Razzle Dazzle everywhere
The German sandbags were a variety of colors, black, pink, yellow, beige, green, etc. They were not arranged in orderly patterns, but scattered haphazardly throughout the parapet. The belief was that the cacophony of contrasting colors made it harder for the human visual processing system to make sense of what it saw. Optical illusions and confusion were the natural result of a chaotic visual display. It was effective.
The Germans were the first to deploy steel plates with loopholes for their snipers to shoot through. These bulletproof shields provided effective cover against small arms fire. In particular, the small loophole was a tiny target for a counter sniper to hit, making the Germans feel quite safe during the early phases of the sniping war.
The British adapted to counter the sniper shields by using large bore big game guns, which packed significantly more wallop than the standard issue army .303. Imagine, there’s some German sniper sitting snug behind his steel shield while an English big game hunter is taking aim with an elephant gun! Later custom sniper and game rifles were also capable of penetrating the single layer steel shield.
The ultimate form of the sniper shield was a sort of steel box, with a plate in front and another behind. The secondary plate was installed at an angle, so that any bullet penetrating the front plate would strike a glancing blow and be deflected away.
In addition to having the second plate, the loopholes of the two plates were slightly misaligned (as appropriate for the shot) thus making a countersniper shot far more difficult.
These strong armaments and fortifications were one of the big reasons that dealing with snipers was frequently left to artillery. Once the sniper nest was located, observers would monitor it for activity and call in a barrage when it was occupied.
Countersniping is either a fencing duel of supreme marksmanship and skill, or a millstone dropped on an egg.
Trajectory Tracking Tricks
A major mechanism of finding sniper nests was to map the trajectory of bullets back to their source. In principle the idea is simple: have a sniper shoot a three dimensional object, leave the object in situ, and sight down the holes created by the bullets passage. The sniper nest will be located somewhere along that trajectory.
The simplest implementation of this trick was leaving shiny tin cans, or other enticing targets for snipers to zero their sights on at the front. Germans would leave cans on the parapet for snipers to shoot at. Due to the high contrast and easy visibility of these targets, they were attractive for naive snipers to use while adjusting their sights. A grave and often fatal error.
The recommended target to use when adjusting sights was a puddle of water with a reflection on it. This would allow the sniper to adjust accurately, while providing no side channel metadata about the source of the bullet to any observers.
A more sophisticated and specialized counter sniper device was created by the British. The device consisted of a target lure and a wooden base with a groove for a rod holding the target. This allowed the elevation of the target to be marked and duplicated after the sniper took the bait. The target itself was a paper mache head that was painted in lifelike colors, and which was further enhanced with helmet or field cap, and other accessories to make it appear more genuine. One important addition was a cigarette adapter, literally a flexible tube that allowed the scout to smoke a cigarette stuck through the dummy’s mouth. A periscope could be affixed alongside the head to allow the scout to manipulate the dummy head and observe the environment.
The scout would raise the head above the trench and attempt to get shot by a German sniper. Apparently the sensation of a bullet slamming into a target held mere inches above your head while you were smoking through it was rather bracing.
Once the lure target had been shot, it was retracted below the parapet. A trajectory for the bullet was determined, and then a trench sniper rifle could be lined up, raised the appropriate hight (based on the elevation of the target as recorded by the support rod), and a counter sniper could attempt to shoot back, or more likely, once the sniper nest was located, call in an artillery strike.
Concealment for loopholes
The British created a sniper shield, a steel plate system, that was extremely highly regarded. Firstly, it was the box configuration, with two protective plates and two loop holes for firing. Secondly, the front plate was covered with the partially filled sides of sandbags so that it was indistinguishable from any other forward face of sandbags. During the night a hole would be created in the British parapet and the sniper shield substituted for a portion of the parapet. Once in place, it was perfectly concealed as just a part of the hundreds of thousands of sandbags on the front.
Speed and accuracy
It was found that not only did a sniper have to be accurate, but that most opportunities for shots where only a couple of seconds. The target had to be acquired and shot in two seconds. This was a major challenge.
It was not enough to be good, you had to be fast.
The observer scouts located targets for the sniper, and confirmed whether there was a hit or a miss. It was an important lesson learned that a lethal shot would mostly cause the victim to pitch forwards, rather than backwards. Officers with binoculars were favorite targets, and so the general rule of thumb was that if the binoculars fell towards the British lines then the target was killed. If they fell backwards, then the target was alive, either ducking out of sight or wounded.
Scout observations of a cat appearing on the enemy parapet over a period of time led to speculation that there was a new dugout for officers. Officers would have a cat to deal with the rats in the trenches. Aerial reconnaissance was ordered over the suspected area and comparisons with previous photographs revealed that a new dugout had been constructed in that location. It was promptly shelled.
A WW2 anecdote, rather than WW1.
The Italian front.
Artillery fired PSYOPS pamphlets over the German positions at lunchtime everyday. As standard operating procedure, the artillery barrage was then postponed for 10-15 minutes so that, according to the propaganda theorists, the enemy could collect the pamphlets. The Germans would dutifully clamber out of their trenches, collect the pamphlets, have a cigarette and a shit, use the pamphlets as toilet paper, and then return to their fortifications. After this had gone on for a while, the American GIs got pretty pissed off about it, and so the artillery men decided to take advantage of the German behavior.
First a shower of pamphlets went over. The Germans hopped out and gathered their toilet paper, got their cigarettes, dropped their trousers and began their noon time ritual. A couple of minutes after the pamphlets, the artillery boys started up a barrage, catching the Germans literally with their pants down.
Apparently the Germans in that sector never quite forgave the Americans and it was unusually hot for a long time.
Takeaway: true deception is to control the enemy. This operation, although born out of frustration rather than stratagem, still enabled the Americans to control German actions and place them at an extreme disadvantage.
Clearing a trench
The approved method to clear a trench was to have two men with bayonets on their rifles, and a few men behind them. Throw a few grenades into the next section of the trench then have the lads with bayonets charge in. Of course the danger with this was that the enemy might decide to throw a few grenades at your lot first. So it would go back a forth over a few sections, each time either side losing two or three men until eventually you tire of the game.
The method that actually worked was to get a few boys with rifles up on the parapet and have them shoot down into the trenches, killing everyone they could. Faster, more efficient, and no silly buggers with grenades flying back and forth.