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Keltbray takes its toll in Bristol

DEMOLITION

Bristol's Tollgate House is a building few will mourn as it is brought down to make way for much-needed regeneration, but owing to constraints around the location, residents did not have the pleasure of seeing it blown up with explosives. Paul Thompson looks at how Keltbray is taking chunks out of the concrete monstrosity

BUILDINGS that gain the sobriquet of 'landmark' normally fall into one of two camps.

The first includes London's Gherkin or the Blink ing Eye bridge in Newcastle. They are instantly loved and instantly recognisable.

The second is reserved for those structures that are often architecturally significant but are rather less than universally liked.

Birmingham's Rotunda is a fine example of such a landmark building, the new Scottish Parliament another.

Tollgate House in Bristol also falls into this category. Since its construction in the early 1970s the grey, three-winged concrete structure has welcomed visitors into the city. And since its construction Bristolians have shaken their heads in despair at the 17-storey monster.

A quick straw poll around the site shows the depth of feeling about the place.

'Oh God , that horrible building at the end of the M32, I'll be glad to see it go, ' says Helen Virgo, a health service worker who has lived in the city for more than 20 years.

'Tollgate House is a vile building, truly disgusting, ' says Dave Doherty, another long-term resident.

Luckily for them, London-based demolition contractor Keltbray has taken the contract to raze the building to the ground as par t of a £3.2 m illion deal that will see Tollgate House and much of the former Broadmead shopping centre beyond it levelled.

Already Keltbray development director Steve Jack and project manager Mark Taylor have hidden the building behind bland protective cladding, an instant improvement to the skyline in this part of north-east Bristol.

And they are well on the way to permanently improving the architectural heritage of the city as they take down the building floor by floor.

'We have a cont ract to take the building down to ground level and take out the ground floor. There is no basement and, rather than face the difficulty of dropping the tower with explosives, we decided to take it down in a staged process, ' says Mr Jack.

That process will involve chopping the separate floors into pieces and dropping them down the lift shafts that form the central core from which the three wings radiate.

Before Mr Taylor and his team could get on with the task of bringing the tower down there were one or two slight problems to iron out.

Having been left standing empty for a good few years, Tollgate Tower, former home to the Department of the Environment, Transport and the Regions, had attracted less welcome residents.

'The building had been taken over by drug users and we had to get them cleared out before we could do anything, ' says Mr Jack.

'Even after we had managed to secure the building in September we still had users loitering around the site.' Because of the recent history of drug abuse at the site Keltbray had to draft in specialist cleaning contractor Rentokill to clear it of abandoned needles and other drugs paraphernalia before Mr Jack's team could get on with the soft strip.

'The whole building was like the Mary Celeste.

Desks and chairs and other office furniture had just been left there. It was almost as if the staff expected to come back in the next morning, ' says Mr Jack.

Keltbray had been unable to do any kind of in-depth survey over the building before it was secured so the initial tender value was not much short of an educated guess using the experience the company has gained on similar sites in city centres around the country.

Finally the team was able to get on site and a Type 3 asbestos survey revealed that there was some present in the lift shafts, plant rooms and internal panels.

With the asbestos strip complete and the soft strip of the buildings ongoing, Keltbray has been able to divert attention to the top of the tower.

Two of Bristol's main arterial roads pass close by the tower and a residential block hems it in on another side, so any thought of explosive demolition was quickly rejected.

That left the team with the only option of lifting men and equipment onto the roof and cutting each floor down piece by piece, shovelling the debris down the lift cores.

'We have our own in-house structural engineers, Wentworth House, who will give us guidance on the methodology of demolishing the building so that areas are not overstressed.

'In this case the building is pretty uniform across most of the floors but the plant room on the top floor has been beefed up, ' says Mr Jack.

Seventeen stor ies up Mr Taylor is co-ordinat ing the cutting and stripping of some of the strengthened sections of the building. There is a lot of rebar in the cantilevered section of in-situ reinforced concrete that forms the building's frame, while a precast concrete panel clads the outside.

'There is a lot of steel at the knuckle of the cantilever, but nothing that should cause us any problems, ' he says.

A mini-digger on the roof of the building pecks through the reinforced concrete of the walls in sections but the rebar refuses to give up just yet on its job of holding the building together. A worker with an oxy-acetylene torch is despatched to cut through the remaining steel.

These larger sections of concrete are being lifted down by crane to ground level where a 30-tonne machine can start smashing and sorting the concrete for recycling.

Eventually most of the aggregate used during the construction of Tollgate Tower will be salvaged and reused during the construction of the new Merchants Quarter shopping development that will take over the site (see below).

Developers will hope the new centre proves more popular than the despised Tollgate House.

A Jack of one trade

STEVE Jack (right), Keltbray's systems and development director, has been in demolition a long time. For more than 20 years he has worked on contracts across the country.

'I started off at the Central Electricity Generating Board then got onto the demolit ion of power stat ions f rom there, ' he says.

A mobile phone ring tone that plays the West Ham United theme, I'm Forever Blowing Bubbles, betrays his footballing allegiances while in his professional life Mr Jack is keen to help give something back to the sector that has served him so well.

He was on the committee that helped draft the BS 6187 code of practice for demolition projects and sits on the management council of the Institute of Demolition Engineers.

'The whole industry is much safer than it used to be but we still have problems attracting younger staff, ' he says. 'One of the industry's biggest failings is getting young people interested. Once we do get them interested we have to make sure we can retain them.'

Merchants Quarter

THE DEMOLITION of Tollgate House is part of a planned £500 million revamp of Bristol's outdated Broadmead shopping centre.

Broadmead was one of many shopping centres thrown up after World War II. It replaced a mish-mash of medieval timber framed houses that the German Luftwaffe had managed to destroy during an air raid in 1940.

Keltbray's client, Bristol Alliance, a joint venture between developers Land Securities and Hammerson UK Properties, aims to inject some much needed glamour back into this forgot ten part of Bristol city centre.

Up-market department store Harvey Nicholls has already signed up to the Merchants Quarter vision and more are expected to take an interest in a project that Bristol Alliance hopes will see 240 homes built, 15 new major stores and 100 other shops.