July 07, 2005

Cellphones in the Tube?

A couple thoughts on today's vicious London bombings:

The apparent shutdown of the London cell network probably has more to do with overuse by users, or possibly expanding the emergency frequency range, than preventing further attacks... cellphones aren't a reliable remote triggering mechanism in subways, unless the metro and trains themselves are rigged for wireless.

The City of London recently announced plans to put wireless antennae in the Tube, but presumably coverage is still spotty at best... they may well reconsider those plans now.

With remote detonation by cellphones an unlikely possibility, that leaves a timed detonation as the most likely trigger for the London subway bombs. (note: see below)

The interesting leftover is the bus attack. Half an hour later than the others, and in an location that doesn't indicate a lot of planning (logically, you'd think you'd want it to go off on the lower deck of the bus for maximum effect). A second-wave attack (to get people using the bus instead of the now-dangerous subway) seems somewhat illogical, too... the better place for that would be close to an entrance, and besides, the bus was going towards an affected station (Russell Square), not away from one carrying survivors. A likely possibility is that this was a fourth subway bomb that failed to be planted in time (would you want to be in the subway tube with a bomb with a timer anywhere within fifteen minutes of its planned detonation time?) and switched by its carrier to a secondary target. In which case, it probably could have been worse (the subway fatalities so far have averaged 11 per bomb, while the bus explosion may have killed as few as two).

UPDATE: Just to be clear, this doesn't mean they might not find cellphone parts in the bomb debris. The Madrid bombs were detonated with cellphones, but using a cellphone timer function to create a timed detonation: something similar is certainly possible in this case. Shutting off a cellphone network will have no effect on such a device, obviously, and it will work fine even deep in a subway tunnel. This is different from a typical Iraqi IED cellphone bomb, which uses the cellphone for remote command detonation of the device by its planter just as an American vehicle passes over it, and so needs to have the ability to make the wireless connection.

UPDATE, Friday: We're now up to 36 dead and climbing for the three subway bombings, and 13 dead for the bus attack, possibly mooting one of the subpoints, above.

Posted by BruceR at 02:03 PM