Historic gas holders present cast iron challenge

Three cast iron Victorian gasholders are being re-erected as part of a prestigious residential scheme in Kings Cross, London. Standing independently, the Grade II Listed nineteenth century structures surround three new circular apartment blocks containing a total of 144 flats.

Known as the Triplets, because they are joined and share columns at three points. Gasholders 10, 11 and 12 were originally built in 1860 as part of the Pancras Gasworks that had more than 20 holders in total.

As the 20^th Century drew to a close, the gasworks was closed down and the Triplets were dismantled in 2001 to make way for the enlargement of St Pancras Station.

The columns and the rest of the cast iron framework lay dormant on site for almost ten years before being refurbished and rebuilt on a nearby site as part of a new development.

The three gasholder frames were sent to a specialist engineering company in Yorkshire for refurbishment and after a two-year programme they were ready to be delivered back to London for re-erection.

Bourne Steel has been employed by the project’s main contractor Carillion to undertake the erection process as it was decided a steelwork contractor would have the specialist knowledge for this job.

“Erecting the frames isn’t a simple job or one to be rushed, the 150-year old cast iron is fragile and needs to be treated with care,” explains Bourne Steel Contracts Manager Colin Hillier-Daines.

“The re-erection was made even more complex as the residential buildings were constructed first and so we had to work around them.”

Each gasholder is a different size, number 10 is 42m in diameter, number 11 is the widest at 43.5m diameter, and 12 is only 31m in diameter.

In total there are 41 columns surrounding the three gasholders – including three shared columns where the frames touch – with each column divided into three sections.