Northumbrian Gunner: Op La Boisselle

Friday, 12 September 2025

Op La Boisselle - Lochnagar Crater

The Lochnagar mine was dug beneath a German fortification known as the Schwabenhöhe (Swabian Height) in preparation for the Battle of the Somme.

Lochnagar Crater IJ

The digging of the mine started on 11th November 1915 by 185 Tunnelling Company Royal Engineers. It was completed by 179 Tunnelling Company when they took over in March 1916. The entrance to the Tunnel was in a communication trench named 'Lochnagar Street'.

The tunnel sloped down to a depth of 30 metres then out to 274 metres until it was below the Schwabenhöhe. Two chambers,18 metres apart, were prepared and filled with ammonal explosives. One was charged with 16,330 kg (36,000 lb), the other with 10,900 kg (24,000 lb).

The Lochnagar mine was detonated at 07:28 1st July 1916, two minutes before zero hour. The explosion created a crater 21 metres deep and 100 metres wide. An officer in the Royal Flying Corps, 2nd Lieutenant Cecil Lewis, on air patrol in the skies two miles from La Boisselle descrided the explosion;

We were over Thiepval and turned south to watch the mines. As we sailed down above all, came the final moment. Zero! At Boisselle the earth heaved and flashed, a tremendous and magnificent column rose up into the sky. There was an ear-splitting roar, drowning all the guns, flinging the machine sideways in the repercussing air. The earthly column rose, higher and higher to almost four thousand feet. There it hung, or seemed to hang, for a moment in the air, like a silhouette of some great cypress tree, then fell away in a widening cone of dust and debris.

Lochnagar Crater

At 07:30 the infantry of the 34th Division assaulted forward from their trenches. The Lochnagar Crater was secured by the Grimsby Chums, the 10th (Service) Battalion, The Lincolnshire Regiment. They continued onto their first objective where they were repulsed by a German Counter attack and withdrew to the crater. Stragglers and wounded from across the 34th Division, including Tyneside Scottish and Tyneside Irish, took shelter in the crater.

Those sheltering in the crater were harassed by both German and British artillery fire. By the evening of the 2nd July a communication trench had been dug to the crater.

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