National Plastics & Rubber (NPR, Australia) makes wheel chocks for mining equipment in two formats: MineChock™, a workshop wheel chock you position standing up with a handle and wheels (NPR07999-10 and NPR08304-10), and 10 one-piece polyurethane chocks, from 1.5LW to 7LW, for tyres from 400 to 4500 mm. Endeavant supplies both ranges in Peru.
What is MineChock™ and how is it different from a standard chock?
MineChock™ is a workshop wheel chock made by National Plastics & Rubber in Brisbane, Australia, from high-density industrial polyurethane. Conventional chocking makes the operator bend over repeatedly and reach under the wheel to place the chock. MineChock™ is carried by a handle, rolls across the workshop floor without lifting, and is positioned standing up, without going under the tyre. That cuts the risk of lower-back injuries from repetitive bending during everyday workshop work.
It carries a clearly visible Spanish-language «Do not drive over» plate to prevent it from being crushed by accident. It is designed for workshops and low-slope areas, and won the Innovation & People's Choice Award at the 2022 QLD Mining Health & Safety Conference.
What MineChock™ workshop sizes are available?
MineChock™ comes in two sizes by tyre width, each with its own NPR part number:
- MineChock™ standard (NPR07999-10) — 34 kg: universal size for the usual tyre width of haul trucks in the workshop.
- MineChock™ Size 4 (NPR08304-10) — 21 kg: for equipment with narrower tyres, such as graders and smaller trucks.
How do you position a MineChock™?
- 1. Bring it in: pull the handle down, levering on the rear wheels, and push the chock as close to the tyre as possible.
- 2. Set it flush: tip it onto its front wheel and bring the rear into position: it must sit straight and flush against the bottom of the tyre.
- 3. Chock both sides: with one chock on each side of the wheel, the truck is secured. To remove it, reverse the motion.
Which wheel chock size does each machine need in the field?
For field use, NPR makes 10 sizes of one-piece, anti-slip polyurethane wheel chocks that do not rot and resist chemicals, salts, fuels, oils and solvents. You choose by tyre diameter: the right chock is the one whose range contains your tyre. Each size has its own NPR mounting holder to keep chocks stored on the vehicle when not in use:
- 1.5LW (NPR01895-00): 400–800 mm tyres, 180 × 115 × 110 mm, 0.7 kg. Light vehicles. Holder NPR01945-00.
- 2LW (NPR01180-00): 400–900 mm tyres, 210 × 200 × 150 mm, 1.6 kg. Light vehicles. Holder NPR01951-00.
- 3LW (NPR01181-00): 900–1400 mm tyres, 340 × 220 × 200 mm, 3.5 kg. Medium vehicles. Holder NPR02013-00.
- 3.5LW (NPR02097-00): 1200–1800 mm tyres, 340 × 250 × 225 mm, 6.2 kg. Medium vehicles. Holder NPR02266-00.
- 3.7LW (NPR01891-00): 1200–2200 mm tyres, 475 × 305 × 255 mm, 6 kg. Medium vehicles. Holder NPR01944-00.
- 4LW (NPR01329-00): 1800–3000 mm tyres, 570 × 340 × 280 mm, 9 kg. Large and extra-large vehicles. Holder NPR02016-00.
- 5LW (NPR02155-00): 2200–3500 mm tyres, 621 × 343 × 323 mm, 11 kg. Large and extra-large vehicles. Holder NPR02136-00.
- 6LW (NPR00984-00): 2800–4200 mm tyres, 680 × 337 × 355 mm, 14 kg. Large and extra-large vehicles. Holder NPR02017-00.
- 7LW (NPR05024-00): 2800–4500 mm tyres, 445 × 385 × 400 mm, 16 kg. The largest haul trucks. Holder NPR05535-00.
- 4/3LW (NPR01476-00): 2800–4500 mm tyres, 559 × 330 × 280 mm, 8 kg. Medium-large vehicles. Holder NPR02029-00.
How many wheel chocks do you need on a slope?
- Level ground: one chock at the centre of the tyre, parallel and flush, on both the front and rear of the wheel.
- Slope, loaded vehicle: four chocks on the downhill side of each tyre.
- Slope, empty vehicle: two chocks on the downhill side of the two outer tyres.
Before using any chock, NPR asks you to confirm the size matches the tyre diameter, check it is free of damage and complete your own risk assessment. MineChock™ is for workshops and low-slope areas; on grades, use the field chocks.
Why polyurethane wheel chocks instead of steel or timber?
- One piece: the field chock is a solid polyurethane block, with no parts that can work loose or come off.
- Lighter: NPR rates them much lighter than steel or timber without giving up strength; the 6LW for tyres up to 4200 mm weighs 14 kg.
- Anti-slip: a firm grip on the ground and a long service life on site.
- Built for workshop and pit: waterproof, rot-proof and unaffected by chemicals, salts, fuels, oils or solvents.
What do regulations say about wheel chocks in mining?
In the United States, MSHA rule 30 CFR 56.14207 requires mobile equipment parked on a grade to have its wheels chocked or turned into a bank. In Peru, the mining health and safety regulation (Supreme Decree 024-2016-EM) requires every operator to have written standards and safe work procedures, and wheel chocking in the workshop and in the pit is usually defined in each site's own standards.
Where can you buy MineChock™ and wheel chocks in Peru?
Endeavant S.A.C., based in Miraflores, Lima, supplies the full MineChock™ and NPR wheel chock range in Peru: both workshop sizes, the 10 field sizes and their mounting holders, with advice on choosing the chock for each machine and tyre diameter. The same workshop typically uses Tray Support blocks for haul truck trays and Stacko™ cribbing blocks; our guide to support blocks for mining maintenance covers both.
Wheel chock FAQ
How is MineChock™ different from a standard wheel chock?
MineChock™ is an NPR workshop wheel chock with a handle and wheels: you move and position it standing up, without bending down or reaching under the truck's wheel. NPR's field chocks (1.5LW to 7LW) are one-piece polyurethane blocks placed by hand.
What size wheel chock does a haul truck need?
Choose by tyre diameter: the chock whose range contains it. The 6LW (NPR00984-00) covers 2800–4200 mm tyres and the 7LW (NPR05024-00) reaches 4500 mm. In the workshop, the MineChock™ standard NPR07999-10 suits the usual haul truck tyre width.
How many wheel chocks are needed on a slope?
According to NPR's guide, a loaded vehicle needs four chocks on the downhill side of each tyre; an empty vehicle needs two chocks on the downhill side of the two outer tyres. On level ground, chock both sides of the wheel.
Are wheel chocks for mining equipment different from truck chocks?
Mining wheel chocks are sized for much larger tyres. NPR's range covers tyres from 400 mm on light vehicles up to 4500 mm on the largest haul trucks, and each size has its own mounting holder so the chock travels with the vehicle.
Where can I buy MineChock™ wheel chocks in Peru?
Endeavant S.A.C., in Miraflores, Lima, distributes NPR Australia products in Peru, including MineChock™, the 10 field chock sizes and their holders, and helps you choose the right model for each machine.