July 7th People's Independent Inquiry Forum -> Nature of the Explosions/Explosives

Nature of the Explosions/Explosives, Power surges? High explosives? Timers?

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Bridget

Posted: Nov 4 2009, 01:33 PM

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A couple of reports mentioned here, I don't know if we can get hold of copies:

QUOTE

Explosions and Blast Injuries
By Charles Sorbie, MB, ChB, FRCS(E), FRCS�
ORTHOPEDICS 2009; 32:804

Explosions deliberately set to harm people are an increasing problem for health services. Knowledge of their effects on the body is important and most physicians should have an understanding of the nature of blast injuries and perhaps also blast physics. Blue Notes reported the trauma that followed London�s bombings on July 7, 2005 (2006; 29[4]:299).

S.J. Wolf et al have provided a full account of explosives and the human damage they can cause (Lancet. 2009; 374[9687]:405-414).

In the explosions at the Nairobi US Embassy in 1998, shattered glass became sharp bullets, and much of the medical help needed was for plastic surgeons. When buildings of masonry, steel, and wood collapse, orthopedic surgeons are needed for crush injuries.

A chemical explosion results from the almost instantaneous conversion of a solid or liquid to a gas that rapidly expands. The blast wave of wind or water pressure that follows can propel objects or people far from the center of the explosion. Injuries are caused during the pressure buildup to the blast �over pressure� at the peak of the wave. The wave moves faster in water than in air.

Lancet articles.

This post has been edited by Bridget on Nov 4 2009, 01:53 PM

Bridget

Posted: Nov 20 2009, 12:15 PM

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QUOTE

Last update - 05:27 20/11/2009

Special IDF explosives lab attracts international experts
By Anshel Pfeffer, Haaretz Correspondent

Over the past decade, a small compound of single-story buildings at the IDF base in Tel Hashomer has become a Mecca for munitions and explosives experts from the world over. These buildings host the materials laboratory for the experiments and quality assurance units at the technological division of the ground forces.

The lab is considered to be one of the world's top centers in the field of improvised explosive devices (IEDs), a kind of weapon the IDF has been dealing with for decades, and which in the last few years began taking a high toll among American and British soldiers in Iraq and Afghanistan.

Any weapon component that reaches the IDF - whether confiscated from smugglers, captured in raids on terrorist explosives labs, or collected and pieced together as shards of shrapnel from bombs aimed at IDF soldiers and vehicles - finds it way to this lab sooner or later. The lab's commander, Lt. Col. Eran Tuval, can outline the developments in a terrorist organization's methods by tracing the ingredients of the bombs and their construction.

In some cases, the labs get the actual bomb assembly manuals, neatly written in school notebooks. In other cases, they themselves need to dismantle and rebuild bombs to understand their construction and origins. The lab then produces guidelines for forces in the field to deal with the newest generation of explosives.

Lt. Col. Tuval, a jumpy man with a goatee and a faint Italian accent, is relishing his image of a mad scientist as he carries out controlled explosions in the yard with a cigarette lighter, and skips among the items exhibiting the components of explosive devices currently en vogue in the Gaza Strip. Some are fertilizers and foodstuffs allowed into Gaza as part of humanitarian aid packages. Others are smuggled into Gaza through tunnels under Rafah.

The attempts by Palestinian organization to simplify explosive devices while increasing their impact has led them to try materials not often used in explosives; one example is R-salt, known to Israelis as white cubes for lighting barbecues, which has not been utilized in bombs since World War II. Another innovation is copper covering, which turns the bomb into hollow charges, allowing them to inject a jet of molten metal into armored vehicles - this was how an IDF scout patrolling the Gaza border in his armored jeep was killed in January.

"We see continuous improvement in the materials they use," says Tuval. "They now put copper where they used to put tin. You also get all kinds of chemicals."

Recently, the American military began studying the IDF experience. "They never imagined IEDs like that. They're still back in the 1980s, fighting the Soviets. They're making this huge review and came to us to learn everything about the materials and how to take the things apart," says Tuval.

Delegates from other armies fighting in Afghanistan, including the British, Italians and Germans, have also visited the lab to study the threats ahead. British experts, this time from Scotland Yard, also visited the lab in 2005 to learn the types of explosives used in the 2005 London bombings, which were different from bombs they knew from the IRA.

The lab also cooperates with the IDF dog-handling Oketz unit, providing samples of the explosives the dogs are trained to discover. Reports by the lab are used to construct instruments to trace explosives in airports.

The staff is also studying Qassam rockets, and produced instructions for the IDF to build exact copies of the Palestinian Qassam, which they then fired at practice targets, trying to determine the type of protection that would withstand a Qassam strike. All improvements in the Qassam construction, range and explosive force are being duly documented by the lab.

Often the lab only gets the complete materials weeks or months after the event. When the lab was investigating the attack on the tank from which Gilad Shalit was captured, they received new evidence several months after the skirmish - but managed to determine that the rocket-propelled-grenade used by the militants was armed immediately, unlike standard RPGs that arm only after flying for at least 30 meters. This allowed the militants to fire from a very close range.

In other cases, the lab is requested to produce results in real time. During Operation Cast Lead the lab deduced from shrapnel embedded in a paratroop officer's helmet that he was not injured by an IED but by a sniper's bullet, thus making the army aware a sniper was operating in that area.

Sometimes the lab influences the political arena, too. After the Second Lebanon War, Israel accused Russia of providing a large part of Hezbollah's missile arsenal. The Russians, for their part, denied the allegations, claiming the missiles were produced elsewhere. A report by the Tel Hashomer lab's metallurgy expert, Dr. Menachem Retzker, showed the alloy used to produce the missile met specific Russian standards. It was sent to the Kremlin, leading to the removal of a senior weapons export official. This particular accomplishment led to renewed interest by the army in the lab, and to greater funding.

However, despite its many roles - which also include assisting in forensic tests of civilian casualties and quality control of all new weapons introduced into the IDF - the lab is still encountering recruiting problems. "The problem is, we don't have the glow, the aura," says Major Marianne Bitton, who heads the chemical department of the lab. "A lot of our work is classified, and we're not considered to be a sexy unit, so it's hard to bring the right people here."

Like other technological units of the IDF, the lab, too, complains of a shortage in qualified young people with technological background. Tuval is trying hard to persuade veteran officers to stay in the lab, while also hunting for recent immigrants from the former USSR with technical knowledge you can't learn in Israeli schools.

Bridget

Posted: Dec 2 2009, 12:32 PM

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QUOTE

Page last updated at 11:27 GMT, Wednesday, 2 December 2009

Forensics machine to boost hunt for bomb fragments

By Paul Rincon
Science reporter, BBC News, Fort Halstead

Machine helps to find bomb clues VIDEO

The guidance for visitors informs us that we will receive a warning prior to the detonation of an explosive device.

It urges us not to be alarmed and to "be prepared for a bang".

The advice is welcome, if not entirely unexpected. It's a reminder of the vital and hazardous work carried out here at the UK's Forensic Explosives Laboratory (FEL).

Situated in Kent's leafy North Downs, FEL is the world's oldest forensic science laboratory, established 130 years ago.

Though it operates under the aegis of the Defence Science and Technology Laboratory (DSTL), the large part of its work is with police forces.

With more than 60 staff, the high-security lab deals with all types of incidents involving explosives.

Sifting through tonnes of debris left in the wake of an explosion is not an easy job
Garth Shilstone, DSTL

These range from rash experimenters using improvised chemical mixtures right up to major terrorist attacks such as the London bombings of 7 July, 2005.

The lab's work is usually kept out of the public gaze, but insights have emerged when FEL scientists have been called as expert witnesses in trials.

For example, following the botched London bombings of 21 July, 2005, and the two car bombs parked in the West End in 2007, FEL researchers blew up replicas of the devices to test their explosive potential.

Specialists use a variety of scientific techniques to characterise explosives, their residues and the components of a device, providing valuable evidence in a police investigation.

After arriving at FEL's complex at Fort Halstead, near Sevenoaks, we are escorted to a briefing with Phil Morley, team leader in forensic support.

Mr Morley, an engineer by training, runs the facility we have come to see - a brand new machine designed to sort through debris from explosion scenes.

The dry debris is poured into a drum for screening

The machine is housed inside an anonymous brick building with a shuttered fa�ade. Set on two levels, large metal drums and ducts gleam under the strip lighting. The equipment is operated by two men wearing white overalls, blue hard-hats and face masks.

The facility will enable large quantities of rubble from a crime scene to be quickly sifted and sorted into different sizes, preparing fragments for examination by forensic case officers.

Security minister Lord West was visiting the new processing facility as part of a general overview of FEL's work. He told BBC News: "When you think of a dreadful explosion such as the one on the tube system [on 7 July 2005]� there was so much debris, so much stuff to pull out, go through and sift. It has to be done very meticulously."

Designed from scratch

Dr Garth Shilstone, FEL group leader, comments: "Sifting through tonnes of debris left in the wake of an explosion is not an easy job, but it is vital in order to gather forensic evidence that could point to the cause of an explosion."

The equipment previously used by FEL was derived from agricultural machinery and required more manual handling. A few years ago, after the 7/7 bombings and the failed 21/7 suicide attacks, DSTL staff were asked to outline requirements for a new debris processing facility.

Services provider Serco was contracted to build it with Home Office funds of �500,000 over two years. Among other things, the requirements emphasised operator health and safety and the environmentally friendly disposal of waste.

Wreckage might arrive at the facility in discrete or in large quantities, depending on the severity of the incident.

Millimetre-sized fragments are examined in fume cabinets

"Debris comes to us from a crime scene via the police. The police will normally carry out a pre-sift activity, so we'd only receive material that needs finer examination," explains Mr Morley.

When it arrives, the debris is usually wet, having being hosed down at the crime scene. Red plastic boxes are filled with up to 25kg of debris and raised to the facility's mezzanine level where the contents can be "tumble dried" in modified cement mixers.

The modifications include new motors allowing their speed to be regulated. They are also equipped with de-humidifiers and extractors to assist the drying process.

Once they have finished drying, the fragments are poured into a screening machine on the ground floor. After activation, the machine's vibrating drum produces a thunderous sound; we are handed earplugs before being treated to a demonstration.

Inside the drum, debris is separated into different grades based on the size of the particles. There are three grades - 12mm, 6mm and 2mm.

The facility has two of these large screening machines set a few metres apart: "The two process lines mean we have the capability to keep one line as a back-up or use both for the quick and efficient processing of large quantities of debris from one or more major incidents," says Dr Shilstone.

If both machines are used, they will process debris from the same crime scene in order to prevent cross-contamination. When technicians have finished with material from an incident, the equipment is stripped down and washed thoroughly - another precaution against contamination.

Staff look for items that "don't belong" in the background environment

Phil Morley acknowledges the possibility that human tissue could find its way into debris handled by the facility. He says staff members receive appropriate inoculations and support from an onsite occupational health team.

After sorting into different grades, the rubble passes through separate ducts to a forensic examining room next door. Here, technicians scour the debris by hand in ventilated search cabinets.

The examining room hosts three of these "fume cabinets", each with a differently coloured worktop: one black, one white, one green. The different inlays assist with visual discrimination of the debris, says Mr Morley.

The fume cabinets are equipped with magnets to quickly identify any fragments of metal. Mechanical elements of the bomb such as the remains of timing devices or wires could potentially be linked to a suspect by police.

Out of place

Mr Morley's team works on behalf of a forensic case officer, who is responsible for the crime scene material. At the beginning of the sifting process, the case officer will have briefed the search team on the background environment from which the material has come.

"We're not looking for anything specific, we're just looking for things that are alien to that background environment," Phil Morley explains. When team members find fragments that "don't belong", they put them aside for a case officer to assess in detail.

Case officers undergo rigorous training for a minimum of four years to equip them with skills necessary to safely handle explosives and to examine bomb debris.

The DSTL laboratory has a scientist on-call 24 hours a day to advise UK police services on explosives. Scientists from FEL can be deployed to the scene of an incident on police request.

Paul.Rincon-INTERNET@bbc.co.uk

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