Surface rigs get most of the attention, but a large share of exploration and definition drilling happens underground, where the working space is a drift or a chamber rather than an open pad. Headroom is limited, ground conditions change from one heading to the next, and holes often need to go up or sideways rather than straight down. This week we're featuring the UN1000, our underground drilling rig, which is designed around exactly those constraints.

Drill in Any Direction

The UN1000 drills at any angle from 0° to 180°, which means downward, horizontal, and upward holes can all be drilled from the same rig. Rated depths depend on both hole size and direction:

• B size: 1,300 m downward, 1,300 m horizontal, 800 m upward
• N size: 1,000 m downward, 1,000 m horizontal, 500 m upward
• H size: 500 m downward, 500 m horizontal, 300 m upward

For underground programs, that flexibility matters because fan drilling and angled holes from a single set-up are routine, and a rig that only drills well in one orientation forces a compromise on the drilling plan.

Pressure Applied in Both Directions

One of the UN1000's defining design choices is its drilling pressure system. The main oil cylinder applies pressure bidirectionally, rather than pushing in one direction only as in traditional single-side pressure designs. According to the manufacturer's specification, this keeps operation stable and safe in complex terrain, and it removes the need for weighing during operation, which is a significant advantage over the traditional pressure-increasing and pressure-decreasing approach.

The feed system provides a 1.8 m feeding stroke at 0.8 m/s, with 108 kN of both feeding force and lifting force.

Simple, Safer Rod Handling

Rod handling is where underground work gets cramped and risky, and the UN1000 addresses it directly:

Linked holder. The holder is linked to the rest of the system, which keeps operation simple and effectively prevents the risk of drill pipe falling. It uses a nitrogen oil cylinder with 118 kN of axial clamping force and a maximum through-hole diameter of 170 mm with the cover removed.

One-handle operation. Make-up, break-out, rapid feeding, and rapid retraction can all be carried out with a single handle, and a built-in floating function ensures threads aren't damaged during make-up and break-out.

Three construction modes. Drilling, rod feeding, and rod retrieving each have their own mode, and the chuck and holder work automatically and in coordination according to the procedure for each, so the operator isn't manually sequencing the two.

Power and Drive

The UN1000 is driven by a 75 kW electric motor running at 1,450 rpm, which suits underground environments where diesel exhaust is a concern. The hydraulic system includes a main pump delivering up to 145 L/min at 30 MPa and an auxiliary pump delivering up to 65 L/min at 24 MPa.

At the spindle, the rig delivers a maximum torque of 1,650 Nm at speeds from 0 to 1,400 rpm, through a 93 mm spindle through-hole.

Winch and Mud Pump

The winch provides 12 kN of lifting force on an empty drum and 4 kN on a full drum, with 1,300 m of rope capacity on 5 mm steel wire rope. Rope speed is 250 m/min on a full drum and 90 m/min on an empty drum, with a working pressure difference of 20 MPa. The mud pump is rated at up to 10 MPa and 160 L/min, matched to the rig's B, N, and H hole sizes.

Small Footprint, Modular Layout

Underground, a rig has to fit through the same space it works in, and the UN1000 is built accordingly. The main rig measures 3,800 * 980 * 1,890 mm, the power station 2,080 * 1,100 * 1,660 mm, and the operation platform 420 * 700 * 1,100 mm. The bed weighs 1,900 kg, the power vehicle 1,100 kg, and the operation platform just 80 kg, roughly 3.1 tonnes across the three units. Splitting the system this way keeps individual components manageable to move and position within a working heading, and the separate operation platform lets the operator control the rig from a position suited to the heading.

A Step Up: The UN1500

For programs that need more depth or torque, the UN1500 uses the same design principles with a larger specification: 90 kW drive, up to 2,450 Nm of torque, a 188 L/min main pump, and rated depths of up to 1,500 m in B size (downward and horizontal), 1,100 m in N size, and 600 m in H size, with 1,500 m of rope capacity on the winch.

Who It's For

The UN1000 fits underground exploration and definition drilling where a rig has to work in confined space, in more than one direction, with a small crew and a minimum of manual rod handling. If you're planning an underground program and want to talk through whether the UN1000 or UN1500 fits your headings, hole sizes, and depths, our team is happy to go through the specifications with you.