A factory supervisor was burned to death after being trapped in an industrial oven at a kayak factory, a court heard on Thursday. Father of three Alan Catterall tried to escape using a crowbar, but died a “horrific” death because co-workers were unable to hear his cries for help, a jury heard.

Catterall, whose wife also worked at the factory, became trapped after automatic doors on the oven closed when it was switched on. After 10 minutes inside the oven, which reaches 280C, he suffered severe burns and died of shock. The accident was only noticed when smoke began seeping out of the oven.

Andrew Thomas QC, prosecuting, said a series of health and safety flaws led to the incident in December 2010.

Catterall’s employers, Pyranha Mouldings of Runcorn, are accused of corporate manslaughter, and two directors, brothers Graham and Peter Mackereth, face health and safety offences.

Alongside them at Liverpool crown court is Paul Keddie, 49, a self-employed electrical engineer, of Llangollen, who designed and installed the electrical control systems for the oven. All deny the allegations against them.

A jury heard that the huge oven had been switched off for an hour after a fault developed. After it was fixed, it was switched on by fitter Mark Francis, who was engaged to Catterall’s eldest daughter, Sarah. He did not realise his future father-in-law was inside.

Thomas told the court that it was in a new rotational moulding oven for making kayaks that the accident occurred.

“The design of the oven was such that the moment it was switched on the doors automatically shut and coked with metal pins which dropped into place on the outside. Mr Catterall was trapped within the oven. There was no means of escape and no means of raising the alarm.

“The oven is lined with insulation material and on the noisy factory floor there was no chance of anyone hearing [Catterall’s] cries for help,” said Thomas.

“The evidence indicates that Mr Catterall made efforts to escape – he had a metal crowbar – but it was to no avail.

“He suffered severe burns and died as a result of shock. The first anyone knew about a problem was when smoke started seeping out of the oven.”

Thomas told the court that the defence may suggest Catterall may have intended to kill himself by deliberately climbing into the oven knowing that his prospective son-in-law was about to switch it on.

He had been under stress and had written to his bosses 10 months earlier mentioning work-related stress leading to suicidal thoughts. Thomas told the jurors they could easily dismiss that possibility.

An investigation by Cheshire police and the HSE found the oven had been designed by Pyranha Mouldings and they were responsible for safety. “Many serious failings were revealed by the investigation. Serious failings which went right to the top of the company and in particular to its directors,” Thomas claimed.

The oven, described as being the height and width of a Ford Transit but one and a half times longer, had two doors, but anyone operating the control panel did not have a clear view all the way through the oven. The default position of the doors was to shut automatically to keep the heat in and save fuel.

It was common practice for workers to go in to scrape up blobs of plastic and staff were fearful of being trapped inside, the court heard. There had been a previous incident when someone was inside when the doors started to close and on another occasion a fitter was working underneath when it was switched on.

Francis switched on the power after the fault had been fixed. That meant the automatic doors defaulted to their closed position and he then pressed the buttons for the oven to go into its warmup procedure.

Thomas said the defendants claim they discharged all relevant duties in respect of safety of their staff and any faults “were the faults of others. In particular they say that Alan Catterall and other staff working on his shift that day failed to make simple checks which they say might have avoided this accident.”

The trial continues.