Digging a one square wide trench

Digging 4x4 tiles just to make an underground pipe is kind of a hassle, particularly when there are nearby buildings.
A way to make one square wide trenches would be great. Of course, only a small extractor would be able to do that. It would be a good reason to keep one available later in the game.
There could even be other ways to make use of such trenches: irrigation, below ground conveyors, ...

Or maybe a trench digger? https://www.vermeer.com/getmedia/5ceb040d-7c24-4c9d-af2d-11de41105051/t955-pipeline-trencher-feature?width=525&height=350&ext=.png Having to have some specialized vehicles would be awesome IMO.