http://edition.cnn.com/2005/WORLD/europe/07/27/luton.bombs/
this is a CNN article from 07-27-2005 that shows the pictures of some "jar bombs" found in the trunk of a car several days after the first london bombing. these pictures have been posted on several threads here on FR.
the pictures can be viewed on the right sidebar adjacent to the article.
http://www.totse.com/en/bad_ideas/ka_fucking_boom/162155.html
the above link takes you to an internet article on the construction of "acetone peroxide detonators." the reason i went to this web page is that an article in the Belfast Telegraph
http://www.belfasttelegraph.co.uk/news/story.jsp?story=654560
this article contains the sentence:
"The devices, consisting of acetone peroxide packed into jam jars wrapped with a band of metal, were found in a car rented by the suicide bomber Shahzad Tanweer. It was left at the car park of Luton railway station"
and that is why i searched for acetone peroxide.
so, putting the pieces together, we have the stash of bombs in the trunk of a car, where the terrorists can retrieve them as they wish. but the bomb maker did not get good instructions, for, the article on the "acetone peroxide detonators" clearly states:
...."These detonators should be used within 7 days of their manufacture and should be stored in a cool, dry place. .." probably not good to keep them in the trunk of a car.....we have to presume that the terrorist bomb maker made a bunch of these devices, then put them in the trunk of a car, parked somewhere the others could retrieve them as needed....but the mixture was degraded by the passage of time and the heat of the sun....thus explaining why the second attack two week after the first resulted in only partial detonations.....perhaps the bomb maker did not read the instructions on the internet that i copied for you.....
so that is my understanding of what the bombs were, where they were stored, and why the second attack failed.
i am not clear, however on whether these "jar bombs" were detonators for more explosives worn on the suicide bombers themselves, or if they were the entire package.
and, i posted this information a few days ago, without the actual picures on this thread here at FR:
http://www.freerepublic.com/focus/f-news/1453304/posts
and it only got a few comments