We had a problem in that the basement of our building was partially covered with dirt, and concrete window wells held that back from the windows used to light light into the rooms. It would have been prohibitively expensive for us to pay to remove the concrete conventionally, but it turned out that with the construction of a set of simple tools (there were no really good high-pressure swivels available at the time – hence the orbiting action of the nozzle as it moved over the slot) we were able to cut the walls relatively simply and quickly.
Figure 1. Cutting the window well protecting the wall. (Over 30 years ago)
In this first video segment I mis-spoke when I spoke of the nozzle as rotating, it was actually being moved over the wall in an oval pattern, as will be more evident in the second segment (below the fold).
As noted in the video the support platform for the rig is a simple platform shop lifter and the rig is held on the platform with a couple of G-clamps. There is relatively little reaction force and so the rig can be made very simply out of available tools. The lesson we learned very early on was that the rebounding water carried the removed cement and aggregate particles, so that PPE was important, and keeping folk back even more so.
After the window wells were removed we had to cut an entrance through the main wall of the building – about 14-inches thick.
Figure 2. Cutting the main wall behind the window well.
Note that it was not necessary to remove the glass in the window until after the walls had been cut, and it was time to remove both window and wall.