Ove Arup played a major part in the creation of the Barbican Estate.

Arup, as it is now called, is a firm of engineering consultants founded in 1946 by Ove Arup. The website describes him as ‘a gifted engineer-philosopher’ which even if it is true goes to show that you should never give the marketing people too free a hand. Arup is still an independent firm. Sydney Opera House, the Pompidou Centre, Terminal 5 – there really is a long list. The Barbican Estate need not feel ashamed to be counted in that list.

When it became clear in 1959 that the residential development of the Barbican site would probably go ahead, the Barbican Committee brought in Ove Arup to advise on essential structural matters. They produced a report in 1959, in concert with the report Chamberlin Powell and Bon were preparing.

The first important matter they dealt with was the question of the subsoil strata and the nature of the foundations which would be necessary for the erection of the towers in particular, but also the terrace blocks. They relied on various sources of information. Ove Arup had previously worked on the Golden Lane estate project and they were able to employ their knowledge of the soil test results for that estate in the evaluation of the foundation conditions for the new estate. Their recommendation on the sub-soil condition was:

“These conditions are normal for the London area. The foundation problems therefore are not unusual for large buildings on London clay. Except above the hump in the level of the Woolwich beds, underneath the brewery, the foundations will be entirely in the London clay.”

The reference to the brewery may seem odd, since the brewery is on Chiswell Street, beyond the boundaries of the Barbican. But this was relevant to the construction of Cromwell Tower which is the closest of the Barbican buildings. Ove Arup were pointing out that there was a weakness in the ground below Cromwell Tower, requiring extra foundation work. They had to advise on how that would be dealt with. They also had to advise on how foundations could be created above railway tunnels.

For the towers, they were able to advise on a system of concrete foundations and piles which would carry the load. (At the time of the report, they were dealing with proposed 37 storey tower blocks, not the 43 and 44 tower blocks, which were eventually built.)

They also had to take account of the need to ensure that none of the piling and concrete filling of the subsoil would divert underground water channels which currently went under St Paul’s cathedral. There was concern at the time that the Barbican development might lead to the ground drying out under St Paul’s and creating structural damage for the cathedral. Ove Arup concluded that the risk was quite small and that even if there were to be a problem:

“the flow is likely to be so small that it will not be a crippling expense to replenish the depression or saucer under the cathedral.”

The greatest influence on the change in appearance of the towers was the work of Ove Arup, who designed the eventual shape of the towers. The curved forms the jutting balconies were designed to reduce wind resistance.

The rather monumental use of concrete in the Barbican estate was not a feature of Chamberlin Powell & Bon’s original designs for the estate, but reflected Ove Arup’s input as construction was under way.

Ove Arup recommended the adoption of the cross wall construction system for the terrace blocks. (Cross wall construction is also called box frame structure.) This allows many flats to have wall-to-wall and floor to ceiling windows.

It was essential to make sure the railways under the site would not disturb concert or theatre performance in the Barbicn Centre, or flat owners. Ove Arup carried out a study of vibration on rail lines and brought in two acoustic specialists as consultants. These were Dr P. Grootenhuis, and Dr Parfitt from the Building Research Station at Watford. Their proposed solution was to mount the railway tracks on rubber bearings which would reduce the amount of vibration reaching the ground and the structure of the buildings. This has worked.

This is no more than a selection of the major contributions Ove Arup made to the design and construction of the Barbican Estate. It is merely the items I have fortuitously come across in my research. I am sure there is a much larger story to tell.