The Madrid railway bombings have brought the threat of mass slaughter to Britain's doorstep. Andrew Mylius asks what can be done to prevent a repeat on home soil.
Suddenly there is a mood of deep unease in the UK. The bloody loss of life in the Madrid train bombings two weeks ago shocked and horrified. And they seared on the consciousness of every Briton that such carnage could all too easily be repeated here.
Ramming the point home, a recording claimed to be from Al Qaeda last week threatened that 'a battalion of death' would be unleashed against Britain, Australia and Saudi Arabia. Metropolitan Police commissioner Sir John Stevens has issued an explicit warning that terrorist attacks here are 'inevitable', calling on the public to be vigilant for potential dangers.
'Anything that will to grab attention or strike at UK plc is likely to be a target - iconic buildings, critical infrastructure such as a motorway junction, a water main or gas supply, public events, airports, harbours, ' says John Moore, director of security and consulting engineering firm MFD International.
Of course, terrorism is far from new to the UK. Guy Fawkes' attempt to blow up Parliament in 1605 remains the most famous act of religiously inspired terrorism on home soil.
The nation has lived with the threat of Irish republican violence since 1881, when the IRA launched a four year bombing campaign against public buildings and underground stations in London (see history below ).
As a people, the British are practised at looking over their shoulders to protect themselves and thwart attackers, says Institution of Highways & Transportation deputy chief executive Carlton RobertsJames. And they are good at picking themselves up and dusting themselves off in the aftermath of a terrorist strike.
Emergency services, infrastructure operators and local authorities are well drilled in responding to an event. 'We have more of a tradition of managing terrorism issues than any of our European neighbours, perhaps with the exception of Spain, which has lived for some time with attacks by Eta (the Basque separatist group), ' he says.
However, following 9/11, the Bali, Riyadh and Istanbul bombings, and now Madrid, people are looking for greater reassurance and better protection. As designers, builders and custodians of the built environment and public space, there is a role for engineers in providing it, says Moore.
'The intelligence and policing communities provide the primary line of defence against terrorism. Local authorities and emergency services are in the role of providing damage limitation and looking after the sustainability of systems (like road transport, water and power) in the event of a terrorist strike, ' he says. 'And there's a bit in the middle where the engineer can play an enormously important role, strengthening structures and systems.'
Engineers can start by carrying out risk assessments.
Buildings, structures and construction sites are made vulnerable by their location, their occupier and how they are used, Moore says. 'You may not be an obvious target for terrorists yourself, but if your are within a 100m of the American Embassy, say, you need to be hardening yourself against a strike.'
In a building, this typically involves reducing the risk of injuries from flying shards of glass, explains TPS Consult defence director Chris Bowes.
Surveillance needs to be stepped up so that it becomes impossible for anyone to secrete packages close to the building unobserved. Entrance to the building needs to be strictly controlled - 'once a bomb gets into a building the human consequences become far greater'. Bowes adds: 'If you can't keep a terrorist out of the building, you have to stop them getting access to critical areas. In the design of new buildings we're heading back to the idea of castles and keeps.'
Vehicles need to be kept as far from the building as possible.
'You want to make it so difficult for a terrorist to plant a device inside, outside, or anywhere close to your building that they'll opt for a softer target, ' sums up Moore.
'It may sound cruel-hearted, but counter-terrorism is about survival of the toughest.'
Engineers also need to think carefully about evacuation routes and congregation points, to ensure that staff fleeing a bomb are not caught by a secondary device, advises Gary Sullivan, managing director of security consultant Wilson James. 'Evacuation to basements is growing in popularity as, even though you are not removing people from the building, you are preventing them from running from one danger into another.'
Engineers need to insist that clients allow them to address the risk of terrorism in building design and make provision for counter-terrorism in their construction budgets, says Moore.
He claims these steps are rarely taken (NCE 26 February).
Management of construction sites has come under increasingly tight control, says Sullivan.
'Depending on the client, landlord or end user, and the project's location, building sites pose a risk to their neighbours and are at risk themselves.
'Terrorists always have the upper hand because you never know when they're going to strike or where.' The best counter-terrorist weapon in the construction professional's arsenal is meticulous attention to detail, Sullivan advises.
This has been exemplified during construction of London's Paternoster Square development, he says. The project sits cheek-by-jowl with St Paul's Cathedral and the Old Bailey law courts, which are both considered iconic structures and therefore at high risk of attack. The threat to St Paul's has been heightened by the Queen's golden jubilee celebrations in 2002 and an Iraq war dead memorial service; the Old Bailey is regularly used for the trials of high profile criminals, including terrorists.
During the five years of building work on Paternoster Square, therefore, all site personnel have been vetted, and are checked into and off site to intercept interlopers. An eagle eye has been kept on deliveries to ensure no unexpected vans or lorries roll up on site: 'Construction sites are busy places, and if you expect four trucks but a fifth parks up you may not normally notice, ' Sullivan notes.
If terrorists were to infiltrate a site the impact would be swift, he believes. For the terrorist, it is too dangerous to hide explosives away within a new structure to be blown up later on, as the succession of snagging checks and follow-on work as different trades move over the site, would almost certainly lead to discovery of the bomb.
Protecting infrastructure systems poses much greater challenges than individual buildings or construction sites.
'Transportation is vulnerable across the board. You have individual cases of attacks against bus drivers in the US. On the other hand we've seen attacks against trains and metro systems in Tokyo, ' notes Roberts-James.
'There have been numerous hijackings. Planes or vehicles can be both a target of terrorism and a method of delivering it.'
Terrorist attacks are what Roberts-James calls 'low probability high consequence events'.
In the US, engineers are putting a major effort into combating terrorism in the transportation sector, involving scrutiny of assets. 'On a highway these could be individual structures where a bomb placed underneath could wipe it out, leading perhaps to loss of life, and making a major economic impact.
'What providers can do is carry out criticality assessments to identify the value of discrete parts of their infrastructure system. A bridge across a river is absolutely essential, ' he says in illustration. Operators need to find ways either of monitoring people using the bridge and of reacting quickly to an emergency - 'although once someone's parked a van on it I'm not sure what you can actually do' - or of strengthening it to the point where it will survive all foreseeable attacks.
And engineers and providers need to develop 'network resilience' so that transport systems continue to function even when a part is disabled.
All the principal UK transport operators have closely guarded contingency plans, worked up in conjunction with the emergency services and local authorities.
'The terrorist threat is very high. We are looking at what happened in Madrid and reviewing arrangements already in place to mitigate against that kind of attack, ' says a British Transport Police (BTP) spokesman.
But Network Rail, the Highways Agency and London Underground all admit that it is impossible to protect a large network completely. 'Without knowing what the specific threat is you can't plan a specific course of action, ' says the BTP.
'We inspect track and structures every week as a matter of course, ' says a Network Rail spokesman, 'but there's 10,000 miles of line. Virtually the whole network is accessible. Security fencing has been suggested as a way of keeping trespassers off the line before, but there's no way in the world you could raise a fence - it would be impossibly expensive.'
Arup Security Consulting director John Haddon believes it is impossible to safeguard against repeats of Madrid-style bombing. 'Unless we are prepared to go for the type of system you have in Israel where you have almost airport type security at railway stations - screening passengers and baggage before they go into a rail terminal - we just can't catch would-be bombers. CCTV and passenger vigilance is probably as good as it's going to get.'
Highways Agency network resilience manager Mike Wilson admits there are concerns about junctions, bridges and underpasses. The Agency has carried out detailed risk assessments highlighting vulnerable points in its system. Some critical points in the road network, including the Dartford Tunnel crossing the River Thames east of London, have been strengthened to resist bomb attacks. Wilson says the Agency has worked out alternative routes so that traffic can be re-routed if part of the network is knocked out. But he is tight lipped on details.
Meanwhile, Atkins head of security and counter-terrorism, Keith Carter, says the firm has recently completed a review of the central London road network, focusing on underpasses and culverts in which bombs might be placed. 'Our assessment has involved looking at the likelihood of being able to get to these, how robust they are, and how bad the disruption would be if they were hit.
'The outcome was that, in many locations, if a bomb went off it would shut down areas for quite some time - you'd have to close off the affected area of London. It would have a huge economic effect.'
Above ground the roads are easier to monitor using CCTV, he adds. Anyone tampering with bridges would almost certainly be caught on camera.
On London Underground (LU), 'the threat is severe general - there's a high state of alert but no specific threat', says a spokesman. This makes it impossible to justify the cost of strengthening any individual part of the system. LU has instead focused on increasing its surveillance, so it can pick up on dangerous situations as soon as they become apparent, and on its methods of response. 'We've been working extra hard to prepare ourselves for an attack and reduce the impact since September 11, but LU has been living with the threat of terrorism for years. As a result we have one of the most extensive CCTV networks in the world - there are more than 6,000 cameras trained mainly on stations, and the number will be extended to 9,000 in the next year or so.'
New stations have been designed to provide clear lines of sight. Detailing is important:
there are no dark recesses beneath seating where bags can be shoved out of sight. Kiosks and vending machines have steeply pitched tops, which bag bombs would simply slide off.
However, the new terrorist threat as epitomised by Al Qaeda appears so far to be pursuing different ends to the terrorists who have plagued the UK in the past. Where the IRA in recent years focused mainly on causing damage by hitting economic targets and infrastructure, the new breed of terrorist is pursuing what Arup Security Consulting senior security consultant David Smith describes as 'holocaust' - mass loss of life. 'Fanatical attacks are almost impossible to design and protect against, ' he sums up.