> what if the Army could cut and cover 100 meters of precast tunnel segments in a day

If you have the precast tunnel segments to do that why wouldn’t you just plop them down on the ground? What benefit does cutting and covering provide?

Also how would you protect your construction crew and construction supply chain as they are slowly plodding along 100m a day?

Once built, could this cut and cover tunnel be disabled by hitting it anywhere along its length with a “bunker buster” amunition? Or a backpack full of explosives and a shovel? Or a few cans of fuel down the ventillation and a lit rag?

And if the answer is that you will patrol the topside to prevent such meddling, how do you protect your patrols? And if you can protect them why don’t you do the same for your logistics?