You can contact me at rogercdavies(atsquiggle)

This blog has evolved into a review of historical and modern explosive devices, and responses to them. Links are drawn between historical activity and similar activity in the world today. Mostly I focus on what are now called IEDs but I have a loose personal definition of that and wilingly stray into discussions of more traditional munitions, the science and technology behind them, tactical employment and EOD responses. Sometimes it's just about interesting people in one form or another. Comment is welcome and encouraged but I do monitor it and reserve the right to delete inappropriate stuff. Guest posts are always welcome. Avoid any stuff that makes the enemy's job easier for them.


Entries in 1600-1700 (16)


Westminster - an Explosive Past in a 100m Radius

The recent murder of people on Westminster Bridge and the stabbing to death of a policeman at the gates of the Houses of Parliament New Palace Yard have highlighted that the British centre of government and state power has a natural attraction to terrorists.  In my blogs I often look at threads in history of terrorism.  One can find, occasionally, interesting threads in the warp and weft of time, and usually I follow technical threads as far as I can.  But Westminster provides another thread, at right angles, the thread of geography, in a history of explosives and munitions. Bear with me as I recount the explosive history of Westminster - some of which you will know and others you won’t. I have underlined certain specific locations in order to make the point about repeated locations. Westminster is a surprisingly compact place and most of the incidents listed below occurred within about 100m of each other.   For context here's a plan of the explosive incidents in the Houses of Parliament, just about all within a circus of 100m radius:
Locations and Dates - Westminster
1605.   The Gunpowder Plot.  Of course you will know that the Gunpowder Plot targeted Parliament itself, and there is little new I can repeat here. But one aspect is interesting in the light of very modern accusation of “fake news” and “false flag” operations. There has been a school of thought over the ages since soon after the plot itself, that the Gunpowder Plot was a false flag conspiracy dreamt up by loyal royalists to discredit the Catholic opposition. The suggestion is that Sir Robert Cecil, the Royal Chancellor, coordinated a "false flag" operation for political motives, to persuade the public and the King himself that harsh measures were needed to keep persecuting Roman Catholics in England. There is also a suggestion that the gunpowder recovered from the 36 barrels discovered in the Westminster Undercroft had deteriorated so much that it may not have exploded anyway.  In another interesting parallel with today, and attitudes towards Muslims after the recent Westminster attack, King James himself, speaking to both Houses of Parliament five days later made clear that he believed that the plot had been the work of only a few Catholics, not of the English Catholics as a whole. By modern terminology the device was a large timed IED, the timing component being burning fuze.


A report from a few years after the PlotThe Conspirators

1885.     Dynamite Saturday - As part of a dynamite campaign Irish American “Fenian" terrorists planned and executed ”Dynamite Saturday" detonating a number of devices across London. One device exploded as it was being moved by policemen in Westminster Hall.

PCs Cole and Cox are blown up in Westminster Hall

PC William Cole was a London Police officer on duty in the Houses of Parliament on 24 January 1885. He was notified by a visitor, a Mr Green, about a smoking black bag on the steps between the St Mary Undercroft chapel and Westminster Hall, both within the Palace of Westminster. The bag was on the third step of the staircase that lead to the main part of Westminster Hall.  Bravely, Cole picked up the smoking bag and ran up the stairs of Westminster Hall with the intent of moving the bag outside into New Palace Yard. He was preceded by Mr Green who shouted “Dynamite!” to clear the way.  But before he could reach the door,  the bombfuze began to burn his hand, causing him to drop the bag - a second later the bag fully exploded. Cole and his colleague PC Cox, were injured, their clothes largely blown off them  and they lay, blackened in the crater caused by the bomb.  Mr Green was injured in his eyes and his two female companions were “bereft of their upper garments".  Other police and the Deputy Segeant at Arm's wife, Lady Horatia, rushed to attend to the injured. Cole was unconscious, and Cox was "rolling about, talking incoherently and hitting out with his fists although two constables held him down.’  Both officers were described in the politically incorrect language of the time as “black as n*****s”.  Seconds later, another bomb exploded in the empty House of Commons.   In one of those interesting pieces of history (given my interest in the Government’s Inspector of Explosives of the time, Colonel Majendie), Lady Horatia, the wife of the Deputy Sergeant was coopted by the police in the aftermath to help control access to the Hall. Imagine the scene,  the redoubtable Victorian lady assuming the role of gate guardian to a terrorist bomb incident. A short, bearded foreign gentleman approaches and demands access in a German accent, to inspect the scene. Lady Horatia is having none of it and physically blocks his path , firmly instructing a footman to “put him out”, ejecting him from the Hall.  It was in fact Dr August DuPre, the German born Chemist who was Col Majendie’s most important technical assistant and official Home Office consulting chemist who played a key and official role in investigating explosive crime.   PC Cole (later promoted to Sergeant) regained consciousness the next day, and was awarded the Albert Medal for his bravery, which was presented to him on the exact site of the explosion.  Mr Green suffered permanent injury to his sight but was not compensated despite the efforts of the Deputy Sergeant at Arms (probably prompted by the fierce Lady Horatia). Interestingly the body of PC Keith Palmer who was fatally stabbed in 2017 was kept overnight in St Mary Undercroft before his funeral.   My assessment of the device based on an interpretation of the reports and the fact that a James Cunningham was seen lighting a  fuze on a similar bomb that same day at the Tower of London was that the device was a timed IED, with less than 2.5kg of explosives, with burning fuze being the timing element. James Cunningham and an accomplice, Harry Burton, were sentenced to life imprisonment for their role in the bombings. Interestingly this bombing changed the ambivalent feeling of the USA towards the Fenians. Prior to this UK governmental efforts to encourage the US to constrain Fenian activity had fallen on deaf ears, but with an attack on parliament, wheels began to turn.


1939-1945. Although not terrorist attacks, the Houses of Parliament were subject to explosive attack frequently in WW2.   It was hit by German bombs on 12 occasions (nine exploded, 3 were defused) and the House of Commons was destroyed in a subsequent fire after an incendiary bomb attack - one of numerous incendiary bomb attacks.  The buildings were hit three times by our own anti-aircraft guns, one hitting Big Ben. Here’s a Pathe film of the aftermath of one attack.    Particular damage was caused by an explosive bomb on St Stephen’s Cloister on 8 December 1940, and the incendiary attack that destroyed the House of Commons and damaged the roof of Westminster Hall occurred on 10 and 11 May 1941. Three people were killed in all the attacks.

Bomb damage St Stephens Cloister, 1940

1974.  During the construction of the Underground carpark beneath New Palace Yard, the IRA was able to exploit the poor control over a large number of casual workers employed on the contract to place a bomb in a ladies toilet adjacent to Westminster Hall.  It exploded at 8am on 17 June, igniting a gas main causing considerable damage (photo).

1974, Westminster Hall Bombing

The IRA claimed it contained 20 lbs of explosive. That might be an exaggeration.  The device was probably on a  mechanical timer and laid the previous evening, I suspect. The authorities in Westminster have deliberately not removed all the black soot and sign of burning from one corner of Westminster Hall, where is remains to remind those present of the threat to democracy

1979.  The Irish National Liberation Army (INLA) planted a bomb on the car of MP Airey Neave. the device exploded as Neave drove his car out of the underground car park in New Palace Yard. Neave died shortly afterwards. the device probably contained less than 2kg of explosive and was probably initiated by a ball bearing tilt switch. It is possible that the device was placed on the car before it entered Parliament buildings

Neave Assassination

From this list I have excluded a number of nearby incidents, including:

1. A Fenian bombing of the underground between Westminster Bridge station and Charing Cross station in 1882.

2. A suffragette bomb planted in Westminster Abbey in 1914.

3. An IRA mortar attack on Downing Street in 1991.

There are also a number of unsuccessful plots (other than 1605) relating to Westminster which I’m still gathering data on - the strangest is a post WW2 plot to drop bombs contained in adapted fire extinguishers on Parliament by an extreme militant zionist from a charted plane flown from France. More later on that!
Of course the nature of the target of these incidents attracts attention because of the political focus of power from the geography of the target. If I may be allowed a slightly political comment, following the stabbing of PC Keith Palmer and the associated murders on Westminster Bridge some commentators expressed the opinion that London was running scared from terrorism, and that the terrorists were winning. The silly phrase “London has fallen” was used by some of the alt-right to describe the incident, and people talked of Londoners being fearful and terrorised. I don't believe that to be true.  With the possible excerption of the Gunpowder Plot of 1605, none of the other incidents ever caused anyone to suggest that terrorists could defeat our democracy and culture even though they penetrated the buildings of Parliament themselves. In 400 years, attackers have penetrated parliament many times and British culture and democracy remains. The perpertrator of the attack in 2017, armed with his mothers kitchen knife was shot before he entered the building and we can now forget his name.  

Intriguingly Similar Designs of Improvised Munitions Over Decades

One of the most notable improvised weapons in the last 15 years has perhaps been the “IRAM”.  This “Improvised Rocket Assisted Munition” appeared in 2004 in Iraq, using the rocket motor of a 107mm rocket with a “bolted on” over-calibre warhead. This is a relatively short-range munition with more target effect than a standard 107mm, but quite difficult to range and target.  The IRAM munition came in various designs. Here’s one variant:
IRAMs 2004


Such munitions appear to be being used now by Syrian government forces and others in Syria. See this report from the excellent Brown Moses/Bellingcat website from 2013:  Sometimes the users seem to have not fired these from 107mm tubes (with the overcalibre warhead “left out the front”) but from tubes with a greater diameter. See: .  In this variant the rocket motor is "under-calibre", in effect.
When the IRAM appeared in 2004 it was commonly thought to be a new type of improvised munition. But as readers of this blog might already suspect, it wasn't new at all - the concept was used in the early part of the Vietnam war. Here's the image of Viet Cong overcaliber warhead that was fitted to a 107mm rocket, just as they are today. The image provider suggests that the warhead was cast iron, but the welds in what is probably rolled mild steel are clearly present.  These early Viet Cong "IRAMs" were fitted with what were described as WW2 Japanese impact fuzes. 
Viet Cong over-calibre warhead for 107mm rocketJapanese WW2 impact fuze on Viet Cong warhead
Now here’s another interesting thing - probably coincidental. The design of the Viet Cong over-calibre warhead is remarkably similar to a Provsional IRA mortar bomb warhead. This image is from a de-fuzed Mk 12 mortar bomb taken in 1991.  The IRA warhead was of course not on a rocket but on a mortar, but the design structure of the mild steel welded warhead looks remarkably similar to the Viet Cong warhead, does it not and is of an almost identical construction. The Mk 12 mortar of course is a horzontally fired anti-armour weapon with a copper cone liner, but the outer form of the warhead is remarkably similar.  
PIRA Mk 12 Mortar bomb with identical shaped warhead
Keen readers of this blog will recall too that Irish revolutionaries were firing rockets horizontally at the British Military as early as 1803, using a rocket designed in 1696. 




Command-initiated IED described in 1650

I'm steadily working through a book that was published in Latin in 1650, "The Great Art of Artillery" by Kazimierz Siemienowicz.  The book was translated into French, then from there into English in 1729 and of course that's the version I'm studying. The breadth of subjects covered is remarkable, including physics, chemistry, mathematics, explosive processing, explosive storage and other related things.  There's a lot about artillery and some interesting rocket technology related to my earlier post about the English rocket experimenter Robert Anderson who was making his rockets in 1696. I have an interesting blog post "cooking" on the technical similarities of rocket design from these two engineers, working in different countries 46 years apart. And readers of this blog will recall that the revolutionaries in Dublin in 1803 used Anderson's rocket manufacturing instructions and it is very possible that one of the revolutionary Irishmen went to Woolwich in subequent years to assist Congreve in the manufacture of his rockets. Give me a few weeks to bottom out that detail and assess the apparent links, but this 1650 document is pretty remarkable in its technical detail, with multi-stage rockets being explicitly manufactured. 

As well as covering artillery and rocketry, amongst the book are also numerous references to improvised explosive devices. For example there's reference to a large barrel or cylinder shaped IED used in the Seige of St Andrews in 1546 that killed 321 and injured hundreds of beseigers. Ths large barrel containing "powder, stones and Iron bolts" was rolled down amongst the enemy.  I'm trying to find a cross or supporting reference for that, as that's pretty early in my historical time line of IEDs. Siemienowiz quotes his reference to the St Andrews device as being written by an Italian in a book called "Precepts in the Modern Art of War" that must have been published prior to 1650. Unfortunately the name of the Italian author is not clear and varies between translations and I have yet to unearth it. 

Here's another example from Siemienowicz referring to command initiated improvised devices using the flintlock mechanism I have described in some recent posts - remember this was written in about 1650.  This text below is from a 1729 translation:




Clocks, locks, energy and initiation

I’ve written before about the evolution of gunlocks, from matchlocks, through wheel-locks to snap-huances and then flintlocks because although these initiation systems were designed to initiate firearms they also enabled initiation mechanisms for explosive devices.  This post returns to that subject to discuss a couple of more elements to that story that I find interesting, namely engineering development and some fundamental issues about “energy” chains that apply both to these firearms systems and explosive devices.  In this post I have made some generalisations and simplifications in my description of the technology - forgive me, but otherwise the post turns into a book and neither you or I have time for that.                                                                      
Firearm initiation systems, and in parallel explosive initiation systems, are about initiating a quantity of explosives at a time that the operator chooses.  Thus, in the simplest of all firearm systems, a burning “match” is placed in contact with a small quantity of blackpowder in a “touch-hole” which then initiates a larger amount of blackpowder in the barrel of a gun.   This system worked for hundreds of years in the cannons you see fired in all the movies.                                                                                                                                                
The gun is aimed and the application of the burning “fuse” simply initiates the blackpowder.  The energy in the arm of the man holding the fuse, and the energy in the already burning fuse is enough to initiate the stored chemical energy in the blackpowder in the barrel.                                                                                                                                                                                                                                                               
But in a small firearm there’s an issue of the man pointing the gun and initiating it at the same time. Generally these firearms were pretty large and required two hands to point at a target.  So quite often the firearm was supported with a crutch allowing the firer to point it with one hand, sight the barrel with an eye at a target and use the “spare hand” to place the burning fuse on the touch hole. 
Firing an early firearm without a trigger and serpentine
But let’s face it, that’s a bit fiddly. The touch hole is small and it might be a bit awkward. The firer is concentrating on doing two things, keeping the target in line and finding a small hole with the burning fuse in one hand.   So, with some very simple engineering the matchlock was developed.    All that happened was that a simple S shaped lever was introduced onto the body of the firearm. One end of the lever held the burning fuse in  a specific position, the centre of the “s" shaped piece of metal was a pivot joint and the bottom end of the s was pulled with one finger.  The placement of the s shaped lever (a “serpentine) ensured that the burning match always found the touchhole or the pan at the entrance to the touch hole, and the firer could use two hands to aim the firearm, concentrate on the target and just use a finger to pull the “s" shaped piece of metal.
A very early, simple matchlock arquebus
 Now , manufacturing such a firearm was pretty simple, and within the engineering skills of the average door-lock manufacturer of the 15th century which simply used levers and pivots.   So matchlock firearms were relatively easy to manufacture and relatively cheap. Matchlocks continued to be produced from the 1400s for about 250 years.  I think this is important to understand - although better technology was invented in a series, starting in the early 1500s, match-locks remained a simple and cheap firearm and so were the most common at least until well in to the 1600s.
A nice image of a Japanese matchlock mechanism showing a pan cover
Now, there are some operational weaknesses with the simple matchlocks.  In the simplest of all matchlocks the pan or the entrance to the touchhole  is permanently exposed to the elements. So in poor weather the firearm simply won’t work.  Also the glowing match gives away both the position of the firer and the nature of their weapon.   Both these weaknesses were partially addressed.  Firstly a mechanism of a sliding or levered cover to the Pan or the entrance to the touchhole was developed, requiring some more intricate engineering so when the serpentine was moved then a cover was moved out of the way allowing the match access to the pan.  A bit complex.  Some attempts, too, were made to hide the burning match in a box, but not very effectively. Burning fuse also, by the way, made the weapon unsuitable for those guarding stores of ammunition.  So in the early 1500s the wheel-lock was developed.                                                                                                                    
In large part the wheel-lock invention was enabled by advances in engineering, and specifically advances in engineering from clock making.  On a fundamental level, the wheel-lock utilises, for the first time in a firearm, “potential energy” in a spring.   A wheel-lock, consists of a steel wheel, which has a small chain wrapped around its axle. The wheel is rotated with a spanner, this wraps the chain around the axle and the other end of the chain is attached to a spring.  Thus when the wheel is rotated it induces a potential energy into the spring. The spring is then held by a trigger. A second spring is then set up to hold the serpentine. In this case the serpentine doesn't hold a burning fuse, but a small lump of iron pyrites.  The spring acting on the serpentine holds the pyrites in contact with the rim of the steel wheel which usually has grooves on its circumference and some small notches to encourage friction.  When the main spring holding the chain attached to the wheel is released by pulling the trigger, the steel wheel rotates and, because it is in contact with the iron pyrites, sparks are formed.  The sparks initiate blackpowder in the pan.
So we have the potential energy in the spring, making kinetic energy in the wheel , which initiates chemical energy in contact with the pyrites, which initiates the chemical energy in the blackpowder, which converts to kinetic energy in the projectile, and that kinetic energy is transfered t o the target t cause damage.  A nice little chain, but one which requires a significantly more detailed engineering capability than a match-lock.                                                                                                         
The wheel-lock however has several advantages.   It is safer, in that safety catches can be applied to both the serpentine and the wheel.  The presence of a firearm is not given away by the burning fuse.  It can be prepared well in advance of use (if the springs don’t deform as some where liable to)  The firearm can be concealed. Since it is possible to conceal, the firearm was then made smaller, and so the pistol appeared for the first time, able to be held about a person, and the same person could indeed carry two or three wheel lock pistols. Since this is a blog about explosive devices, then of course the wheel-lock became a potential initiator for IEDs - the device could be hidden and initiated at a point of the firers choosing, perhaps say with a string to the trigger or a potential booby trap switch. IEDs are more suited to initiation by potential energy.
But now we have economics at play. The high level of engineering and therefore cost required for a wheel-lock would make it usually unsuitable for a one-time-use in an IED, although possible.   Only the rich could afford wheel-locks.  So wheel-locks and match-locks existed side by side for decades and indeed for at least 150 years. The economics of the engineering had some other interesting implications.  Matchlocks are simple utilitarian devices usually without decoration through the 16th century. Wheel-locks however, bought by the rich became covered in ornate art, and became models of fine engineering and artistic excellence.  Here’s some images of highly decorative wheel locks.
The fact that wheel-locks were used by the rich also had an effect on the manner in which warfare was conducted.   Ordinary infantrymen could not afford wheel-locks but the aristocratic and rich cavalry could. Cavalry tactics then evolved to make benefit of the capabilities that two or three wheel locks could provide. The cavalry galloped forward to a point within range of their wheel-locks, fired, and galloped back.   The tactics of cavalry using wheel-locks then had an impact on the types of horses and armour being used by the military. The huge horses required for armour encumbered cavalry with lances were replaced with smaller, quicker more agile horses. This perhaps lead, by connection, to the evolution of horse racing and blood stock management.   The armour, designed to to defeat the weapons of the medieval horseman was discarded - armour could be produced to protect against the bullets fired from wheel-locks but frankly it was too heavy.  So the nature of warfare rapidly evolved.  One could say that the nature of warfare evolved over the period of between 1500 and 1620 entirely because of the initiation system moving to a potential energy storage device (a spring) for the initiator rather than a chemical energy storage initiator (the burning match).                                                              
Subsequent evolutions of the gun-lock technology brought together the principle of a potential energy store (from the springs in the wheel-lock), with simpler engineering requirements.   I think that the spring-held serpentine of the wheel-lock got people thinking. Firstly pyrites wasn't always a solid enough material to hold reliably in the jaws of the serpentine, and indeed the spring holding the pyrites wasn’t designed to cause the pyrites to impact with the steel wheel, just hold it against it.  I think that the metallurgy of springs improved throughout out the 16th century.  A powerful spring could cause a flint to strike a steel firmly and reliably enough to set a spark - earlier technology wouldn't allow that - the springs would break or the springs would deform very quickly. But the evolution of clocks and associated engineering developed through the 16th century so that steel suitable for using in springs evolved.  All of a sudden there was a metal available that could be used in a  spring that could force a serpentine holding a flint hard enough to cause sparks. The “snaplock” then developed in about 1540 utilised the same serpentine used in the match-lock and wheel-lock, but this time powered by a strong spring to strike a “steel” to cause sparks - subsequent developments of the snap-huance and then the flintlock were simply improvements on that design, improving its reliability and weather protection.  Essentially then in energy terms, the potential energy inherent in the spring that powered the wheel in the wheel-lock was changed to potential energy in the main-spring of the flintlock. Crucially though the engineering required of the flintlock was still considerably simpler than the technology used in the wheel-lock. Flintlocks could be pretty much mass produced while wheel-locks remained the product of a highly skilled craftsmen. As an aside, the engineering tolerances required of the wheel of the wheel-lock needed to be much tighter than the engineering tolerances in a flintlock. In a wheel-lock the wheel rotates through a slot in the “pan” and if the slot is too big then the gunpowder falls through it.   The fact that flintlocks used potential energy , but were also cheap and able to be mass produced means that they became attractive to use in “one time use” IEDs such as this device . The first mine , Samual Zimmerman's "fladdermine" also use a flintlock mechanism.                                                                                                                                              
It is clear from reading up about the history of clock development that many of the principles of engineering in clocks developed during the period of about 1550 - 1750 were subsequently applied to the production of munitions fuses. There’s probably another blog (or book!) to be written about that. 



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.