Gareth Newlands had worked at the farm for four days

But the sheriff also criticised the way that the emergency call was handled by an ambulance service controller.

And he has called for ambulances to be fitted with more modern navigation equipment.

Mr Newlands was injured after a bale grab he was painting toppled onto him at Blackhillock Farm, near Forres.

Farm workers called the emergency services - but an ambulance never arrived and the 17-year-old died more than an hour after the accident.

A fatal accident inquiry was held at Elgin Sheriff Court last year.

Detailed directions

In evidence, Eric Brown - the operations manager at the Scottish Ambulance Service's Aberdeen control room - said he had taken the emergency call.

He said he was given detailed directions to the farm, but did not pass on this information - even when the crew called in.

He was unable to explain why he had not done so.

The inquiry was told that a crew from Nairn, some 15 miles away, was despatched instead of local crews which were available. The ambulance lost its way.

Blackhillock Farm is near Forres

Mr Brown was also unable to say why an ambulance with a local crew had not been asked to attend when it had been available for calls nearly two minutes before Mr Brown passed the emergency to colleagues in Inverness.

In his determination, Sheriff Penman said Mr Newlands' employers Grampian Country Pork could have easily avoided the accident by securing the machinery he was painting.

The teenager was a trainee stock worker who had only been at the farm for four days.

The sheriff also criticised failures by Mr Brown.

He said that the decision to dispatch a crew from Nairn which had no local knowledge had been nothing less than a disaster.

'Untimely haste'

Three other crews had been available in nearby Elgin.

Sheriff Penman said that Mr Brown had shown an untimely haste in passing the emergency call onto another control room.

And he recommended that ambulances should be fitted with modern equipment such as global positioning systems so they could reach their destination as quickly as possible.

The Scottish Ambulance Service admitted that it had fallen short of its high standards.

It said that the sheriff's determination pointed to human error as a contributory factor.

The service is now carrying out an internal disciplinary investigation.