BAUER Foundation Applications Series: Why Kelly Drilling Sets the Standard

This story begins 50 years ago. A BG 7 was the first drill rig BAUER built in 1976 and marked a significant milestone for BAUER. Since then, BAUER rigs kept their core design criteria the same—to build the most efficient equipment solution for the most challenging geotechnical projects worldwide. 

In this blog series, we break down some of the most widely used BAUER foundation methods in North America, explaining where each application delivers the most value and why BAUER equipment consistently outperforms alternatives. Insights throughout the series are provided by Gordian Ulrich, ECA Vice President of Bauer Product Sales & Service, whose experience spans decades of real-world foundation construction projects from around the world across all types of geotechnical challenges.

Kelly Drilling: The Foundation of Every BAUER Rig
Kelly drilling is the backbone of BAUER BG rigs and the starting point for understanding BAUER’s design philosophy. From drilled shafts and caissons to fully cased holes, Kelly drilling remains the most versatile and reliable method for deep foundation construction, especially in variable and difficult ground.
Built for ultimate performance 

BAUER rigs are purpose-built to deliver high torque with controlled down crowd and fast rotational speeds, supported by large winches to get the tool and spoils out of the ground. The down crowd in combination with high torque is just one of the several unique features which allow conventional tools to cut through the toughest formations and rip the rock apart instead of just grinding material inefficiently.

Another reason for their high performance is the fact that BG rigs are built robustly. “When drilling hard rock with conventional tools you better have some weight behind your tool which allows you to crowd down. But weight without stiffness doesn’t help you either. If the mast just bends back when applying down crowd you are not getting the force into the teeth of the tool. You are actually damaging the Kelly bar and rotary head at that point. BAUER rigs come with the most robust kinematic systems which allow the energy to be transferred from the motor, pumps, rotary head and winches to the tool, and it is not lost in mast movement. In order to build those high performance rigs you need to fully dedicate your design decisions around building a drill rig and not using an excavator and try to convert it into a drill rig,” Ulrich said. 

Why Sectional Casings Matter
Kelly Drilling, or any drilling method is always about three steps—loosening, lifting, and stabilizing. Applied to the Kelly Drilling application, you first loosen or break up the material with your teeth on the auger, then you lift that auger up using the winch tied to your telescopic Kelly bar and lasty you need to have some form of borehole stabilization measure in place. 

ECA strongly recommends sectional casing systems for Kelly drilling because they provide clear safety, performance, and quality benefits:
•    The safest way to stabilize a borehole
•    Adjustable lengths to match site-specific conditions
•    Operator always controls weight on bit when spinning casing
•    Wall thickness allows the design of exchangeable BETEK casing teeth capable of drilling into rock 
•    Easy maintenance of these teeth with no welding required
•    Adjustable overcuts using different size teeth but they all use the same pockets

Sectional casing also delivers superior verticality of the borehole which is critical if the hole needs to be on target. Because the “stiff” casing leads the drilling, it doesn’t deflect as much as an auger, and the tool is guided inside it. This method provides the precision required for applications like secant pile walls where alignment is critical.

The ECA Advantage
Kelly drilling success goes beyond the rig itself. It is a combination of drill rig, drilling tool and the operator running it. BAUER builds the best foundation equipment, and ECA supports contractors with learning how to use them efficiently and safely. We provide operator training, application expertise and engineering support, all from one source. This integrated approach reduces risk, shortens learning curves, and improves overall jobsite productivity.

See our latest inventory of BAUER Casing and Tooling.