AROUND 500 explosive charges will be used to “blow down” a large Bradford office block when it is demolished shortly.

Formerly occupied by Bradford Council staff, Jacob’s Well is being pulled down to make way for a planned £20 million public sector hub on the site.

The 1970s up to nine-storey building on Nelson Street has been empty since the Council vacated it in the summer of 2016.

Phil Harrison, senior demolition officer at Bradford Council’s demolition and works unit, explained how the building is to be brought down.

“It’s a ‘Trent’ pre-fabricated concrete building and it was all factory made, brought up and bolted together. It was decided that the best method to demolish it would be by explosives.

“A firm of consultants came in and assessed the building - the weight, where over-loads are, the type of building it is, so they could design where the explosive charges should go and how we can demolish it.

“Once that design was done, it was independently checked and then the pre-weakening works were done, drilling holes in the walls. It’s also drilled for the explosives.

“The pre-weakening is designed to ensure the building comes down how we want it to. There will also be five blast floors, so we are blasting on the lower ground, upper ground, first, third and fifth. All the columns are drilled and explosive charges are put in, and in the lift well and stairs too.

“The central core will be detonated first and then there is a millisecond delay and the two wings will be detonated next. The idea is that the central core comes down and the wings come in on top of it.

“We expect the debris pile to be two, two and a half storeys high.”

Measures have been put in place to protect the nearby Jacob’s Well pub while the demolition is carried out including vibration surveys and barriers in place in the event of any large pieces of debris rolling down the pile after the building comes down.

The exact date and time of the “blow down” is being kept under wraps for safety and security reasons.

But there will need to be a 250 metre exclusion zone and nearby offices and flats to be evacuated, as well as road closures and diversions in place.

Local firm Thomas Crompton is the main contractor for the demolition of the building, and it is McLaren Developments that has been granted the option to develop the site.

The scheme will comprise initially 100,000 sq ft of Grade A office space and is part of the Government’s One Public Estate initiative.

Plans were first unveiled by the Council in 2015, when it was announced that the privately-financed hub could bring up to 3,500 public sector jobs into the city centre.

The goal was to sell the land to private developers who would then build a 200,000 sq ft public sector hub for organisations like Government departments, the NHS or the Police to relocate to.

At the time, 1,700 Council staff were based in the Jacob’s Well building, but they have since moved to other offices, such as Margaret McMillan Tower, Sir Henry Mitchell House, and Britannia House.