it has taken over a week to prepare my house to be pumbled, but pumbling is happening today, and boy howdy
they brought what looks like one fucking inch steel cable. i can't imagine the tensile strength on this shit, but they're going to hook it up to this massive steel torpedo (the "bursting head") and drag it through the existing pipe. the taper on the leading end will detonate the concrete sewer line and push it into the dirt; they need a cable this stout because it's going to have to fight the pressure of the earth on all sides.
the ass end has a set of interior jaws spread by another taper. they're gonna push the new pipe (6" HDPE with half-inch walls, I think; hubba hubba) onto the jaws, which will grip it from the inside, replacing the old pipe with new pipe as they pull it through.
i was thinking at first that the second taper was threaded, but that would be an obscene amount of force for threads to withstand, so i wonder if it's just free-floating and the tension from the pull cable just tugs on the taper. would be problematic if they had to release tension mid-pull I suppose, the pipe could come loose.
in any case: god damn, what a bitchin setup.
