Tallboy explodes in Poland
 

Sorry, can't fathom links but the Beeb are reporting that a WW2 Tallboy bomb that was being defused in Poland has exploded.
No casualties and the bod in charge says " The bomb no longer poses a risk."! Which is one way of looking at it!

They don't make them like they used to.

What's the Polish for "That's a much bigger bang than the one we were expecting."

To znacznie większy huk niż ten, którego się spodziewaliśmy

It was a heck of a 'deflagration' :8

That's one way of dredging the canal..............................that'll be a nice big crater in the canal bed.

I don't know how it was situated on the canal bed, but I can't help but feel the bang would have been bigger if all 2.5+tons of explosive had gone off with the full, original as-new blast energy. Perhaps some of it had degraded, or perhaps it was quite well embedded in the mud (they were designed as ground penetrators), or (just as likely) I don't know what 2.5 tons of explosive looks like when it goes off under water!

Still, pretty impressive none the less, nice of someone to put up a camera drone, and clearly it was a disposal job professionally done :ok:

I took the car ferry across there few years back.

[QUOTE=msbbarratt;10903934]I don't know how it was situated on the canal bed, but I can't help but feel the bang would have been bigger if all 2.5+tons of explosive had gone off with the full, original as-new blast energy. Perhaps some of it had degraded, or perhaps it was quite well embedded in the mud (they were designed as ground penetrators), or (just as likely) I don't know what 2.5 tons of explosive looks like when it goes off under water!

Still, pretty impressive none the less, nice of someone to put up a camera drone, and clearly it was a disposal job professionally done :ok:[/QUOTE

Imagine that seventy-five years ago, hundreds of them, falling and exploding all over the place😮

What were they aiming for that was in Poland?

That’s one way to go fishing.

Apparently the target was the Lützow

https://www.bbc.co.uk/news/world-europe-54522203

Great pictures - but where's the bang??!!!

[QUOTE=Neektu;10903949]
The Tallboy was an earth penetrating bomb designed by Barnes Wallace for use on specific targets. They were never hundreds exploding all over the place. It could penetrate 16 feet of concrete, which gave a surprise to those in U boat pens.

Not a deflagration, a detonation.. deflagration is for low explosives like black powder...HEX detonates and exhibits Munroe Effect

[QUOTE=Fourteenbore;10903986]That depends on the pen I suppose. I did a tour of the Keroman base in Lorient last year. It took a direct hit from a tallboy. The bomb went through the first few 2 metres of concrete but then dissipated in the blast void above the main 4 metre roof.

The article states,How would they attempt to deflagrate the bomb, and why would the process then fail and cause an explosion?

Deflagration and detonation are two ways energy may be released. If the combustion process propagates outward at subsonic speeds (slower than the speed of sound), it's a deflagration. If the explosion moves outward at supersonic speeds (faster than the speed of sound), it's a detonation.

While the action of deflagration is to push the air in front it, objects do not explode because the rate of combustion is relatively slow. Because the action of detonation is so rapid, however, detonations result in shattering or pulverizing objects in their path.

Exactly like you said Megan...you got it right!

Tis OK, found the answer to my question. In some situations, a subsonic flame may accelerate into a supersonic flame. This deflagration to detonation is difficult to predict but occurs most often when eddy currents or other turbulence are present in the flames. This can happen if the fire is partially confined or obstructed.

What was the explosive used in these bombs?
Also were there few enough of them manufactured and delivered for them all to be accounted for now?

Kudos to the bomb disposal unit, whomever they may have been.

Cheers,
Grog

Torpex explosive is 42% RDX, 40% TNT and 18% powdered aluminium.

854 built.

Back then TNT or Tetryl

Just as a side note I have a BS in chemistry and other topics, just so that I could understand fireworks and explosives, in greater detail.

In HEX there is a pressure gradient,as gas expansion occurs, not flame expansion. The best way to delineate between HEX and LEX is that HEX exhibits the Munroe Effect... which I leave that one for Ms Google

One item at the borderline between the two is flash powder. In the US it's considered a HEX 1.1G for storage purposes. Flash does not need to be confined tightly to explode. And an explosion involving flash looks like a detonation
I don't know if flash exhibits the Munroe Effect though
​​​​

according to google: Torpex + some TNT.

tallboy link

"The Torpex filling was poured into the base of the upturned casing by hand, after melting it in "kettles". The final stage of explosive filling required that a one-inch layer of pure TNT be poured over the Torpex filling, followed by sealing the base with a 4-inch (100 mm) layer of woodmeal-wax composite with three cylindrical recesses fitted with the explosive boosters and into which (when the bomb was finally armed), a total of three chemical time-fuses were inserted."

I just looked up Torpex it's a mix of RDX (cyclotrimethylaminetrinitramine) and TNT
'Research Department eXplosive' or Royal Demolition Explosive

plus aluminium powder (which based on what I read is rather significant element).

I forgot that one, Al powder increases the heat of reaction thereby increasing blast wave pressure... it's also used in flash powder for creating huge booms that everyone loves during a fireworks display. Don't try this because there's many safety precautions and rules that must be followed but Flash powder ( the safest one) is 70% Potassium Perchlorate and 30% Dark pyro aluminum.

No bloody intention of trying it! :ok:

My chemistry master at school had lost an eye earlier in his career when an experiment was rather more spectacular than planned, put me off making things go bang for life.

Sorry, didn't see your post at first

As others have said good way of dredging canal and getting some fish as well. The Gulls were certainly in quickly. I wonder how they found it after all this time ?
Cheers
Mr Mac

I've been making things go bang since I was 15... especially my beloved fireworks... I've synthesized TNT, Trintro aniline ( tetryl) Ethylene glycol dinitrate, And trinitrophenol (picric acid) don't ask me where I got the chemicals and the apparatus. and how did I get blasting caps Lol

and the heavy cruiser Prinz Eugen. Eighteen Lancasters of 617 took part with fourteen carrying Tallboys. Escort was 127 fighters but the opposition was solely flak.

One Tallboy exploded between the Lutzow and the side of the canal smashing in her arrmour plating below the waterline and she gradually settled by the stern. As this was in shallow water her guns remained in action until the Russians occupied the port when she was blown up. The Prinz Eugen survived the raid.

Most of 617's aircraft suffered flak damage and one was lost over the target. Sadly no survivors. Apparently the RAF film unit's mosquito accompanied the raid so there maybe something on you tube.

Here you go, the Lutzow raid on film (from 0:50 to 1:15 on film): https://www.britainatwar.com/2019/10...000lb-tallboy/

msbbarratt

According to an article I read the other day it was found NOSE UP in the mud. Had it been 180 degrees about the effect would have been much greater!

Aaron.

I think that wartime raid film shows this Tallboy making a splash in water, as there is a splash that is a lot smaller than the other Tallboys that clearly explode, and its a big enough splash to be a 12000lb Tallboy hitting the water and not going off.....and if you freeze frame both films and screen shot it, it does look very close to being the same one.....but I'm not an expert.
The ship would have been in front of the saw tooth dock structure that has been built since, but the jetty coming down from the two U-Boat pens on the opposite site appears to be roughly the same still.

https://cimg3.ibsrv.net/gimg/pprune....c5520521e5.jpg

854 built.[/QUOTE]
Thanks for that.
Do you know how many of those were dropped?

Now that is some impressive research - nice work 👍

Thanks for that.
Do you know how many of those were dropped?[/QUOTE]
My source says 879 tallboys dropped on active service plus an unknown number used in trials.