Vietnam War, Operation Carolina Moon
While reading a book about the US bombing campaign to down the Thanh Hoa Bridge during the Vietnam War yielded a very good account of Operation Carolina Moon....using C-130E Transports to drop five River Mines with an explosive charge each yielding the equivalent of One Kiloton explosive force 20-30 feet above the device as it floated down the Song Ma River.
The mining was done at night, hand flying at 100 feet AGL and 150 knots until about a mile and half from the bridge then "popping up to between 400-700 feet to drop the five Mines by parachute.
As if that was not bold enough....one must recall the Thanh Hoa Bridge known as the Dragon's Jaw by the Vietnamese was one of the most heavily defended targets in all of North Vietnam with small arms, AAA, Missiles, and at times....Mig Fighters.
The first attack went as planned except there was no damage to the bridge.
The bright sparks in command ordered a repeat attack the very next night....resulting in the loss of the attacking C-130 with all of its Crew.....and the bridge was undamaged.
The book entitled "The Dragon's Jaw" by Stephen Coonts and Barrett Tillman, recounts the US Air Force and Navy's bombing campaigns in North Vietnam with the writer keeping a focus on the one bridge.
I don't know about you....but I tip my hat to those C-130 Crews....the thought of trundling down a river at night....at a 100 feet...and a mere 150 KIAS in a C-130.....alone is a rather impressive feat but to do it at the Thanh Hoa Bridge during the War......no thank you!