel toward the cap. Naturally the welded down cap pops off and is propelled upward.

Now remember that the camera was 160 frames per second which means that since the cap was visible in one frame and gone in the next it went a quarter mile in 1/160 of a second. Doing the math this means the cap was doing at least 144,000 mph when it departed the top of the shaft…or 45 miles per second.

I decided to check this out and did a little googling…and I told you it was a very deep rathole didn’t I…there are numerous web pages on the web dealing with both this test, it’s possible speed, what happened to it, did it get into orbit and tangentially what are the fastest manmade objects.

First off…turns out that Voyager isn’t even close, it’s only in 3rd place at best. Both Helios 1 and Helios 2 which were solar probes in the 1970s achieved higher velocities…142,000 and 157,000 mph respectively as they passed perigee near the sun as they orbited it in elliptical fashion. So so much for Voyager’s relatively pedestrian 38,000 mph.

Following the rathole farther…there’s considerable reason to believe that the 144,000 mph speed of the shaft cap from Pascal-B was a minimum speed and not a maximum speed. Because of the way high speed movie shutters worked back then…the difference between the end of one frame and the beginning of the next could have been as little as 1/320 of a second…which would mean that the cap departed the shaft at up to 288,000 mph. The camera wasn’t fast enough to capture the plate in flight so more precise calculations are impossible…so we’ll stick with the speed of the cap (or manhole cover in internet legend-speak) as minimums. Even the 144,000 number is over 6 times the escape velocity for the earth.

Since no trace of the cap was ever found and it was most likely ejected straight upwards…what happened to it. Four possibilities come to mind from perusing the internet…it went into interplanetary space, it went into orbit, it crashed, or it burned up.

Interplanetary space can’t be ruled out except by inference. Recall (or maybe you don’t recall…but it’s readily googleable) that meteors are traveling at about 66,000 mph as they enter the atmosphere and you know what happens to them, right? They burn up…or at least slow way down so that they crash into the earth. Would 1,900 odd pounds of flat plate steel burn up or maintain enough speed to escape earth’s gravity? Nobody knows. Would the friction/air compression deform the plate into a teardrop shaped and more aerodynamic shape so as to cut down on heating/slowing? Probably but again nobody knows. 

Orbit can pretty much be eliminated as the departure trajectory of straight up (or nearly so depending on how it tumbled) is the wrong direction. Orbital launch trajectories go up and then gradually fall over to the almost horizontal so that the velocity at orbit is parallel to the earth’s surface and hence the orbiting object continually falls around the earth.

Crash…yeah, that coulda happened and just nobody found it but lack of finding it doesn’t provide evidence that it didn’t happen.

Burning up/coming apart is the most likely result from analysis of the pages I found…while it’s initial velocity might have been 45 (or 90 if you buy the 1/320 of a second argument) miles per second…but it surely didn’t stay at that velocity very long. Even in the first half second as it passed through the majority of the atmosphere it slowed down a lot and remember it was doing 2-4 times the speed of a meteor and was transiting much denser portions of the atmosphere…most meteors burn up at >50 miles in altitude.

Some of the rathole even suggested that this was the first object in space…thereby beating out the Soviet Sputnik 1 which was orbited later in 1957…but even Sputnik wasn’t the first object in first, it was just the first orbital object in space. The first object in space…generally defined as being above 100 km or 62 miles in altitude…was the German V2 rocket first launched in the 1940s…they reached 170 miles in altitude before crashing into London and the surrounding area.

If you’re really, really, really bored…here are a couple of links you can look at…but I gotta warn you it’s a deep, deep rathole.

Personally I found the whole exercise intellectually stimulating, educational as I thought Voyager was the fastest object ever, and interesting reading for an hour or so.

You can thank me for the edumacation later:-)

OK, a couple of funnies for ya and I gotta go.

Now its your chair

The I in Team

Engineering Flow Chart

We have eaglets…two of ‘em. E7 and E8 were born on January 26 and 27 respectively and are now being brooded and fed by Harriet and dad M15. I’m sure that the adults are happy that the rainy weather of the past 2.5 days is over and although it’s cool today in the mid 60s…the sun is out and it’s gotta be a lot warmer for the babies. The eaglets will grow quickly and by the time they fledge 80 days or so into life they’ll be physically as large as M15 at least.


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5 Responses to Is This The Fastest Manmade Object Ever?

  1. seamus says:

    by george, i think she’s got it…

    i would suggest that vaporization be given fair consideration, given the following factors –

    1 – Heat – no mention is made of any thermal calculations relative to the testing protocols used at the time, probably late 30s, early 40s… it is entirely feasible that at that time the technology to measure the temperature inside the pipe accurately was neither available or recoverable. consider: if you light a firecracker, set it on the ground, cover it with a saucepan and hold your hand on top, you will feel the heat transfer. needless to say heat generation during these tests was massive, probably unmeasurable even with todays’ technology.

    2 – Metallurgical – while metallurgical technology was advancing as an integral part of nuclear research at the time, we do not know the exact chemical make-up of the steel used for the pipe and cover – how much carbon? beryllium? nitrogen? my guess would be ordinary pig-iron, a fairly soft, porous, relatively unrefined metal which is malleable and has a lower melting point than more refined metals. even todays’ modern complex metal formulations cannot be given sufficient heat protection – as an example, even the space shuttle outer skin has ceramic panels to dissipate heat upon re-entry. take the SR-71 spy plane; leaks like a wood bucket on the runway, leaves a trail of fuel behind it; it’s designed to do that. on takeoff, heat causes the fuselage to expand, thus sealing the leaks; kinda shadetree, but it works…


    not only was the concrete plug vaporized, it is probable that the pipe and mhc were instantly vaporized as well. core samples from the strata at the site both pre and post test would bear this out if it had been done at the time – i’m thinking 360 circle radiating outward from the site. there would no doubt be empirical data available from the soil samples as regards chemical makeup both pre and post detonation. had thermal imaging been available at the time, it might very well show that vaporized particulate was the end result – nuthin’ but gas… this brings us to the photography angle – could the lack of evidence suggest an optical illusion ? my thinking is this – have you ever seen a propeller- powered airplane running? the prop starts spinning, disappears as it picks up rpm’s, and if/when it reaches a certain velocity it appears again, almost looking like it’s not running at all ? if you have ever seen the airplane races out west you’ll know what i mean – the prop is spinning so fast it seems to be stopped or spinning very, very slowly. i’ve got to surmise that the camera speeds of the time were far too slow – i’m thinking in terms of milliseconds here, which begs the question – is it even possible to develop a set of parameters to measure a “speed/rate of vaporization ? we can photograph a hummingbird in stop-motion, but i’m betting this would be much faster… to quote the german guy on “Laugh-In”, velly interesting…

    i mighta hadta guess nuclear colliders were da fastest… even faster than amanda in her first car…

    fastest non manmade ? chipmunks… little bastid zipped ‘cross dat loggin’ road, hadta stop an’ let his stripes catch up…

    yall be good.


    • Neil Laubenthal says:

      From an engineering standpoint…it most likely was a combination of vaporized by the initial blast, shredded by the acceleration, and melted/fragmented by air friction…so it most likely departed the top of the shaft in the process of all that other stuff happening.

      It was a neat story though.


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