You can contact me at rogercdavies(atsquiggle)  If you have a comment and the system won't let you post it, ping me using the @ for (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.

A note on moral perspectives. Throughout this blog there are descriptions of all sorts of people using IEDs, explosives, or suffering the consequences. Some of the people using IEDs are thought of as heroes by some and terrorists by others. One person's good guy fighting for a cause is another person's evil demon.  It's complicated, and history adds another series of filters too. All of us too live in a narrative made up around however we were brought up, what we were taught and what we learned along the way, rightly or wrongly. So if you sense moral ambivalence, one way or the other, well, I'm guilty and I'm not perfect.  By and large though, I have unapologetic sympathy for those dealing with the devices, whether they be soldiers, cops, or whatever, even those who are part of Nazi or other nasty regimes. That's the cool thing about EOD techs - we don't really care who the enemy is.


Entries in 1500-1600 (18)


Command initiated explosive device from 1582

I'm steadily working my way through more military handbooks from the late 1500s when there appears to have been a lot of revolutionary thought going into military technology and explosive device development in particular. My previous post on a grenade was dated 1578, you may recall that Giambelli's ship explosive device was 1584, and I've written before about a postal device in the city of Pskov in 1581.  I've also written before how "gun-locks" were used as initiating devices for explosives over a 250 year period

On that latter point I've just found a gun lock (in this case a wheel-lock) drawn in a manuscript from Germany, dated 1582. The drawing is here and as you can see the design is very clear.

The wheel-lock was a progenitor of the flintlock which came in a few years later, in about 1600. In a wheel-lock a spring-loaded wheel spins against some pyrites held in the cock.  Here you can see how the gun lock has been removed from a firearm and fastened to a frame. A string is attached to the trigger, led around a pulley and away to the person initiating the device. When the target presents itself, the person pulls the string, which pulls the trigger. On pulling the trigger a spring mechanism spins the steel wheel against the pyrites held in the cock. This causes sparks which ignites the fuse. The fuse leads to a barrel of gunpowder hidden nearby.  In a post a few years ago I have an image showing a multiple IED attacks against a military convoy employing these exact devices, so it's good to corroborate the attack with a contempory IED design.

So, this is another example of how explosive device design appears to have developed rapidly at this peculiar point in history, across Europe. I think it is the publication of these handbooks and manuals of military science that seems to be helping - bu I'm afraid I'm not a good enough historian to identify other causes of this bubble of ideas. Comments from proper historians welcome!



The 55th device - 1578 - The force is mighty and commeth with such a terror

I have been hinting that I had found an early printed book containing interesting matters with regards to ordnance, military engineering and explosives. Having worked initially from second-hand reports of the publication and an original manuscript version (a digital copy) which I couldn't read at all, I finally tracked a printed copy down and literally got my hands on it, in the British Libary, last week and so it's time to start discussions of it.

The book is "Inventions or Devices" by William Bourne, or to give it it's full title as it appears in the British Library catalogue " Inuentions or Deuices, Very necessary for all Generalles and Captaines, or Leaders of men as wel by Sea as by Land", written and printed (I think)  in 1578.  Here's the cover page:

Bourne appears to have been a well-travelled Naval gunner and mathematician with experience in of wars in Europe. The book is an odd list and description of military ideas and  "inventions", mostly practical or pragmatic. Some are startlingly obvious but others are quite fascinating and a little bit obscure.  On one level he offers advice that a modern munitions specialist or ordnance officer would recognise in terms of "proofing" and inspection of ordnance. These ideas include safely unloading a fully loaded breech-fast projectile stuck in a cannon, methods of checking the barrel of cannons and a device for consistently assessing the power of a sample of gunpowder with a mechanical testing device. Other matters include various naval maters and the sapping and mining of castle walls, countermining and the design of assault ladders. 

I'll go through a number of these in future posts because the ideas are worth exploring and this is a very early publication, I think, for some of the technical ideas discussed. For now though, to start us off, here's his description of a large grenade-like device. I'm going to post a couple of images of the actual pages then attempt to translate some of the archaic language. This is the earliest decription I can find in a primary source about the design, manufacture and use of a metal cased grenade. The method describes using a mould for a 5" cannonball to make a hollow grenade by using a clay insert in the casting.  The case of the "grenade" is bell metal or brass, with iron nails providing the spacing to the void (and adding to fragmentation) which is filled with good quality gunpowder and a fuse.  

 Here's my attempt at a translation:

The 55th Device.

As diverse Gunners and other men devised sundry sorts of fireworks for the annoyance of their enemies, yet as far as ever I have seen or heard, I never knew nor heard of any good service done by it, neither by sea nor by land, but only by powder, and that hath done great service, for that the force of it is mighty and commeth with such a terror. But for their other fireworks, it is rather meetest to be used in the time of pleasure in the night then for any service. And for to make this kind of ball, do this: Prepare the mould of a double culvering shot (a sort of cannonball) that is five inches high, and then take clay, and make it round in a ball, as much as a minion shot (another smaller size of cannon ball) that is three inches, and let it be dried as the Founders (Those who work in a foundry) do use to dry their moulds, and then stick that clay round about with iron nails, leaving the nails an inch without the clay, and then put that mould of clay into the moulde of the culvering shot, and look that the nails do bear that the ball of clay do stand right in the middle of the mould of the culvering shot, and also make the mould of clay so that it may have a touchhole to come into the clay, and then take bell metal or other coarse pot brass, and then fill the mould of the culvering shot with that metal, and that being done, then it is finished and so make as many as them as you list, and then that being done pick out the clay again that is in the ball, that was cast in the culvering shot mould and then fill that with good corne powder (good quality gunpowder), and then that being filled near full, then take some receite (? fuze?) of soft firework that will not burne too hasyily and fill up the rest of the ball, and then it is perfectly finished.  And then in the time of service, either by sea or by land, it is very good to throw in amongst your enemies, where they do stand thick, as they be very good to defend a breach or such other like causes, as this, to take it in his hand and to fire it, and then throw it amongst your enemies, and as soon as the firework is burned into the powder, the ball will break in a thousand pieces and every piece in a manner will do as much as an Arquebus shot (a bullet) so that there is no kind of firework comparable to this kind of ball, for service in the time of need. 

This publication predates the adoption of such things (grenades) by armies several decades later in the 17th Century. 

More of Bournes "Devices and Inventions" will follow in later blog posts.


Detecting tunnellers with dried peas

In an earlier post I wrote about a peculiar technique allegedly recommended hundreds of years ago to detect buried explosives   I have been on the hunt for more very early explosive devices and EOD techniques.  I'm currently deep into a startling book published in 1590. Forgive me but I'm going to keep the name and author of the book to myself until I've finished working out what it says.

For now here's an intruiging technique from the book for detecting sub-terranean tunnelling such as was used for mining the ramparts and walls of fortified castles. Tunelling is of course still used by all sorts of terrorists, and others. Apologies if I have mistranslated any of the description from quite archaic (for me) language. For ease of reading here's my explanation of a couple of the words which may not be familiar to you, followed by the full description:

"lattine bason"  = tin basin, or tin pan

"peason" = dried peas

"woll" = wool

As touching thus for to know whether there be any undermining in the ground, and where that they be, it is thus knowne: - Take a lattine bason, and goe unto the place that you doo suspect that underminers may bee, and set that bason uppon the ground, and then put five or sixe peason in that bason, and if that there bee any underminers neere at hand, then at everie stroke that they are in the ground doo make with their tooles, the pease will make a jarre in the bason; and also the effect will the more appeare, if that you doo binde a sackfull of woll as hard as you can, then setting the bason with pease uppon that, you shall heare every stroake that is made in the ground, and this is one of the best things that may be devised to be placed in any place, for to knowe where that underminers be.

I find the counter-intuitive idea of tightly bound wool to aid the "coupling" of the tin pan with the ground to be very interesting. If I had anything other than tinned peas in the house I'd do an experiment right now...

More to follow on other fascinating matters from this book in weeks to come.


EOD Equipment 1573 and 1971

I have finally found a picture of a wheeled EOD shield from 1971 - courtesy of RLC Museum. Compare these two largely similar tools, the first from 1573, and the second from 1971 - 402 years apart. I believe the shield was used operationaly in Hong Kong in the sixties, and quickly went out of service after limited use in Ulster in the early seventies.

circa 1573circa 1971

My earlier post on the subject of historical ROV's is here. 




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.