Battle of the Somme 3 - "U day" - the bombardment begins

Stockpiling 18lb shells near Albert

The scale of battle preparation was unprecedented. The logistical requirements of transporting, feeding, commanding, retrieving and burying victims of an army of half a million men (and scores of thousands of horses) had never before been tackled - and nearly all of it done with mechanical engineering, steam power and pencil and paper. Just imagining the effort required is dizzying -  they had to do it 70 years before the spreadsheet and lacking any electronics or information and communications technology.   At the line itself a limited amount could be done in  extending the trenches where possible and building 'assembly trenches' to accommodate the great numbers expected. However in front and behind the line prodigious efforts were made. On 24th June the most significant part of the preparation began - a one-week bombardments of such intensity that it was plainly heard along the English south coast and far inland.

Ideal for tunnelling, but
Somme chalk was unsuit-
able for road building.

In front of the lines, night time raids and harrying attacks were ordered by Haig along all of the British part of the front, to gain intelligence and to discourage the Germans from focusing their defence on the Somme. These periods also provided some cover for dangerous night time tunnelling and trench building out into no man's land. The existing army instructions gave 200 yards as the maximum distance for infantry to rush in an assault, and in many places no man's land was much wider. Multiple deep trenches, or saps were dug for this purpose. This was addition to the mining activity, which was to produce large explosive caches beneath strategically important parts of the front. The chalky terrain was ideal for this (see picture) and warrens of tunnels were created by both sides.
Behind the lines even greater efforts were required, and soldier not on frontline duty spent many hours of heavy labouring. Large scale and detailed rehearsals for the opening day from mocked up trenches; road building for supply horses and vehicles; building up the ammunition and provision supplies; organising hospital services for the wounded; PoW pens for captured Germans; mass graves for inevitable casualties - these were all required. Ston had to be brought from other parts of France and England to build the road, the local chalk being unable to bear the heavy loads. Water requirements were huge, and miles of piping from newly sunken wells were sunk.
In the air, The British held the upper hand at this stage of the war. This was helpful both during the build up and to some extent during the bombardment.
Perhaps the busiest groups of all were the artillery, preparing themselves for the greatest continuous barrage ever launched, outdoing even the Germans 'drum thunder' at Verdun. In the uproar and crisis of weapon shortages in 1915, Lloyd George had been appointed Minister of Munitions ( see posts 11/5/15 and 19/5/15). He had delivered on his promises to boost output.

More of the heavy Howitzers were needed to inflict
damage on the Germans' deepest defences

The provision of artillery and munitions was sufficient to allow artillery pieces to stand almost wheel to wheel along the whole front. The Germans would not have faced anything comparable in the war to date. More shells would be fired by the British in this episode than in the whole of their first year in the war. There were however, two drawbacks - firstly, relative dearth of the heaviest Howitzers needed to crush the deepest German defences; and secondly a loss of quality in the finished product of shells and fuses, meaning that many (in some estimates nearly one third) were duds.

As the countdown to the bombardment continued, the tensions between the Generals continued. Gough moved into an offside position with Allenby, as he found himself without the promised infantry troops, and lost one of his three cavalry divisions, moved elsewhere. He had been reduced practically to a reserve corps of Rawlinson's army, and was not best pleased. Haig asked Rawlinson again to shorten the barrage from five to three days to improve chances of surprise. Rawlinson had blind faith in the power of his artillery, and would not agree. Haig did not insist, perhaps because he was still new to his role, and 'Rawly' got his way.

And so on 24th the 5 day barrage commenced early in the morning. Each day had a letter designation U to Z - Z-day being the D-day equivalent -  and each day followed the same pattern: firstly a concentrated two hour concentrated assault by all guns, thereafter 50% of guns continuing in rotations. At night there was further reduction, but the addition of heavy machine gun fire to the rear trenches to dissuade Germans from emerging to supply their front line, or to look for raiding parties.
These night time raids were unpopular with the men, and produced mixed messages about the damage to the Germans and the success of the barbed wire cutting. When any of this adverse evidence reached HQ it was brushed aside. Any good news was seized upon as confirmation of the all destructive effects of the bombardment. Forty years before cognitive dissonance theory 'Rawly' dealt with his own by rubbishing or dismissing any countervailing evidence, and insisting the barrage would destroy German defences. This certitude transmitted itself to his senior commanders -any demur was dismissed or threatened with disciplinary action. Absurd reassurances were given to officers by Rawlinson's Corps commanders, and passed down the line. Most of the men were pleased with the reassurance; those with the evidence of their own eyes were very unhappy, and this applied to a proportion of the junior officers who would be leading their men over the top.

Rawlinson's 4th Army comprised 11
Divisions in 5 Army Corps. Allenby's
VII Army Corps, with 2 divisions faced
a hazardous diversionary action at
Gommecourt

Heavy storms throughout 'W' and 'X' days caused significant flooding in the trenches and approaches, and on 'Y' day, the 28th (less than 24 hours before the attack) the decision was taken to postpone, and extend bombardment. Imagine the disruption to all the meticulously prepared timings. The extra days gave a final total of more than 1.5 millions shells poured onto German positions in seven days - ironic, considering Haig's plea to reduce from five days to three.
After two agonising day of further waiting, by the night of 30th June, the men were poised for action.
The infantry men in each Division moved towards their opening positions. They lined up as shown in the diagrams, thirteen Divisions of 12-15,000 men - around three quarters of them designated for first day action. Each Division had 2-3 brigades of around 4,000, each brigade with its Battalions 1,000 strong. Four Companies per battalion each had a number of Platoons of 60 men. The men were to move forward in waves per company, at one minute intervals. Each carried at least 70 pounds of equipment, the later waves carrying even more, such as barbed wire and entrenching tools. They were to advance at slow pace, making no noise, and were not permitted to run until less than 40 years from the first line trench.
All was in place for the dramatic opening and catastrophic actions of the first day