You forgot PVC pipe.
I remember reading an article I think in The Economist or something which I don’t normally read but it went into how the cartels had invested in horizontal fracking drill machines to send small PVC pipe hundreds of feet under the Border and these micro tunnels had twine pulley systems with a little cart pulling bags of drugs from one side to the other, kind of like Steve McQueen in the Great Escape except with weed and the US border
