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“There’s no way we’re not going to be successful!”


John Durbin says it’s a mighty fine 5-ft. rock core pulled with their 3230DT! John and Josh Caldwell spent a couple days in Kansas training on their new sonic, and successfully pulled this sample at their first rock coring site.

John Durbin says it’s a mighty fine 5-ft. rock core pulled with their 3230DT! John and Josh Caldwell spent a couple days in Kansas training on their new sonic, and successfully pulled this sample at their first rock coring site.

Dolese Brothers in Oklahoma City, OK, was founded before Oklahoma became a state, back in 1902. They have been transforming the state’s raw rock into roads, bridges, skyscrapers, and foundations throughout Oklahoma for 115 years. That also means they are very experienced at knowing what type of equipment they want to work with.

After a review of other drilling equipment and a tour with demos at Geoprobe® HQ in Kansas, John and Josh with Dolese Brothers knew a Geoprobe® 3230DT was what they wanted for their aggregate business.

“We liked what we saw. The people, the service, everything was excellent,” Josh Caldwell, Dolese Exploration Specialist said. “From the company values, to the cleanliness of the facilities, the follow-up, and seeing how people took pride in what they did ... the experience as a whole was awesome!”

Although the rig is new and the guys are just getting experience at the controls, their level of excitement is high. “I really like the three-winch combo we have,” John Durbin added, also an Exploration Specialist. “I was the assistant driller on our old rig, so I was the guy throwing the bits and taking the bits off. This will be safer and easier!”

Josh also added that there is no comparison between the 3230DT and their old machine. The old machine had one safety bar. “The 3230DT has safety’s all over it, and the idea of safety to Dolese is our Number 1 priority,” he said. “There’s so much this rig will do. There’s no way we’re not going to be successful!”

After collecting DT35 sand cores on their first project at one of their Oklahoma quarries, they mobilized the rig to southeastern Oklahoma for several weeks of rock coring. What was it like using the 3230DT pulling full 5-ft. rock cores? “Nothing to it!” Josh said.

Both Josh and John see “unlimited possibilities” with the 3230DT. “I cannot begin to tell you all the jobs that are lined up and the excitement from management on down about this rig!” Josh said. “In the past, Dolese has had to contract out the rock coring.  Never before have we been able to do so much inhouse with one machine!”

Contact Us

1835 Wall Street
Salina, Kansas 67401
Phone: (785) 825-1842

3230DT drill rig combines rotary and direct push functions

3230DT Drill Rig

Combine geotechnical augering and high-speed rotary with advanced direct push capability to offer additional services to your customers, quickly going from coring rock to pushing CPT - all in one drill rig.

Photo Gallery


John Durbin says it’s a mighty fine 5-ft. rock core pulled with their 3230DT! John and Josh Caldwell spent a couple days in Kansas training on their new sonic, and successfully pulled this sample at their first rock coring site.
John Durbin (left) and Josh Caldwell, Exploration Drillers for Dolese Brothers, believe their new 3230DT rig has unlimited possibilities!
Josh Caldwell, Dolese Brothers, is at the controls of the 3230DT in southeastern Oklahoma. DT35 sample cores will make for easier sampling and provide the company with high-quality information to know what’s in their quarries and to know where to blast.

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