Fascinating facts about the Barbican estate’s construction

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In the building industry it is traditional to have a ‘topping out’ ceremony when a building is completed. On a particular occasion on the John Laing site, to honour tradition they put the City of London flag and the Union Jack on the top of the building ready for the ceremony the next day. There was a large number of Irish builders working on the site. Overnight some of them switched the Union Jack to the Irish flag – green, white and gold. It wasn’t noticed until the ceremony was already well under way. Apparently, one of the Royal family was there. There was a panicked scramble by the managers to swap the flags.

All the walls and floors of the buildings were made on site.  Carpenters had to create boxes – called ‘shuttering’ – as frames to contain the wet concrete for the size of the required wall or floor. The shuttering was made using three-quarter inch plywood. Then the concrete was poured in and left to set.

The walls would also have metal backs bolted to them. Then they would be hauled up by a crane, leaving the shuttering behind. When the walls or floors were dropped in place they would be bolted together.

The concrete walls were thicker at the bottom because they had to carry more weight. The slabs might be 2 feet or 18 inches think. Higher up the building, with less weight to carry, the walls might be reduced to 12 inches thick.

As many as a thousand workers were employed on the site at the height of the construction process.

When work on the Turriff site started, the toilet for the workers was a hole in the ground with quick lime. The company refused demands for flush toilets. They said they would only install some then the buildings were two storeys high. (This is what passed for incentive arrangements in the 1970s.) So the workforce started walking to St Paul’s Cathedral to use the public toilets there. Very quickly proper flush toilets were provided on site.

Two main contractors tried to quit the site before their part of the development had even been completed. One succeeded (Turriff).

Industrial relations were so bad that the project was bedevilled with strikes – official, unofficial, and wildcat – culminating in work being suspended for a year on the Myton site. There had to be a Government sponsored court of enquiry to settle the dispute.

On the Myton site, a crane was put up but someone forgot to put in the blocks to hold it in place, and when it picked up a large shutter the crane fell over. No one was seriously injured fortunately.

In May 1976 there was an all-out strike for two weeks at the Barbican Centre site because of Laing’s refusal to remove asbestos safely from the site. They had workers simply sweeping the dust up.

On Laing’s site, a worker was decapitated by a hoist. He stuck his head through a hole in the lift structure to see if the hoist was coming up. It was, but he had not realised that the counterbalance was coming down.

The building companies’ original tenders had been based on a provisional bill of quantities and only about 50 or 60 drawings per site. But when they came to carry out the construction work they had to deal with thousands of drawings from the architects and a continuous procession of building instructions to deal with issues big and small which occurred as problems were encountered in turning ideas into practice. At one point it was estimated that Chamberlin Powell and Bon were so swamped that they were six weeks behind in responding to problems with new drawings.

A major practical construction problem arose from the use of exposed concrete walls. There were tolerances of only 1/8 of an inch on walls 30 feet in length. Since door frames were all pre-made with no architraves around them, there were no tolerances at all on them. Window frames also had very small tolerances. The builders were not used to this. When using bricks and plaster there is considerable flexibility in dealing with tolerances or covering up ‘bodges’ with plaster. You only have to look at the precise holes for lift buttons in the Barbican Centre to see how exact every measurement had to be.

To carry out the Barbican development Chamberlin Powell and Bon split their operation into two offices: one for the Barbican Centre under Charles Greenberg, and subsequently John Honer; the other office for the rest of the estate under Christof Bon.

St Giles Cripplegate, which mostly dates from 1545–50, was half-ruined by aerial bombing during the War. Chamberlin Powell and Bon proposed that it should be used as an occasional concert hall, with practice rooms for the Guildhall School of Music and Drama attached to it. Instead, the church was restored as a working church in 1960 to designs by Godfrey Allen.

The only pieces of history finding their way into the new development (apart from the church itself) were fragments of the City Wall and grave slabs from St Giles’s churchyard. The walls may have started out as Roman but the bits that survive are mainly medieval, and they were mainly exposed from below road level. Grave slabs from the former graveyard were fixed into raised tiled sections in the new podium terrace around the church.