Here is Raina using a Lancelot tool on a bale wall. Notice the important safety helmet and earmuffs. Good job, Raina!
The Lancelot is actually a small chain saw, so it’s not a joke about using safety gear. These are great tools for carving out channels in the bales for electrical wiring or for installing I-beams. And flying bits of straw will go everywhere, so use a dust mask as well under the safety visor.
I-beams get placed in the wall between courses of bales as attachment spots for cabinetry or shelving. There are no wooden studs in a straw bale house that has a timber frame. And the plaster itself is not strong enough to mount anything heavier than a picture frame. So wooden I-beams lie in the walls secured by the weight of the bales above them, and shelves or cabinets can then be attached to these.
Just remember to mark where in the wall you placed the I-beams, so you will know later where to drill! Taking photos is a big help, as well as keeping a written record with the measurements of I-beam placement.