Explosive Mousetrap

I’d like to advise any sensible person not to look for mousetraps on the internet.  Some are bizarre, some cruel, and some very weird and unpleasant, sometimes all of those things at once.

But this one is explosive so, hey, I have an obligation to show it to you.

 

Description of 1944 Render Safe

I’m taking a bit of a gamble with this story. Usually the stuff I post is out of copyright. The excerpts below are from a book published in 1977 by the then Lord Rothschild.  I have contacted his estate to seek permission to quote this small excerpt but received no reply. I think this story is worth telling and shows the man in a good light so I’m going to take a chance and copy some images here.  I will remove if anyone objects and make a donation to a suitable charity if it causes concern.

Lord Rothschild (1910-1990) was one of those larger than life characters, a real polymath if lived a life to the full.

During WW2 he worked for MI5, advising on the vulnerability of British industry to sabotage, and in one or two other related “spooky” activities related to explosives, much of which there is little or no public record of.   In 1944 there were some sabotage devices sent from Spain, I think, to the UK hidden in cases of onions. One arrived, somehow in Northampton and Lord Rothschild went  to deal with this German sabotage device which used 21 day timers.  I have no other details of this German operation.  Below is an extract from Rothschilds telephone conversation with his secretary as he rendered the device safe.  It reminded me very much of the Earl of Suffolk, another Lord involved in Bomb Disposal in the Second World War who I have written about before – he too conducted his RSPs while talking to his secretary on a field telephone.

I understand that it was mainly for this operation that Lord Rothschild was awarded the GM. Good job.  No doubt his secretary then asked “So, how do you think that went?”

 

This excerpt is from “Meditations of a Broomstick” By Lord Rothschild, published in 1977 by Collins.

 

 

 

Invention of the Mechanical Explosive Igniter

It’s been a while since my last post – other things have had my attention. A reader, John C, responded to a post I wrote last year with some thoughts and this encouraged me to look again at this fascinating and crucially important piece of (explosive) history.

This then is a follow up to this post   which I suggest you read through to refresh your memory. In it I explore some interesting technological developments regarding the development of explosive initiators in the early 1500s.  Why is this important?

    1. Until the early 1500s, explosives (gunpowder) could only be initiated by the physical application of fire. Gunpowder was initiated by applying a burning match to a small quantity of gunpowder which then ignited a larger charge, whether that be inside a gun or inside a larger container.
    2. Effectively this limited the use of explosives/gunpowder, because a prior step was needed to ignite a match and keep it burning until such time as it could be used.  This limited how explosive devices or firearms could be used, slowing the process or making it more obvious. So the technology development described below allows for speed of action, timeliness and concealment – all important characteristics of explosive devices.
    3. The invention of a mechanical igniter gave much more flexibility and did away with the need for a burning match. Devices could be placed, concealed and left. Firearms could be concealed.  Devices or firearms could also be initiated almost exactly when needed rather than after a delay.
    4. Mechanical igniters such as this enabled booby traps (Victim operated devices) (perhaps with a trip wire), enabled command operated explosive devices (via a pull string) and even enabled timed explosive devices (where a clock hand could pull a string). As far as firearms are concerned the jump from matchlock to wheel-lock is a very significant technological leap.

So in the history of firearms and in the linked history of explosives (as the site purports to be, in a sense)  these mechanical devices described in my earlier post are quite significant.

In the earlier post last year I included a copy of beautiful diagram of a mechanical igniter from a date of about 1505. Historically speaking this is technically a wheel lock but I think was invented before a similar device was fitted to a hand held firearm. It’s maybe the first wheel lock mechanism.  This device and one or two others were carefully drawn and included in the“Loffelholz Kodex”. At the time I hadn’t worked out how this igniter had functioned. I’ve now spent some time scratching my head and doing a little research and I think I may have an answer. But I’m only about 60% certain, so if you think I’m wrong, please correct me. I’m very open to alternative interpretations of this intriguing machine.  For ease of explanation I have included the diagram again here below but with some annotations.

I originally thought the device had a coiled spring hidden behind the wheel (F) to cause it to turn, but I no longer think that is true. Importantly I don’t think coiled springs of the type I had envisioned had been invented at this time.  Rather, like the simpler device seen in the last post, there is a cord wrapped around the wheel’s axle. The horizontal J shaped main spring (B) has its longest arm, along the bottom and this is the spring which pulls the cord down, causing the wheel to spin. The wheel is prevented from turning by the Brake (C) in the middle to which a pull string is attached. Pulling that away from the wheel is like releasing a parking brake. In normal conditions this Brake (C) is held in place by the brass bar running in parallel to it acting as a spring.  The bit I’m slightly unsure of is the Cord tensioner (G). This holds the cord tight against the axle. You can see the finger holder that you pull when winding up the wheel(F) with the winding key (E).

So… let me describe the preparation and action…

1. The winding cord is tied to the end of the J shaped main spring and the other end to to the right hand contraption. The right hand contraption is tensioned using the finger guard to pull the cord.
2. The wheel is turned using the “ring key”. This causes the cord to wrap around the axle of the wheel. (Somehow!)
3. As this is done the J spring is flexed upwards, and held there by the cord.
4. The “brake” acting on the wheel prevents the tension of the cord to act on the wheel. .
5. After a few turns the brake is engaged, holding the wheel.
6. The tray is primed with gunpowder or tinder.

The action on firing is as follows:

1. At the chosen time the string is pulled.
2. This pulls the brake away from the wheel.
3. The J spring now acts pulling the cord down that is wrapped around the wheel’s axle.
4. The wheel rotates
5. The serpentine holds the pyrites against the rotating wheel
6. Sparks are generated and thrown into the gunpowder/tinder in the tray. The ignition of this gunpowder or tinder can then be used to ignite the main charge though some sort of channel.

I’m not quite sure about how the cord is wrapped on the axle – this important component is hidden from view.

The Loffelholz Codex was produced at roughly the same time as Leonardo da Vinci was also developing spring powered wheel locks. Frankly his diagrams are much harder to interpret that these in the Loffelholz. I have no idea which came first, and it doesn’t really matter perhaps. Other technologies which enabled this design include:

    1. Metallurgy and the ability to produce, shape and utilise Spring steel, which seems to have occurred in the late 1400s.
    2. Clock technology, and associate manufacture of relatively carefully produced metal components.

The impact of this development was significant – in 1512 such mechanisms were banned in at least one European country because of the capabilities it provides to those with nefarious intent, and therefore a threat to society of the time. There are interesting parallels with trying to control and constrain explosive technology today.  Wheel locks continued to evolve into neater, smaller designs designed to be mounted on or built in to firearms, usually with some clever spring design – but this early example is entirely separate from a firearm in this form.

South Armagh Command Wire IED – 1921

UPDATE!!!

This story below, based on contemporaneous news reports, turns out to be incorrect.  I’m indebted to JB for sending me the Irish History statement of an IRA member of the time describing how the tracks were manually removed causing the train to derail and crash.  So the story below doesn’t stand up.  But I’ll leave it here because its interesting on a number of levels:

a. how the press reports will vary from the truth quite dramatically.

b. The geography of the area that I assessed as being useful for a command-wire attack, also enable this manual sabotage operation.

Here’s what I wrote originally:

During the 1970s, 1980s and 1990s South Armagh in Northern Ireland was a tricky place for IEDs. Only the best and most experienced EOD teams were deployed there.  And one particular part of South Armagh posed more problems than most and that was the railway line that snaked sinuously through the countryside.  As the line gets towards the border, it can be viewed as if in a large amphitheatre, and can be observed for miles, and with the border close by providing escape routes, things were pretty challenging.   At the time no-one told us this place had history. But exactly 100 years ago there was a very significant attack on the British Army here, blowing a train of the track and killing soldiers and horses. Here’s a brief outline.

The new government in Belfast had just been formed. A British Army Cavalry unit, the 10th Hussars, normally based in Dublin, had travelled North by rail , in three separate trains with their horses, for the parades and pageantry associated with the opening of the new Ulster parliament by the king. On 24 June 1921, the unit were travelling back to Dublin again by three trains.   It was the third and last train that was attacked.  The front carriages contained the soldiers and the rear carriages the horses. A few mile beyond Newry the line runs through open countryside with Slieve Gullion on the right and the Ravensdale hills on the left.  In the 80s and 90’s I knew this place as the “Drumintee Bowl” and in those days it was under a lot of observation from the British Army.  In 1921 though it was just pretty rolling wild countryside.  Both then, and in the 70’s,80’s and 90’s the place provides an “arena” for the IED – long views, little high hedged lanes, and a border to escape across. Tricky place for an EOD team, who can feel very exposed there.  A lot of detailed procedural techniques were honed and carefully applied during EOD operations in the Drumintee bowl and on the railway line in particular.

The railway line, which still runs today on the same route runs along an embankment, sitting about 7 -10m high, in full view.  The IRA of the time, knowing the trains were to return to Dublin and knowing , presumably when the trains were loaded and boarded at Belfast, had planted two explosive charges under the rails. The press of the time suggested the device had a time fuse, but I think this is unlikely. Much more likely would have been a command wire, run to an observation point a couple of hundred yards away.  Local IRA men had been trained in the use of electrical command -wire IEDs from the previous year and were equipped with the components including coil exploders.

As the train passed the point of explosion, the circuit was made and the device exploded under about a midpoint on the train. One carriage containing a few soldiers took the brunt of the explosion and three of the soldiers were killed. The carriages behind containing the horses then tumbled off the embankment and about 50 horses were killed (all but one). Here’s a  Pathe news reel of the time at this link.

Of course it’s no surprise that the characteristics that made this place attractive to the bombers of 1921 were the same 60 years later. The IRA probably knew fully well about the 1921 attack – I can tell you that the EOD teams operating in South Armagh 60 years later were , to their chagrin, less aware of history than they should have been.   Other attacks planned by the IRA in the 1920/21 era in South Armagh included pumping oil and paraffin in a mix into a police Baracks in Camlough as a pumped “flame thrower” incendiary. This technique was returned to by the Provisional IRA to attack the RUC station in Crossmaglen in 1993. (Guess what, the British Army had forgotten the earlier attack) , and using a large explosive device paced at the entrances to police barracks – another techniques which came around again in the 1970s,  1980s and 1990s in that same place.

The soldiers who died that day in 1921 were Private Carl Horace Harper, Private William Henry Telford and Sgt Charles Dowson.

The attack was carried out by a IRA unit led by Frank Aiken, a notorious man who commanded the IRA volunteers of South Armagh and Newry at the time. In the weeks that followed their were tit for tat reprisals including the shooting of four IRA men by the B Specials, and so on. South Armagh always was a hard place.

 

More early explosive ROVs

In an earlier post here, I discussed some First World War antecedents of modern ROVs, these early one being used to deliver explosive charges – essentially a mobile land mine.  One of the early ones I mentioned was a Schneider “Crocodile” from 1915 which I have not much information on but is pictured here, and which apparently was French developed, but was trialled by a number of nations including Britain and Russia.

Here’s a pic of the controlling team, manning some sort of command interface while the ROV pays out or pulls a cable. I think they are French.

Interestingly I’ve just come across a reference to a number of other Russian devices, some of which seem to have been ROVs. These are referred to as “Sidelnikov’s mobile mine, the creeping mines of Kanushkin and Doroshin, the crocodile mine of Colonel Tolkushin.”     It’s interesting that Colonel Tolkushin’s device was also called a “Crocodile” like the French device. I have only this poor image of it from about 1915-1920:

It seems to be a multi-charge device, on wheels, but to be honest it’s not that clear. Alas my Russian is not good enough to dig out more detail.

Russian ROV technology also preceded some other German technology to deliver large explosive charges in WW2 that I have written about here .  In the 1930s, Russia developed the “Teletank” . One of the versions of this teletank had a large charge (200-700kg) which was “dropped” by the ROV tank like the German Borgward. These were radio-controlled tanks and utilised some early systems which were designed to prevent radio jamming.  Don’t underestimate Russian technology.

 

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