How valid were the criticisms that the 1984 Old Dalby nuclear flask test was too staged?

[OnTheBranchline]

Or do you think it was a thorough, well thought out test?

[BachelorBoy]

2 hours ago, OnTheBranchline said:

Or do you think it was a thorough, well thought out test?

 

I never read any criticisms of it.

[Edge]

1 hour ago, BachelorBoy said:

 

I never read any criticisms of it.

I did read somewhere that the angle of the flask wagon across the track meant that the initial impact simply moved it out of the way when hit and that therefore it couldn’t really be described as surviving the full force of said impact as per the publicity statements. 

 

There was also a comment that the engine of the diesel was removed from its chassis mountings/fastenings to increase the spectacle of the impact. No idea as to the merit of this story, but I do seem to recall that you can see the engine flying out the front of the loco, which is not something I recall happening in any other crash.

 

it’s the bit on fire that comes flying out in the clip below

 

As for the criticisms about the angle - not sure that I entirely agree myself - it still gets a fair old whack in the clip above and doesn’t seem to move to the side at all

[melmoth]

I remember the speculation regarding the engine bolts. It was suggested that they must have been loosened for the engine block to get airborne like it did, and if it had been fixed in place as per normal, a lot more force would have gone through the wagon and the flask, possibly to the point of making the demonstration a failure.

 

I have no idea whether this was valid or not.

[37114]

The engine bolt theory has been mentioned a number of times but the power unit stayed inside the loco.

 

https://commons.wikimedia.org/wiki/File:The_aftermath_of_the_Nuclear_Flask_Test_Crash_train,_Old_Dalby,_Leicestershire_(8)_Nigel_Tout,_Aug_84.jpg

The thing for me is what was the purpose; test or PR exercise? As a test you would want it be in a "lab condition" and effectively set it up in a way that would exceed the real life requirement. For example the wagon an flask appear to have no resistance to lateral movement in that they are lying on the side of the track with nothing stopping them being pushed away. In a real life scenario it is possible the pulling loco would have been on it side in front of it. The reality is this was a PR exercise to reassure stakeholders (public/lobby groups/ government etc) that transfer of Nuclear fuels was safe. Therefore you want a spectacular looking test where the train crashing into the flask absorbs/dissipates energy away from the flask,....

Edited February 27, 2023 by 37114
photo link added

[C126]

I remember a chap from Greenpeace, or one of the environmental protest organisations, on the Radio 4 news saying the results would have differed had a '56' or '58' been used.  I assumed a '46' was chosen, because it was the heaviest loco (141 Tons) in use at the time.

[Edwin_m]

36 minutes ago, C126 said:

I remember a chap from Greenpeace, or one of the environmental protest organisations, on the Radio 4 news saying the results would have differed had a '56' or '58' been used.  I assumed a '46' was chosen, because it was the heaviest loco (141 Tons) in use at the time.

A 58 would have been built to more recent structural strength standards, which would have made the front end less likely to deform on impact, therefore increasing the energy to be dissipated elsewhere and the forces exerted on the flask.  The same may apply to a 56 - not sure when the standards changed. 

 

Today's standards are even more stringent, although the latest ones require energy-absorbing material in the nose.  This is too little to have any effect in a train-to-train collision but intended to improve the outcome in something like a collision with a HGV on a level crossing - so could also mitigate a collision with a flask.  

[simon b]

Greenpeace really did make themselves look silly over this. There were all sorts of claims pushed out that the test was rigged, all of which were proved as false.

 

The engine bolts were not removed, the engine stayed firmly bolted to the frame as can be seen in the link a few posts ago. Iirc it was the stem heating boiler that can be seen flying through the air, not the engine.  Bear in mind this was after they had first tried to say that the engine was removed to lesson the weight of the loco.

 

The flask was positioned at that angle so that the drawhook of the loco impacted the flask lid, this was to put the most force on it. Those who claimed it was so the flask was pushed out of the way need a lesson in physics, the loco is heavier than the flask therefore the flask moves when hit by it. Some wanted another derailed loco or train behind the flask, all that does is create a giant crumple zone to absorb the crash energy and deflect the 46 up and over the flask.

 

The class 46 was used as they were basically life expired at that point, and being withdrawn. They are also very heavy. Why not a 56 or 58? Simply because they are a very expensive asset, not to be thrown away to prove a point. The outcome would still be the same.

 

I'm sure there were more, but those are what I remember off hand.

 

 

[Wickham Green too]

and - er  - a class 46 could be spared ! ...... the 56s & 58s were brand new at the time.

 

Edited February 27, 2023 by Wickham Green too
comments overtaken by simon b

[pete_mcfarlane]

There's a documentary on this (I think narrated by John Craven). There were a load of preceding, far less spectacular but probably more useful, tests where they did things like drop the flasks from a height with them landing on one corner.

 

All of these took place with the flask pressurised with gas (and the pressure monitored, so it was possible to tell if the flask had leaked on impact, which it didn't). 

 

 

 

[The Stationmaster]

Simple answer is a resounding 'no'.   The test reasonably reproduced something which might happen in the real world so what more could have been done when you understand that one of those falsks is mainly metal with not much room for payload inside it.

 

And the simple but little known fact is that when a flask was involved in a real incident and one collided with a bridge abutment at a speed estimated to be as high as 60 mph (I did way estimated, I bet it was lower) the only real damage to the flask was paint worn off and some gouging on some of the fins - the structure remained absolutely safe and there was no leakage of radiation,  The bridge alas suffered somewhat greater hiurt and the entire incident was kept very quiet.

 

There was also the story of some vclowns who smuggled (sic) a cardboard tube onto Stratford (London) station and subsequently claimed that if it had been a rocket launcher (preumably disguised as a cardboard tube) they could have fired it at a flask on a passing train and destroyed the flask duly radiating a good chunk of London.  They ignored the fact that the rocket would most likely have bounced off the flask, assuming they actually managed to hit it, and the little known fact that on many movements the only contents of the flasks are discarded gloves, overalls and boots etc which had been worn by people working in areas where there was low level, at most, radiation. (stuff categorised  as 'low level 'radiation risk') although some flasks obviously contain fuel rods or spent fuel rods.k

[JDW]

Isn't it a case of no matter what you'd done, there would have been someone (probably an "expert" - for some reason experts never seem to get the job, though, and it's always [apparently] left to people who haven't a clue) would have said it was wrong. In a real scenario, yes, there could have been other vehicles ahead of it. Or not, they might have gone down the embankment. Yes, it might have turned square to the track. Or it might have been hit at a steeper/shallower angle than the test. Or maybe instead of a couple of extra vehicles ahead, there's be a dozen if the flask train had collided with the wreckage of a derailed oncoming train before being hit from behind. Or... Or... Or... Or... 

 

And things like "Should have used a 58." - - - >  "But they rarely run on the same route, why didn't you use a 47, they're much more common." For every one of the arguments, you could find one equally circular to counter it with. And no matter how hard you try to replicate a real world scenario, what actually happens in any real accident is unlikely to follow the same path anyway. You could test as many different scenarios as you can think of, and still probably not hit exactly the right combination of factors that occurs in a subsequent real incident. 

[ERIC ALLTORQUE]

At the time it was as good as it gets i think and anything like that will attract press good and bad i guess,lots of it now is that no one had seen a train crash and survived as it was before the CCTV and mobile phone captures everything,i wish we had pushed into more nuclear energy then and we would be far better off now.

the industry publishes some good factual stuff too

https://www.energy.gov/ne/articles/7-things-simpsons-got-wrong-about-nuclear

[ERIC ALLTORQUE]

5 minutes ago, JDW said:

(probably an "expert" -

Like a wife or girfriend................

[pete_mcfarlane]

16 minutes ago, The Stationmaster said:

There was also the story of some vclowns who smuggled (sic) a cardboard tube onto Stratford (London) station and subsequently claimed that if it had been a rocket launcher (preumably disguised as a cardboard tube) they could have fired it at a flask on a passing train and destroyed the flask duly radiating a good chunk of London. 

 

There's a charming bit of naivety there. Presumably a rocket launcher attack on a passing nuclear flask train can only be made from the station platform (in possession of a valid ticket?) and not from a random bit of wasteland half a mile up the line? 

 

[The Johnster]

A 58 couldn’t do 100mph.  
 

I feel that an opportunity was lost on this test to study survivability in the coaches using crash test dummies.  I see no evidence that the test was ‘rigged’ in any way to get a desired result.

[keefer]

Also, remember that the energy in the collision isn't just due to the mass of the class 46 but also the 3 Mk1 coaches attached to it.

The effect of a 58 would be less because the 'body' sections were not part of the superstructure - they are not really load-bearing and are only there to cover the internal components.

[didcot]

The regulations for design, construction and testing of nuclear flasks is pretty onerous as you would hope and expect. Even more so if they are transported in the public domain, which also requires licensing.

[Wickham Green too]

1 hour ago, The Stationmaster said:

... There was also the story of some vclowns who smuggled (sic) a cardboard tube onto Stratford (London) station ...

1 hour ago, pete_mcfarlane said:

... Presumably a rocket launcher attack on a passing nuclear flask train can only be made from the station platform (in possession of a valid ticket?) and not from a random bit of wasteland half a mile up the line? 

There was a lovely footpath off the platform end a Stratford where I 'shot' all sorts of trains : - 

 

21/9/89

 

........ last time I was at Stratford I couldn't recognise ANY of the place !

[Titan]

57 minutes ago, The Johnster said:

A 58 couldn’t do 100mph.  
 

I feel that an opportunity was lost on this test to study survivability in the coaches using crash test dummies.  I see no evidence that the test was ‘rigged’ in any way to get a desired result.

The opportunity was taken, maybe not with crash test dummies but the whole train was wired up accelerometers and other instrumentation for research. Another reason why it was not rigged because it would therefore invalidate those results too.

[Phatbob]

Sorry to pee on the collective bonfire, but this whole debate is a waste of time.  Well before the spectacle of the Old Dalby test the flask design had been subjected to a far more onerous, but less public or "intersting" drop test.

The Nuclear industry, along with others, suffers from the propensity of detractors who don't understand detailed technical arguments to dismiss these arguments with the Mandy Rice Davies defence; 'well, they would say that wouldn't they'.  So less onerous train crash test was put on to try and pursuade Joe Public that these flasks are safe.  The result of which is a lot wasted time discussing conspiracy theories, rather than the desired reasurance! 😉
Sometimes you just can't bl00dy win.

Edited February 28, 2023 by Phatbob
Typo.

[didcot]

I did witness a drop test as an apprentice in the late 80s. Said flask was rigged to drop on a corner. 

Flasks aren't light either. Built to withstand impacts and also lined with shielding material as well. 

[keefer]

I think it would be even worse today - 'activists' of all kinds always decry the use of  'fake news' by Government, politicians, big business etc. but are more guilty of it themselves.

I wish I could remember what it was about but fairly recently, someone who was comprehensively called-out on their 'error' basically just said it didn't t really matter because everyone knew they were on the (morally) 'right side'.

Any yet such behaviour from MPs etc leads to screaming and wailing about dishonesty and lies.

You can't have it both ways, it's either wrong to lie or not.

Edited February 27, 2023 by keefer

[45125]

I worked with several individuals helped prepare the 46 for the test. Nothing was loosened off. 

 

[Grovenor]

More detail of the aftermath here,

http://www.nigeltout.com/html/crash-test-old-dalby.html