Tallboy explodes in Poland

[Tashengurt]

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!

[Fareastdriver]

They don't make them like they used to.

[VX275]

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

[Jhieminga]

https://www.bbc.com/news/world-europe-54522203

[ETOPS]

To znacznie większy huk niż ten, którego się spodziewaliśmy

[Sidestick_n_Rudder]

It was a heck of a 'deflagration' :8
https://www.youtube.com/watch?v=-iSRkvAupT8

[GeeRam]

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

[msbbarratt]

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:

[TerryCherry]

I took the car ferry across there few years back.

[Neektu]

[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😮

[Lookleft]

What were they aiming for that was in Poland?

[West Coast]

That’s one way to go fishing.

[Glevum]

Apparently the target was the Lützow

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

[tartare]

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

[Fourteenbore]

[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😮


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.

[Pugilistic Animus]

It was a heck of a 'deflagration' :8
https://www.youtube.com/watch?v=-iSRkvAupT8
Not a deflagration, a detonation.. deflagration is for low explosives like black powder...HEX detonates and exhibits Munroe Effect

[soarbum]

[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.

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.

[megan]

The article states,Naval forces used a remote-controlled device to try to "deflagrate" the bomb - a technique that if successful burns the explosive charge without causing a detonation, the deflagration process turned into detonation.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.

[Pugilistic Animus]

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

[megan]

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.

[kangaroota]

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?

[capngrog]

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

Cheers,
Grog

[Waypoint Short]

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?

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

854 built.

[Pugilistic Animus]

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?
Back then TNT or Tetryl

[Pugilistic Animus]

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
​​​​

[Beamr]

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?
according to google: Torpex + some TNT.

tallboy link (https://military.wikia.org/wiki/Tallboy_(bomb))

"The Torpex (https://military.wikia.org/wiki/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 (https://military.wikia.org/wiki/Explosive_booster) and into which (when the bomb was finally armed), a total of three chemical time-fuses were inserted."

[Pugilistic Animus]

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

[Beamr]

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).

[Pugilistic Animus]

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.

[treadigraph]

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.

[Pugilistic Animus]

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

854 built.
Sorry, didn't see your post at first

[Mr Mac]

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

[Pugilistic Animus]

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.
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

[Brewster Buffalo]

Apparently the target was the Lützow
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.

[Beamr]

Here you go, the Lutzow raid on film (from 0:50 to 1:15 on film): https://www.britainatwar.com/2019/10/10/polish-navy-grapples-with-unexploded-12000lb-tallboy/

The Lutzow raid Youtube

[AARON O'DICKYDIDO]

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.

[GeeRam]

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.org-vbulletin/1076x403/tallboy_2_242eb7dd427ba793d8cbb566b449dcc5520521e5.jpg

[kangaroota]

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

[Fonsini]

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.org-vbulletin/1076x403/tallboy_2_242eb7dd427ba793d8cbb566b449dcc5520521e5.jpg

Now that is some impressive research - nice work 👍

[Brewster Buffalo]

854 built.
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.

[Brian W May]

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?

LOUD . . . . !!!

[CAEBr]

The Tallboy was an earth penetrating bomb designed by Barnes Wallace for use on specific targets

Switching Pedant mode on, Tallboy was designed by Barnes Wallis, not some random Scotsman.....

[Dun Staaken]

Well done GeeRam. What a wonderful find great research . This is why I love pprune.
Its a miracle that during all the reworking of the waterway post war, this UXB wasnt disturbed earlier.
That would have taken the edge off someone's day.

[Brian W May]

Well done GeeRam. What a wonderful find great research . This is why I love pprune.
Its a miracle that during all the reworking of the waterway post war, this UXB wasnt disturbed earlier.
That would have taken the edge off someone's day.

I suspect that was why the bomb was found nose up, I reckon there's a very lucky dredger crew around there . . .

[WB627]

They found as a result of dredging operations

https://www.sciencealert.com/five-tonne-bomb-dropped-in-1945-has-just-gone-off-in-poland-during-defusal-op

It was discovered last year embedded at a depth of 12 metres (39 feet) with just its nose sticking out during dredging close to the port city of Swinoujscie in northwest Poland.

Amazing film footage from the raid

[Red Four]

Now that is some impressive research - nice work 👍
Totally agree, even the missus found it interesting! Best of Pprune award certainly.

[tdracer]

It was discovered last year embedded at a depth of 12 metres (39 feet) with just its nose sticking out during dredging close to the port city of Swinoujscie in northwest Poland.
Assuming the part about it being nose-up isn't a reporting error - that's very curious. Although dredging may have disturbed it, it would be unlikely to rotate it 180 degrees while leaving the bomb almost entirely covered.
I wonder if the tail fins detached/failed, and the bomb tumbled instead of heading in nose-first. That could also explain why it didn't detonate - landing tail first.

[GeeRam]

Assuming the part about it being nose-up isn't a reporting error - that's very curious. Although dredging may have disturbed it, it would be unlikely to rotate it 180 degrees while leaving the bomb almost entirely covered.
I wonder if the tail fins detached/failed, and the bomb tumbled instead of heading in nose-first. That could also explain why it didn't detonate - landing tail first.

Yep, that's my view as well. Wallis designed the Tallboy fins to spin the bomb on decent, so it would go down vertically, for the penetrative earthquake effect, so a problem with the fins and landing tail fist would indeed account for this.

[cattletruck]

The saw tooth dock structure appears to have been created by subsequent bombs hitting the dock a few seconds later.

Agree this really is a great find.

[gypaetus]

I met Barnes-Wallis when I were a young-un many moons ago at Vickers in Weybridge, he seemed a very calm, well-mannered gentleman, maybe a little eccentric, but even then his fame for his achievements was enough to shut up the brash youngster I was then. There used to be a Tallboy and Grand Slam parked against the Brooklands circuit clubhouse, probably still there and if so I'd recommend anyone who has the chance to go and look at them, impressive does not do them justice and it brings home the enormity of what they, BW and the RAF achieved.

[ericferret]

I met Barnes-Wallis when I were a young-un many moons ago at Vickers in Weybridge, he seemed a very calm, well-mannered gentleman, maybe a little eccentric, but even then his fame for his achievements was enough to shut up the brash youngster I was then. There used to be a Tallboy and Grand Slam parked against the Brooklands circuit clubhouse, probably still there and if so I'd recommend anyone who has the chance to go and look at them, impressive does not do them justice and it brings home the enormity of what they, BW and the RAF achieved.
https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/800x533/geograph_6260775_by_adrian_s_pye_1baf88d0155f4b315f47cce8d5e 6898cb8327346.jpg
Lost something? Scrap yard near Tetney, Lincolnshire

[Doors to Automatic]

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

It’s along the lines of “Alle strzelilo“ :-)

[gypaetus]

A Tallboy in a scrapyard!! Well, after the war I guess there was not much need for them for a while, but it does seem an unfitting place for such a thing! Though perhaps better than in a 617 squadron bomb bay!

[kangaroota]

How were these things detonated? Presumably you didn't want them going off on impact but wait until they buried themselves a bit.

[Jhieminga]

There used to be a Tallboy and Grand Slam parked against the Brooklands circuit clubhouse, probably still there and if so I'd recommend anyone who has the chance to go and look at them, impressive does not do them justice and it brings home the enormity of what they, BW and the RAF achieved.
They moved them inside in the 90s, Brooklands Museum has an example of all the bombs Wallis designed.

There was a story about a Grand Slam or Tallboy on display somewhere that, after years on display, was found to be still filled with explosive. Does anyone remember where?

[GeeRam]

There was a story about a Grand Slam or Tallboy on display somewhere that, after years on display, was found to be still filled with explosive. Does anyone remember where?

RAF Scampton IIRC.

[Democritus]

I took this photo at RAF Lossiemouth in 2009 - Tallboy, Upkeep and Grand Slam....I met Barnes Wallis in 1963 when I attended a lecture he gave. Fascinating guy, quite unassuming.

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/850x565/lossie2009_191c7325252aa5d73ae99a3387714d30c143a403.jpg

[POBJOY]

When I went on ATC camp to RAF Catterick several decades ago there was a very large bomb behind a curtain in one of the hangars.
Upon asking to see it I was informed it was secret and then we were escorted out.
In the evening going to 'dinner' I noticed the side door to this hangar slightly ajar, and popped in to have a peek. It looked remarkably like a tall boy, but of course had no name on it.
RAF Catterick at the time was an RAF Regiment station which makes sense. In fact it was a great camp (with very good food) and a fire/rescue dump that would make you weep today, with 'Many' complete airframes of seemingly new (old) machines which included wonderful Piston Provosts and several early Hunters.

[Pugilistic Animus]

They moved them inside in the 90s, Brooklands Museum has an example of all the bombs Wallis designed.

There was a story about a Grand Slam or Tallboy on display somewhere that, after years on display, was found to be still filled with explosive. Does anyone remember where?

TNT and RDX are very stable explosives.

[chevvron]

Didn't meet Wallis but in about 1965, we did a school visit to Brooklands and were ushered into the great man's office in the old race control tower where we were told he still came in to work a few days per week; his Swallow VG models (used in the early experiments at Predannack(?) were there.
Years later in 1973 when I was training at Northern Radar, RAF Lindholme, the RAF bombing school had a Tallboy outside along with a Blue Steel.
More years later at Farnborough, I had the privilege of 'controlling' the Vulcan which did a flypast salute at his home in Surrey after he died.

[chevvron]

LOUD . . . . !!!
Would you have heard it though? It was supposed to detonate underground; sure there would have been a helluva shock wave but would you have actually heard much?
We felt the shock wave from the explosion at the Hemel Hempstead oil terminal years ago (whole house shook) and we're 30 odd miles from there in Surrey.

[Beamr]

How were these things detonated? Presumably you didn't want them going off on impact but wait until they buried themselves a bit.
Apparently it had three tail pistols no. 58 mk1. The description is as follows: https://bulletpicker.com/pistol_-tail_-no-58-mk-1.html

Regarding the Tallboy description, is as follows per "British Explosive Ordnance NAVORD 1665 10th June 1946", page 49
Detonators—Sensitive type, delays up to 60 min. as required operationally.
Exploders
- Primary: 2 ring and 2 solid C.E. pellets; 4 solid RDX/Beeswax pellets
- Secondary: 2 ring and 2 solid large RDX/ Beeswax pellets (placed in a special exploder tube into which the standard exploder container fits).

https://bulletpicker.com/bomb_-12000-lb-dp_-mk-1-tallbo.html

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/931x1096/1394_051_212171dc74fa188cb0211844a2df47e068f126c2.png

[kangaroota]

Thanks for that Beamr.
Are there any recorded instances of the Germans trying to defuse one?

[Beamr]

Thanks for that Beamr.
Are there any recorded instances of the Germans trying to defuse one?

Take a look at this, apparently they succeeded: https://www.britishpathe.com/video/VLVABS2TY2H715307WE6BK0ECDBDT-WEST-GERMANY-MORE-TALLBOYS-DISCOVERED-IN-GERMANY/query/GERMANY

Seems like the tail section and detonators are already removed. I wouldn't want to do that for a living.

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/548x439/tallboy_1959_fd1cf7161e26ca5b7c3bc9fa9af982261bf24cf3.jpg

[Beamr]

Interestingly, apparently in total three Tallboys were found unexploded at Sorpe dam in ´58/´59. The first one found in 1958 was defused 6th of Jan 1959, and this is mentioned in many sources throughout the internet.
BUT: the Reuters news video linked above has the headline "More Tallboys Discovered In Germany" with comment "Two more RAF 5 1/2-ton 'tallboy' bombs were found, Jan 19, in the drained Sorpe dam reservoir, North Rhine-Westphalia."

So its four tallboys with the polish one counted for, I reckon there must have been more. Or be more yet to be found.

[Brewster Buffalo]

Interestingly, apparently in total three Tallboys were found unexploded at Sorpe dam in ´58/´59. The first one found in 1958 was defused 6th of Jan 1959, and this is mentioned in many sources throughout the internet.
BUT: the Reuters news video linked above has the headline "More Tallboys Discovered In Germany" with comment "Two more RAF 5 1/2-ton 'tallboy' bombs were found, Jan 19, in the drained Sorpe dam reservoir, North Rhine-Westphalia."

So its four tallboys with the polish one counted for, I reckon there must have been more. Or be more yet to be found.

Sorpe dam raid took place on 15th October 1944 by eighteen Lancasters of 9 Sqn. Sixteen bombed with two hits on the crest and another three on the air side. However there was no breach possibly due to the Germans lowering the water level so reducing the pressure on the water side of the dam. No losses.

All of the bombs were supposed to be fitted with delay fuses - twelve with a 11 second delay and the other six on a 30 minute one. However it later emerged that at least two bombs were fitted with direct impact pistols. Again there was a mosquito camera aircraft present filming the attack.

[upperecam]

Perhaps a little something lost in the translation?

[Downwind.Maddl-Land]

Post attack recce picture of Sorpe Dam post Tallboy raid. No wonder UPKEEP couldn't do the business!https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/569x746/sorpe_dam_tallboy_strikes_03b2a772290230c77465788e7b55979141 df6df8.png

[Beamr]

Post attack recce picture of Sorpe Dam post Tallboy raid. No wonder UPKEEP couldn't do the business!

Makes me wonder, since three of those were later found unharmed in the reservoir and one in a riverbed, if the design of the bomb (tailfuse for use against hardened structures) caused it to fail when hitting water with sufficient depth.

[MrBernoulli]

The saw tooth dock structure appears to have been created by subsequent bombs hitting the dock a few seconds later.
Actually, the "saw tooth dock structure" is a ferry loading/unloading dock. I doubt it was created soley because of the bomb. See here:
https://goo.gl/maps/Af61GwnvF58ByLU8A

And here is a post-bombing recce photo, taken 25 April 1945 (attack occurred 16 April) showing the damage to the canal vicinity, and the Lützow settled in the shallow water. The visible craters all match up nicely with the strikes seen in the video linked earlier in this thread. It is clear from this photo just how devastating that bomb between the dock edge and the battleship hull must have been!
https://commons.wikimedia.org/wiki/File:German_cruiser_L%C3%BCtzow_in_Kaiserfahrt_canal_on_25_A pril_1945.jpg#/media/File:German_cruiser_Lützow_in_Kaiserfahrt_canal_on_25_April_ 1945.jpg

The ship would have been in front of the saw tooth dock structure that has been built since, ...
Spot on, I'd say, as this 'quick and dirty' overlay of the recce photo on a modern Google Earth shot shows! ;)


https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/973x1032/l_tzow_ace994adc4a74b0711572f197b5089e4a11902b0.jpg

[Pugilistic Animus]

I love the details of the fuze and bomb body, I would love to see one in action live just not too close

[Mr Mac]

Take a look at this, apparently they succeeded: https://www.britishpathe.com/video/VLVABS2TY2H715307WE6BK0ECDBDT-WEST-GERMANY-MORE-TALLBOYS-DISCOVERED-IN-GERMANY/query/GERMANY

Seems like the tail section and detonators are already removed. I wouldn't want to do that for a living.

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/548x439/tallboy_1959_fd1cf7161e26ca5b7c3bc9fa9af982261bf24cf3.jpg
While working on a project in Munich in the mid 80,s a 4000lb RAF Blast bomb was found on site. It looked like a water tank or immersion heater but was identified as a bomb by German Project Manager who called out local German bomb disposal unit, who turned out to be very matter of fact about the thing, as it was not unusual back then, and indeed is still not that unusual today. Talking to them later, they explained the failure rate on allied bombs was quite high, I think it was 15% from memory, but it was a while ago so it could be more, or indeed less. The reason they said was that allied bombs when being developed were typically dropped onto harder ground than that which covers most of Germany, and many bombs just literally sank into the loam. I am not sure if that is correct, but it would seem logical, or it was just poor manufacturing. They said Berlin was the worst place for unexploded ordnance of all types due to the extensive street fighting as well as the heavy bombing, the next worst unsurprisingly was the Ruhr valley cities.
Cheers
Mr Mac

[Asturias56]

"TNT and RDX are very stable explosives."

A wise man who wishes to live long will treat that as a relative statement

it's best to treat all explosives as if they are loaded guns - they're really designed to go off

[Rory57]

How were these things detonated? Presumably you didn't want them going off on impact but wait until they buried themselves a bit.
The full story in this book, which I recommend.
https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/325x475/51v456hjmcl_61205b93e692d4052cb10693ddf63a489824e58c.jpg

[papa_sierra]

Big brother of Tallboy here at Bielefeld Viaduct https://www.youtube.com/watch?v=zeUQKl81aN4

[kangaroota]

Speaking of fuses, I read about a device - limpet mine I think - that used a boiled lolly as a delay.
Water got in, dissolved lolly, and BANG. Talk about effective low tech!

[Pugilistic Animus]

Speaking of fuses, I read about a device - limpet mine I think - that used a boiled lolly as a delay.
Water got in, dissolved lolly, and BANG. Talk about effective low tech!
The assembly of the detonation powder train of a bomb is called a "fuze".

Cool mechanism as a timing device, the lolipop



​​​​​Sorry for pedantry

[India Four Two]

I recently drove to the Bomber Command Museum in Nanton, south of Calgary, to see the reproduction Grand Slam and Tallboy that the museum had recently acquired. Very impressive to see in "in the flesh".


https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/2000x1504/grand_slam_and_tallboy_img_7732_cfa51053504d476f50032c2a0d16 d51331d604b3.jpg

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/2000x1504/grand_slam_sideimg_7731_f438b9d921205d06804fee984e5e0afe438a 3066.jpg

On the starboard side of the Lancaster is an Upkeep mine. I didn't take a picture of it, because I thought I had one!

https://www.bombercommandmuseum.ca


PS Pugilistic Animus, do pedants have short fuses? ;)

[megan]

The reason they said was that allied bombs when being developed were typically dropped onto harder ground than that which covers most of Germany, and many bombs just literally sank into the loam.Berlin is in an area of low-lying marshy woodlands with a mainly flat topography, part of the vast Northern European Plain which stretches all the way from northern France to western Russia. The load bearing ability is such that Hitler had a 12,000 ton test building erected to see if the soil would be able to support the planned buildings of Germania. The test piece still exists.


https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/267x200/267px_berlin_belastungskoerper_776c019e60ec3ee1fa572ba64afcf 0ee60426f90.jpg

[Pugilistic Animus]

[QUOTE=PS Pugilistic Animus, do pedants have short fuses? ;)[/QUOTE]
I think that I have a pretty long fuse because I am a firework :}

[RickNRoll]

according to google: Torpex + some TNT.

tallboy link (https://military.wikia.org/wiki/Tallboy_(bomb))

"The Torpex (https://military.wikia.org/wiki/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 (https://military.wikia.org/wiki/Explosive_booster) and into which (when the bomb was finally armed), a total of three chemical time-fuses were inserted."
Not a job I'd do. Melting explosives and pouring them in by hand.

[DaveReidUK]

The assembly of the detonation powder train of a bomb is called a "fuze"
cool mechanism as a timing device.

​​​​​Sorry for pedantry

"Two nations divided by a common language" :O

[Pugilistic Animus]

Not a job I'd do. Melting explosives and pouring them in by hand.
TNT has a fairly low melting point and that's is the reason why it was so popular. Because it can be poured into shells and other ordnance. Melting TNT is safe RDX however has a relatively high melting point

Firework are actually more dangerous to make and require immense amount of safety precautions to do safely and they must at the same time be asthetically pleasing.

In all reality, fireworks are extremely difficult to master and fireworks are more dangerous than HEX...and they are very unforgiving

[Pugilistic Animus]

"Two nations divided by a common language" :O

Well in the case of fuze vs fuse, a fuse is the part of the the primary ignition source and the first part of a powder train...like.... fuse... blasting cap or fuse.... bursting charge. A Fuze is the complete powder train leading to the detonation of HEXs...a Fuze is most commonly associated with ordnance.

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Just to add to the confusion there's also a fuseé which is a flare

[FlightlessParrot]

Well in the case of fuze vs fuse, a fuse is the part of the the primary ignition source and the first part of a powder train...like.... fuse... blasting cap or fuse.... bursting charge. A Fuze is the complete powder train leading to the detonation of HEXs...a Fuze is most commonly associated with ordnance.
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In what context does that distinction apply? It is not made in normal English, either UK or US, in which "fuze" is a less frequent variant spelling of "fuse" in all senses (so it's not the -s- -z- variation, which is typically UK vs US usage, except for Oxford University Press house style, which mostly uses -z-). It might be that in the technical language of some particular part of the explosives community that distinction is made, but it would be nice to know what part. It's not a general distinction.

[Pugilistic Animus]

In what context does that distinction apply? It is not made in normal English, either UK or US, in which "fuze" is a less frequent variant spelling of "fuse" in all senses (so it's not the -s- -z- variation, which is typically UK vs US usage, except for Oxford University Press house style, which mostly uses -z-). It might be that in the technical language of some particular part of the explosives community that distinction is made, but it would be nice to know what part. It's not a general distinction.

See, Dr. Tenny Lombard Davis " The Chemistry of Powder and Explosives"Professor Emeritus of Organic Chemistry, MIT

[WHBM]

I can't believe the line that the explosion was unexpected. All sorts of perfectly pointed cameras and even drones aimed at exactly where it went off.

Regarding still finding unexploded ordnance, only a few years ago the at the gasworks which is north of the east end of the London City runway, an unexploded bomb was discovered at the bottom of one of the large gasometers, it had been laying there for 70 years underneath n million cubic feet of gas. Records showed it had been holed, not found at the time so written off as shrapnel damage.

[WB627]

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.org-vbulletin/1076x403/tallboy_2_242eb7dd427ba793d8cbb566b449dcc5520521e5.jpg

The second bomb went in very close to the one that was in the process of exploding, both in distance and time, could the first bomb have slowed the descent of the first one in the water or toppled it enough to stop it exploding?

[Ex Cargo Clown]

TNT and RDX are very stable explosives.

RDX isn't that stable. Surprised they didn't use PETN. Still an interestingly designed bomb. This is from a Chem MSc grad before a black Vectra pulls up outside my door. Biggest bang I've ever heard was when some idiot put H202 into the waste organic jar. Not a great idea. Took out most of the tiles in the fume cupboard. I'd assume you'd class that as a detonation.

[Pugilistic Animus]

RDX isn't that stable. Surprised they didn't use PETN. Still an interestingly designed bomb. This is from a Chem MSc grad before a black Vectra pulls up outside my door. Biggest bang I've ever heard was when some idiot put H202 into the waste organic jar. Not a great idea. Took out most of the tiles in the fume cupboard. I'd assume you'd class that as a detonation.
I've never heard of RDX based C4 undergoing degeneration, ie producing brown fumes
I wish that I could have done PETN but if I ordered the reagents for it... someone would have gotten suspicious
I don't have the data on RDX but the RE and brisance of RDX and PETN are close
The most powerful explosive synthesized in large amounts is HMX
( Cyclotetramethylaminetetranitramine)
' fume cupboard' LOL....here in the US, it's the fume hood
H2O2 oxidizing everything...:\

[Pugilistic Animus]

I forgot to write this above
HMX ( US) High Melting eXplosive (UK) Her Majesty's eXplosive

Right up there with HMX is good ol' nitroglycerin but clearly it cannot be used due to it's sensitivity to shock... pure Nitroglycerin is still used in a few applications such as extinguishing oil well fires but generally it is stabilized by the addition of a solid medium. There are several forms of dynamites but for the most part it has been replaced by EGDN (ethylene glycol dinitrate) based Tovex...

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Never attempt to synthesize Nitroglycerin or EGDN!!!

Both Nitroglycerin and ( rarely) PETN are vasodilators and are used in the treatment of angina. Exposure to either in large quantities can induce a migraine.

One fun fact, HMX is edible. Google Aunt Jemima's explosive..it's fascinating

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[Asturias56]

"I can't believe the line that the explosion was unexpected. All sorts of perfectly pointed cameras and even drones aimed at exactly where it went off."

They knew exactly where it was - that's why the Bomb disposal team was there - they just ran the cameras as they record (remotely) the guy actually defusing the bomb. What you see is a minute or so of what is hours of recordings.

[Bergerie1]

Has this video been posted before? https://www.youtube.com/watch?v=gpfZX9nLSpQ