You were only supposed to blow the bloody doors off...
Updated: Mar 9, 2019
There are some stories that stick with you.
The newspaper article that spawned Scapegoat is one of them, and a story I was told in a bar in Romania another.
It started off the way many stories do - talking about something else.
In fact, we were talking about fireworks which, it turned out, were something my travelling companion had made earlier in his life.
‘What’s the largest firework you’ve ever made?’ I asked by way of conversation.
My companion described his best effort before adding the footnote which led me to this fascinating story.
‘Arguably the Americans made the largest firework in 1957 – a 500ft Roman candle,’ he said.
I think you’ll agree that that is one of those statements you can’t just leave hanging.
‘What do you mean?’ I asked.
‘The American’s Pascal-A test,’ came the reply, ‘when they tested what would happen if you accidentally detonated one of the plates on a nuclear bomb.’
I stayed silent.
‘They put this bomb at the bottom of a 500 ft deep shaft in Nevada, effectively fired a shotgun at it and expected to see a minor explosion which was the equivalent of 1-2 pounds of TNT,’ my companion paused for dramatic effect. ‘What they actually got was fifty thousand times bigger; the equivalent of 55 tons of TNT.’
Legend has it that this night-time test then created a jet of multi-coloured flame and expanding gases which shot thousands of feet into the air.
Hence the world’s largest Roman candle.
‘But that’s not the interesting one,’ my companion continued, pausing to sip his beer, ‘that was the next one - Pascal-B - when they tried the same thing but put two tons of concrete over the bomb and a steel plate at the top of the shaft to stop the embarrassing Roman candle effect.’
‘Why is that one more interesting?’ I asked, assuming the concrete and the steel plate would do their job.
‘Because they still anticipated 1-2 pounds of TNT for the size of the explosion, but got a larger one even than the roman candle.’
‘Oh, how much bigger?’
‘This time they set off the equivalent of 300 tons of TNT at the bottom of the shaft.’
This is an extract from the US Government Report of the "safety experiment":-
Now, I don’t know about you, but my experience with TNT is pretty limited.
Aside from lighting a banger under a tin can, I have nothing to gauge this against, but I’m guessing at this point that the equivalent of setting off 1,200 conventional bombs at the bottom of a sealed tube is going to have some consequences.
‘Interestingly, it wasn’t the explosion itself that dislodged the metal plate on the top,’ my story-teller continued, ‘but the vapourised concrete shooting up the tube as a ball of expanding gas at fifty six kilometers a second.’
No. I can’t picture what’s happening here either.
‘Which meant the 900 kilo metal plate on top of the shaft not only got dislodged, but propelled upwards so fast it didn’t register in anything other than the opening frame of the high speed film they took of the incident. In one frame it was there, in the next it had vanished.’
The experiment designer, Dr Brownlee, later gave his considered, measured, scientific account of the speed the manhole cover was travelling.
“It was going like a bat,” he told a reporter.
Speed estimates vary - anything up to Mach 194 - or 147,600 mph.
Whichever figure you believe, the manhole cover departed the Nevada countryside travelling fast enough to make it into orbit.
This is the stuff of internet legend.
You’ll find online great debate over whether this bit of steel made it into space. It certainly set off with enough velocity, but I think the consensus is that it vapourised before it got there.
But while there is a tiny chance that it made it into orbit, we have the wonderful picture of the first object being fired out of our atmosphere not being Sputnik, but a manhole cover accidentally shot into space by the Americans in 1957.
Can you imagine looking out of your space-station window and watching a 900 kg manhole cover float by?
There is a follow-up to this story I discovered whilst looking some of this up.
The Americans did actually toy with the idea in a project called “Thunderwell” of using this principle to fire a rocket into orbit – using a conventional nuclear bomb under a stack of water and propelling the rocket upwards using the propulsion from the vapourised water.
This isn’t too dissimilar a process to the one my old-fashioned pop-gun used to fire its cork; albeit this version used a nuclear bomb instead of a seven-year-old pumping the handle.
After scientists considered the idea, there was one elephant in the corner of the room.
Not that it wouldn’t work, but the rate at which it would accelerate the rocket.
To put this into perspective, the average Ferrari will cover ¼ mile in about 10 seconds; by comparison the astronauts would travel upwards of 20 miles in the first second and have made it from London to Liverpool by the time the sluggish Ferrari had reached the 1/4 mile marker.
Of course, the human body isn’t designed to accelerate from zero to fifty kilometers per second in the blink of an eye, so the elephant the scientists couldn’t ignore was that the astronauts would be decorating the cockpit’s rear bulkhead by the time they’d reached the outskirts of London.
That said, there probably is some merit in putting this suggestion forward to our esteemed Government.
If they think HS2 is a good idea, can you imagine how excited they will be at a transport system capable of getting people to Birmingham in 5 seconds?
'Good morning ladies and gentlemen, welcome aboard this Very High Speed train to Birmingham which will shortly be departing. First Class is at the front of the train. The buffet car is in the centre of the train. Toilets are located throughout the train.'
5 seconds later...
'And now that we've arrived, can you please make sure you remove yourselves and all of your luggage from the rear wall of this train where you will also find a tangled mass where First Class, all the toilets, the buffet car and the rest of the passengers are now located.'