AT 7.30am on July 1, 1916, the guns stopped, the mines exploded, the whistles blew and the British soldiers climbed up out of their trenches and walked into no man’s land towards the German lines.

After seven days of non-stop bombardment by heavy guns, they hoped the Germans had been obliterated.

But the 1.6 million shells the British had fired were not as effective as expected – many were duds – and the Germans had been dug in far deeper than had been calculated.

So at 7.30am, when the British guns suddenly stopped and the whistles blew, the Germans knew it was the signal that the long-expected attack was beginning. They pulled themselves out of their dugouts, lined up their machine guns and fired at the waves of British men coming towards them.

By the end of the day, the British had made negligible gains along the 15-mile front on the north bank of the River Somme. But they had amassed a staggering 60,000 casualties – 20,000 of whom were dead.

County Durham pitman Gunner George James was there on this blackest day in British military history.

And he survived.

Today, he would have been sending out tweets. Back then, he found a few seconds amid the carnage to take out his pencil and record a few thoughts in his diary, which his family still treasures.

Gunner George, as regular readers will know, was 21. After leaving school at 14, he worked down the mine in his home village of Littletown, near Durham City. When the First World War broke out, he joined the Royal Field Artillery, and he arrived on the Western Front in November 1915.

Just as he was well respected in his chapel community in Durham, so he must have been in the trenches as he was selected to work as a signaller – going down to the frontline and signalling back to the heavy guns where they should aim their shells.

Memories has been following his diary for eight months.

On June 24, 1916, Gunner George found himself on the northern bank of the River Somme, near the village of Carnoy, beginning the bombardment that was a prelude to troops going over the top on Z-Day five days later.

However, as his diary shows, raiding parties reported from German lines that the bombardment – heavy enough to be heard in London – was not as effective as had been hoped.

Therefore, the British added two more days of bombardment – Y+1 Day and Y+2 Day – which stopped at 7.30am on July 1, Z-Day, 98 years ago this week.

This is Gunner George’s eyewitness account of the opening days of the Battle of the Somme:

June 27

Our guns maintain heavy firing.

The 190lbs trench mortars opened fire today. Germans put over more stuff today. We were lying low with 4,700 rounds of ammunition waiting till our infantry charge.

June 28

A raiding party of 31 men went over to the German front line, all returning except one man who was left dead on the enemy’s barbed wire.

Heavy firing still kept up. Germans retaliate very fiercely.

June 29

Bombardment still carried on. Saw one of our planes bring down two German aeroplanes after an exciting scrap. Germans bombard our trenches with heavy enfilade fire (note: enfilade was firing up and down the enemy trench). Using gas shells, wind in our favour. Advance anticipated soon. I think we are waiting for favourable wind for our gas and fire.

July 1

1pm: The charge came off this morning at six o’clock. We’ve advanced so far about two miles. Was there ever such a bloody, horrible, hellish day in history? A good many hundred prisoners, almost every one of them looked cowed. I’m sure they are fighting against their will.

All the prisoners seemed to be overjoyed at being taken. Many of them saluted and murmured something about “Kamarade”.

Saw one little fellow about 13 years old.

2.30pm: Artillery advancing. Two of us signallers had to follow up after the infantry. (I) advanced with telephone wires. Communication trenches full of wounded and prisoners.

In no man’s land, our men were lying thick where they had been mowed down. The havoc our bombardment had created in the German lines was terrible. Enemy suffered heavily. The German trenches were a ghastly sight, heaps of still grey forms, dead and dying. English and German dead lay side by side.

Many of them while dying pulled their letters and photos out of their pockets to have a last look at the pictures of those they loved, but would see no more, and then laid them by their side.

Some Germans died in the act of surrendering. Many died at their posts fighting to the last. Others buried alive in their dugouts. Others were bayoneted on the parapet.

A little way down the communication trench where we laid the wire, I saw one poor fellow (German) badly wounded, but still alive. I gave him a drink, the most I could do for him.

He murmured comrade. We left him. When I came back next morning, he was dead. He had scribbled a note, probably to his people at home, but which would never reach them.

Further down the trench was a German artillery officer who had made a gallant stand. Standing round a traverse, he had kept our infantry back with bombs until he had been shot.

July 2

Consolidated gained ground. 7th Div on the left advancing. British successful everywhere. French are advancing. Enemy seem to be demoralised.

July 3

We are still standing fast, bombarding all through the night. Fricourt just about surrounded. Our infantry have captured Caterpillar Valley.

Preparing for assault on Boche reserve trenches to which he has retired, three miles behind the original lines.

So far the British have been very successful: Montauban taken, Fricourt lost, and retaken. Trones Wood captured with five guns.

GUNNER George had made it through! But the Battle of the Somme was only just beginning. As George’s diary suggests, the fighting became bogged down. How much longer could he last? More next week...