A “catalogue of basic errors” led to a train maintenance worker being crushed to death in 2017, a rail safety leader has said.

Chief Inspector of Railways Ian Prosser urged Siemens plc – which operated the depot in west London where the incident happened – to “avoid a repeat of this terrible event”.

He made the comment after the company was fined £1.4 million over the death at the Old Bailey on Tuesday after pleading guilty at an earlier hearing to one charge of contravening a health and safety regulation.

Ian Parker, 58, was killed when a 1,433lb (650kg) motor fell on him at the Siemens Train Care Facility in White City, west London, on June 13 2017.

The court heard that the father-of-two was a self-employed contractor working as part of a heavy overhaul team at the depot.

The team was tasked with removing several traction motors for routine refurbishment from electrically powered Heathrow Express trains.

Mr Parker was crushed when a motor fell after he prematurely removed items holding it in position.

In her sentencing remarks, Judge Anuja Dhir KC said this was a “tragic accident” which Siemens “ought to have prevented”.

The Office of Rail and Road (ORR), which launched the prosecution, said after the hearing that its investigation revealed defects in “task planning”, including a failure to carry out an appropriate risk assessment or allocate responsibility for supervision.

Mr Prosser said: “Our thoughts remain with the friends and family of the deceased.

“A catalogue of basic errors resulted in this tragedy.

“ORR's thorough investigation highlighted that it is imperative any work undertaken for Britain's rail network requires a safety risk assessment appropriate to the task and involves staff who are fully trained to carry out that task under constant supervision.

“We hope Siemens have learnt from this and avoid a repeat of this terrible event.”

Siemens said in a statement: “Our thoughts are first and foremost with the family and friends of Ian Parker, as has been the case since the tragedy in June 2017.

“We are deeply saddened by the events that transpired and would like to reiterate our genuine and sincere apologies to the family of Ian for the loss and suffering that they have had to endure.

“Ian's death had a significant impact on our business – and our people, who were shocked and saddened by the loss of a colleague and friend.

“Following the tragic incident, the leadership team made a commitment to drive forward a number of health and safety initiatives in order to reduce the likelihood of a similar event in the future.

“In the year following the incident, the business accelerated work that was already under way, promoting a new approach in the core areas of health and safety management.”