A member of CONIAC, the Health and Safety Commission’s Construction Industry Advisory Committee, has attacked safety standards on high-level gantries and hoists following a fatal accident on the Avonmouth Bridge, near Bristol.

Transport and General Workers Union construction officer and CONIAC member Bob Blackman delivered the attack in the aftermath of last week’s accident in which four steel workers plummeted to their deaths as the gantry they were working on fell 25 m from the bridge.

The men fell into a car park below the bridge and were killed instantly. The high winds blew part of the gantry into the Avon River, and an 11 m long section was left hanging from the underside of the bridge.

Blackman said he believed unfavourable wind conditions were a contributing factor in the accident, and questioned whether the men should have been working on a gantry on the day of the accident.

Blackman said: “Questions need to be asked about the wind speeds on the day. People should not be working on gantries in conditions of high winds, or even if the winds are inconsistent.

This region has a poor accident rate and poor safety record.”

Michael Cosman, head of operations at the Health and Safety Executive’s Wales and Western region, which is investigating the tragedy, agreed that weather conditions may have been a factor in the accident.

An HSE spokesperson said the conditions that the men were working under, including wind speeds, were crucial to the investigation. She added: “We take this very seriously. It is unusual for four people to die.”

A spokesperson for contractor Kvaerner Cleveland Bridge, employer of three of the men, said it was unable to comment until the HSE had completed its investigation. The three workers were members of general union GMB. The fourth man was employed by Scottish steel firm Motherwell Bridge, and is understood to have been a member of electrical union AEEU.