Looks like angle grinder cuts to me. You could also go after it with circular saw with abrasive blade or sawzall.
I could get through a couple slats in ~15 minutes will battery powered tools.
Sauce - construction/demolitionfag
>are those post SOLID steel ?
No. Looks like 1/8 - 3/16 steel filled with sand. Sand would act as a heat sink to make torch cuts harder.
Holy crap thats a lot of traffic!
>I want a VERY STRONG WALL
>NO COMPROMISE
We could kill two birds with one stone, and use the nuclear waste stockpiles to make a plutonium/steel alloy.