Dublin Port Tunnel has reopened following the evacuation of the 4.5km tunnel at lunchtime as a result of a crash.
Some 40 vehicles were stuck in the northbound bore of the tunnel from 11.41am when two lorries crashed, with the first vehicles emerging at about 1.10pm and the last at about 2pm.
Tunnel operators also closed the southbound bore, the designated route to evacuate motorists, once interlinking doors between the tunnels are opened.
The National Roads Authority (NRA) said both lorries were travelling in the same direction at the time of the crash.
The spokesman said the evacuation had been complicated by a second incident in which a motorist reported chest pains, and the evacuation was delayed for a while because of the need to get an ambulance in to assist him.
According to the NRA about 40 motorists and their passengers had been caught in the tunnel as a result of the crash and the medical emergency. The NRA said the shutdown of the tunnel had commenced as soon as the crash was detected at 11.41am, the gardaí and the Dublin Fire Brigade were contacted at 11.42am, and the shutdown of the tunnel was completed at 11.43am.
The NRA said control of the situation had been handed over to gardaí at 11.50am who had asked drivers and their passengers to remain with their cars, as the level of incident did not require an emergency evacuation on foot.
A spokesman for the NRA said one of the lorry drivers was taken to hospital by ambulance, but a second ambulance was later called to deal with the medical emergency. Following this the large safety doors between the north and southbound tunnels were then opened to allow trapped traffic to do a U-turn. He added that emergency procedures worked well and the evacuation went smoothly.
He said motorists were alerted to the danger through public service announcements over a public address system in the tunnel. The tunnel operators were also able to break into all radio stations that are received within the tunnel to advise drivers of the situation.
The NRA spokesman said he could not speculate on what had caused the crash. Lorries are forbidden from passing one another within the tunnel, and following traffic should maintain a distance of two "chevrons", markings painted at uniform distances throughout the tunnel, from the vehicle in front.
It is expected the tunnel's video surveillance will provide essential information on how the crash happened. The gardaí have opened an investigation, and it is understood that the Health and Safety Authority will also open its own inquiry. The HGV ban in Dublin city centre was lifted during the closure.
The well known public relations specialist Terry Prone was one of the motorists caught in the tunnel. Speaking to The Irish Times Ms Prone said the tunnel operators had done "a great safety job, but a lousy communications one".
She said she could not understand the public address announcements, which were "saying nothing understandable" . Car radio announcements were a female voice telling motorists to turn off their cars and await further instructions while remaining. "How could people listen to the radio with cars turned off," she asked.
Ms Prone said she had entered the tunnel at about 11 30am and had been inside for two hours. The atmosphere among the drivers was good, she said, although there was some hand waving among lorry drivers who were missing connections and motorists heading for Dublin airport.
