Cooling towers collapse during storm

Three of eight cooling towers at the Ferrybridge C power station in Yorkshire collapsed during a storm on November 1, 1965, when wind gusts reached 130 km/h. The other five towers remained standing despite being exposed to the same conditions.

Positioning determined the collapse

The three towers that fell were located downwind of the others, in the row intended to be sheltered from the wind. This arrangement, meant to protect them, instead made them vulnerable to forces the engineers had not anticipated.

Vortices created by grouping

An investigation by the Central Electricity Generating Board (CEGB) found that wind flowing past the first row of towers created vortices that struck the second row. This effect, caused by the grouping of structures, had not been considered in the original design calculations.

Design flaw in wind load calculations

The towers were designed based on wind load tests conducted on a single tower, without accounting for the turbulence caused by multiple structures. Additionally, the calculations used average wind speeds over a minute, ignoring short, intense gusts that can be more damaging.

Global engineering standards revised

The Ferrybridge incident led to a worldwide revision of construction standards for cooling towers, incorporating the effects of grouping and short-duration wind gusts. These changes aimed to prevent similar failures in the future.

Legacy of the Ferrybridge collapse

Despite the updated standards, similar incidents occurred at other sites in the following decades, showing that the lessons of Ferrybridge took time to be fully applied. The collapsed towers were eventually demolished between 2019 and 2022, but the event remains a key case study in engineering education.