Hehe no :) you have a central ignition away from the street (hidden in a bush under bridge etc) and it looks often like a sewer cover, if you uncover it you hav

Hehe no :) you have a central ignition away from the street (hidden in a bush under bridge etc) and it looks often like a sewer cover, if you uncover it you have 8-16 holes, on top of them you have to place your correctly encoded metal-plate then you place the igniter in the metal-plate-hole, that igniter fires another igniter and the whole bridge/street goes boom, if its the wrong hole (or wrong encoded metal-plate) you just destroy the main igniter and nothing will and can ever happen. EDIT: The first ignition (the one in the plate) is manually fired often hundreds of meters away thru a fuse-cord, but you can "in theory" automatize it (trip wire or other technique's) witch is absolutely illegal, same with claymore's...they just have holes in the splinter to safe some weight ;) BTW: DON'T try to open those sewer covers, you WILL have big problems in a matter of minutes.