Digging trenches for underground piping is so Victorian (not that I’ve got anything against Victorian construction: most of it is still standing).
These days, if you want to lay down pipes without closing the roads and building a trench network, directional boring techniques can be used, but it’s all pretty elaborate, costly and short-range.
Today’s invention is a way to build underground conduits without disrupting the streets above too much.
A hammer (orange) is used to drive a stiff, thin-walled curved pipe underground. The hammer arm length and pipe bend radius can be selected beforehand according to the required distance to be piped.
Segments of pipe are attached together in a sequence (using different bend radii can provide extra directional control).
When the pipe surfaces, it can be driven backwards by the hammer, attached to a reamer of slightly bigger diameter. Finally, a conduit (perhaps containing fibre cables) can be driven through the arc-shaped tunnel and cemented in place.