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 1860-1870 (15)


Attacking Railway Lines with IEDs using Firearm Initiation Systems

I think I have a final piece of the jigsaw here, that links the IEDs used by Lawrence of Arabia, with IEDs used by Jack Hindon in the Boer War and now, the final piece, with a specific IED designed in the US Civil War.  

My intent here is to show how a specific IED design, improvised from commonly available battlefield materials, that used the weight of a target train on a gun lock trigger mechanism to explode a charge, seems to have begun in 1864, and that design, or very close approximations of it were then seen in the Boer War decades later, and again in WW1 more than ten years after that.  It is of course possible that the design was independently invented - but my supposition is that it was not, and the concept was known by those who deal with explosives in one form or another. The attack mode proved useful in what we would call today "guerilla warfare", often associated with a firearms firing on the resulting shocked and disorientated survivors.

In bringing these together in a historical sequence I am in part repeating earlier blog posts. In uncovering the details I worked backwards but now I'm laying this out in sequential historical sequence, covering a period from the early 1860s to WW1.  I'm specifically looking here at attacks on railways where the weight of the train causes a trigger on a gun "lock" to be initiated - components of firearms were of course used in other sorts of IEDs over many centuries and I have blogged about that here, but that's outside the scope of this post.

1. US Civil War. Union IEDs designed to attack Confederate trains.  As I have blogged before IEDs (then called "torpedoes") were used extensively by both sides in the US Civil War, with perhaps the Confederates making most application of them. After the end of hostilities the Chief Engineer of the US Army, Brigadier General Delafield collated numerous reports on various Torpedos used in the conflict and put them into a historical context, examining the efficacy and appropriateness of use.  I find it intruiging that Delafield, in the decade prior to the US Civil War was one of the US Army's observers in the Crimean War which saw extensive use by the Russians of IEDs.  In the collated reports is a letter written to Brigadier General Delafield by 1st Lieut Charles R Suter, Chief Engineer in the "Department of the South, Hilton Head, South Carolina, on 26 October, 1864. The letter reads as follows:

By direction of Major General Foster, I have this day forwarded by Adams Express, a box containing a railroad torpedo, tools and drawings showing its use.

This torpedo was devised by Charles F Smith, 3d U.S.C.T.

We have not yet been able to try them on the enemy's railroads, but they have been thoroughly tested in experiments. The magazine holds 20 to 30 pounds of powder, and this is sufficient to blow a car off the track besides utterly destroying it. Two magazines can be used with one lock and by regulating the length of the powder train, any car of the passing train may be blown up.  The accompanying tools are simple and light. The idea of the inventor was, to send small parties of men, 3 or 4 in each, with these torpedoes and return. Each magazine is a load for a man. Another man can carry the lock and another the tools.

The manner of laying these torpedoes is as follows: -

The spikes are drawn from three consecutive ties on one side.  A hole is then dug, and the lock placed as indicated in the drawing. The rail is then sprung up and iron wedges placed on the adjacent ties to keep the rail from springing the lock by its own weight. When thus secured, the lock is cocked and capped, and the box closed. The magazine is then buried in the proper place, and the connection made. By using a little care in excavating and carrying off the superfluous earth to some little distance, the existence of the torpedo would never be suspected. The bottom of the arched rail should just touch the lever. Any shock by the bending down the rail pulls the trigger and explodes the torpedo.

In our experiments, a torpedo of 18 pounds was exploded by giving a car sufficient impetus to run over it. The car was entirely destroyed, and rails, ties and fragments of the car were thrown in every direction. One rail was projected 40 feet. 

These torpedoes can probably be used with success in some of the larger armies. Their greatest efficiency lies in destroying the locomotive, which cannot be replaced, whereas a torn up track can easily be relaid.  the magazine should be tarred before being used.

I am, General,

very respectfully,

Your obd't serv't


1st Lieut, U S Engineers & Chief Eng'r D.S.

Here's the accompanying diagram:



The diagram shows a "lock" from a firearm, with a lever engaging the trigger system. This has been "pre-packaged" is a small box with the initiation mechanism causing a fuze to be lit. The fuze is then connected to two containers ("magazines") placed under adjacent sleeper ties.

Despite much research I cannot find a report of a "gun-lock" initiated railway IED in the Franco-Prussian War in 1870, five years after the end of the US Civil War.  But railway IEDs were used, initiated by the weight of a train on the fuze removed from an artillery shell and was the subject of my last blog post here

2. The Boer War.  Gunlock initiated IEDs were used by the Boers against British Trains in the Boer war in 1901.  Here's a diagram of the adapated Martini-Henry gun lock. The similarities of the US Civil war design of 1865 are clear.

Pictures of actual gunlocks from these devices are at this page 

3. WW1 - Lawrence of Arabia and Bimbashi Garland's attacks on Turkish trains in ArabiaLawrence of Arabia's campaign against the Ottoman Turks in the Arabian peninsula in WW1 often attacked the railway lines running south. The IEDs that Lawrence used were pretty much identical to the Boer devices, but had been developed by his ordnance specialist "Bimbashi Garland" and former Ordnance Corps laboratory technician who had been co-opted in the Arab Bureau because of his interest in archaeology.  I have no doubt that Garland was aware of the Boer methodology and simply used the same technique. Details are here

In summary then I think it is clear that the use of a gunlock placed under a railway line to initiate an explosive charge began in 1865, with the invention by Charles Smith, for the Union Army.  This technique somehow found its way to ther Boers in 1901, and then was copied again by Garland and Lawrence of Arabia in 1917. 




Augmented reality and explosive initiation - an historical mystery

There is much focus today on "augmented reality” technology and a fair proportion of this is in the defence world. Systems like the Google Glass project and a number of others can be used or adapted to add visible data and tactical information and analysis to a soldier, overlaying that data on what he is seeing. Very hi-tec. So I was surprised when during some research I came across the details of a genuine Augmented Reality technology being used for a defence fire control system in the 1860s over a 150 years ago.

During the 1860's a room-sized camera obscura was used to conduct military research in Belgium. The system was set up to project a "live view" of the River Scheldt in which an electrically initiated underwater mine had been placed. That view was projected onto a large table. The operator of the camera obscura marked the position of the submerged mine on the viewing table, in effect as a data overlay with the image. An enemy ship passing over the mine could therefore be seen and as it approached and when in the optimal position, the mine could be exploded by remote control. The experiment was repeated in Venice in 1866 by Austrian engineers who then held the city, with more elaborate steps to pinpoint the location of the mine, and in this case a series of mines.  As a small boat laid each mine, the operator recorded that position and marked it on the image table.  The boat then did a full circle, I’m guessing 20ft around each mine position, and the operator recorded that circle on the viewing table, in effect becoming a specific kill zone, for each individualy activated mine, presumably numbered,  overlaid on the live image.  This ingenious arrangement was never tested in action.
Doing some more digging on this subject I have found oblique references to the connection with Samuel Colt the American inventor. Colt did indeed develop systems for initiating observed river mines in the 1830s, and this poor diagram, dated 1836 labeled "Submarine Batary first thorts 1836”, drawn by Colt, seems to indicate a reflecting lens which might project an image onto some form of viewing screen. To me that looks like a version of a camera obscura.
This second diragam, an overhead diagram, might be interpreted as a viewing position with a lens in the building at the very top, which projected a view of the scene over a set of terminals for initiation.
This third diagram, again by Colt begins to make sense, perhaps. Note the large lens in the upper right, I think reflecting the camera obscura image onto the actual reflective control panel.  Thus the image is projected onto the swiches. I think….
Colt was incredibly secretive about his inventions, but I think there is a very good possibility Colt had invented something similar to (and possibly more sophisticated than) the 1866 Austrian camera obscura system, but 30 years earlier, or at least had the concept in his head. Due to Colt’s obsessive secrecy I can't be quite sure.  It is possible that as well as protecting the commercial rights to the system with this secrecy, Colt was also very aware that the observation towers housing the “camera” had to be placed on prominent, well visible, high ground - making them potential targets for the dastardly British fleets which his systems were designed to combat. There were plenty of good reasons to keep the observation system secret.  So it is intruiging to wonder how a system, somewhat similar ended up on the River Schelde some years later.
It would be interesting to replicate Colt’s augmented reality fire control system of 1836, wouldn't it? 



Coal Torpedoes

A “coal torpedo” was the name given by Confederate Secret Service agents for a crude IED disguised as a lump of coal. The device was then introduced into the stocks of coal on ships and trains with the aim of causing an explosion in the boiler when it was shoveled into the engine.

The coal torpedo seems to have been invented by Capt Thomas Edgworth Courtney of the Confederate Secret Service.  Courtney proposed the idea to Jefferson Davis motivated probably by the financial rewards promised by the Confederacy which were suggested could be 50% of the value of Union shipping destroyed by new inventions. In this case, financial reward became the mother of a number of inventions. Courtney was commissioned and formed a Secret Service Corps of 25 men with direction to to attack any Union vessel or transport carrying military goods found in Confedserate waters, with his rewards (no salary) being paid in Confrderate war bonds.

Details of Copurtney’s plan leaked to the Union who put a price on his head. Courtney escaped to England, and tried to sell the design of the Coal torpedo to the British Navy, the French, the Spanish and Turkey, without success.

The Union naval forces on the Mississippi under Admiral David Porter issued General order 184 accordingly:

The enemy have adopted new inventions to destroy human life and vessels in the shape of torpedoes, and an article resembling coal, which is to be placed in our coal piles for the purpose of blowing the vessels up, or injuring them. Officers will have to be careful in overlooking coal barges. Guards will be placed over them at all times, and anyone found attempting to place any of these things amongst the coal will be shot on the spot.

Details of the actual ships destroyed by this means are unclear as records have been destroyed but it appears likely that a number of the devices functioned as intended.

Courtney’s torpedoes were manufactured carefully at the 7th Avenue Artillery shop in Richmond, Virginia. Actual lumps of coal were used to form a mold into which iron was cast. The walls of the devices surrounded a hollow sufficient to hold about four ounces of blackpowder.  After filling, the void was closed with a threaded plug, dipped in beeswax and rolled in powdered coal to disguise it.  The device, although small, could rupture the pressure vessel of a ship, causing much greater secondary damage.

The concept of coal torpdeos carried on. After the American Civil War the Fenian Brotherhood (see previous blog posts) had connections with both sides and there appears to have been a plot in the 1860s and 70s to use such devices to place in the furnaces of New York hotels and British shipping .

In WW1 German saboteurs operating in the US planned to use such devices to attack munitions ships, and in an earlier post I mentioned that such devices were found by US forces after overrunning the Germans in France in 1918.

In WW2 both the OSS and the SOE used similar devices, as did German spies. I have found reports that the Japanese also developed a similar tool at the Noborito research Institute, and they were used by Japanese commandos in raids in New Guinea.  There is also a hint that the CIA explored this as a tactic to be used in Vietnam.

The OSS didn’t do things by halves and developed a coal camouflage kit for such devices, with a range oif paints to enable the device to match variations in coal supplies.


Confederate IED organization

Careful reading of the excellent book “The sinking of the USS Cairo” by John Wideman, has allowed me to piece together some of the Confederate “IED” organization in the US Civil War and pull together some threads of incidents I’ve previously blogged about. Here’s a simplified summary with a series of links to the relevant posts

The leader of many usch IED activities was Brigadier Gabriel Raines. Raines’s interest in IEDs went back to the Second Seminole Indian war in Florida, where he deployed IEDs against the Seminole Indians in 1840.

Gabriel Raines

Later, when the US civil war began he rapidly proposed the use of similar devices, and used them successfully in the retreat after the Battle of Williamsburg in 1862

This book is a reprint of Raines technical notes about a number of munitions and IEDs.

Raines oversaw the Confederate use of such devices from the Confederate War department’s Torpedo Bureau ("Torpedo") being a term that then covered a range of land and sea explosive devices).  At the beginning of the war, Raines's devices were very much improvised, but eventually volume requirements and industrial processes evolved such that eventually many can be considered manufactured munitions.  Within the confederate forces the use of explosive devices was broad ranging and what follows is not the sum total, but there appear to have been two units.

The first was the Confederate States Navy submarine Battery service, under Hunter Davidson which appears to have been responsible for coastal defence sea mines and the like, often electrically initiated.  In  particular this unit had significant success on the James River. Later in the war attention turned to spar torpedo boats (boats with an explosive charge attached to a long spar which were used to ram enemy boats) . Hunter Davidson is an interesting character who I’ll write about in the future.  Here’s an angry letter he wrote in 1874 when some impertinent Brirtish Engineer officers claimed to have invented electrically initiated sea mines

The second unit, was commanded by the one-armed perpertrator of the sinking of the USS Cairo on the Yazoo River, Zere McDaniel 

Zere McDaniel was responsible for

  •  Riverine IEd operations such as the sinking of the Cairo
  •  “Land torpedoes” in defence around Richmond, that used artillery shells adapted to detonate when stood upon (designed by Raines)
  •  “Behind the lines” IED and associated sabotage and intelligence operations.

The latter enterprises were as head of a Confederate secret unit “ Company A, Confederate secret service. The unit was formed in 1864 according to instructions that can be seen on this web page – a lovely document!

Some examples of the “behind the lines” operations included the explosion at City Point by Maxwell who reported directly to McDaniel and who used a time bomb or “horological torpedo” 

Attacks on trains by Zere McDaniel himself using an IED which I’ll discuss in a future blog once I have found more detail.  Suffice to say that the initiation mechanism appears to have been an improvised wire hook which protruded from under the track and “hooked on” to the front of a passing train, probably pulling a friction initiator.

The confederate use of IEDs appears to have been positively encouraged and a secret law was passed awarding a bounty to confederate supporters who designed IEDs and used them to attack Union forces, awarding the designer 50% of the value of the target. McDaniel himself tried to claim for his attack on the Cairo, but failed in his appeal.   In 1864 McDaniel reported that his unit were engaged in continuous active operations , with elements operating “behind enemy lines” in Kentucky, Virginia and elsewhere

I see interesting parallels between the innovative use of munitions and explosive devices in the US civil war and the remarkable inventiveness of Syrian opposition forces in today’s Syrian civil war.


Pull primers

In my chronology of initiation systems, a couple of posts down, I omitted the evolution of the "pull primer" as a means of initating charges, including artillery pieces.  I think it's worth a look at, especially since they were clearly used to initiate the IED used to sink the USS Cairo, below.

  • Originally in cannon, bags of gunpowder were stuffed in the muzzle and pushed to the far end of the cannon.
  • The bag was then pricked so the priming fire could reach the main charge, by inserting needle like device through the vent hole into the bag charge. The vent is a small hole drilled at the rear of the cannon that led to the inside of the barrel where the bag of gunpowder sat.
  • Then loose gunpowder was poured in to the vent.  That loose gunpowder was then ignited with a slow burning fuse, red hot iron, or other flame like a portfire to the touch hole, or top of the vent. At one stage a paper tube was inserted that held a preloaded quantity of powder to allow a preloaded quantity of powder.
  • That method was a little crude, and in 1765 an improvement was developed, which was to insert a tin tube containing blackpowder into the vent.  This ensured that the end of the powder train in the tube was in the right physical position to ignite the main charge, increasing reliability.
  • Later the tin tube was replaced with a goose quill. 
  • In the late 1700s a flintlock mechanism began to be used to initiate the vent powder.
  • In 1846 a Hanoverarian artillery officer invented the pull primer. This consisted of a tube (usually copper) which contained blackpowder as before, but also a friction sensitive match compound. Inserted into the tube was length of flattened, serrated wire, which when pulled through the match compound created enough heat from friction to cause the match compound and then the powder to ignite.  This became a reliable, weatherproof, initiator for artillery pieces, and the post on the sinking of the USS Cairo below demonstrates how such a mechanism can be used for IEDs as a command initiation system from a distance, or as a component of a booby trap pull switch.


In typical pull primers the base of the tube is closed by varnished paper, and the top by shellac putty and varnished paper. A ring is attached to the top of the wire that protrudes through the shellac putty.  The operator used his "lanyard" to clip onto the ring and pull from the side - lanyards now are an archaic part of a lot of military uniforms.   The match composition was usually a mix of potassium chlorate and another compound. 

Friction primers were eventually repalced by percussion primers, which essentially were a percussion cap fitted to the top of the tube, which a mechanism on the gun struck.