Disaster waiting to happen?

Recent disasters have called the safety of European tunnels into question. Is the
UK doing enough to ensure its ageing tunnels are as safe as they can be? Or are we merely lucky that a major accident hasn’t happened?

Over the past four years there have been five serious fires in Alpine road tunnels, all started by lorries in an over-congested space. Fifty people died in the Mont Blanc and Gotthard tunnels alone, in France/Italy and Switzerland. Poor detection, warning and escape procedures were blamed for exacerbating the situation.

Experts agree that it is impossible to create a risk-free tunnel, but what level of risk is unacceptable? ‘If you have high-density traffic in a confined space it is inevitable that accidents are going to happen,’ says John Anderson, an independent consultant with 25 years’ experience with the Health & Safety Executive. ‘The safety systems have to be able to cope when something that is foreseeable happens.’

It is against this background that UK road tunnels were criticised in a safety report published earlier this year by European motoring organisations in which the AA was a leading partner. The survey of 30 tunnels in 10 countries was undertaken by experienced German inspectors. It gave the two Blackwall tunnels in London, each used by 50,000 vehicles daily, a ‘very poor’ rating and the Tyne tunnel was described as ‘poor’. The Mersey Queensway and Dartford tunnels were deemed ‘acceptable’, while the Mersey Kingsway was ‘good’, being the only UK tunnel tested to make the top 10 . None of the six UK tunnels was rated as ‘very good’ and the Blackwall tunnels (North and South) were rated 28th and 29th out of the 30 tested.

AA policy director John Dawson believes motorists face avoidable risks from tunnel fires – one of the main hazards identified. ‘None of the UK’s tunnels have modern, sophisticated systems where the fire ventilation equipment is automatically activated and the tunnel automatically closed when a fire breaks out,’ he says. ‘Basic emergency facilities such as fire extinguishers, emergency escape routes and lay-bys are also missing in some cases.’

The report highlights the lack of automated fire detection and emergency response systems, with the lack of fire extinguishers in the Blackwall southbound tunnel – the site of a fire last year – particularly criticised. It also found room for improvement in areas such as emergency telephone soundproofing and the monitoring of speed limits.

Tunnel operators have criticised the report as taking a simplistic view, concentrating on a checklist of measures, some of which may be impractical or impossible to adopt in all situations. Indeed, management of tunnels can be a critical safety factor, and UK operators were praised by the inspectors for their day-to-day work: the way they control traffic and the passage of hazardous materials, well-equipped fire brigades and good video surveillance.

Nevertheless, no one would argue with the proposition that tunnels should be made as safe as possible. It is all a question of investment. ‘What we have to do is undertake a risk assessment and determine the likelihood and consequences of an event such as a fire, and act accordingly,’ says Peter Heather, Director of Operations at Transport for London (TfL), the highways and traffic authority responsible for the Blackwall tunnels. ‘Our response must be proportional: we must spend where it is most sensible and has the greatest effect.’

Experts argue that the latest in fire detection and suppression systems, active ventilation, communications, monitoring and traffic management should all be installed irrespective of the age of tunnel. Of course other considerations – such as whether lay-bys, escape routes or safety tunnels should be provided, or whether tunnels carrying two-way traffic (a prime source of accidents) should be replaced by uni-directional twin tubes – eventually come down to the huge cost of underground construction.

The UK, with its ageing stock of tunnels, some over 100 years old, faces a real problem. Tunnels built to the standards of 100 or even 30 years ago just don’t match up to today’s requirements and many would prove impossible or ruinously expensive to update fully.

Even seemingly obvious measures such as sprinkler systems are also controversial. Some experts argue that ceiling-mounted systems can cool rising smoke, making it sink and hampering escape. Rising heat can turn sprays into scalding steam. As a result, trials with wall and floor-mounted systems have been held, with no conclusions yet drawn.

Rather than demand expensive structural features, experts are taking a more pragmatic view. They are asking: what can be done to gain the most impact? A report by the UN Economic Commission for Europe (UNECE) concluded that it was just as critical to provide clear information for users, including signs within tunnels telling the public what to do in an emergency; safe havens every few hundred metres; and public information campaigns aimed at users. People should have a fair chance of saving themselves, UNECE decided, and these measures are just as critical as expensive safety technology.

Anderson points out that the Gotthard tunnel had sophisticated safety systems, including safety refuges supplied with fresh air, but still drivers died. ‘You have to tell people what to do – whether to sit tight, or get out of their cars, or move in this direction – and you must be able to see your way to the safety exits if they are provided.’

However, real improvements can be made by installing the latest in traffic management, fire detection and control, ventilation and signage systems. This is what is currently being done with the Blackwall southbound tunnel in a £15mprogramme that started this month. The refurbishment will include the complete refit of the 1967 structure with state-of-the-art systems.

The pace of change in this technology, and what is accepted as adequate provision, is illustrated by the fact that the adjacent northbound tunnel, built in 1897 and refurbished just 10 years ago, is already in need of updating, and some of its systems may be replaced in a parallel operation to the work in the other tube.

Similarly, when the 11.6km Mont Blanc tunnel reopened in March it had been fitted with a fire-resistant lining, more traffic lights and flashing warning signs. Thirty-seven pressurised emergency shelters were built at 300m intervals, each with a video link to one of three command posts; 116 smoke extractors (one every 100m) and 76 new fresh air vents had been fitted. Heat sensors at the portals scan vehicles entering and 120 video cameras monitor traffic at all times.

But who is deciding which safety precautions are needed? In the absence of international safety standards it is left to individual countries to establish their own standards. Responsibility in the UK – and in many other countries – rests with the tunnel operators, with no equivalent of Health and Safety Executive inspectors to make sure that regulations are enforced around the country.

Though new tunnels are covered by Highways Agency design recommendations, safety in operation is not, although the number of new tunnels being built is negligible compared to the stock of existing structures in use. Both the HSE and DTLR claim that tunnel safety is also the responsibility of the Highways Agency. In turn the agency says it is down to the individual tunnel operators.

It is claimed this arrangement is satisfactory, with pooling of experience and expertise and ‘best practice’ between them. ‘The system works very well,’ says TfL’s Heather. ‘Operating companies in the UK have a responsible view of tunnel safety, unlike some examples in Europe where no one is really managing the tunnels. Properly managed, a lot of risks can be minimised.’

However, in the face of a lack of statutory standards or enforcement, some question whether users’ safety is being given the correct priority. ‘Why should the public be any less safe driving through one UK tunnel than another?’ asks Anderson. ‘There should be adequate safety standards in place, with some sort of policing body breathing down the neck of the individual operators. It is a legitimate public concern.’It is all a question of motivation,’ he adds. ‘We have had a lot of warnings, but will it take a UK disaster before this matter is taken seriously and effective safety standards for the UK are agreed?’

Sidebar: How tunnel operators could ensure safety

Short-term measures

Inform users about safety facilities such as escape exits, emergency telephones, fire extinguishers and breakdown bays

Employ suitable traffic management to ensure safe distances between vehicles, avoid stationary traffic and so on

Improve communication systems using radio traffic broadcasts and loudspeakers installed in prominent positions

Install variable traffic signs or signboards

Clearly signpost escape routes and emergency exits

Restrict access for vehicles transporting hazardous materials

Undertake thorough checks of tunnel safety by independent experts

Medium-term measures

Improve traffic management to avoid tailbacks

Agree and introduce internationally accepted pictograms for specific situations such as accidents, fire and so on

Introduce and continually update synchronised plans for alarms and emergencies

Train and equip fire services

Conduct regular practices for all emergency services in disaster procedures

Check that ventilation systems comply with modern standards

Equip all tunnels over 1,000m long with automatic fire warning systems; improve fire detection using combined systems of heat detectors throughout and visibility sensors at particular points

Install breakdown/emergency bays

Install escape chambers or rescue areas where other escape routes do not exist or cannot be provided (by converting ventilation channels into escape routes, for example)

Long-term measures (within 10 years)

Create escape and rescue routes; construct additional tunnels and links to an existing second tunnel

Link existing escape chambers to external escape routes

Add a second tube to single-tube tunnels