Standing Well Back
21st Century

Rockets, again

This week the police in the Republic of Ireland held a press conference where they displayed a range of weaponry seized from Republican terrorists. Included in the display were rockets which were described as similar to “kassam” rockets used by Palestinian militants in Gaza.  Here’s a picture of one of the rockets.


And here’s some Kassam rockets for comparison:

Now of course there is some alarm at this, and understandably so, but regular readers of this blog will know that a recurring theme of mine is that terrorist weaponry, well, has a recurring theme. And this is a great example. One might think from the press coverage that the occurrence of terrorist rockets is new in Ireland, and that these terrorists might have been exchanging technology with Palestinians. I’m not going to comment on that, but let me highlight something – rockets used by revolutionaries in Ireland aren’t new at all. A couple of years back I ran a series of posts about Irish rebel improvised rockets used in Dublin in 1803. That’s 216 years ago. And frankly they weren’t that dissimilar, a little smaller, but not much so.  And I made the point that the designs used by Emmett’s rebels in Dublin in 1803, were actually built on instructions from an English rocket designer, Robert Anderson, from over a hundred years earlier, in 1696. Here’s two pages of those three-hundred-year-old build instructions:

 

By the way, I still believe that Congreve, who claimed to have invented military rockets in about 1805 was copying Emmet’s designs and inadvertently copying the even older design by Robert Anderson.

Here’s the links to the posts about the Dublin rockets of 1803 and their links to the 1696 design.

http://www.standingwellback.com/home/2012/12/24/revolution-and-invention-comparing-syria-in-2012-with-irelan.html

http://www.standingwellback.com/home/2012/12/28/the-mystery-of-the-the-man-with-no-history-other-spies-and-e.html

http://www.standingwellback.com/home/2012/12/27/woosh-bang-ohnasty.html

http://www.standingwellback.com/home/2012/12/28/rockets-a-reassessment-a-mystery-and-a-discovery.html 

1710-1720

18th Century TPU, 19th Century Grave Robbers

I’ve blogged before about the use of flintlocks and other gun-lock mechanisms used as initiators in IEDs between the end of the 16th century and the middle of the 19th century.   Some recent digging has made me think that the integration of a timing mechanism with a flintlock mechanism was a widely used system, perhaps not regularly within an IED but widely enough that it’s use must have been well known, even if only as a potential initiation system.  Here’s some images of a couple of peculiar alarm clocks which I think make the point well. The operator sets a time on the clock which when reached released a spring loaded trigger on a flintlock.  A small amount of powder is then initiated which also ignite the wick of a candle which then by a linked spiring stands up in the box. These are I think from the period 1715- 1740 or thereabouts. Nowadays we’d call these a Time and Power Unit (TPU)

 

I have also found a “set gun” which attached a flintlock to a tripwire, used as a deterrent for both for both poachers and grave robbers. Here’s an image of one of these.

 

To be clear I’m not suggesting any of these are IEDs, just that such a mechanism could have been used at the time to initiate explosive devices.  The set guns were outlawed eventually but in 1878 an inventor, Mr Clover of Columbus, Ohio then came up with a “coffin torpedo” to deter grave robbers who opened a coffin with something like a shotgun cartridge, initiated by the opening lid.  “Torpedo” was the name given to IEDs at that time.

In 1881 a Mr Howell invented two “Grave Torpedos”, much more like IEDs and images from the patent application is shown below. These were much more like an American Civil War land mine, placed on top of a coffin with a plate above it, designed to be initiated when the grave robbers dug down.

 

 

These were effective – a grave robber was killed by the device and an accomplice wounded:

1920-1930

History lessons

Some earlier posts discussed the home made explosives and IEDs manufactured by Irish republicans shortly after WW1 (around 1920), and I’ve returned to the trove of information I have discovered on this subject. One of the themes of this blog has become the way in which today’s counter-terrorist operatives can learn lessons from the past, and this is a particularly good example.   During the 1980s one of a number of explosive devices designed by the Provisional IRA was a “drogue bomb”.  This basically consisted of a tin full of explosives, with a striker fuze behind it, and it was lobbed at vehicles with plastic strips trailing behind it to ensure it hit the target nose first so activating the striker by momentum.  To the EOD operator this was simple but “new” device.

What is interesting is that it wasn’t new at all. In about 1920 the IRA had previously developed what they called then a “drogue bomb”, and the diagram is shown below.  For obvious reasons I’ve left off some of the technical detail – if you are an appropriately accredited EOD operator contact me and I’ll give you the full diagram.   There are of course some differences between this 1920 design and the one from 60 years later in the 1980s… the striker mechanism has switched from the front to the back, and the steel case in the earlier device is thicker.  Those of you knowledgeable of other IRA mortars from the 70’s, 80’s and 90’s will also recognise certain aspects of the fusing from this earlier device.  I can tell you that EOD operators of my generation had no knowledge of the history of Irish republican device design from earlier campaigns. More fool us. As I’ve shown in earlier blog posts, improvised munition design used by Irish republicans goes back not only to this post-Easter Rising period, but to much earlier back to almost 1800.   Previous blogs to have highlighted the similarity between an IRA mortar of this 1920 period and the British Stokes Mortar of WW1.

 

 

Of course there are similarities to this device and Russian grenades, and I believe also to WW1 German trench grenades which I suspect this device is derived from.

1910-1920

Warflour, Paxo and Irish Cheddar

I’ve been doing more research on the IEDs used by the Irish “volunteers” between 1919 and 1922 and found some interesting aspects.   One should remember the time-line of Irish Republicanism that these events of 1919-1922 sit on – Irish revolutionaries were using explosive devices much earlier, certainly as early as 1803, IEDs were used extensively by the Fenians in the latter half of the 19th century, again in 1939 and of course from 1970 onwards.   The window of 1919-122 is just one point on the time line, but is worthy of study for all that.

Firstly, explosives, and I apologise for being somewhat circumspect in the detail here – no need to give modern day revolutionaries with other causes the full recipes. EOD folk can approach me directly of course and I’ll point you in the right direction if I know you. At the beginning of the campaign the explosives used was gelignite stolen from quarries, along with “No 6” detonators.  This supply began to become more difficult to obtain and so the Irish volunteers identified chemists and pharmacists and those with military experience from WW1 to develop home made explosives (HME).  There were three types, each given a nickname. I won’t describe their manufacturing process:

“Warflour”: Warflour was a nitrated resin, using the ingredients of resin, flour, acid and potassium chlorate.

“Irish Cheddar”:  This was the nickname for a form of cheddite, an explosive used quite extensively in the early 20th century, its ingredients being potassium chlorate, nitrobenzene and castor oil. Some sources suggest that “Cheddar” included home made DNT.  As an aside, this HME was used extensively by the Polish underground in WW2 in their IEDs, which I’ll write about in a future blog post.

“Paxo”. This was a mix of potassium chlorate and paraffin wax.  It was the favoured HME in the 1939 campaign but was developed during this period.

The IRA also developed its own detonators at the time, and I won’t describe them here other than to say that interestingly they were non-metallic and quite an effective design.

In terms of IEDs, and further to my earlier post, the IRA of the time made several thousand grenades, mostly under the Dublin Bicycle shop at 198 Parnell St and latterly at other facilities. It appears that the design of these were copied from the German “Egg” grenade of WW1. These were essentially quite a simple design,small and preferred because they were easier to conceal than a larger grenade.  They used the standard sort of fuze with a spring-loaded fly-off lever.  Occasionally larger improvised grenades were used – this is a diagram of one of them, made by an IRA engineer involved in their manufacture.

IEDs used for roadside ambushes were usually cylindrical pipes, either drain pipes or preferably the cylinders from a  cart axle, filled with gelignite or HME and electrically initiated.  The IRA of the time were ambushing British troops on the roads and certainly learned the trick of laying multiple roadside IEDs at the same spacing as convoy vehicles.  I can find little record of timed IEDs of the time, but the later 1939 “S-Plan” campaign in Great Britain concentrated on the use of timed IEDs.  The cylinders were closed by two end plates – initially with a bolt running down the central axis, and later by a bolt that fitted to the outside of the cylinder.   Command wire initiated devices of this type were occasionally adapted to be come booby traps by the use of a grenade striker system.   The diagram below, drawn by an IRA man shows one such IED.

Further research into the improvised IRA mortar described in my earlier post has thrown up more interesting facts. The background to the IRA requirement was that their roadside campaign was increasingly forcing the police and military to confine themselves to barracks (today we might call them “FOBs”), and the IRA leadership felt they needed a means to attack these barracks directly.  A number of IRA members had fought in the British Army in WW1 and had experienced trench mortars, either as a user or recipient.   The IRA funded a secret delegation to visit Germany and buy arms on the black market , including a German trench mortar but this mission was unsuccessful.  As a fall-back they asked their engineers to develop a home made mortar based on the British “Stokes” trench mortar.  I’m not sure how closely they followed the design, but the IRA version appears to have been of same calibre as the Mk 1 Stokes mortar (3 inch) and projected  an 11lb mortar bomb, again the same as a Mk 1 Stokes mortar.  It appears that the IRA was able to obtain British Army manual for the Stokes mortar.  the tube was made by Matt Furlong’s brother, Joe, at a railway workshop, and Matt (who later died testing a version of the mortar) made the bombs for it at 198 Parnell St.

Additional research leads me to believe that the additional safety feature in the mortar fuze that Matt Furlong removed before his accident was remarkably similar to a fuze safety feature I saw in 1990 or 1991 – on another IRA mortar.  That’s seventy years apart, and essentially the same safety feature being used on an improvised mortar.

1910-1920

IRA Improvised Munitions 1919 -1922

Earlier bogs have reported the use of Irish revolutionary improvised munitions as far back as 1803.  Use of IRA improvised weapons has been a theme for hundreds of years.   I have found a long and detailed statement by an IRA weapons engineer called Patrick McHugh, given in 1952 which sheds some remarkable insight into IRA improvised weapon production between 1919 and 1922.   It is generally thought that IRA imporvised mortar development started in 1970, but this shows that that date is out by about 50 years.

In 1919 the Irish volunteers established an “underground” muntions factory at 198 Parnell St in Dublin, under Michael Lynch, disguised in the cellar of a cycle business called “Heron and Lawless”. The facility was equipped with a furnace and a mould trough for casting grenade casings, a forge and a lathe.  An electric light was controlled by a switch to the shop above and used to warn of danger. In such an emergency grenade casing and parts could be hidden in the forge bellows.

All moulding and casting of grenades and “shells”  was done in small moulding boxes, each box containing eight shells.  Both brass and iron were cast – brass for the fuze fittings.  Then subsequent machining of the cast components was also undertaken at the premises.  The output was about 100 improvised grenades a week, and the cost was established as 9 shillings per grenade.

The grenades , empty, were taken to a room in a house in Dominick St were they were filled with gelignite explosive and fuzed. The grenade was small and described as the size of a duck egg.   This is a description of the fuze mechanism, verbatim from McHugh:

It is a little difficult to interpret without a diagram.  My assessment is that a safety pin held a spring striker.  The striker struck a centre fired bullet case, with bullet and propellant removed and a short length of delay fuse inserted, and the other end having a detonator crimped on.

The detonators were commercial and obtained from quarries. The time delay was nominally set for 4 seconds.   Amusingly the lathe used had originally belonged to a jewellers, “Ganter’s”.  When WW1 started the lathe was requisitioned by the British government and used in manufacturing shells for the British war effort.   Mr Ganter than made a a formal application for it to be returned. When he got it back he sold it to the IRA for the same purpose.   Other tools were obtained from the Broadstone works of the Midland railway. The springs for the grenade fuzes were obtained by a front business importing long springs from overseas and cutting them down to size.  Strikers were iron rivets with the head turned down in a lathe to a sharp point.  As an aside I have on my desk in front of me another IRA striker from a fuze mechanism and it’s a much cruder design from 1991.  The facility was raided twice by the British but on both occasions they found nothing.

Michael Lynch then designed an improvised mortar in 1920.  The propellant charge was a 12 bore shotgun cartridge with shot removed and more propellant (black powder) added. The impact fuze was adapted from the grenade fuze, but without the delay. The mortar bomb weighed 11lbs.

The IRA under Matt Furlong conducted some extensive trials of this improvised mortar system in October 1920 in County Meath. First a number of dummy mortar bombs with propellant only were fired, to establish ranges and calculate the propellant charge needed for a range of 100 yards.  Then three bombs were fired without a main charge but with an impact fuze fitted to test initiation.   The trials established that the bomb tumbled through the air, but despite that, the fuze appeared to work however it struck the ground.  One of the engineers believed that the impact fuze was being initiated on “set back” within the mortar tube and not on impact at the target.  Attempts to fire a live mortar failed as the bomb got stuck in the tube.  Probably fortunately.

The engineers involved were concerned about the impact fuze functioning on “set back” within the mortar tube, so they added an additional safety mechanism (which I won’t describe here) and this was was built in to the fuze for subsequent trials. The second set of trials took place near Kells in County Meath.  After firing a live shell with the new safety feature which then failed to function on impact, an argument ensued between Furlong and McHugh.  Matt Furlong insisted on removing the additional safety feature and firing the mortar as originally designed. McHugh, nervous, stepped a few yards away.   The others retreated. As the mortar bomb was launched it did indeed explode in the tube, severely injuring Matt Furlong, who later died in hospital.

The loss of the mortar was seen as a significant blow to the IRA in Dublin who had expected to be able to mortar British positions and barracks with impunity mounting the mortar on the back of a vehicle, a tactic that they applied successfully 60 years later in the North.

198 Parnell St in Dublin then upped its production of grenades and became a significant munitions store – because it was no longer possible to conceal the product, a steel plate was fitted behind the shop counter and a pistol and grenades kept at the counter itself.  In the end the British came across the munition factory and store by accident when no-one was there.


British Forces outside the bicycle shop after the raid.

Other grenade production facilities were established in 1921, with a production capacity of 1000 per week. Later production facilities became even more industrial with revised casting technology improving manufacture.  Security too, improved. Every production facility was emptied as work finished so any raids would be inconclusive.  Finished munitions were kept in hides, and there was a full time organisation to move them around the city. Faked books to disguise legitimate production runs of legal products were generated, and secret dumps of reserve material were established. McHugh claimed to have personal knowledge of still extant dumps from that time even in 1952 “just in case”.

In 1922 work began on a new IRA mortar, this time based on an oxygen gas cylinder (I kid you not!). The cylinder was used for a barrel, and the mortar bombs were cast iron, pear shaped with 4 fins. The launch tripod was fitted with a quadrant and pendulum to set the angle. The propellant was a shotgun cartridge, again with an augmenting charge of blackpowder. (In 1997 I was still encountering improvised mortars using a blackpowder charge).  Trials were undertaken in late 1922 outside Buttevant Barracks. The mortar bombs launched, tumbling as they reached full height then fell nose first.  The mortar was used by the IRA in an action against Free State forces in Kilmallock and again at Macroom.

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