Rock bolting rig

01

Match coverage, hole size and bolt type

Siton describes its DS2 hydraulic rock bolting rig (narrow type) as combining drilling, bolting and meshing for mine ground support, customisable for pipe-seam (friction) bolts, resin bolts or a combination. It lists overall dimensions of 9,397 × 1,600 × 2,080/2,780 mm, coverage from 3.5 × 3.5 m to 5.1 × 5.6 m, hole diameters of Φ32–64 mm, drill steels of 2,175, 2,475 and 2,700 mm giving hole depths of 1,950, 2,185 and 2,460 mm, drilling speed of 0.8–2 m/min, a WHC25 rock drill (WHC28 optional), ±180° feed roll-over, 1,200 mm boom telescope and 410 mm feed extension. [1]

The DS2 carrier has a 56.5 kW diesel engine, ±38° articulated steering, 10.00-15 tyres, 9 km/h tramming speed, 265 mm ground clearance and wet multi-disc service brakes; the electric power pack is 55 kW, total installed power 62 kW at 380 V, with air supply up to 11.6 L/s at 0.8 MPa, water up to 50 L/min at 2.5 MPa, a 180 L hydraulic tank and a total weight of 12,500 kg. [1]

Editorial calculation: drill steel length minus hole depth is 225–240 mm across the three steels (2,175 − 1,950; 2,475 − 2,185; 2,700 − 2,460); 11.6 L/s of air is about 0.70 m³/min. [1]

Give the supplier the drive or tunnel dimensions, bolt pattern and spacing, bolt types and lengths, mesh handling, rock type and strength, hole diameter, power supply (voltage, frequency), water and air available, ventilation and emissions limits, gradients, and service support.

02

Check the ground-support rules the bolts must meet

In US metal and nonmetal underground mines, 30 CFR 57.3203 requires a manufacturer's certification that rock bolts and accessories covered by ASTM F432-95 were made and tested to it; bearing plates where needed; finishing bits within ±0.030 inch of the recommended hole diameter for the anchor; no damaged or deteriorated grout cartridges; tensioned bolts set to at least 50 % of the lesser of bolt yield or rock anchorage capacity, and no more than either; torque checks on the first, every tenth and the last bolt each shift; and, where grouted fixtures can be torque-tested, the first fixture in each workplace tested to 150 ft·lb. [2]

In US underground coal mines, 30 CFR 75.204 adds requirements that bear directly on the rig: tensioned bolts that form a beam of laminated strata must be at least 30 inches long, and suspension bolts must anchor at least 12 inches into the stronger strata; test holes must reach at least 12 inches above the anchorage horizon of mechanically anchored bolts; in each bolting cycle the first tensioned bolt installed by each drill head must be measured for torque or tension, then at least one in every four; angle-compensating devices are required where bolts are installed more than 5° from perpendicular to the bearing plate; and the first non-tensioned grouted bolt of each cycle must withstand at least 150 ft·lb without rotating. Bearing plates against the roof must be at least 6 inches square (5 inches where the roof is firm and not susceptible to sloughing). [3]

Editorial calculation: 150 ft·lb is about 203 N·m, and ±0.030 inch is about ±0.76 mm, the tolerance set for finishing bits. [2]

Editorial calculation: 30 inches is 762 mm and 12 inches is 305 mm, so a rig whose shortest hole is 1,950 mm, like the DS2, covers the minimum beam-bolt length; the one-in-four torque measurement per drill head is a reason to ask whether the bolting head records installed torque. [3] [1]

Operator noise is a second rig-level check. Peterson and Azman of NIOSH's Pittsburgh Mining Research Division (Seminars in Hearing, 2023) give the MSHA permissible exposure level as an 8-hour time-weighted average of 90 dBA with a 5 dB exchange rate, against a NIOSH recommended exposure limit of 85 dBA with a 3 dB exchange rate. On roof bolting machines, NIOSH's beamforming analysis identified the drill steel, excited by the bit cutting rock, as a significant noise source; underground tests of a drill bit isolator cut noise at the operator's location by 3 dB against baseline drilling, and NIOSH lists a collapsible drill steel enclosure and a drilling chuck isolator as further controls for roof bolters. [4]

Editorial calculation: with a 5 dB exchange rate, the 90 dBA PEL allows 8 hours, 95 dBA allows 4 hours and 100 dBA allows 2 hours; a 3 dB cut at the operator therefore moves exposure by a little over half an exchange step under MSHA's rule, and halves it under the 3 dB NIOSH criterion, as the paper itself notes. Ask the supplier for the operator-position sound level while drilling and which drill-steel or chuck noise controls the rig carries. [4]

03

Two underground bolting rig makers: Siton and KAMACH

Jiangxi Siton Machinery Manufacturing Co., Ltd. lists its DS2, DS3 and DS5 hydraulic rock bolting rigs; KAMACH MINING lists two-boom hydraulic rock bolting rigs among its underground drill rigs.

Ask any supplier for coverage and bolt lengths, hole diameter range, rock drill model and power, feed and boom geometry, bolting head and bolt magazine, mesh handling, carrier engine and emissions, electric power pack, air and water needs, cab or canopy (FOPS/ROPS), weight and dimensions, and service support underground.

04

What the boom, bolting head and power pack each do

05

DS2 figures and the gaps a bolting rig quotation must fill

Every example value is from Siton's DS2; feed force, rotation speed, bolt installation time, noise and vibration are not on its data sheet, so ask for them in writing.

06

Send the opening, bolt and site data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Opening: [width × height; gradient]
Bolts: [type; length; pattern]
Mesh: [yes/no]
Rock: [type; strength]
Holes: [diameter; depth]
Power: [voltage; frequency]
Services: [air; water]
Rules: [MSHA or local ground-support standard]

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