cool idea, but how are you going to get through all the ack to get to said radar tower, etc? then of course you'd have to have a 5-10 sec wait period while you "arm" said tnt
it would be a cool idea tho for bridges/etc. blow a bridge when a trains over it and you get a train kill.
or better yet, use it against tanks. sneak up behind a tank, plant enough tnt to blow it up. or atleast take out a track.