Canadian pipe mine facts for kids
The Canadian pipe mine, also known as the McNaughton tube, was a special type of landmine used in Britain during World War II. It was created to help defend against a possible invasion in 1940–1941. This mine was a long pipe filled with explosives, buried horizontally underground. When detonated, it could instantly create a huge ditch, blocking tanks or making roads and runways unusable for the enemy.
How the Idea Started
In November 1939, a Canadian general named Andrew McNaughton met with engineers and mining experts in Toronto. They talked about new ways to use a drilling method called "diamond drilling" for military purposes. Diamond drilling uses special drills to bore deep holes. McNaughton thought it might be possible to place explosives or even gas underground using this method.
As McNaughton prepared Canadian soldiers to go to Britain, he suggested forming a special group of engineers. This group would be made up of experienced diamond drillers. He wanted to see if their drilling skills could be used for military tasks. Colin Campbell, an experienced engineer, agreed to lead this new group.
In early 1940, McNaughton went to France to inspect the Allied defenses. He saw that some defenses were not strong enough. He thought his diamond drillers could help by placing explosives to clear out German soldiers if they captured parts of these areas.
Later, at a meeting in Aldershot, England, McNaughton suggested another use for the pipes. He thought they could create surprise obstacles to stop a German advance. This would involve pushing pipes into the ground at a shallow angle, filling them with explosives, and then detonating them. A powerful hydraulic jack (a tool that lifts heavy things using liquid pressure) attached to a tank transporter could quickly push the pipes into the ground. McNaughton reportedly got this idea from people who smuggled alcohol in Windsor, Ontario, who used similar methods to push pipes underground during a time when alcohol was illegal.
Developing the Pipe Mine
Colin Campbell and his team of drillers arrived in England in February 1940. They began testing their ideas in a quarry. Campbell showed that his team could create unexpected obstacles that tanks could not cross. This demonstration helped convince others to support McNaughton's plan to expand the drilling section into a larger tunnelling company.
By May 1940, McNaughton assigned the tunnellers to help prepare defenses in England. As France fell to German forces, the tunnellers focused on anti-invasion measures. McNaughton noticed that ditches were being dug across unused airstrips to stop enemy planes from landing. However, he realized that active airfields might be bombed, making these unused strips suddenly very important.
By June, British engineers agreed that the pushed pipes filled with explosives were a good idea. They started getting large amounts of pipe to destroy runways quickly if needed. By the end of June, the tunnellers successfully showed off "surprise" anti-tank obstacles near Shornmead Fort.
The drills and pipe-pushing machines buried pipes about 3 inches wide. Each pipe was about 55 feet long and was pushed into the ground at a shallow angle, reaching a maximum depth of about 8 feet. The pipes were placed about 25 feet apart in an overlapping pattern. When detonated, the explosives created a very effective anti-tank ditch. This ditch would be about 28 feet wide and 8 feet deep, with loose soil at the bottom. This kind of ditch could stop a tank or force it to slow down, making it an easy target for anti-tank weapons. These pipe mines could also be placed near bridges or embankments, ready to be blown up instantly.
The device was first called the Canadian Pipe Mine. Later, it was renamed the McNaughton Tube Tank Obstacle to honor Lieutenant-General Andrew McNaughton.
On August 9, 1940, General Alan Brooke, who was in charge of defending the UK, saw a demonstration of "McNaughton's secret A/T obstacle." By October 1940, the Canadian engineers were in high demand. Plans were made to train more British units to install these devices. A new company, the 179 Special Tunnelling Company of the Royal Engineers, was formed. About 40,000 feet of these obstacles were installed, using around 90 tons of explosives.
How They Were Used
A secret report highlighted how valuable this obstacle was:
The element of surprise makes this obstacle especially useful for influencing the enemy's plan. It allows us to trick the enemy into attacking a spot that looks weak in our anti-tank defenses, while still being able to stop them.
It is very useful for quickly setting up road blocks after our own troops have passed through.
It's important to remember that surprise is the main feature of this obstacle, not speed.
Regular anti-tank obstacles were easy to spot from the air. But these pipe mines were almost invisible from above. This meant they could be used to surprise the enemy at what seemed like a weak point in the defenses. Also, the mines could be put in place without stopping the normal use of the land. So, they were placed under roads and railways that might need to be blocked quickly, and under runways that might need to be made unusable for the enemy on short notice.
Problems Found
Over time, some problems were found with McNaughton's tubes. The explosives, called blasting gelatine, were expected to last for several years. However, by 1941, it was clear that water had affected the explosives in some tubes, making them much weaker. A special brass spearhead on a long rod was used to try and pull the explosives out. But in some cases, the explosive had turned into a mushy substance.
Second Lieutenant Cameron, who used to be an oil drilling engineer, suggested washing out the explosives with water. The mushy explosive, along with small drops of nitro-glycerine (a dangerous chemical), was collected in burlap bags and safely disposed of. The pipes were then refilled with new, stable explosives.
After World War II ended, most Canadian pipe mine installations were removed. However, a few were missed and found many years later. These discovered mines had to be handled with extreme care. In April 2006, 20 unexploded pipe mines were found under a runway at a former Royal Navy air base called HMS Daedalus in Lee-on-Solent, Hampshire. The original 265 mines were each 60 feet long. The 20 discovered mines contained 2,400 pounds of explosive. Removing them was a huge operation, thought to be the largest of its kind in peacetime Britain. It led to about 900 homes being evacuated over five weeks. The mines were safely destroyed by controlled explosions.
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