At intervals of approximately 100 yards the Germans had built reinforced concrete emplacements, with usually the top of the emplacement, or pill-box, from a foot to 18 inches above the surface of the surrounding ground. These well-nigh impregnable positions were all very ingeniously camouflaged, and could not be detected by the sharpest eyes from the direction of our trenches until one was almost on top of them; and even then the only thing to be seen were one or two firing loopholes. The illustration shown here was from a photograph taken in the Hindenburg line from behind the "pill-box," where, of course, no screening was necessary.
It will be readily seen that this emplacement had not been damaged much; in fact, it was practically intact, only small pieces of concrete having been chipped off by our shells. The trench itself had been almost obliterated by our artillery-fire, and the sides so destroyed that it was possible for a tank to cross. The emplacements in the Hindenburg line, as elsewhere, were variously used as machine-gun posts, observation-posts, trench-mortar positions, snipers' posts, etc. The British referred to this type of concrete pill-box as a "Mebus." It was a matter of considerable difficulty to destroy them from above by artillery-fire, and even if our gunners made a direct hit with a heavy shell it was seldom put out of business.
About a week before the time I have referred to we were informed that two infantry assaults had come "unstuck" and the parties composing them nearly all "scuppered" by reason of the heavy and accurate fire coming from a double machine-gun concrete emplacement some 200 feet in front of our most advanced barricade in the Hindenburg trench opposite the village of Fontaine-les-Croisilles. The artillery had endeavored several times to destroy this position, but were not successful. It became necessary to remove it.
The division staff then inquired of our company commander as to whether we could do anything from below. He thought we could and my section was detailed for the job. My company commander, Captain Miller, incidentally one of the finest sportsmen I ever wish to meet, was delighted with the opportunity.
The subsoil here was a hard chalk, and the top-soil a sandy clay, the latter averaging from seven to ten feet in thickness. It was essential to the success of our scheme that we confine our underground tunnel to the clay, it being possible to excavate in the clay almost without noise, while in the chalk below this could not be done.
Starting from an old dugout entrance we constructed a tunnel approximately four by two feet for some distance, and from this point to our objective continued a "rabbit-hole" three feet by two in size. As we had only an average of two feet of clay above our gallery we were considerably bothered by our own shells landing near, and on one occasion they destroyed it with an eighteen-pounder. At other times we broke through into shell-craters on our way over. One night after a heavy rain I was on duty in the tunnel when we were pretty close to the German pill-box and their crew. The earth sloughed away from the top of the gallery and exposed the timber of our gallery-sets. We blew out the candles at once and very carefully placed some muddy sand-bags over the exposed portion. Being so near the Boche sentries, we were fearful that they would have spotted our light, heard our low whispering, or even our heavy breathing.
The next night we struck the concrete of the emplacement, and very carefully excavating down to the bottom of the clay against the position, we placed a charge of some 500 pounds of high explosive, carefully inserted the usual detonators and electric leads tamped the gallery for some 30 feet back in the tunnel, and the next dawn at the "zero" hour fired the charge the instant the infantry went over the top.
The resulting explosion very satisfactorily disposed of the troublesome "Mebus" and largely enabled the 4th King's Liverpool Regiment to capture some 200 yards of the trenches. Some 12 hours later the 2d Argyll and Sutherland Highlanders continued the attack and captured an additional 300 yards, as far forward as the River Sensée (at this time a dried-up stream). In addition to a large number of Germans killed, they captured many wounded and over 60 unwounded prisoners that day, the latter caught in the underground tunnels completely by surprise. Early the next morning the Germans attempted a counter-attack in force, but the assembly having been observed by the F.O.O.'s, the gunners promptly and efficiently broke up the party.
I noticed the next day that smoke was issuing from a number of the tunnel entrances in the area captured, and other entrances were badly burned. In conversation with one of the Scotch officers it developed that the Jocks invited the Huns to come up out of the dugouts only once with their hands up to surrender. If they failed to respond promptly, bombs would be thrown down into the tunnels to expedite matters. This officer complained that he had posted sentries to guard the prisoners at each dugout entrance, but that as soon as his back was turned some trouble would occur, which necessitated more bombing practice on the part of the Scotch sentry. This was only a small affair, a battalion stunt. Everywhere along this front each day some attacks would take place, perhaps a regimental or brigade attack, or at other times just a small company raid.
For a day or two after this attack our trenches here were filled with the bodies of Germans and British. H.E. and bombs are terrible things.