These look like atlas F silos. If I recall it took something like 2 hours to get the 75 ton doors open, the rocket lifted out on an elevator then fueled on the surface before the could launch.

The idea was these location could withstand a direct nuclear blast. Inside the missile tube the whole lift assembly and missile were attached to the rock via massive springs to absorb the shock waves from a direct strike, the control room were the men were simmally suspended but on pneumatic air shocks. Ceazy stuff.