- Pull-back
- 35,000–65,000 lbs
- Power
- 290–513 hp, Stage 5
- Rods on board
- Up to 1,200 ft
- Methods
- Mud · Air · DTH
The rig geothermal contractors measure others against
GT Series geothermal drilling rigs are built for one job above all: putting ground loops in fast, safely and every day of the week. They drill vertical boreholes for ground source heat pump (GSHP) systems on domestic and commercial sites around the world, and every model drills mud, air or DTH hammer without a change of rig.
The range runs from the compact GT35 to the GT65 and the dual rotary GT45DR and GT65DR, with Cummins and Doosan Stage 5 power, Eurodrill top drives and between 35,000 and 65,000 lbs of pull-back. Every rig carries our own rod rack and loader as standard — the most robust, reliable and safest rod handling system on the market — because on a loop field, rod handling is where the hours and the injuries go.
We are drillers as well as a manufacturer. Decades of refinement in hydraulics, cooling and heavy-duty components come from our own crews and our customers’ — which is why the GT45 has become the benchmark geothermal rig that others try to match.
How deep each GT rig drills
Every string is drawn to scale, to the depth that rig’s spec sheet rates it. Dashed is further depth the sheet says it can reach.
- GT35 650 ft rated · 1,300 ft+ capable
- GT45 800–1,000 ft
- GT65 1,000 ft and beyond
- GT45DR 850 ft and beyond
- GT65DR 1,000 ft and beyond
Rated depths from each rig’s September 2026 spec sheet. Actual depth depends on formation, drilling method and tooling.
GT Series single-rotary rigs
65,000 LBS
PULL-BACK513HP
CUMMINS ENGINE25FT DRILL RODS
1,200FT ON BOARD RODSEURODRILL TOP DRIVE – RH24X
TORE OF 17,700 LB-FTDRILL BEYOND
1,000FT
46,000 LBS
PULL-BACK380HP
CUMMINS ENGINE20FT DRILL RODS
880 FT ON BOARD RODSEURODRILL TOP DRIVE – RH16X
TORE OF 11,897 LB-FTDRILL BEYOND
850FT
35,000 LBS
PULL-BACK290HP
DOOSAN ENGINE20FT DRILL RODS
880FT ON BOARD RODSDRILL BEYOND
650FT
GT Series dual-rotary rigs
46,000 LBS
PULL-BACK380HP
CUMMINS ENGINE20FT DRILL RODS
880FT ON BOARD RODSEURODRILL TOP DRIVE – RH16X
TORQUE OF 11,897 LB-FTEURODRILL CASING DRIVE – RH26X
TORQUE OF 14,976 LB-FT
65,000 LBS
PULL-BACK513HP
CUMMINS ENGINE25FT DRILL RODS
1,200FT ON BOARD RODSEURODRILL TOP DRIVE – RH24X
TORQUE OF 17,700 LB-FTEURODRILL CASING DRIVE – RH40X
TORQUE OF 29,500 LB-FT
The GT65DR, GT45DR, GT65 & GT45 rigs are all fitted with Eurodrill heads as standard, widely accepted as the best on the market
Single or dual rotary?
Single rotary
A single-rotary GT drills with one top drive and handles most geothermal ground: stable overburden, rock close to surface, open-hole or cased with the table and clamps.
Dual rotary
A dual-rotary GT45DR or GT65DR adds a casing head that advances casing while the top drive drills inside it — up to 29,500 lb-ft (40 kNm) of casing torque. It keeps the borehole stable through collapsing overburden, gravels and the formations that stop single-rotary rigs.
Built in from the start
- Rod rack & rod loader, as standard
- Our own rod handling system is fitted to every rig — the most robust, reliable and safest on the market, and the reason crews ask for it by name.
- Sideshift sliding head
- The drill head slides clear of the hole, with adjustable high/low rotation and torque so one rig covers soft ground and hard rock.
- Clamps with a 12½ in opening
- Double or triple clamps, one rotating, opening to 12½ in (320 mm) — triple clamps earn their keep when you are running a lot of casing.
- Height-adjustable working table
- Set the table where your crew works best. It doubles as a casing extractor.
- Centralizing rollers & breakout wrenches
- Hydraulic centralizing rollers and a hydraulic breakout chain wrench, with a sliding rod wrench available for crews who would rather not rely on clamps alone.
- Two independent winches
- A main winch and a wire/sandline winch, independent of each other, rotating through 90° and extending.
- Angled drilling
- Drill at 20° as standard and up to 45° with the table travel moved.
- Dual controls, remote travel
- Run it from the lead driller’s side, the second man’s, or both. Tracks travel on a wireless remote and four hydraulic legs lift and level the rig.
GTData: the rig, live
Live data at the driller’s controls and on a cloud dashboard, with alerts that catch bit wear, formation changes and maintenance early.
- Rate of penetration (ROP)Tracks drilling progress; an alerted drop identifies bit wear
- TorquePrevents overloading; flags formation changes or stuck pipe
- RPMOptimizes bit performance and drilling efficiency
- Mud pump pressureEnsures hole cleaning and formation stability; avoids stuck pipe
- Mud volume / flow rateMonitors fluid usage; supports environmental compliance
Questions drillers ask
Something we have not answered? Ask a driller.
What is a geothermal drilling rig?
A geothermal drilling rig drills the vertical boreholes that carry the ground loops of a ground source heat pump (GSHP) system. It needs to drill many holes quickly through changing ground, handle a lot of rod safely and move between holes on a tight site. The GT Series is built around exactly that: tracked, self-levelling rigs with our own rod rack and loader, drilling mud, air or DTH.
How deep can a GT Series rig drill?
The GT35 is designed for boreholes up to 650 ft and can reach beyond 1,300 ft (400 m). The GT45 is ideal for 800–1,000 ft, the GT45DR drills beyond 850 ft, and the GT65 and GT65DR are built for 1,000 ft and beyond. Real depth always depends on formation, method and tooling — tell us about your ground and we will tell you what to expect.
Do I need a single rotary or a dual rotary rig?
Choose single rotary for most geothermal ground, where the hole stands up or casing can be run from the table. Choose dual rotary — the GT45DR or GT65DR — where overburden collapses or you are drilling through gravels and boulders: the casing head advances casing while the top drive drills inside it, with up to 29,500 lb-ft (40 kNm) of casing torque.
Which drilling methods can the GT Series use?
Every GT rig drills mud rotary, air rotary and DTH hammer. For mud, the rigs are configured for dual mud pumps — two centrifugal pumps, or one centrifugal and one MP1200 triplex piston pump (317 gpm at 580 psi). For air and hammer drilling they carry a water injection mist pump and a DTH lube system.
Can GT Series rigs drill water wells too?
Yes. Every GT spec sheet lists the rig as a geothermal and water well drill rig, and the same features that make a fast loop-field rig — rod handling, mud and air capability, casing handling — make a capable water well rig.
How much rod does a GT rig carry?
Between 800 ft and 1,200 ft of rod on board, depending on the model and rod size — 20 ft rods on the GT35 and GT45, 25 ft rods on the GT65 and dual rotary rigs. For holes deeper than the on-board capacity, the TC tracked carrier can be fitted with a second rod rack and loader.
What support comes with a GT rig?
On-site commissioning, training and inspections by our North American and global service teams; a service kit covering the first 2,000+ operating hours; parts stores in New Hampshire, Ontario and Tonbridge (UK); and remote diagnostics through GTData. Support packages can be built around your fleet.
Can I see a GT rig working before I buy?
Yes, and we encourage it. We arrange site visits to see GT rigs on live commercial projects, so you can watch one drill and talk to the crew running it.