The 220 ton heavy cap to the silo could be slided with the means of a very powerful motor and gearbox. It took some five minutes to slide the cap. To me, this seems like a vulnerable point - destroying this mechanism or by other means obstructing it, the missile could not be launched. Given the weight, just a small crack in the concrete or jam to the mechanism would be enough...

This particular site is unique in the means that there is still metal left. Other installations I've seen are completely stripped. Even rebars and individual bolts have been removed by looters selling the scrap