Jumbo drill

ZJ21 / ZJ21B

  • Face coverage 66 sq. m 710 sq. ft.
  • Maximum drifter size JZD27 (27 kW) JZD27 (27 kW)
  • Maximum feed length 4.9 m 16 ft.

Exceptional flexibility and innovation in a common platform

Designed for flexibility and productivity, the ZJ21 is a jumbo drill on a common-carrier platform that makes operator training and adoption on the controls easier and faster. The ZJ21 also offers excellent useable coverage in a small jumbo platform.


The ZJ21B offers a battery-electric driveline option with identical capabilities and features as the ZJ21 model. This electric drilling rig features a modular battery driveline with 83 kWh of onboard energy for the most demanding tram cycles and challenges of underground mining.

  • Usable face coverage up to 66 m2 for getting the most from your application use cases
  • Engineered for higher uptime*
  • Improved operator adoption with simplified training on an easy-to-use, intuitive platform
  • *Higher uptime based on factors that include optimizing drifter and feed service intervals, ground level-maintenance and a boom geometry that limits damage to the front-end

Features and benefits

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Battery powertrain

The ZJ21B drill rig is operated on battery power, which supports our customers on their journey to electrification and sustainability. It features a modular battery driveline with 83 kWh of robust onboard energy for less charging time.
Komatsu ZJ21 ZB21 chassis side view

Smart, opportunistic charging

Leverages preexisting Komatsu technology for a system designed to boost productivity. The electric ZJ21B features Komatsu’s innovative approach to BEV — onboard charging, smart opportunistic charging and 100% compatibility with existing infrastructure.
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Simple, reliable, industry-proven pilot hydraulics

Auto-paralleling gives you 100% accuracy across the face with a maximum of ~1 degree error. Fast cycle times with less setup between holes for increased productivity.
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Common control system

Hydraulic pilot control system with universal drilling and bolting layout. Intuitive, common controls offer advantages in operator adoption, training and performance, as well as maintenance benefits.
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Telescopic and fixed drilling feeds

Lightweight, durable and cost-effective drilling feed delivers superior drill performance and reduced daily maintenance.
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ROPS/FOPS-certified operator enclosure

Designed with zero-harm, ergonomics and comfort in mind. Standard hydraulic height-adjustable canopy. Enclosed cabin option with climate control available.
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Drifters with improved consumable life

Proven energy recuperation, hydraulic dampening, and progressive blow energy technologies help you to get the most from drilling. Drifter model options include Komatsu JZD10, JZD12 and JZD21, manufactured by Montabert.
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Innovative boom geometry

Boom geometry prevents carrier interaction with the feed for added protection and less repair downtime. The ZJ21 and ZJ21B share the bolter boom lift geometry for excellent coverage (up to 66 m2) and allows a drill steel of up to 16 feet to be used inside the 3 x 3 m tunnel dimensions.
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Common carrier design

100% design commonality from rear skirt to boom mounting structure. This innovation provides your operation with versatility while simplifying maintenance and training.
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Application flexibility

Outstanding coverage in a small platform. Unique front-end geometry enables operators to reach lifters and perimeter holes easily, and drill more comfortably on various grades. The ZJ21 and ZJ21B can even back up a two-boom jumbo in larger development headings.
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Productive boom design

Superior aisle navigation in a 3 x 3 m heading (with 16-foot drill steel option), boosting output by pulling longer rounds in small headings.
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Reliable, proven powertrain

The diesel ZJ21 model is powered by a dependable diesel drive Dana T12000 Series with an integrated torque converter and three forward/reverse speed options.
Support you can count on

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