No doubt more speculation and some more actual details will emerge from the trial of the six men who are in court over the failed July 21st 2005 bomb attacks on the London Tube and Bus system.
Panic during the ensuing manhunt, led to the shooting to death of the innocent Brazilian Jean Charles de Menezes by the Metropolitan Police.
The Times reports a few details of the home made bombs:
The Times January 16, 2007
How high street ingredients 'could become weapons for mass murder'
The ingredients of the July 21 bombs were acquired in the high street and required little more than a rudimentary knowledge of chemistry to make up. The shopping list of the alleged bombers included hydrogen peroxide — widely used in hairdressing — chapati flour, nail polish remover (acetone), sulphuric acid, batteries, torch bulbs, electrical wires, cardboard and half a dozen food storage tubs, Woolwich Crown Court was told yesterday.
The components were taken to the flat of Yasin Omar for assembly into improvised explosive devices.
That one-bedroom council flat, on the ninth floor of Curtis House, a tower block in New Southgate, North London, was described at the court as the alleged terror cell’s “bomb factory”.
There, three members of the gang are said to have spent long hours sweating over the electric cooker in the small kitchen, boiling huge panfuls of liquid hydrogen peroxide to reduce the chemical into a stronger concentration.
Mr Omar, who has studied for a GNVQ in elementary science at Enfield College, Muktar Said-Ibrahim and Manfo Kwaku Asiedo were said to have worked in shifts from 5am until 11pm each day.
Two large saucepans and a frying pan that were recovered from the building revealed, after scientific examination, clear traces of concentrated hydrogen peroxide.
The liquid peroxide was the most important ingredient. Increasingly it is used in the hairdressing trade as a cream but the gang was said to have identified outlets in Finchley, Tottenham and Finsbury Park where they could buy it as liquid in an 18 per cent concentration. Between the end of April and July 5, 2005, they are alleged to have bought 443 litres in either one-litre or four-litre containers.
Therefore this was not an improvised "copycat attack" following the July 7th bombs.
The peroxide was to form the bulk of what Nigel Sweeney, QC, for the prosecution, described as the main charge of the bombs.
Mr Sweeney said: “The explosive was intended to consist of liquid hydrogen peroxide, concentrated, mixed with chapati flour, the flour being the fuel that would burn and the hydrogen peroxide providing oxygen, so that when fired by a detonator the mixture would explode.”
This concoction was placed inside a series of 6.25-litre plastic kitchen storage tubs that were sealed with a lid. A hole was cut in the bottom of the container, into which a detonator was inserted.
443 litres of 18% hydrogen peroxide solution.
5 x 6.25 litre plastic tubs
Could they have made rather more than 5 bombs with this amount of hydrogen peroxide ?
The detonator was made from a small carboard tube packed with the homemade explosive triacetone triperoxide, better known as TATP.
This was, in turn, to be set off with a small torch bulb attached to one end of the TATP tube and linked by wires to a 9-volt battery, the court was told.
If they could make TATP for the detonators, why not for the whole bomb like the July 7th bombers ?
There seems to be reports of anything like the industrial refrigerator unit which the July 7th bombers installed in their Leeds bomb factory.
How they did not set themselves on fire just using a saucepan or frying pan and an electric cooker, to concentrate the hydrogen peroxide solution, is a mystery.
Extensive tests were carried out by the Forensic Explosives Laboratory using the bomb recipe that was allegedly deployed on July 21 and a variety of detonators. In all cases the devices proved to be “functional”.
Is the Forensic Explosives Laboratory still at Fort Halstead near Sevenoaks in Kent , part of the Defence Science and Technology Laboratory, i.e. the bit of the UK Government's military research and development that was not privatised as Qinetiq ? Conceivably the new Counter Terrorism Centre at Porton Down (.pdf) in Wiltshire, also under the DSTL, might also have been involved in analysing or trying to replicate the bombs.
On July 21, it was alleged, something had gone wrong with the mixture of the main charge in all four bombs that the gang tried to detonate. Another bomb was abandoned.
With one of the accused having left the country 6 weeks before the attack, and another having ditched his bomb on the day of the attack, the possibility of deliberate sabotage of the main explosive charge chapati flour (any finely divided fuel might have done instead) and concentrated hydrogen peroxide oxidising agent should not be ruled out.
There has been a quite a bit of reporting and speculation as to what extent the July 7th bombers had been under police or MI5 surveillance, but there has been much less about any actual surveillance of this gang of East African refugees and immigrants.