3126GT Geotechnical Drill Rig

Six functions along the 28-inch centerline head side shift simplify traditional geotechnical applications — augering, mud rotary, SPT, Shelby tubes, hard rock cores, CPT – and even direct push. Features GH63 percussion hammer 4-speed rotary head with 4,000 ft-lb, DH104 hands-free automatic drop hammer, CPT push/pull assembly, and a rod grip pull system. Head shifting speeds up drilling and minimizes the time driller spends in danger zone.

With 170-lb, 300-lb, or 340-lb options, the hands-free automatic drop hammer reduces strain when driving SPT samples. Advance borings for SPT testing by augering, driven casing and sampling, or wash boring.

The winch mast telescopes into place, allowing for flexible height options based on work environment. This also adds a layer of safety during setup when working near overhead power lines or other obstacles. 

Taller telescoping winch mast specifically designed for geotech work with heavier winch options, 105-inches head travel, and 36,000-lbf push and 48,000-lbf pull at the head-feed cylinder means greater pull back – ideal for drive and wash – and head travel. Allows tripping out of 20-foot lengths of rod when combined with 3-foot extension. 

Align the probe cylinder and tool string on a straight – or angled – path to the subsurface while the machine remains stable with the built-in oscillation, standard on all machines. 

Drill mast features extend, swing, mast dump, oscillation, and fold. Mast dump provides 36.5 inches of vertical travel to allow room for a mud pan. Optional outriggers available.
 

A dual winch option is typically configured with a 6,800-lbf winch for the more difficult pulling and an 1,800-lbf. with quick-change hook. When ready to switch from pulling to coring, simply swap out the swivel hook for the overshot clevis installed on your overshot and continue working. It’s quick, simple, and can all be done by hand.

Additional winch options include 2,500-lbf and 1,100-lbf. 

Also available is a third winch with 1,100 lbs of line pull, well suited to trip additional tooling out of the hole. Equipped with the Geoprobe^® exclusive quick change hook, operators can switch over to wireline coring in seconds. 

While customers are proving the rock coring capabilities of the 4-speed rotary head on the 3126GT, some customers have requested more bottom-end torque for their geotech jobs. True to form, Geoprobe^® responded by designing the 6-speed GR6.5 rotary head with 70 percent more torque.

"The GR6.5 has 6,800 ft-lbs of torque, which is 2,800 ft-lbs more than the GR4.1 on a typical 7822DT, without sacrificing top-end speed (720 rpm)," Ryan Kejr, machine engineer lead, said. "We also added an additional intermediate-speed range, which further enhances the unit's wet and air rotary capabilities."

All functions are at your fingertips in a well-organized, compact control panel. The systems display provides real-time systems analysis and a suite of built-in diagnostic tools. Also included are system safeguards that protect the main engine and hydraulic components when important operational parameters are compromised.

Hands-free rotary and head feed controls on the 3126GT reduce strain on driller when completing applications like mud rotary. CPT feed rate and hydraulic limit functions are standard.
 

The 7-inch single breakout firmly grips casing with a clamp force of up to 21,000 pounds of force. The breakout can be positioned either under the hammer or the rotary drive, as well as swung away from the machine.

An optional Coring Upgrade Kit (217024) is also available to firmly grip thin-walled 2.75-inch OD casing without damage to the casing. The kit includes formed jaw pads and a circle wrench with carbide inserts.
 

The rear blade can be used for tool transport. During site setup, a tooling drop rack can be placed in front of the machine for easy access. This eliminates the need to walk around the machine for tooling, which saves time and conserves energy in the field. 

Ample, well-spaced storage includes two stacked tool boxes, helper-side storage compartments, and control panel storage bin/trays.

The pivoting winch mast option for the 3126GT is designed for customers who prefer to haul their rig in an enclosed trailer or truck, lowering the transportation height by 15 inches.

"This reduces the transport height of the 3126GT from 114 inches to 99 inches," Ryan Kejr, machine engineer lead, said. "We accomplish this with a simple, mechanical ratcheting actuator. This is easily accessible from the ground when the drill mast is in transport position."
 

MWD (Measurement While Drilling) is a method of collecting digital data from the drill rig to log parameters pertaining to drilling operation. These methods are common in other parts of the world where it has been standard to log or measure drilling parameters in the oil, gas, and mining industries.

Starting in 2024, Geoprobe^® 31 series geotechnical drill rigs are MWD capable. The option can be added at any time to include an MWD kit allowing drilling parameters to be recorded

• Common parameters for MWD are crowd force, torque, penetration rate, mud pump pressure, mud flow rate, holdback pressure, head rotation speed and hole depth.
• Follows ISO 22476-15 International Standard for MWD.
• All sensors utilized are common Geoprobe^® components with proven experience and reliability.
• MWD sensors are easily integrated into existing rig electronics to maximize usefulness of sensor data being currently collected.
• Calibrated outputs are delivered to the data logger of your choice via J1939 CAN Bus network on the drill, simplifying the rig’s wiring.

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