Eurotunnel chief executive Jacques Gounon said on Wednesday that the possibility of changing over to covered wagons or on-board sprinkler systems had been ruled-out.
He said the company was looking at new ways to protect their asset in the aftermath of the 11 September fire which damaged up to 800m of interval six of the north tunnel.
He said Eurotunnel would bring a number of suggestions to its meeting with the Intergovernmental Conference, that acts as the tunnel's regulator, in January to discuss safety issues with running HGV shuttles in the tunnel.
Gounon stood by Eurotunnel's safety record: "Since the Channel Tunnel opened, more than 14M HGVs have passed through the tunnel and only two have caught fire, one of these [the 1996 fire] was found to have been started maliciously."
Gounon went on to stress that there have been no fatalities or serious injuries in the tunnel, suggesting that this proved the efficacy of safety and evacuation procedures in the tunnel.
He nevertheless questioned the need for prolonged forced ventilation of the tunnel once evacuation of passengers/HGV drivers had been established. Air being forced through the tunnel to aid evacuation was, said Gounon, a contributory factor to the fire spreading through almost 1km of the tunnel.
The arrival of fire-fighting crews at the scene a full 75 minutes after the fire broke out was another issue that urgently needed to be addressed said Gounon.
Among the measures already put in place even before the findings of the French judicial and BEATT/RAIB investigations are published are:
More training for the staff of the club cars on HGV shuttles
Evacuation procedures being displayed in nine languages in the club car.
Repairs on schedule
Repairs to the tunnel are moving ahead well within schedule. Hundreds of metres of damaged concrete have been removed by hydrodemolition, using high pressure water jetting down to sound concrete.
This system was not employed during repairs following the 1996 fire when much of the spalled concrete was removed using hammers and chisels.
Hydrodemolition has the added advantages of taking the concrete back the required 20mm to 30mm without damaging the steel mesh reinforcement. Shotcrete is then reapplied once core-testing has established the soundness of the concrete in a given segment.
Eurotunnel maintains that the project manager SETEC and civil engineering group leader Freyssinet (the same team that carried out the 1996 repairs) can bring this repair job in for €60M (£54M) and within a four month timeframe. Commercial operations are scheduled to begin again on 15 February.
The 20,000m2 site works round the clock with 100 men per eight hour shift taking the train from Coquelles for the 17km journey to the work site. A Shotcrete plant comprising a concrete supply unit of three 10m3 tanks and an airtight mixer unit has been set up on site to produce the estimated 4,000t of concrete needed for reinstatement.