Jam jar bombs

[Simon R]

I've searched but cannot find any refs. on the forum to the manufacture of British jam-jar bombs c.1914-15.

Does anyone have any idea if any designs or drawings for these were ever produced, maybe even post-war studies, and if so, where would they be?

Examples of their use would also be appreciated, though I am primarily interested in how to make these (from an entirely academic and research based point of view!!).

Simon.

[joseph]

Simon,

From a Yearbook published in 1918, There is a written discription Ill type it in if you want it.

Regards Charles

[joseph]

Simon,

Seems intresting so did it anyway,

The first grenade to be issued was known as the “jam tin bomb” on account of its similarity to the tins in which the inevitable “plum-and-apple” was supplied and which were often used in the manufacture of improvised copies of the official model.

It consisted of a tin cylinder containing a number of shrapnel bullets with a compartment in the centre to hold the explosive, which was generally ammonal. Fixed in the lid was a hollow tube into which the fuse and detonator were inserted before use, the fuse being kept in place by a piece of copper wire soldered in the lid.

In some cases the fuse consisted of a Brock lighter, which is a device resembling an exaggerated fusee. It is provided with a match head which can be struck on a lighter similar in appearance and composition to the side of a match-box which is worn on the throwers arm; the stem is of ordinary safety fuse, and is timed to burn for 5 seconds.

Regards Charles

[RodB]

I find this interesting Joseph, as all the literature I've read up to now talks about jam tin bombs as being improvisations originated by troops in the field, replaced by successively better official designs leading up to the Mills bomb.

Would this commonly held view then be incorrect, or is this an example of officialdom telling the folks how to do something after they've already done it themselves ?

[joseph]

Rod,

Im not 100% but have seen a photograph of ladies making jam tin bombs in a factory type setting, the follow on from the Jam-tin bomb was the ball grenade.

Regards Charles

[Max Poilu]

There has been some previous discussion on jam tin grenades (or No.8's etc) - they were both made in the field as well as in factories. They are one of the emergency patterns created to plug a gap in supply. The links below should be helpful but a general search for 'grenade' will bring up tons of previous discussion and pictures.

search

This topic specifically:

http://1914-1918.invisionzone.com/forums/i...18&hl=emergency

And here in a current thread more discussion of emergency grenades::

http://1914-1918.invisionzone.com/forums/i...ic=32266&st=260

And specifically here a find of a No.8:

http://1914-1918.invisionzone.com/forums/i...ic=32266&st=400

Sorry that many pictures are missing from the above topics - I thought the webmaster had re-instated all the missing pics but all old topics I seem to view still have some missing!

[Tony Lund]

I got these instructions from the Official History, 1914 I think, but it may have been 1915. A few regular soldiers were left in the trenches to show the 49th Division how to make these in April/May 1915 when they first took over trenches.

A jam tin bomb was an empty jam tin filled with a mixture of shredded guncotton and nails, or any handy small pieces of metal, with a Number 8 detonator and with a short length of Bickford’s fuse inserted, the top was then sealed with clay. A hairbrush bomb was simply a piece of wood shaped like a hairbrush with a handle, which allowed it to be thrown a bit further. Guncotton was secured to the timber with wire and a detonator and fuse added. In both cases once the fuse was lit the bombs were thrown as soon and as far as possible.

Tony.

[Simon R]

Many thanks, I was thinking of making a mock up version, but I see they are available from tommyspackfillers for reasonable price.

[RodB]

Thanks.. but they don't seem to cover the issue of what came first, the improvised design in the field or the official design. Things like this are important to me as they have a bearing on who was actually running the show, the troops or the brass. I suppose here all we can go on are dates - do reports of first usage of jamtin bombs (early 1915 ?) predate the "official" jamtin bomb design" ?

[Max Poilu]

Thanks.. but they don't seem to cover the issue of what came first, the improvised design in the field or the official design. Things like this are important to me as they have a bearing on who was actually running the show, the troops or the brass. I suppose here all we can go on are dates - do reports of first usage of jamtin bombs (early 1915 ?) predate the "official" jamtin bomb design" ?

Not sure if your reply is directed at me? There is quite a lot of info and pictures in the links above on the whole issue of emergency patterns and their introduction.

Here is a bit more for you! Obviously soldiers have always improvised but the actual official jam tin grenade alongside other patterns was an 'official' idea. A chap named Jackson (a DG at the Ministry of Munitions) with a distinguished career in fortifications and military engineering was employed by French to deal with the shortage of grenades. Amongst other designs the jam tin or officially (No.8 and No.9) was one of his. As described in the links above they were manufactured by Robburite and Ammonal (amongst others) in the official 'double cylinder' style but manufacture was also improvised at the front (under direction of the RE's) using an empty standard tin filled with HE and any small pieces of scrap iron. They first appeared very early in 1915.

I guess the 'brass' run the show.

As in the links above describing the history of grenades, at the end of the day the simplest model is a container with explosive content and a means of initiating. It was ever thus and the soldiers at the front made up what they could. The official jam tin grenade was a double cylinder No.8/9 but no-one can say for certain that a front line soldier stick a charge in a tin and launched it before an official grenade appeared in early '15 thus 'inventing' the jam tin himself...

All combatants in 14-18 used 'emergency' patterns - the British had the jam tins and hairbrushes (No.12) as well as Pippens, Pitchers, No.6's, Battyes etc - all were basic emergency designs. The French had a variety of artisans grenades, most common was the hairbrush type 'Petard' and the Germans used pipe bombs and 'hairbrush' type grenades. In the German's case the hairbrush would be developed to become the ubiquitous stick-grenade.

If you want to make a model of a front line jam tin type grenade then a simple tin, period label and a dummy fuze will suffice. However, an official jam-tin or more correctly a No.8 or No.9 will need a brazed double cylinder and other parts as described in links above.

[Robert Mueller]

Simon,

From a Yearbook published in 1918, There is a written discription Ill type it in if you want it.

Regards Charles

It is interesting to see that mercury was used in the detonator. Does anyone know if this was a common ingredient at the time? And would the quantiies be sufficient to cause battlefield contamination? Yet another reason to leave relic be.

Robert

Edited 5 January , 2006 by Robert Mueller

[Max Poilu]

Detonators of the time as with primers employed fulminate of mercury as the active initiating detonation compound - a very unstable and very explosive ingredient. It is not the familiar shiny liquid metal but powdery yellow grains formed by dissolving mercury in nitric acid and precipitating this in alcohol.

The amount involved is tiny and it is easily made inert although detonators found in the ground today still remain dangerous - a couple of friends in France have been maimed in this way. However compared to other things in the soil any poison risk from old detonators is infinitesimally small and I do not think it is anything to worry about!

It is perfectly legal to own inert ammuniton (propellant removed) with intact primers - they are usually oiled to make them inert as here:

http://cgi.ebay.co.uk/INERT-303-Rounds-ALL...1QQcmdZViewItem

[RodB]

Thanks for the great research info Giles ! It seems to point towards the basic idea coming from the top and being passed down to the troops to implement using whatever was available in the field.

I'm interested in this because general histories tend to present this design as an example of troops forced to improvise at the front, and in so doing may be perpetuating a myth, whereas the evidence seems to indicate that those above were very active in trying to come up with better & innovative equipment for the troops.

[Max Poilu]

Thanks for the great research info Giles ! It seems to point towards the basic idea coming from the top and being passed down to the troops to implement using whatever was available in the field.

I'm interested in this because general histories tend to present this design as an example of troops forced to improvise at the front, and in so doing may be perpetuating a myth, whereas the evidence seems to indicate that those above were very active in trying to come up with better & innovative equipment for the troops.

Rod - I think your summary is probably very correct. However, throughout we need to be careful to differentiate between the official and more complicated double cylinder factory manufactured No.8/9 (that was known in slang as the jam tin) and the frontline made simple bog standard actual jam tin of explosive and old nails. It's a bit chicken and egg but as I say regardless of any instructions soldiers in dire straits have always improvised. A 19th century soldier may have 'invented' a bomb of black powder in an old clay vessel in just the same way!

[barrieduncan]

Was re-reading Lyn MacDonald's 1915, there is a small mention of the jam jar bombs

"...The troops themselves displayed some ingenuity in supplying the deficiency. Dumps were scoured for empty jam tins and the engineers, who had spent most of the night improving the defences in the line, spent hours during the day filling them with old nails, tamped down with gun cotton to make primitive bombs. The bright sparks of the 15th Field Company Royal Engineers of the 24th Brigade even manufactured a trench mortar. It was only a length of drainpipe soldered up at one end with a touch-hole bored above it and was ignited by a match and gunpowder. But it fired the jam-tin bombs a good distance towards the Germans and, despite a few unfortunate accidents in the course of its erratic performance, it cheered the troops wonderfully."

Lyn MacDonald 1915: The Death of Innocence, p33

[Guest geoff501]

Was re-reading Lyn MacDonald's 1915, there is a small mention of the jam jar bombs

"

Lyn MacDonald 1915: The Death of Innocence, p33

A similar story is in The Worcestershire Regiment In The Great War, p55, at Neuve Chapelle New Year 1915:

[Simon R]

All good stuff, I may see if there are any surviving examples knocking around in UK museum collections.

[ian turner]

In case of further interest, posting a pic of some improvised and early grenades.

Ian