Explosive remit

Whether it is a hand grenade from the Second World War in someone's loft, a discarded holdall in a sensitive location or a terrorist device, the possibility of a bomb is a serious matter. Long experience of the Provisional IRA and the more recent threat of international terrorism have made the Metropolitan Police's bomb-disposal unit a vital asset to the force.

The Met's bomb squad was formed in 1964 and its original remit was tackling safe-cracking thieves. Plaques from dozens of safe manufacturers from the last century are on display at the squad's headquarters. However, when the PIRA began its bombing campaign in London, the unit began to devote more and more of its time and resources to dealing with the terrorist threat.

While the PIRA threat has all but vanished from London today, the main concern for the unit, aside from discarded bags and wartime explosives, is international terrorism, although domestic extremists also pose a threat.

Outside the London area, all bomb disposal activities are carried out by the Army's 11th Regiment, which specialises in explosive ordnance disposal (EOD), or the Royal Navy bomb disposal team, which responds to maritime EOD. No police force other than the Met has the resources or manpower to have a standing bomb disposal unit.

Personnel

The unit is made up of an undisclosed number of explosives officers, with senior, deputy and assistant explosives officers providing leadership and advice on equipment. The explosives officers, who are actually police staff and not police officers and therefore have no power of arrest, are supported by a team of police drivers, each of whom has around 20 years' experience of driving fast response vehicles in London.

Would-be members of the squad must have accumulated extensive experience before they can be considered for recruitment. They must be at least Warrant Officer Class 2 within the Army, which typically means they must have around 20 years' experience. They must also have a conventional munitions disposal license and a high-threat improvised explosive device disposal qualification, typically gained from tours in Northern Ireland. They must be certified in biological and chemical munitions disposal and also have an advanced manual techniques qualification.

They have extraordinary experience and have learned to be calm in any situation. Since the squad's creation, it has only lost two of its members to bombs.

The squad is active 365 days a year and its location in central London means it can effectively reach any of the operational areas it covers. At any one time, there is a heavy deployment team, a light deployment team, a CBRN response unit and an operational support team on standby. Each is equipped with appropriate equipment, ranging from robotic vehicles to chemical agent detectors.

In addition to tackling the explosives and suspect packages that are discovered each day in London, the bomb squad supports specialised police units such as CO19, the Met's firearm command.

Equipment

The bomb squad uses a range of specialised equipment to deal with various explosive threats. One of the squad's most recognisable pieces of kit is the Wheelbarrow. This tracked robotic platform is used to defuse bombs remotely and can be used to investigate any unsafe device. It has a 360-degree rotational turret and can be controlled by radio control, fibre optic cable or remote wire.

The Wheelbarrow can be fitted with a range of equipment, including four cameras to give the operator total visibility, a mechanical grabber, charge dropper or ceramic cutter. Other devices can be attached to the Wheelbarrow to disarm bombs in a variety of ways. It is carried to a scene in specially modified armour-plated vehicles that protect the officers and equipment.

The Cyclops 4D is a smaller version of the Wheelbarrow and can be carried in fast response vehicles. Owing to its small size, the Cyclops can be used on aircraft and trains and can even climb stairs. It can be fitted with the same video cameras and weapons platforms as the Wheelbarrow.

Explosives officers have a range of protective equipment they can wear when approaching a device, depending on the type of explosive they are investigating and the officer's own judgement. This can range from ballistic vests and helmets to full EOD kit, which is heavy and cumbersome, weighing as much as 50 kg. EOD kit can protect an officer when reaching down to, or standing up from, working on an explosive device.

One officer says: "It is important to note that the blast wave from a bomb can kill you. The fragments can cause damage and so can the aftershock of the weapon." Different gear is used to stop fragments from a bomb than is used to protect against the initial blast, for example.

Another officer also noted that there are times when he would not wear the full kit at his disposal for fear of causing panic among the public.

The squad also can also call upon several diagnostic technologies. An X-ray machine can identify the location of components within a device and prints off an image in a similar way to a Polaroid camera. The squad will soon begin using a digital alternative that will offer better visibility of the inside of a bomb.

A chemical diagnostic machine identifies substances passed across an infrared beam. Electronic personal dosimeters measure the presence of nuclear particles in the air, while Geiger counters measure radiation.

One officer notes: "The unit is led by the threat it faces and we are always looking at how other squads from around the world deal with threats and the kit they use. If we see something we like, we can obtain similar kit for ourselves."

The threat

In 2004, the bomb squad was called out to deal with 1,618 incidents; in 2005, there were 1,665, which included the events of 7 July. So far in 2006 there have been 991 incidents.

Aside from false alarms, the squad typically faces three types of threat. These include conventional munitions, including grenades and unexploded bombs; improvised explosive devices; and chemical, biological, radiological and nuclear (CBRN) devices.

While the government is spending a lot of money in tackling the latter issue, such incidents are rare and there have only been a handful of occasions where they have been used since the Second World War, most notably the Sarin attack on the Tokyo subway in 1995.

Despite this, explosives officers from the squad note that while making explosives is a relatively easy task, having the intent to use them and coming up with a suitable delivery mechanism is much more difficult.

There have been a number of incidents in which people experimenting with devices in their kitchens, and even experienced PIRA bomb-makers, have detonated explosive devices unintentionally, often with fatal results.

The members of the bomb squad are faced with daily alerts that typically turn out to be mislaid bags or misidentification of inert devices. However, every time the squad responds to an incident, there is the possibility of an explosion. As such, enormous responsibility is placed on the explosives officers.

Upon arriving at a scene, officers take control of the incident until a device has been made safe. But there is often great pressure on them to react quickly to restore normality. If a device were found on Oxford Street in London, for example, shopkeepers would lose around GBP1 million (USD1.9 million) for every hour the street was closed in an emergency.

With international terrorism increasing and information on how to build devices easily accessible, the role of the Met's bomb squad seems unlikely to diminish in the near term.