the drilling experts


The InsideAir™ drilling rig, commonly referred to as ‘skid’ drilling, was designed, engineered, and developed here at United Drilling, and is maintained by our personnel. It is a unique, specialty piece of equipment in our industry. Inside drilling historically received the nickname of skid drilling because older style indoor drilling rigs were transported on a pallet or a ‘skid’. This method of drilling or transportation no longer applies to United Drilling, but the name has stuck. The InsideAir, trademarked to United Drilling alone, can fit through a standard 30” doorway and can access any hoistway that a wheelchair can access. It does not create slurry while drilling; it does not utilize the rails and does not require any power from the General Contractor.

The InsideAir is supported by the hoisting beam at the top of the elevator shaft and is powered by a 1600 air compressor which is towed behind the support truck to every job site. While the support truck and air compressor do require 70’ of parking they allow us to work without requesting power from the General Contractor. Compared to other inside drilling rigs, the InsideAir is cleaner, faster and more efficient. An added benefit is the size; this rig has the ability of full access through a standard doorway. The InsideAir can drill as deep and as large as our outside rigs; we have drilled a handful of 36” diameter holes and as deep as 91’ inside existing buildings. While the hole is being drilled we shovel the spoils into 55-gallon drums; these drums are lifted out of the pit and rolled outside of the building. The General Contractor can then select to give us a dumpster for spoils placement or have them placed at a predetermined location onsite. Spoils removal from the job site is available at an added cost.

The cost for drilling inside a building is higher than standard truck drilling due to several factors: equipment, increased labor, increased time, and research and development. If you want to see the rig in action, please call or email our office and we will let you know the next time we are in your area with an InsideAir.