METROLINK bosses have vowed that safety is their "number one priority" after a passenger was dragged along by a tram.

The incident happened at around 1.33pm on May 30 after a passenger's hand became trapped in a closed door near to the rear of the vehicle at Bury Metrolink stop.

The departing tram then dragged the man about 15 metres, reaching a top speed of 10km per hour, before the driver reopened the doors and the passenger boarded the tram.

Following the incident an investigation was launched by the Government's Rail Accident Investigation Branch (RAIB), whose finding were published today.

According to the RAIB report, the passenger had arrived on the platform just as the driver started the "door closure sequence", using a push-button in his cab.

It added that as the doors were closing the man hurried to the tram, putting his hand between the double-doors on the rearmost carriage, which became trapped as the doors fully closed and locked.

The driver then made a final check on his CCTV monitor, showing the tram doors from an external camera on the front of the tram.

Seeing the passenger and a group of people close to the tram at rearmost doors, he concluded that the passenger was part of this crowd and did not intend to board.

The driver finally checked the green "doors closed" light was illuminated in the cab and set off.

He continued to look at the CCTV monitor as he departed and "was aware of the people at the rear of the tram", the report said, adding: "When he saw the passenger moving alongside the tram he decided to stop because he was concerned by the developing situation."

The RAIB report concluded that the "incident occurred because the driver believed that the illuminated ‘doors closed’ light, shown in the driving cab, meant nothing was trapped in the closed and locked doors, so the tram was safe to depart.

"The light actually means that no object has been detected between the closed doors by the door obstacle detection system."

It added that the system is designed to automatically reopen the doors if it detects objects at least 30 mm thick. However, "objects thinner than 30 mm are not necessarily detected.

"The driver stated that he was not aware that thin objects could be trapped in the closed doors and not detected by the door obstacle detection system.

"He was aware that the final door visual check was important to monitor passenger behaviour, but not aware of its role in avoiding departure with an object trapped between closed doors."

Responding to the RAIB report, Aline Frantzen, managing director at KeolisAmey Metrolink (KAM), said: “Safety is the number one priority for KAM and, following the incident at Bury, an internal investigation was launched and is ongoing.

“KAM gave information to the Rail Accident Investigation Branch, who decided not to carry out a formal investigation.

“KAM implemented immediate measures after the incident and we continue working with the RAIB and The Office of Rail and Road to monitor and assess the effectiveness of those measures.”

In February this year the RAIB issued urgent safety advice to all UK tramways after an empty pushchair was dragged after its plastic rain cover became trapped in the closed door of a tram in Nottingham, last December.

Tram operators were advised to confirm or ensure that tram drivers perform thorough checks after doors interlock, and before moving, to confirm nothing is trapped in the tram doors.

It also cautioned drivers not to solely rely on the "door interlock system".

Manchester Metrolink issued an individual, face-to-face safety brief to drivers on February 9 this year and gave then a copy of the briefing document.

However, a revised version of the document clarifying the requirement of Metrolink's rule book, but omitting problems with relying on the door interlock system, was then issued ten days later.

Metrolink noted that this was an unintentional error.

The RAIB report said: "Manchester Metrolink has stated that, after the incident, it briefed its drivers to undertake the final door visual check with the CCTV monitor in ‘split-screen’ mode showing the view of the tram doors obtained from an external camera mounted on the rear of the tram in addition to the front camera view used at the time of the incident.

"It has also stated that this method of working is being embedded into its driver training programme."

The incident in Bury is one of a number incidents where passengers or items have been trapped and/or dragged by trams and trains in the UK in recent years.

The RAIB report said: "RAIB investigations have shown that trap and drag events are a potential risk on both tramways and railways, with some resulting in serious injuries, and some with the potential to cause fatal injuries."

In June 2007 a passenger was dragged after their hand or clothing became trapped in the closed, locked doors of a departing tram at the Wellesley Road stop in Croydon, London.

An RAIB investigation found the passenger's hand/clothing had not been detected by the door detection system, and neither the trainee nor instructor driver did a final visual door check.

Similar incidents involving trains also occurred at Hayes and Harlington, station, London, in July 2015 and at ­Bushey station, London, in March 2018.

Keolis Amey Metrolink and Transport for Greater Manchester have been approached for comment.