“Blasting – substitute for delay caps – The non-availability of delay caps called for the innovation of some type delay firing system. The problem was successfully solved by removing the rheostat from a fan speed control box so that five (5) circuits could be fired in rapid sequence by simply turning the knob.” – Lieutenant Colonel John R. Manning, “Operational Report – Lessons Learned, Headquarters, 168th Engineer Combat Battalion, Period Ending 31 July 1967 ”