Komatsu ZB21 ZJ21Komatsu introduced the ZJ21 jumbo drill and the ZB21 bolter for underground hard rock mining. Both use a groundbreaking common carrier and control system, and offer improved productivity and lower capital costs over predecessor competition.

The common carrier and controls allow conversion from the jumbo to the bolter, or the reverse. Conversion requires a kit from Komatsu, up to three shifts, a dedicated space for the entire timeframe, and an overhead crane.

An operation with both machines can benefit from efficiency gains and reduced costs, Komatsu reported. Maintenance can be streamlined and seamless. Inventory is reduced and inventory management is simplified. The units are designed for ground-level maintenance of all major functions. The common controls allow for an operator to easily transition from operating one to operating the other.

The rig has a conventional mechanical powertrain. Not including the boom, it is 1.7 m wide, 6.1 m long, and 2.8 m high. It is designed to tram in a 3-m by 3-m heading, while capable of stability on a 90° turn.

The ZJ21 is the longest machine in its size class, but can still make a 90° turn in a 3-m by 3-m heading. It delivers up to 66 m2 of face coverage, and is capable of drilling ramps, crosscuts, and truck loading bays. In a main development drift, it could back up a two-boom jumbo that was down for maintenance, Komatsu reported.

The drifter is manufactured by Montabert and offers best-in-class consumable life and operating costs.

The ZB21 allows operators to bolt in any direction, and can handle up to an 2.4-m bolting head. The entire bolting cycle can be performed from inside the enclosure using an integrated screen handler and the chemical injection system.
The bolter has a vertical reach of 7 m, a horizontal reach of 7.5 m, face coverage of 50 m2, and a boom weight of 2,200 kg. It is designed for use in smaller mine sections, and is capable of face bolting using mechanical, frictional, chemical and Swellex bolting technology, Komatsu reported.

The feed has comparatively few moving parts and therefore low maintenance requirements.

The units are the first two of 14 planned new models.