A pub bombings survivor has told of escaping through a hole blasted in the wall – as inquests heard there were just 15 police on duty in Birmingham city centre that night.

On Thursday, David Grafton, then 20, told how he was standing at the bar of the Tavern In The Town pub when he was knocked flat by a 30lb (13.5kg) high explosive bomb, planted just yards from where he stood.

Factory worker Mr Grafton, who was meeting a friend at the pub for a pint, told jurors he had just raised his drink off the bar when there was a “flash” followed by “total blackness”.

Hunt For The Birmingham Bombers TV programme
The 30lb bomb planted at the Tavern In The Town detonated with such force it blew out the floor above, as pictured here (PA)

After helping others escape, he scrambled up a pile of rubble, through the hole and into the basement of the neighbouring HMV record store before getting up to the street above.

Mr Grafton is the first survivor to give evidence at the hearings.

The inquests at Birmingham Civil Justice Centre into the 21 victims killed in the blasts got under way this week after a 44-year wait for the bereaved families.

Opening the proceedings, coroner Sir Peter Thornton QC told jurors they would hear evidence of how the two bombs ripped apart two pubs on what was a “perfectly ordinary evening”.

The devices, detonating in “massive explosions” just minutes apart inside the Mulberry Bush and the Tavern In The Town, brought “devastation”, jurors heard.

Earlier in the day jurors were told how police numbers had been cut to just 15 officers across “busy” Birmingham city centre, that night.

Birmingham pub bombing inquest
As it looks today, the alcove where the IRA bomb was placed on the night of November 21 1974, in what was then the Tavern In The Town. The site is now a Chinese buffet restaurant (Richard Vernalls/PA)

Manpower had been “denuded”, according to an official police report from the time, in order to cover funeral transport arrangements for provisional Irish Republican Army bomber James McDade.

The inquest also heard that, when the bomb warnings were phoned in at 8.11pm on the night of November 21, police reinforcements were only called in after the explosions.

It was not until 9.10pm that extra officers started arriving at the scenes.

At the time, the West Midlands was in the grip of an IRA bombing campaign, the jury was told.

There had been 53 separate explosive and incendiary devices used between 1973 and the pub attacks.

Two separate bombs had gone off previously at the Rotunda, where the Mulberry Bush was, in both April and July 1974.

Birmingham pub bombing inquest
The former site of the Mulberry Bush pub in the base of the Rotunda off St Martin’s Queensway, Birmingham (Richard Vernalls/PA)

Jurors heard from barrister Lesley Thomas QC, representing several of the bereaved families, that the city would have been “busy” that night.

Thursday was late-night shopping day, and many people had also received their wages, he said.

Seven days before the blasts, McDade had been killed while planting a bomb at the Coventry telephone exchange.

Security arrangements for the cortege taking McDade’s remains to Birmingham Airport for flight back to Ireland had seen police leave and training cancelled, and shift manpower cut, jurors heard.

In all, West Midlands Police had gathered 1,680 uniformed officers for the operation, while 352 officers from Staffordshire, West Mercia and Warwickshire forces were held in reserve.

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The Mulberry Bush in the aftermath of the powerful blast. (PA Wire/PA)

On Thursday, the inquests heard that 135 of those officers were taken from “A division”, the unit which policed the city centre where both pubs were.

That night, just 10 officers were at the nearest police station in Digbeth, and five more at the division’s other base in Steelhouse Lane.

In an official police report following the pub blasts, a force superintendent said: “The bomb incidents in Birmingham occurred while the city centre was denuded of uniformed police officers who were engaged at Birmingham Airport, but it is felt that this in no way affected the organisation and efficiency of the police at the scenes.”

Documents on officer numbers were formally introduced as evidence by Anthony Mole – who is unconnected to the bombings but is an ex-counter terrorism police commander with 30 years’ experience.

Birmingham pub bombing inquest
Sir Peter Thornton QC (right), in New Street, Birmingham, during visits on Thursday to the sites of both 1974 pub bombings (Richard Vernalls/PA)

Asking questions on behalf of three of the bereaved victims’ families, Heather Williams QC asked Mr Mole about a passage in an official police report regarding A division’s staffing of the funeral, and its impact.

The report stated that officer numbers had been “partly achieved by reducing strength of second day watch and night duty”, leaving the nearest police station with just six constables, not including other ranks, to respond to incidents.

Mrs Williams asked: “What is being said is these were the only officers available on outside duty in the city centre on the early evening of 21 November 1974?”

The jury heard that Digbeth police station alone had sent 60 constables to the funeral.

Mrs Williams asked: “So we can conclude that’s six constables in all, as against 60 constables that were to deploy to the McDade funeral arrangements?”

Mr Mole replied: “Yes, although I don’t know what the normal strength is on a night shift.”

James McDade hearse
Police link arms as the police driven hearse with the coffin of IRA bomber, James McDade, leaves Coventry mortuary on the first stage of its journey to Belfast (PA)

Jurors also heard that both pubs were busy that night, with “about 40-50” in the Mulberry Bush and some 200 in the Tavern In The Town.

In the Mulberry Bush, at the foot of the Rotunda, the blast was so violent the 25lb (11kg) device left a metre-wide crater, shattered windows, and blew-out the staircase and bar.

A report by a chief superintendent, after the bombings, said the first police officers to be pulled back from the McDade funeral detail only arrived at 9.10pm, 59 minutes after the warning call.

It then emerged that the McDade officers were not called back “until after the explosions”.

Earlier in the day, jurors were taken to visit the former sites of both pubs.