The MX Trench Construction Project

As an important part of the concept validation phase of the MX Advanced ICBM development program, Air Force System Command's Intercontinental Ballistic Missiles (ICBM) Program Office developed and demonstrated large trenching and cast-in-place equipment for placing many miles of buried concrete tunnel rapidly and economically. A tunnel or "buried trench" containing a mobile ICBM is one of the candidate basing models for MX. Upon remote command, the cannister housing the missile would break out of its concrete tunnel and earth overburden by erecting itself to a suitable angle and then launching the missile. The ICBM Program Office developed two each trenchers, cast-in-place machines, and breakout mechanisms, as well as a mobile concrete truck unloader. The machines were demonstrated in varying soil conditions in the southwest US. The breakout mechanisms were demonstrated nearby as well. This chapter describes the development program, the machines, and the demonstrations. No manuscript received