Cheltenham Magistrates Court heard that Spencer Gosney from Yeovil, and Matthew Brewer from Nottingham, had been subcontracted to build a concrete core as part of a new GlaxoSmithKline factory.

On August 12 2009, the two men were building the core using a large piece of climbing formwork.

As the tower got higher, the formwork was lifted up and fixed in place enabling the men to work at the top to set more concrete.

But one of the anchor points holding the section of formwork where the men were standing came out of alignment before the concrete was poured in.

The men used a bolt not suited for this use in its place, but fixed it at an acute angle. The bolt was unable to withstand the weight of the concrete and broke, tipping the platform upon which the men were standing, sending them falling to the ground.

Gosney suffered a laceration to his head and severe bruising to his internal organs and leg. Brewer fractured his hip and pelvis and has still not returned to work.

Sue Adsett, the HSE inspector who investigated the incident said: “It is vital all work is properly planned and checked in order to prevent or reduce the impact of falls. Safety-critical parts of temporary work equipment should be checked before use.

“This incident occurred because neither of these things was done. Crucially, Chalcroft Ltd had no formal procedures in place to make safety-critical checks.

“These checks would have revealed that the working platform was not secure, and this failing has caused serious injury to two men.”

Chalcroft Ltd, of Keytec 7 Business Park, Pershore, Worcestershire, admitted breaching Construction (Design and Management) Regulations 2007 Reg 22 (1)(a) and was fined £14,000 with £23,236.28 in costs.