Pineapple grenade

[Sentryduty]

Does anyone have any evidence that the raised sections are intended to fragment and if so could we see it, please?

I do not have any evidence to share but I do have a good understanding of explosions and am experienced in the use of grenades.

Re: Theory of waffle designs in grenades for fragmentation.

It makes sense in a manner, if an iron sphere is cast perfectly with no imperfections and variations in composition it should explode into equal little pieces. By casting in designed weak points in the structure (in a waffle pattern) it would be reasonable that the grenade would split at the thin sections and distribute little injury inducing cubes of iron in a uniform and radial pattern.

However once we leave the simple blackboard, the whole plan falls apart.

Grenades are not perfect spheres.

Casting is not uniform.

Due to the delay fuse, the explosion is not initiated perfectly centre inside the grenade body, it is usually towards a certain side which aids:
The engineered weakness in the waffle casing is not the weakest part of the grenade body, in most cases stress risers will initiate cracking near the edges of the fuze hole or other orifice.

Explosions are just expanding gasses and will try to escape containment, always seeking the path of least resistance, once a crack is formed all of the gasses will try to escape through that one rupture point.

Once that crack has opened far enough, and the explosion has built sufficient pressure the grenade body will break apart along that fault line and disassemble into randomly shaped pieces.

Here is a modern M67 note the "peels" from top to bottom.


German Egg grenade dig ups:


Two piece besozzib design, failed where it screws together and only generated 4 lethal fragments.


I can't comment on the original intent of Mr. Mills design, but I can say that Grenades (and other sundry offensive explosions) generally kill from blast, while perforation of the body by the casing is obvious if one is unlucky enough to catch one, however other small fragments projected outwards from the explosion can prove fatal after the initial injury.

I have personally been 3 metres away from an exploding M67 fragmentation grenade on open, level ground, and I came away uninjured by simply lying prone. If the same situation were to take place inside an enclosed area like a bunker, or vehicle, I would not have come out unscathed.

Further reading on hand grenade mechanism of injury from this medical incident review, jump to the "discussion" section for summary:
Hand Grenade Blast Injuries: An Experience in Hospital Universiti Sains Malaysia

[browningautorifle]

What I always found interesting Darren is that although we were committed to teach the troops the M67 has a coiled, segmented wire inside...you can clearly see it's not. It's a stippled solid steel casing.

We had one go blind in that it only blew the ends out and no more.

Another myth "Exploded" if you will.

I too have pieces but didn't feel the urge to carry on this ridiculous argument.

[earlwb]

Thanks for the information. That really bums me that they were telling us that there is a coiled steel wire inside the grenades when there isn't. Another myth killed.

[browningautorifle]

That really bums me that they were telling us that there is a coiled steel wire inside

On the side of the people that wrote the books that we had to teach out of, I'm sure that's what they were told or told to teach. Perhaps there's no other way for the manufacturer to describe it...but we sure found a way. Grenades like the one Darren has and loose shrapnel would be collected and run through the ammo wing to be declared safe so we could put it into the training system. I still have pieces...and other stuff.

[Sentryduty]

What I always found interesting Darren is that although we were committed to teach the troops the M67 has a coiled, segmented wire inside...you can clearly see it's not. It's a stippled solid steel casing.

On the side of the people that wrote the books that we had to teach out of, I'm sure that's what they were told or told to teach. Perhaps there's no other way for the manufacturer to describe it...but we sure found a way. Grenades like the one Darren has and loose shrapnel would be collected and run through the ammo wing to be declared safe so we could put it into the training system.

I would have to go back and look but the "coiled wire" probably still on the books, or at least added to lectures as repeated oral history. I know even military fiction sometimes references "wire" fragments from a grenade.

M67


This older M26 "Lemon" grenade might be the source of the wire wrapped myth. They were adopted in the 1950's but I have never used one, they have been replaced in CDN service by the C13 (M67) entirely.


I do have a 40mm HELV (M203) cutaway, I should share a photo of it, the fragmentation material in that is about the size of #7 Birdshot, which we know is not a terribly fatal projectile on humans.

[Flying10uk]

Thanks for your informative posts, Darren. I don't know why you call it a ridiculous argument in your Post 22, Jim. All I have stated is where I got my information from regarding the raised sections/bumps of the Mills grenade being for grip not fragmentation. After remembering it was from Wikipedia I stated the fact here. The Wikipedia article gives Mill's, original notes, the grenade's designer, as the source of this information. I don't have the computer skills to reproduce the Wikipedia article here myself but anyone wishing to see it only needs to tap "Mills Bomb" into Wikipedia.

[Sentryduty]

The Wikipedia article gives Mill's, original notes, the grenade's designer, as the source of this information.

I read the wiki article, and while the article does claim that Mill's notes describe the grooves for grip. However, the wikipedia article does not actually link or cite the source of these notes, I have finished reading the 1915 patent documents of his device and it makes no reference to the grooves in the body at all. The majority of the patent focuses on the fuze design, and method of installation. None of the other cited article sources link to anything of real value, just enthusiast webpages mostly.

If there are notes from Mr. Mills about this topic, they are not directly quoted or cited in that article.

I trust very little I read on wikipedia, it is an enthusiast website and evolves daily in what "facts" it states on a topic, any person can edit, regardless of how much or little they know of a topic.

[Peter Laidler]

As for the No36 '.... not fragmenting well' in spite of the build of the actual casing with its weak points. All I can say is that I have been onto the grenade ranges many times in the No36 era and seen zillions of large and small razor sharp fragments in the danger area. It's also a shrill warning when you hear those xxxxxxg great razor sharp cast iron whizzzzzzzing overhead when you're crouched in the throwing bay.

I went up and collected a small box full of No36 casing fragments from one grenade range before it was moved over a bit, to use in the grenade display. They didn't generally follow the fracture lines/pattern but in a LOT of cases, the cast iron bottom ring part remained as a big fearsome sharp ring. One thing that did bring it home was the depth that the sharp shrapnel dug into the thick wooden sleeper protective walls of the throwing bay - including plenty of the brass fuze bases. So deep I couldn't dig them out!

As a matter of interest, the last factory gate price of a No36 grenade to the UK Military in the early 80's was £1.36p. That's killing on the cheap!

[bigduke6]

Certainly an interesting thread, as Peter has mentioned the No36, thought some pics would go down well, one of these I've had since I was 15..... the other two a No5 and No36 I picked up at the War and Peace show this year with the intention of moving on.... strange as it sounds the wife actually likes them.......... the No5 was with out the lever or spoon as described in previous threads, but everything else was with it including the striker, the guy around the corner was selling repro bits which I bought the lever and pin, although it really belongs to the No23 but will do the job until I find one.

Pic below the No5 is on the left, the other two are No36, the right one has a No5 1916 base plug, this is the one I've had since I was a kid.





the main difference between the two is the top



Parts of the No5

[Flying10uk]

Peter, have you had any experience of the No69, the black bakelite/plastic, grenade being used/tested? I do have an inert (all explosive material removed) example and these were supposed to be made by the bank note printers, Del La Rue or a similar sounding name. The grenade had a large ball bearing as part of the fuse which was claimed to be fairly lethal to anyone in the vicinity including the person who threw the grenade.


Has anyone seen grenade casings, No5 or No36, made into children's pocket money savings tins/receptacles? Just imagine the Media reaction if someone tried to market such a Politically Incorrect product in today's world.