“Lastly the three high towers rising up into the sky will give dramatic contrast to the otherwise horizontal treatment of the buildings and, by their distinctive form and relationship to each other, will both mark the change of axis at ground level and give identity to the neighbourhood from afar.”

Chamberlin, Powell & Bon, Architects “Barbican Redevelopment” April 1959

 

The three towers of the Barbican Center,  Lauderdale, Cromwell and Shakespeare,stand out in the London skyline, looking unfinished and “broken” because of their dramatic design. They were the  London’s tallest residential towers, until they were surpassed by the Pan Peninsula development near Canary Wharf. The top two or three floors of each block comprise three penthouse flats. The towers are (from east to west) the Cromwell Tower, completed in 1973 and named after Thomas Cromwell, then the Shakespeare Tower, completed in 1976 and named after William Shakespeare, and, the last one, the Lauderdale Tower, completed in 1974 and named after the Earl of Lauderdale.

Here an extract form Barrets Solicitors, to learn more about some structural features  http://www.barbicanliving.co.uk/d5a.html

The towers’ height (above podium level) is 43 storeys in the case of Cromwell Tower and 44 storeys in the case of Lauderdale and Shakespeare Towers. The design of the towers underwent changes after the original plan in 1959. An irregular roof line, triangular projecting balconies, and vertical structural members were introduced to the design. Among the buildings which influenced this design was the Price Tower designed by Frank Lloyd Wright in 1953 to 1955 which Peter Chamberlin visited in the early 1960s.

The tower blocks were constructed on the same principle as the Victorian industrial chimney. The load-bearing structure is mainly round the outside. The problem -not faced by chimney designers – was how to combine an outer shell with the requirement for windows. It was solved by using a network of pre-cast frames of reinforced concrete, which together form a monolithic framework over the entire face of the buildings.

The vertical structure is formed by the inner core of lift shafts and stair wells, with a system of split piers and beams round the perimeter. This structure provides the necessary lateral stability against wind-forces and support for the vertical weight. Direct overturning forces are resisted by the inner core. Rotation forces caused by the non-coincidence of the centre of pressure and the centre of reaction are resisted by the outer system of piers and beams.