Welcome to the video series Site Study: Ypres Salient, my name is Brad Manera.
The Western Front was a very, very complex battlefield and so there's no simple way to describe the nature of warfare on the Western Front.
The big killer on any battlefield of the late 19th and early 20th Century is artillery. For artillery to be effective you've got to be able to see where your ordinance is hitting because that's the thing that's doing most of the damage. Artillery can kill men and animals and destroy lines of communication by breaking the telephone lines and smash road surfaces. It is vital that artillery falls where you want it to.
Artillery can either be air burst shrapnel, that is hundreds of tiny, little lead balls, bursting out of a single shell and spraying the ground like shotgun pellets with the intention of killing men and horses that are not under cover. Artillery can deliver high explosive shells that create a massive blast and dig hugh craters. It can destroy men and equipment that have dug themselves into defended positions such as trenches and dug outs.
Artillery was particularly important at Ypres due to the topography of the battlefield.
The battlefield at Ypres consisted of the town of Ypres and the flat ground around it, controlled by the British and allied forces, surrounded on three sides by a line of hills where the Germans had trenches controlling the high ground. The trenches surrounding Ypres created a bulge in the line of the Western Front which became known as the Ypres salient.
The Germans built their defensive lines just below the reverse slope of the summit of the ridge line. It meant that they couldn't be seen by the British without them using observation balloons or having aircraft fly over and take photographs of enemy troop movements and enemy concentrations.
In contrast the British were much more easily observed by the Germans, either from the high ground or with observation balloons. This meant that the air war over the Salient was a very significant part of how the ground war was conducted and how artillery was targeted and used.
At the same time other new strategies were developing. During the Battles of the Somme in 1916 the Germans had learned to hide in very deep bunkers to protect themselves from artillery. As soon as the artillery barrage stopped, the Germans would come out, re-man their defensive positions, bring their machine guns out of protected nooks and wait for the British to get out of their trenches and try and cross No Man's Land.
By 1917 the British had learnt that they need to get their soldiers as close to their own exploding artillery as they possibly could and that they needed to move their artillery in predicted and incremental advances. This strategy was called a creeping barrage. In 1917, in the Ypres Salient, the creeping barrage become a very sophisticated exercise in cooperation between an infantry advance and supporting artillery.
The Germans tried to counter the creeping barrage by constructing concrete blockhouses.
It was very difficult to dig deep in the Ypres Salient because the water table is so high. The Germans built concrete shelters above ground. There are some 4,000 of them on the ridge lines around the Ypres Salient. This meant that although the German frontlines were difficult for the British to see from their trenches, they could see these concrete blockhouses.
The fighting on the Salient from the British point of view was one of attack and the German one was of defence.
Blockhouses had to be attacked by men. They had to be surrounded and the occupants killed or captured before the attacking force could advance to attack the front lines beyond. It was a very delicate balance. For the British it became essential to knock out the blockhouses with a minimum number of casualties. Blockhouse fighting was bloody and savage. Our official historian, Charles Bean in Volume 4 of the Official History wrote a description of how intense it became, making the observation that he could recognise a good officer because he could stop his men killing [once the occupants of the blockhouse had surrendered].
In some cases the British and allied soldiers realised that certain blockhouses were so solid that no artillery was going to break them. Aircraft at that time were not sophisticated enough to carry the sort of heavy ordinance that we would see used in the Second World War. They could not break up the massive concrete emplacements.
And so they came up with the idea of digging underneath them. Tunnelling companies were created to dig mines from underneath their own lines, all the way beneath No Man's Land to underneath the German blockhouses. And they would pack those mines with high explosives and fill them in behind and at a given time would detonate them.
The blast created would develop into an earthquake. The blockhouse would be shattered and its occupants blown to pieces or, if the structure collapsed, buried alive.