A wire to pull a trigger

Historically, firearm mechanisms have often been used to initiate explosive devices, and I’ve blogged about plenty over recent years. Most recently this device here from 1582  shows a very early and very simple example.

I’ve come across a few more devices from the early 20th Century that apparently used a similar technique, perhaps perpetrated by Harry Orchard (aka Albert Horsley, aka Tom Hogan)  as part of the Colorado labor wars in 1903-1905.  I’ve blogged about some of Orchard’s stranger command IED switches before but I didn’t mention then the use of a command pull to pistol trigger.   Orchard was certainly comfortable making, placing, and laying command pull switches and perhaps he saw a pistol trigger as a more reliable system than pulling a cork from a bottle of acid!

Orchard’s case is complex – he worked, apparently, for both sides of a violent labor dispute and there are many accusations of “false flag” attacks. As to whether he committed the crime I’m about to mention, and why, I can’t be certain, but in one sense, for our purposes it doesn’t matter because we are interested in the mechanism and not the motivation or perpertrator.

On 5th June 1904, about 60 strike-breaking miners were on the platform of the Independence Railway Depot in Colorado. They were waiting for a train to take them home in a nearby town. The miner’s union had been in a long and violent dispute with the mine owners.  The perpertrator had planted explosives under the platform, to be initiated by a loaded and cocked pistol placed immediately next to it. A 200ft (some reports suggest 400ft) wire had been  tied to the trigger and led away to a firing point at a safe distance.  The wire was pulled, the device exploded and 13 miners were killed and 9 injured, perhaps one of whom died subsequently.

There are conflicting reports about the nature of the explosive itself – some saying blackpowder, some dynamite.

It also seems likely that a similar device may have been used to cause an explosion in the Vindicator Mine, probably by Orchard, in 1906, albeit that may have been set to act as a booby trap /victim operated switch.

More “Stay behind” devices

In a couple of posts over the last few months I’ve discussed “stay behind” devices.

In this post I discussed Russian stay-behind devices in the Crimean War in the 1850s .  The Russians, in ceding Sebastopol to the French and British, were able to predict where attacking troops would be – whether that be to seize high profile buildings or munition dumps, and lay “booby-traps” which caused significant problems.

In this post I discussed Russian stay-behind explosive devices in WW2, used to attack the invading Nazi army. In particular the Russians in many instances were able to predict the sort of buildings that the Wehrmacht would be attracted to use as headquarter buildings – typically large imposing buildings with large rooms suitable for converting into the various facilities needed by a military headquarters. Using both long delay mechanical timers and radio-controlled F-10 devices they had considerable success in Kharkov, Kiev and Odessa, targeting incoming headquarter units , in many cases several days or weeks after losing the territory.  In many cases, including a device personally emplaced by Ilya Starinov,  deliberately “poorly concealed devices” were laid “on top” of the deeply buried device. EOD troops inspected the proposed building, and cleared the obvious device in the cellar  (not realising another much larger device was hidden under it). Three weeks later the massive device was detonated, successfully taking out an entire headquarter staff.

With all that in mind, I have found another use of a very similar tactics, but used by the Germans against the Allies, in WW1. Booby trapped explosive devices were used extensively by the Germans in WW1. In this example, the tactic used by the Russians, against the Germans seems to be identical.

On about the 18 March 1917 Bapaume, a small but strategic town was captured from the Germans. After taking the town, an EOD unit found a mine of some sort in the cellar under the Town Hall, a prominent building – whose cellars were deep enough to provide shell shelter – so an attractive structure for forces “moving in”.  It is believed that the Germans may have expected or hoped that a Divisional Headquarters may have decided to use the place.  I think that in an earlier part of the war the Town Hall had been  indeed previously used by a British or French headquarters.  As it happens that did not occur but about 30 Australians had “moved in” along with a tea stall from the “Australian Comforts Fund”. On the night of 26 March, so about 8 days later, a timer, set before the Germans retreated, caused a massive device to explode, killing most of the occupants.  I have found reports that the charge could have been as large as 10,000lbs, (but I think that unlikely, more likely maybe a couple of hundred lbs) and had two independent “time pencils”, of the type where the delay is provided by acid eating through a steel thread holding a striker under spring tension.  Interestingly there is a suggestion that the German Pioneers who laid the devices defecated on the ground above it, to dissuade careful inspection.  I also understand that the German withdrawal from Bapaume was part of a carefully planned operation to fall back to the Siegfried Line, which will have given time for the preparatory effort.

UPDATE:  I have learned from Ian Jones that the details of the incident aren’t quite as I described. A large, easily found device was discovered and made safe in the cellar. a somewhat smaller device carefully hidden in the tower of the Town Hall was the device that exploded, collapsing the cellar trapping people in there.

Shortly later a German was captured nearby and interrogation of him suggested there were other devices in the area.  Before this warning could be circulated, at 12.37 p.m. On March 26th, the luxurious dugout system on the edge of Bapaume, in which a headquarters had been set up was entirely destroyed by a similar mine. Several other similar devices appear to have been used in the area.

Here’s a diagram of a German delay switch. I think the Germans also had mechanical clockwork delay switches.

German WW1 Boob-traps are very well explained in Ian Jones’s excellent book “Malice Aforethought”   Anyway, I think its interesting that a tactic perfected by the Germans in WW1 was used by Russians against the Germans in WW2.  There are lessons here too about “predictability” of the target’s behaviour in terms of choice of location for an explosive device, and also in terms of disguising stay-behind devices. Of course, booby traps were used by the British, French and Australians too.

Never New, Fact and Fiction

And ye shall hear of wars and rumours of wars: see that ye be not troubled: for all these things must come to pass, but the end is not yet

One of the strange things about terrorism, and suicide terrorism in particular, is that people always think it is “new”. There is something about the fear of terrorism that always makes it fresh, always makes it feel like a new encounter. Add to that the short memories that people have, and the general perception is that suicide terrorism is a newly thought of tactic, or strategy,  but as I have detailed here before and as Iain Overton’s excellent “The Price Of Paradise” covers, these tactics are simply recycled, decade by decade, century by century.

There are themes within this tactic too. Themes that play out in public, in the mind of the public, and perhaps which terrorist groups recognise and copy, or reflect. Fact and fiction become confused.   There is a theme, played out frequently, of the innocent child, an unwitting, unknowing bomber, tasked with carrying an explosive device, without being aware it is going to explode. You’ve that recently, yes?     Nigeria, or was it Yemen? Gaza? Syria? Afghanistan?  Well, yes probably, but it’s not new.

Here’s a clip from a 1936 film by Alfred Hitchcock, called “Sabotage”, which plays on the fear of the public in the mid 1930s, of infiltration by terrorist groups bent on destroying the nation.  Here, an innocent unwitting child is tasked with delivering a package to a tube station in London- Piccadilly. The clip is classic Hitchcock. Having being delayed en route the boy is on a bus, approaching Piccadilly when the bomb detonates.

This is really very peculiar.  Tube stations were attacked in the 1880s with IEDs and again in 1939, three years after this film was made  Then again in the 1970s, including the Piccadilly  bomb which exploded at a bus stop outside Green Park station in 1975. Then more recently buses in 1996 and  2005 were again attacked   and tube stations have also been targeted again. But here in the clip, masterful suspense by Hitchcock weirdly foreshadows numerous attacks. Crowds of people, and military parades included… will the bomb go off?   And of course military bands and mounted units themselves became targets for real in 1982

So, it’s really a strange thing to see this modern essence of a threat, a child proxy suicide bomber in a fictional movie from 1936.  The rest of the movie (which can be found on YouTube in full)  ends with the bomb maker, with a suicide IED hidden in his coat, detonating his device behind a cinema as the police evacuate the theatre and mount a raid to capture him.  He had been discovered by an undercover police operation.  Such modern themes.

 

 

 

Tremble! – The Answer to the Mystery Device

A couple of weeks ago I set blog readers a challenge regarding this device, who made it, what the mystery component in the bottom right corner was, and who rendered it safe.

Well done to KH for his (close, but not perfect) answer. I’ll be buying him lunch soon.  It’s actually a pretty interesting story.  The device was found placed next to a telephone junction box under a manhole cover in a street in Arthur Square, Belfast, Northern Ireland, laid by the IRA , in 1922.  The fuel can “Pratts Perfection Spirit” contained a home made mix and two improvised igniters (not a detonators) in parallel. The EOD team (about more of which shortly) recovered a wooden box with a single slider switch on the outside. Inside was the timing circuit, which had failed. There was a 4 volt “Ever-Ready” battery, an American made clock with a soldered wire switch connection.  The improvised igniter design is quite intricate with a thin copper wire running through magnesium flash powder held in a glass tube, but with a spark gap. The can contained about 20lbs of home made incendiary mix, based on sodium chlorate, some scrap metal and  handful of bullets.  When testing the explosive, it burnt with an intense heat, but interestingly also proved in some circumstances to be “detonable”. I’m leaving out details of the mix for obvious reasons.

Here’s a circuit diagram , done in follow up investigation and analysis.

(This device did not work)

The mystery component is, I think, very interesting, but received scant attention at the time. It is described as a “trembler” but it would be wrong to think of it as an anti-handling trembler switch.  It is in fact an induction coil device for upping the voltage from the 4v Ever-Ready to sufficient voltage to cause the igniters to act as designed. It is actually a car component from a Ford Model T.  This component was known as a “trembler” or “buzzer coil”, and provided sufficient voltage for a car’s ignition system (several thousand volts).  Here’s a video explaining this component.

These trembler switches were popular with ham radio enthusiasts and early electronics hobbyists as an easily available and reliable component.

Finally we come to who rendered it safe. For many recent decades, the lead military agency for EOD in Northern ireland was the Royal Army Ordnance Corps who morphed in the 1990s to the Royal Logistic Corps. And very proud of it we were too!  But in the 1920s, it was the Royal Engineers who provided their expertise to deal with the device and many others.  I can hear my spiritual foundations shaking…

Other devices dealt by the Sappers near Armagh that year were cast into concrete to look like kerb-stones, a technique used more recently in Iraq. They were initiated by command-wire.

Update: Render Safe Procedure used in 1922

I have been asked about the Render Safe Procedure (RSP) used by the Royal Engineer EOD personnel  on this device in 1922. I don’t often discuss these things for obvious reasons but I think I’m OK with this one and its quite interesting.  Here’s what they did:

  1. Filled the manhole with water from a fire hose, submerging the device. Gave it a three hour “soak”.
  2. Removed the wooden box (which was in a sack) from the manhole, cut open the sack. There was a concern over a possible booby trap switch attached to the sacking but none was
  3. The external slider switch was cut off manually, leaving an open circuit
  4. The wooden box was pried open, and components separated after photographing
  5. The cap of the fuel can was removed manually  and the “sand like” HME observed, with the leads leading in.
  6. There was a small 1″ diameter hole in the base of the can covered with some sort of cover.  Apparently this concerned the operator as it may have indicated something clever included in the devices construction. Rather than pull the leads out through the cap, or open the tin with a tin opener or hammer and chisel, the explosive was carefully removed, through the bottom 1″ hole, bit by bit with a a long gouge to eventually reveal the igniters (at this stage assumed to be detonators/blasting caps). These were then cut out.
  7. A series of tests were conducted on the components, quite thoroughly.

 

Senior officers and explosive investigation don’t mix

In the last few days the British Royal Navy  have announced a “large” deployment (their words not mine!) to the Baltic as part of a NATO exercise.     The reports mention that this is the largest deployment to the Baltic for 100 years.

Actually the previous deployments are pretty interesting.  If you don’t know the story of Agar VC, who tore around the Baltic in a fast torpedo boat, delivering and picking up spies for MI6, then sinking Russian cruisers, in 1919 (!)  you should read this life story here.  Jaw dropping stuff.  I have mentioned one of his WW2 exploits here, and he also took part in the Zeebrugge Raid in 1918, so he is a recurring character on this blog.  Nothing to do with explosives but the story of the sinking of HMS Dorsetshire is remarkable.

There also was a significant range of British naval operations in the Baltic during the Crimean war (1855).   I’ve mentioned this in passing in earlier posts but it’s worth revisiting.  The Russians had a major naval base on the island of Kronstadt hat was potentially a target for attack by the British Navy. The Russians deployed a fairly large number of explosive devices, tethered just below the surface of the sea on the approaches to the base, in effect an early sea mine. (Similar devices had been deployed in the Crimea and you can see a superb drawing of one here)

The British Navy on patrol in the Baltic became aware of them, and decided to investigate, sending two ships, with senior officers aboard to recover and examine the devices.

Here’s a Royal Navy diagram:

The device works when the rod A-A is struck by the side of a vessel. This rod then pushes on a glass vial of Sulphuric Acid (D-D), breaking it at the bottom. The acid drops into a container full of Potassium Chlorate (C), causing a reaction which ignites the gunpowder charge. This fuze is called a “Jacobi fuze” although in fact it was designed by Immanuel Nobel, father of Alfred Nobel.

Provided the rods aren’t pushed, (they are held by a spring), it is possible in theory to recover the mine, which is exactly what sailors from a ship carrying Admiral Seymour did. On recovering the device onto the deck of the ship it was carefully taken apart, and there was discussion amongst the officers observing how the mechanism should work.  Admiral Seymour, being a “hands-on sort of chap” worked it out an exclaimed “O no. This is the way it would go off” – and he pushed the bar A-A. The device duly functioned as intended , exploded, and knocked everyone down around it. Seymour survived but was badly injured.

 

The very next day, a ship carrying Admiral Dundas recovered a similar device. Admiral Dundas performed exactly the same trick as Admiral Seymour, the device exploded and Dundas nearly lost his sight.

Senior officers eh?

 

 

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