Tunnelling companies of the Royal Engineers

The Royal Engineer tunnelling companies were a specialist unit of the Corps of Royal Engineers with the British Army, formed to mine attacking tunnels under enemy lines during the First World War.

After the first German attacks on December 21, 1914, through shallow tunnels across No Man’s Land, exploding ten mines under the trenches of the Indian Sirhind Brigade, the British began forming suitable tunnelling companies. In February 1915, eight Tunnelling Companies were created, operational in Flanders from March 1915. By mid-1916, the British Army had around 25,000 trained tunnellers, mostly taken the coal mining communities of South Wales, and the Northeast of England covering Nottinghamshire, Derbyshire and Yorkshire. Almost twice that number of "attached infantry" worked permanently alongside the trained miners acting as beasts of burden.

Background

Main article: Mining (military)

In siege warfare, tunnelling is along held tactic for breaching and breaking the enemies. From the Greek historian Polybius, in his Histories, gave accounts of mining during Philip V of Macedon's siege of the little town of Prinassos, and a graphic account of mining and counter mining at the Roman siege of Ambracia.

Mining was a siege method used in ancient China from at least the Warring States (481–221 BC) period forward. When enemies attempted to dig tunnels under walls for mining or entry into the city, the defenders used large bellows (the type the Chinese commonly used in heating up the blast furnace for smelting cast iron) to pump smoke into the tunnels in order to suffocate the intruders.

WW1 Trench warfare

By the end of May 1915, a continuous opposed pair of defence-in-depth trench earthworks with no vulnerable flanks, stretched from the North Sea coast to neutral Switzerland. With both sides equally well dug-in and deploying comparable troop numbers and armaments, neither was to prove strong enough to force a decisive breakthrough.

The resultant siege meant that tunnelling saw a brief resurgence as a military tactic during the First World War. As in siege warfare, mining was possible due to the static nature of the fighting. Secondly, as the ground was mineable everywhere, the Western Front was a prime candidate for underground warfare.

The first deployment of military mining was by the Germans on December 21, 1914, through shallow tunnels across No Man’s Land, exploding ten mines under the trenches of the Indian Sirhind Brigade.

Formation of units

In February 1915, eight tunnelling companies were created, to fulfil a requirement to break through the German armies defensive positions by mining under the enemy trenches. The companies were mostly made of men drawn from the ranks of the infantry, mixed with men specifically drafted for this kind of work.

This was one of the most rapid acts of the First World War in which men who were working underground as civilians in Great Britain on February 17 1915 were working underground on the Western Front a mere four days later. This action showed the importance of the necessity for a counter-offensive against the aggressive German mining against the British lines. Twelve Tunnelling Companies were ultimately formed in 1915, and one additional one in 1916. A Canadian, three Australian and one New Zealand tunnelling companies were formed by March 1916. All of these companies were occupied on underground work together with the digging of subways, saps (a narrow trench dug to approach enemy trenches), cable trenches, underground chambers, for such things as signals and medical services, as well as offensive and defensive mining.

Methodology

Both sides deployed tunnelling, with the German lead quickly followed by British follow-up. The result was a labyrinth of tunnels within a cat and mouse game of tunnelling, and counter tunnelling and counter tactics. As the tactics and counter tactics deployed against each other became less and less effective, the depth at which the tunnels needed to be dug got deeper and deeper, and hence more dangerous. The result was a greater time to dig, resulting in both a greater vulnerability to both leakage of information and tunnel collapse, and a higher loss of lives in the most hideous of circumstances: entombment, drowning, gassing or obliteration in cramped and claustrophobic galleries beneath no man’s land.

To make the tunnels safer and quicker to deploy, the British Army enlisted experienced coal miners, many often outside their nominal recruitment policy. Upon the declaration of war in April 1914, William Hackett VC applied and was turned down at the age of 41 by the York and Lancaster Regiment. The desperate need for skilled miners saw notices requesting volunteer tunnellers posted in collieries, mineral mines and quarries. On October 25, 1915, despite having been being diagnosed with a heart condition, Hackett was enlisted and sent for two weeks basic training at Chatham, joining the 172 Tunnelling Company.

During tunnelling operations, in side shafts were deployed listening post manned by men who's job was to listen for signs of enemy tunnelling. Initially using just manual methods, the British were eventually equipped with Geophone, which could detect noises up to 50 metres (160 ft) away. Employing two Geophones a listener was able to ascertain the direction of hostile activity by moving the sensors until sound levels appeared equal in both ears. A compass bearing was then taken. When gauging distance only, both earpieces were plugged into a single sensor; this was a skill only gained by experience.

Eventually deploying listeners in different tunnels in triangulation technics, by the end of 1916 the scale of British mine warfare had expanded to such an extent that there were not enough listeners to man every post, and central listening stations were devised. Working electronically like a telephone exchange, the signals from up to 36 remote sensors (Tele-geophones and Seismomicrophones) could be distinguished and recorded by just two men.

Operations

Explosion of the mine beneath Hawthorn Ridge Redoubt, July 1 1916. Photo by Ernest Brooks.

A notable example was the Battle of Messines, when 450 tonnes of high explosive were placed in 21 mines after about two years of sapping. Approximately 10,000 German troops were killed when 19 of the mines were simultaneously detonated. One of the explosive caches exploded years later. The 21st cache was never found and there are still several tonnes of high explosive buried somewhere in the Belgian countryside.

Another example is recorded in Louis Trenker's Berge in Flammen. Whole mountain peaks at the Alps were exploded during the mountain war. Col di Lana, Lagazuoi and Marmolata, were a few of these peaks.

Operations since WW1

Because World War II troop movements were too fluid, and tunnelling too slow, mining proved not to be worth the investment of effort. Tunnelling was used in the Vietnam War, by both sides.