Wheel chocks are the canonical engineering control for preventing the unintentional movement of parked mobile plant in Australian workplaces. WHS Regulation 213 (Powered Mobile Plant) mandates that persons with management or control of powered mobile plant must ensure it is immobilised to prevent unintentional movement. A handbrake alone is not always sufficient — particularly on grades over 2°, when loading or unloading creates back-and-forth movement, when the brake hardware may fail, or when the vehicle is left for extended periods. The wheel chock is the simplest, cheapest engineering control that closes the gap.
This guide is for Australian workshops, fleet operators, loading dock managers, mining safety officers, aviation ground handlers, and workshop technicians using hoists or trolley jacks. It covers heavy vehicle parking, loading dock + forklift safety, mining haul truck immobilisation, aviation ground handling, workshop hoist/jack rear-axle chocking, and plant temporary parking. It explicitly does NOT cover caravan, RV, camper, recreational 4WD, or consumer car parking — those audiences are well-served by Bunnings/Supercheap/RV-specialty retailers. AIMS supplies workshop-tier rubber wheel chocks (Mackay Rubber Wheel Chock, Hansa WC-425 Pair 110 x 120 x 205mm) and sources mining-spec polyurethane and aviation-spec aluminium chocks on request through our load restraints range.
Why wheel chocks matter — WHS Reg 213, roll-away fatalities, and the legal control measure hierarchy
The Safe Work Australia Prevention of Vehicle Roll-Aways Fact Sheet (September 2023) opens with a direct statement: vehicle roll-aways are a major cause of work-related fatalities and injuries in Australia. Roll-aways occur with cars, forklifts, trucks, tractors and trailers — in worksites, car parks, maintenance yards, and on the side of the road. The 2023 update to the model Code of Practice: Managing the Risks of Plant in the Workplace formalised wheel chocks as a canonical control measure.
The legal frame in Australia is straightforward. WHS Regulation 213 (and the equivalent in each state/territory's harmonised WHS Regulations) requires immobilisation of powered mobile plant. The Code of Practice spells out the practical controls: park on a level surface where possible, apply the parking brake, place the gear/transmission in park or low gear, and use wheel chocks when the slope is significant or the vehicle will be left during loading/unloading. Wheel chocks are explicitly described as "an example of a simple engineering control" — wedge-shaped objects with a non-slip bottom surface placed behind or in front of the wheel.
The control measure hierarchy matters. The Hazardous Manual Tasks Code of Practice has been clear for years that "how to lift" training programs do not reduce the incidence of musculoskeletal disorders — only engineering controls do. The same principle applies to roll-away prevention: training drivers to apply the handbrake correctly is a weak control; making chocks mandatory at loading docks is an engineering control. The 2023 update reinforces this with explicit chock-placement guidance.
Industrial scope — and what we're explicitly not covering
This guide is tightly scoped to industrial use. Wheel chocks for caravans, RVs, campers, recreational 4WDs, and consumer car parking are a different product category sold through different channels. Bunnings, Supercheap Auto, ARB, BCF, and similar retailers cover the consumer/recreational space well, and we don't compete with them.
The seven industrial use cases this guide covers:
- Heavy vehicle parking — trucks, prime movers, semi-trailers, B-doubles, road trains parked on yards, in maintenance bays, at depots
- Loading dock + forklift dock work — trailer creep prevention, dock lock backup, OSHA-equivalent restraint requirement
- Mining haul truck + light vehicle immobilisation — Caterpillar/Komatsu/Hitachi haul trucks, light vehicles in pit, NSW Resources MDG 15 control framework
- Aviation ground handling — chocking nose and main gear on apron, beacon-off rule, headset operator clearance protocol
- Workshop hoist + trolley jack safety — chock the rear when raising the front (and vice versa) on 2-post hoists, scissor lifts, and trolley jacks
- Plant + mobile equipment temporary parking — graders, dozers, excavators, telehandlers, scissor lifts on grade
- Yard handling + construction site immobilisation — concrete trucks, tipper trucks at site, formwork delivery vehicles
Note one more disambiguation upfront: AS/NZS 3845 is the standard for road safety barrier systems — crash barriers, bollards, attenuators, end terminals. It appears in some keyword research clusters but does not govern wheel chocks. The standards that govern wheel chocks in Australia are WHS Regulation 213 and the Code of Practice — not AS 3845.
The 25% rule — sizing wheel chocks for ground vehicles
The industrial sizing rule for wheel chocks is: chock height = 25% of tyre diameter. A 600 mm tyre needs a 150 mm chock. A 1200 mm tyre needs a 300 mm chock. A haul truck with a 3500 mm tyre needs an 875 mm chock. This rule is referenced in the SA Department for Infrastructure and Transport Wheel Chock Sizing Guide and is the de facto industrial standard across Australian heavy vehicle operations.
The rule is derived from basic physics. The chock must be tall enough that the tyre can't simply roll over it under gravity alone. A chock that is less than ~20% of tyre diameter creates an angle of contact too shallow to resist rolling. A chock that's larger than necessary is unwieldy and harder to position correctly. The 25% figure is the workshop sweet spot.
| Tyre diameter | Vehicle class example | Minimum chock height (25% rule) | AIMS supply / source |
|---|---|---|---|
| 500 mm | Light truck, ute | 125 mm | Hansa WC-425 (close to spec) |
| 700 mm | Light commercial truck | 175 mm | Mackay Rubber Wheel Chock |
| 900 mm | Medium rigid truck, prime mover | 225 mm | Sourced — Tegral 245 x 200 x 150mm heavy duty (rubber) |
| 1100 mm | B-double, road train tyre | 275 mm | Sourced — MHA Products heavy duty rubber |
| 1500 mm | Mining light vehicle, large rigid | 375 mm | Sourced — polyurethane (NPR Mining / FSP / National Plastics & Rubber) |
| 2500 mm | Caterpillar 777 / Komatsu HD785 haul truck | 625 mm | Sourced — polyurethane mining-spec (NPR Mining) |
| 3500 mm | Caterpillar 793 / 797 ultra-class haul truck | 875 mm | Sourced — aluminium mining-spec (B&D Manufacturing, AME) |
On a slope, increase the chock height. The standard adjustment: add ~50% chock height for every 5° of grade. A vehicle parked on a 10° grade with a 600 mm tyre needs a 200-225 mm chock, not the level-ground 150 mm. The simpler workshop rule: if you can see the chock won't hold when you visualise the wheel pressing against it on the slope, it's too small.
The 10% rule — aviation chock sizing convention
Aviation operates on a different sizing convention. Aircraft chocks are typically 10% of tyre diameter, with an absolute minimum of 50 mm for light aircraft and 150–200 mm for larger transport aircraft. The convention reflects the lower probability of unplanned movement on the apron — the aircraft is in a controlled environment, brakes are applied, and chocks are a secondary control.
The lighter aviation sizing also reflects manual handling. Ramp agents and ground crew place and remove chocks dozens of times per shift, often in cramped space under the wing or beside the nose gear. A 150 mm aluminium aircraft chock weighs ~2-3 kg per pair — easy to carry, easy to position, easy to clear before pushback. A 250 mm rubber industrial chock at the same site would be slower and create fatigue across a shift.
| Aircraft class | Typical main gear tyre | Standard chock height | Common material |
|---|---|---|---|
| Light aircraft (Cessna 172, Piper) | 200–250 mm | 50 mm minimum | Hardwood, rubber |
| Regional turboprop (ATR, Dash 8) | 400–500 mm | 75–100 mm | Rubber, polyurethane |
| Narrow-body jet (737, A320) | 1000–1200 mm | 100–125 mm | Polyurethane, aluminium |
| Wide-body jet (777, A330) | 1300–1400 mm | 130–150 mm | Polyurethane, aluminium |
| Ultra-large (A380, 747-8) | 1400–1500 mm | 150–200 mm | Aluminium, polyurethane |
Aviation chocks must be painted in bright high-visibility colour — typically safety yellow or international orange — so they remain visible on the apron at night under sodium lighting. A black rubber industrial chock left on the apron is a serious foreign object debris (FOD) hazard if it can't be seen.
Materials matrix — rubber, polyurethane, aluminium, steel, timber
Wheel chock material selection comes down to three trade-offs: weight, durability, and environment. Each material has a clear sweet spot.
| Material | Weight | Durability | Tyre contact | Environment | Cost | Best use case |
|---|---|---|---|---|---|---|
| Rubber (natural / recycled) | Heavy (full weight per size) | Moderate — UV-sensitive, can crack over time | Excellent — natural traction ribs grip tyre | Indoor / sheltered workshop | Lowest | Light/medium commercial workshop, truck depot, fleet yard |
| Polyurethane (PU) | 20–50% lighter than equivalent rubber | Excellent — UV, chemical, weather resistant | Good — moulded grip surface | Mining, marine, chemical, outdoor industrial | Mid-high | Mining haul truck, marine, harsh outdoor conditions |
| Aluminium | Light-moderate (alloy) | Excellent — corrosion-resistant | Lower — needs textured face or grip insert | Aviation, ultra-class mining | Highest | Aviation ground handling, ultra-class haul trucks (CAT 797, Komatsu 980E) |
| Steel | Heaviest | Very good — but rust without coating | Lower — needs rubber face insert | Heavy industrial, foundry | Moderate | Specialty heavy industrial (rolling mill, foundry, locomotive) |
| Timber | Light | Poor — splits, rots, single-use in many cases | Moderate — sawn face provides grip | Light commercial, ad-hoc | Lowest | Single-use, emergency, light commercial; NOT for repeat industrial use |
The forum-validated reality: rubber dominates the Australian light commercial market because of cost and tyre-friendliness. Polyurethane has taken over mining (NPR Mining, National Plastics & Rubber, FSP Australia are the AU suppliers) because the weight saving on a 25 kg chock matters when you're carrying it across a pit floor. Aluminium owns aviation and ultra-class mining because the load ratings can't be matched by rubber or PU at the same physical size.
Two material warnings worth noting. Aluminium when damaged develops sharp edges that can damage tyres or injure handlers — inspect aluminium chocks before each use, retire any with deformation or sharp burrs. Aluminium and steel are conductive — don't use metal chocks on electrical transmission worksites, around live overhead lines, or in any application where the chock could become part of an electrical fault path. Polyurethane is non-conductive and the safer choice in electrical environments.
The seven industrial use cases — decoded
| Use case | Typical vehicle | Chock type | Pair / single | Governing rule |
|---|---|---|---|---|
| Heavy vehicle parking on grade | Truck, prime mover, trailer | Rubber or PU 200–300mm | Pair, downhill side first | WHS Reg 213 + Code of Practice |
| Loading dock — trailer immobilisation | Semi-trailer at dock | Rubber pair 200mm + dock lock | Pair | OSHA 29 CFR 1910.178(k)(1) — US ref |
| Mining haul truck immobilisation | CAT 777 / Komatsu HD785 | Polyurethane 600–900mm | Pair minimum, often 4 (both axles) | NSW Resources MDG 15 |
| Mining light vehicle in pit | Light truck, ute, water cart | PU 200–300mm | Pair | NSW Resources MDG 15 |
| Aviation ground handling | Aircraft on apron | Aluminium or PU per aircraft class | Pair at nose, may add mains | Operator SOPs + CASA |
| Workshop hoist / trolley jack | Car, light truck on hoist | Rubber 150mm pair | Pair on unraised end | Workshop SOP + manufacturer instructions |
| Plant temporary parking | Grader, dozer, telehandler on grade | PU or steel-faced rubber 300mm+ | Pair downhill first | WHS Reg 213 + operator SOP |
| Yard / construction site truck | Concrete truck, tipper, formwork delivery | Rubber 200–250mm | Pair, downhill first | Site safety plan + WHS Reg 213 |
Loading dock — trailer creep, dock walk, and why chocks alone aren't enough
The loading dock is the single most dangerous wheel-chock environment in Australian industry. The mechanism is called trailer creep (sometimes "dock walk"): the slow, almost unnoticeable separation of the trailer from the dock edge, caused by the back-and-forth momentum of a forklift entering and exiting the trailer. Each forklift movement nudges the trailer forward by a few millimetres. After 30-50 trips loading or unloading a B-double, the trailer can be 100-200 mm away from the dock — and the gap is invisible from inside the trailer.
The fatality mode is well documented in OSHA records and Australian SafeWork incident reports: the forklift operator drives the forklift off the back of the trailer into the gap, falling 1.2-1.5 m to the ground while strapped into a 3-4 tonne machine. OSHA 29 CFR 1910.178(k)(1) and (m)(7) requires trailer trucks to be restrained by wheel chocks or vehicle restraints during loading and unloading. The Australian equivalent is captured under WHS Regulation 213 and case law has consistently found the receiving business — not the truck driver — liable for trailer immobilisation in the loading area.
The honest read from the dock equipment industry: wheel chocks alone offer only minimal protection against trailer creep at high-throughput docks. Most dock equipment manufacturers (Rite-Hite, Kelley, Pentalift, Safetech) argue that mechanical vehicle restraints — dock locks that hook the trailer rear impact guard (RIG) — are the proper engineering control, with chocks as a backup. The belt-and-braces approach at any high-throughput dock is dock lock + chocks together.
That said, for low-throughput sites without dock lock infrastructure (single-bay workshops, occasional delivery sites, rural depots), wheel chocks remain the primary control. The standard configuration is one chock pair under the rear axle of the trailer, on both sides, snug against the tyre on the dock-side (preventing roll-into-dock) and on the rear-side (preventing roll-away).
Mining haul truck chocks — NSW Resources MDG 15 framework
Mining wheel chocks are a specialty product category — and the rules are different. NSW Resources MDG 15 (Mobile and Transportable Plant for Use at Mines) covers the unplanned movement risk class but doesn't specify chock sizes — the operator's Principal Hazard Management Plan (PHMP) or Trigger Action Response Plan (TARP) defines the actual chock spec for each site.
What's consistent across Australian mining: ultra-class haul trucks (Caterpillar 793, 797, Komatsu 930E, 980E) use either polyurethane or aluminium chocks sized to the 25% rule against a 3500-4000 mm tyre. That means a 900-1000 mm chock weighing 25-45 kg in polyurethane, or 30-60 kg in aluminium. Two operators usually carry these.
The Australian mining-spec suppliers are NPR Mining (polyurethane workshop chocks), National Plastics & Rubber (premium PU chocks), FSP Australia, and AME (urethane workshop chocks). One workshop PU chock from these suppliers is typically rated for the full ultra-class haul truck range — a single chock spec covers CAT, Komatsu, and Hitachi.
Mining-specific considerations: chocks are typically high-vis orange or yellow with reflective tape, often with handle/grab points or extraction loops for retrieval after the truck has chocked against them. Storage usually involves dedicated mounts on the operator's light vehicle or designated chock stands at maintenance bays. AIMS doesn't stock mining-spec chocks but can source through the supplier network — call ahead with the truck class and tyre dimension.
Aviation ground handling — beacon-off rule, nose gear convention, headset clearance
Aviation ground handling is the most procedural environment for wheel chocks. The standard procedure when an aircraft arrives at a stand:
- Aircraft taxis into the stand, applies parking brakes
- Pilot signals beacon off (engines spooled down) — ground crew may now approach the aircraft
- Headset operator connects to ground intercom and confirms with flight crew that brakes are set
- Ground crew place chocks at nose gear first, both sides, snug against tyre
- Depending on operator SOP, additional chocks may be placed at the main gear — some airlines chock everything by the nose only, with the reasoning that rampers are not allowed to walk under wings for any reason, which rules out chocking the mains during turnaround. Other operators chock both nose and one main
- Headset operator confirms chocks placed, flight crew releases brakes
- At departure, the reverse procedure: headset operator requests brake-set, confirms all GSE disconnected and pax stairs retracted, then clears chock removal
Forum-validated insight from Airliners.net ramp agent threads: the nose-gear-only convention is widespread across larger international carriers because of the wing-clearance rule. Smaller regional operations and freight handlers often chock both nose and one main, which is more conservative.
The chock material standard in aviation is aluminium or polyurethane in high-visibility yellow or orange. Black rubber industrial chocks are not used in airside operations — they're a FOD (foreign object debris) risk if forgotten and a visibility risk on dark aprons.
Workshop hoist & trolley jack safety — chock the unraised end
The workshop rule: when raising one end of a vehicle on a hoist or trolley jack, chock the other end. A 2-post hoist lifting the front of a vehicle creates a fulcrum effect where the rear wheels remain on the ground but the vehicle's centre of mass shifts forward. If the rear isn't chocked and the vehicle is in neutral, it can roll backward under the lift arms, dropping the vehicle off the lift.
The same rule applies to trolley jacks. Jacking the front of a car to change a wheel: chock both rear wheels. Jacking the rear to slide under for an oil change: chock both front wheels. The chock should be placed against the tyre on both the inside and outside of the wheel that's staying on the ground — preventing forward or backward roll.
This is the use case where the Mackay Rubber Wheel Chock and Hansa WC-425 Pair are the workshop default. Tyre diameter on a typical car or light commercial is 600-700 mm, so the 25% rule wants a 150-175 mm chock — the Hansa WC-425 at 205 mm in length is the typical workshop pair, and the Mackay rubber chock is sized for the same workshop tier.
NHVR Load Restraint — stationary immobilisation during load/unload
The NHVR Load Restraint Guide applies to heavy vehicles in transit and during load/unload. While the LRG primarily covers tie-down and friction restraint of the load on the vehicle, it explicitly references vehicle immobilisation during load/unload operations.
Cross-link with the AIMS load restraint cluster: Ratchet Strap Guide, Load Binder Guide, and SWL vs WLL vs MBL Guide cover the load-on-vehicle side; this article covers the vehicle-on-ground side. Both are required under WHS frameworks and the NHVR Load Restraint Guide for heavy vehicle work.
The practical NHVR-aligned procedure during truck load/unload: parking brake set, transmission in low gear or park, wheel chocks pair on the rear-most axle on both sides, driver out of the cabin and clear of the loading area, hi-vis on, communication with the loader confirmed. If the truck moves at all during loading, the chocks become the engineering control that prevents roll-away.
Working Load Limit (WLL) — sizing chocks against gross vehicle weight
Wheel chocks have a Working Load Limit just like any other load-bearing engineering control. WLL specifications vary by manufacturer and material but rough benchmarks for the AU market:
| Chock class | Typical WLL | Vehicle GVM bracket | Material |
|---|---|---|---|
| Workshop / light commercial | 5–10 tonnes | Up to 8 tonnes GVM | Recycled rubber |
| Heavy duty truck | 15–25 tonnes | 8–25 tonnes GVM | Heavy rubber or PU |
| B-double / road train | 25–60 tonnes | 25–62.5 tonnes GVM | Heavy rubber, PU |
| Mining haul truck (workshop) | 100–250 tonnes | Up to 250 tonnes GVM | Polyurethane workshop chock |
| Mining ultra-class | 250+ tonnes | Ultra-class haul trucks (CAT 793/797, Komatsu 980E) | Aluminium |
The cheap trap: undersized chocks roll over or split under loaded vehicle weight on grade. The Tegral heavy-duty rubber chock at 245 x 200 x 150 mm is rated to 20 tonnes — fine for a 4.5 tonne light truck or a 12 tonne medium rigid, marginal for a 25 tonne semi-trailer at full GCM. If you're regularly chocking heavy combinations, step up to the heavier rubber or polyurethane class.
Placement rules — pair, snug, square, downhill-first
The four golden rules of wheel chock placement, validated across forum and standards literature:
- Always pairs. Never a single chock. The pair sits on both sides of the same axle (one chock under the left wheel, one under the right) to prevent the vehicle pivoting on the axle.
- Snug against tyre. No gap between chock face and tyre tread. The vehicle should not move at all before contacting the chock.
- Square to the wheel. Chock face perpendicular to the direction of potential travel. An angled chock will let the wheel push it aside.
- Downhill side first on any slope. If parked on a 5° downhill slope, place the chock pair on the downhill side of the wheels first, then add a second pair on the uphill side if available. The Code of Practice 2023 update is explicit on this point.
Common placement errors: chocks placed loosely several centimetres from the tyre (allows roll before contact), chocks placed at angle (deflects rather than holds), chock under the wrong wheel (front-wheel chock on a rear-wheel-drive vehicle parked nose-uphill), single chock instead of pair. Each one shows up in workplace incident reports as the contributing factor.
Wheel chock vs wheel stop vs parking block — three different products
| Product | What it does | Typical use | Form factor |
|---|---|---|---|
| Wheel chock | Wedge that immobilises a parked vehicle | Industrial parking, loading, hoist work, ground handling | Wedge-shaped, removable, paired |
| Wheel stop / parking block / curb stop | Fixed barrier preventing forward roll into adjacent space | Car park, parking bay, dock approach | Long horizontal block, bolted to ground |
| Chockfast / chocking compound | Pourable epoxy resin for machinery alignment | Marine engine alignment, machinery installation | Liquid epoxy, hardens in place |
The terms are sometimes used interchangeably in casual speech but they're three different products with different applications. Epirez Chockfast Orange and the Red variant we stock are chocking compounds — pourable epoxy resin for aligning marine engines, pump bases, motor mounts. They are not wheel chocks. If you've searched for "wheel chock" and landed on a Chockfast page, you're in the wrong place. Wheel chocks are wedges; chocking compounds are resins.
AS 3845 disambiguation — this standard does NOT cover wheel chocks
AS/NZS 3845 governs road safety barrier systems — guardrails, concrete barriers, bollards, attenuators, end terminals on roads. Some keyword research clusters show "AS 3845" appearing in wheel chock searches, but the standard does not cover wheel chocks. The Australian framework that does cover wheel chocks is:
- WHS Regulation 213 — Powered Mobile Plant (mandates immobilisation)
- Safe Work Australia Model Code of Practice: Managing the Risks of Plant in the Workplace (2023 update with chock guidance)
- NHVR Load Restraint Guide (heavy vehicle load/unload)
- NSW Resources MDG 15 (mining mobile plant)
- Operator-specific SOPs (aviation, fleet, workshop)
If a tender or spec sheet references AS 3845 in the context of wheel chocks, query it with the writer — they may be confusing the two standards.
Chock storage, holders, mounts, and hi-vis options
The "where's the chock?" problem is real. A chock that's not within arm's reach when needed often doesn't get used. Industrial chock storage options:
- Wall-mounted chock holders — vertical brackets bolted to the dock wall or workshop wall, one chock per holder. Hi-vis painted so they signal "chock missing"
- Vehicle-mounted holders — clamps or brackets fitted to the side of trucks, trailers, or mining light vehicles. The chock travels with the vehicle
- Chock stands — freestanding floor units with paired chock pockets, used at loading dock or workshop
- Hi-vis chock chains/lanyards — chocks tethered to a vehicle bumper or anchor point with a short chain. Forces deployment and prevents loss
The keyword data shows wheel chock holders carry one of the highest commercial-intent CPCs in the cluster — workshop fit-out and dock fit-out tenders frequently specify chock storage as a project specification item, not just a stocking item.
Brand reality — what's stocked at AIMS, what we source, who's who in the Australian market
| Brand | Origin | Tier | AIMS stocking |
|---|---|---|---|
| Mackay | Australia (rubber products) | Workshop / light commercial | ✅ Mackay Rubber Wheel Chock — stocked |
| Hansa | Workshop equipment AU import | Workshop / light commercial | ✅ WC-425 Pair 110x120x205mm — stocked |
| Tegral | Australia | Heavy duty rubber commercial | Source on request |
| MHA Products | Australia | Heavy duty rubber, 20-tonne rating | Source on request |
| FSP Australia | Australia (mining specialty) | Mining polyurethane, truck | Source on request |
| NPR Mining | Australia (mining) | Polyurethane workshop, ultra-class | Source on request |
| National Plastics & Rubber | Australia (mining) | Polyurethane, full mining truck range | Source on request |
| Safetech | Australia (dock equipment) | Dock fixed + mobile chocking systems | Dock systems through supplier network |
| Checkers / Justrite | USA (Justrite group) | Specialty mining + dock | Source through importer |
| B&D Manufacturing | Canada / USA | Aluminium ultra-class haul truck | Source through importer (aviation + mining) |
| AME International | USA | Urethane workshop, heavy-duty | Source through importer |
Honest scope: AIMS sells workshop-tier wheel chocks. We're not the mining specialist (FSP, NPR Mining, National Plastics & Rubber own that segment) or the aviation specialist (B&D, Tronair, aircraft GSE-specialty suppliers own that segment). For workshop, light commercial, fleet yard, loading dock, hoist safety, and similar applications, the Mackay Rubber Wheel Chock and Hansa WC-425 Pair at AIMS are the right call. For anything heavier — call us on (02) 9773 0122 and we'll source through the supplier network.
Common mistakes — 12 patterns that show up in incident reports
| Mistake | Why it happens | What goes wrong |
|---|---|---|
| Single chock instead of pair | Lazy / didn't have second chock | Vehicle pivots on axle, rolls past unchocked side |
| Chock several cm from tyre | Eyeballed placement | Vehicle gains momentum before hitting chock, knocks it aside |
| Chock angled to tyre | Floor not level / quick placement | Wheel deflects chock sideways instead of being stopped |
| Wrong wheel chocked (uphill vs downhill) | Didn't check slope direction | Chock is on the wrong side, vehicle rolls away |
| Cheap chock under heavy vehicle | Used workshop chock for B-double | Chock splits, deforms, or rolls over under load |
| Aluminium chock on transmission worksite | Used what was nearby | Conductive — becomes part of electrical fault path |
| Single chock at loading dock | Relying on dock lock as primary | Trailer creep + dock lock failure = forklift falls into gap |
| Chock under forklift loading wheel only | Chocked the trailer but not the forklift | Forklift rolls during unload, chock applies to truck not forklift |
| Rubber chock left in sun | Storage failure | UV-degraded, cracks, loses grip — fails on next use |
| Workshop hoist with rear unchocked | Skipped the chock step to save time | Vehicle rolls off hoist when front raised |
| Aircraft chocked before beacon off | Approached aircraft early | Jet blast / propeller hazard — ground crew injury risk |
| Chock not retrieved after vehicle departs | Forgotten / dropped on ground | FOD hazard on apron; trip hazard in workshop; can damage next vehicle's tyre |
AIMS wheel chock supply — Mackay rubber + Hansa pair workshop tier
AIMS stocks two workshop-tier wheel chock SKUs:
- Mackay Rubber Wheel Chock — single chock, Australian Mackay rubber brand, workshop and light commercial tier. Good for car, ute, light commercial truck, workshop hoist use, trolley jack work.
- Hansa WC-425 Wheel Chocks Pair 110 x 120 x 205mm — pair, supplied together, workshop and light commercial tier. Best fit for workshop default use, hoist safety, light commercial trucks at depot.
For anything outside this scope — mining haul truck chocks (NPR Mining / National Plastics & Rubber / FSP Australia), aviation aluminium chocks (B&D Manufacturing, Tronair), heavy-duty 20+ tonne rated rubber/PU (Tegral, MHA Products, Checkers/Justrite), or dock lock systems (Safetech) — we source through the supplier network. Call us on (02) 9773 0122 with the application, vehicle class, and tyre size and we'll come back with options and pricing.
Adjacent stocked product: Epirez Chockfast Orange Marine & Industrial Chocking Compound and the Chockfast Red Deep Pour Epoxy Grouting Compound — but as noted in the disambiguation section, these are pourable epoxy resins for machinery alignment, not wheel chocks.
Selection checklist — the 8 questions that get you the right chock
- Vehicle gross weight — what's the GVM/GCM you'll be chocking? Match WLL accordingly.
- Tyre diameter — apply 25% rule (ground vehicles) or 10% rule (aircraft) to size chock height.
- Indoor or outdoor — rubber for sheltered, polyurethane for outdoor/harsh.
- Grade — if working on slope, increase chock height beyond level-ground spec.
- Environment — chemicals, fuel, UV, heat, electrical: polyurethane is safer in most harsh environments.
- Frequency of handling — high-handling sites (aviation, dock) need lighter material (PU or aluminium).
- Storage — wall holder, vehicle mount, or chock stand? Specify the storage solution at the same time.
- Visibility — hi-vis colour for aviation, dock, workshop floor. Black rubber OK for fleet yard but not airside.
Frequently Asked Questions
What size wheel chock do I need?
The industrial sizing rule is: chock height = 25% of tyre diameter. A 600 mm tyre needs a 150 mm chock; a 1000 mm tyre needs a 250 mm chock; a 3500 mm haul truck tyre needs an 875 mm chock. Aviation uses a different convention (10% of tyre diameter) reflecting the controlled apron environment. Increase chock height on slopes — roughly 50% taller for every 5° of grade.
How many wheel chocks should I use?
Always use chocks in pairs minimum — one on the left wheel, one on the right of the same axle. A single chock allows the vehicle to pivot on its axle and roll past the unchocked side. Mining haul trucks and heavy combinations often use four chocks (both axles), and aviation typically chocks at least the nose gear pair with some operators adding main gear chocks.
Where do I place wheel chocks on a slope?
Place the chock pair on the downhill side first, snug against the tyre. The Safe Work Australia Code of Practice 2023 update is explicit on this. If a second pair is available, add it on the uphill side as a backup. Don't rely on the parking brake alone on grades greater than 2°.
Are wheel chocks legally required at loading docks in Australia?
WHS Regulation 213 (Powered Mobile Plant) requires immobilisation of powered mobile plant to prevent unintentional movement. At loading docks, the receiving business (not the truck driver) is generally found liable in case law for ensuring the trailer is immobilised during forklift loading/unloading. The Australian framework parallels OSHA 29 CFR 1910.178(k)(1) which requires either wheel chocks or vehicle restraints during forklift dock work. The practical reality: dock locks plus wheel chocks together is the proper engineering control at any high-throughput dock.
What's the difference between a wheel chock and a wheel stop?
A wheel chock is a removable wedge that immobilises a parked vehicle. A wheel stop (also called parking block, curb stop, or parking bumper) is a fixed barrier bolted to the ground, preventing a parked vehicle from rolling forward into adjacent space or a wall. They look similar but solve different problems: chocks immobilise, wheel stops define parking position. Both exist; neither replaces the other.
Do I need to chock a forklift while loading a truck at a dock?
The forklift itself doesn't need chocking — it's actively being operated. The trailer being loaded/unloaded does need chocking (or a dock lock vehicle restraint, or ideally both). The risk is trailer creep: forklift back-and-forth movement nudges the trailer away from the dock, creating a gap the forklift can fall into. OSHA 29 CFR 1910.178(k)(1) mandates trailer restraint during forklift dock work in the US; the equivalent Australian framework is WHS Regulation 213.
What's the AS standard for wheel chocks in Australia?
There isn't a single AS standard specifically governing wheel chocks. The framework that does apply is WHS Regulation 213 (Powered Mobile Plant), the Safe Work Australia Code of Practice: Managing the Risks of Plant in the Workplace (2023 update includes specific chock guidance), the NHVR Load Restraint Guide for heavy vehicles, and operator-specific SOPs. AS/NZS 3845 sometimes appears in keyword searches but governs road safety barrier systems — guardrails, bollards, attenuators — not wheel chocks.
Can a parking brake replace a wheel chock?
On level ground with a well-maintained parking brake, the brake alone is usually adequate. On any meaningful slope (greater than ~2°), during loading/unloading where the vehicle experiences back-and-forth force, when the vehicle will be left for extended periods, or when the parking brake hardware may fail (older vehicles, hot brake pads, brake adjustment issues), wheel chocks are required as the engineering control backup. WHS Regulation 213 mandates immobilisation — relying on a single control (the brake) on a sloped or active site doesn't meet that standard.
What's the best material for wheel chocks?
It depends on the environment. Recycled rubber is the workshop and light commercial default — cheap, grippy via natural traction ribs, easy on tyres, but UV-sensitive over time and limited to ~20-tonne loads. Polyurethane is 20-50% lighter than equivalent rubber, has higher load capacity, resists UV, fuel, and chemicals — the right choice for mining, marine, harsh outdoor work, and electrical environments (non-conductive). Aluminium is the right choice for ultra-class mining haul trucks and aviation where the load ratings require it, but it's conductive (avoid electrical work) and develops sharp edges when damaged. Timber is single-use emergency only.
Are aircraft wheel chocks different from truck wheel chocks?
Yes, in two ways. Aviation uses a 10% sizing convention (chock height = 10% of tyre diameter) compared to the 25% industrial convention — lighter chocks for easier handling on the apron. Aircraft chocks are also typically aluminium or polyurethane in safety yellow or international orange for FOD/visibility reasons, while industrial chocks are usually recycled rubber in black or hi-vis. The aircraft chocking procedure is also more procedural — beacon-off rule before approach, headset clearance protocol, nose-gear-first convention.
What's a wheel chock's Working Load Limit?
WLL varies by chock class and material. Workshop rubber chocks are typically rated 5-10 tonnes; heavy-duty rubber 15-25 tonnes; B-double/road train chocks 25-60 tonnes; mining workshop polyurethane chocks 100-250 tonnes; aluminium ultra-class haul truck chocks 250+ tonnes. The Tegral heavy-duty rubber at 245x200x150mm is rated 20 tonnes — fine for a 12 tonne medium rigid, marginal for a fully loaded 25 tonne semi-trailer. Always check the manufacturer rating against vehicle GVM/GCM.
How should I store wheel chocks at a loading dock?
Use designated storage that signals "chock missing" when one is in use. Options include wall-mounted vertical brackets bolted to the dock wall (hi-vis painted so empty brackets are obvious), vehicle-mounted holders that travel with the truck, or freestanding chock stands at the dock edge. Tethering chocks to a vehicle bumper or anchor point with a short chain forces deployment and prevents loss. The commercial-intent signal is strong here — workshops and docks consistently undersize their chock storage solution.
What's the difference between Chockfast and a wheel chock?
Chockfast is a pourable epoxy resin for machinery alignment — marine engine bedding, pump base grouting, motor mount alignment. It hardens in place to a precise dimension. A wheel chock is a wedge-shaped removable physical object that prevents a parked vehicle from rolling. They share the word "chock" but solve different problems. If you've searched for wheel chocks and landed on a Chockfast product page, that's the disambiguation gap.
Do mining haul trucks need wheel chocks?
Yes. NSW Resources MDG 15 (Mobile and Transportable Plant for Use at Mines) identifies unplanned movement of mobile plant as a hazard class. Mine sites define specific chock requirements in their Principal Hazard Management Plan or Trigger Action Response Plan. For Caterpillar 793/797 and Komatsu HD785/980E ultra-class haul trucks, chocks are typically polyurethane or aluminium sized to the 25% rule (875-1000 mm for ultra-class tyres), supplied by AU mining specialists like NPR Mining, National Plastics & Rubber, and FSP Australia. AIMS sources mining-spec chocks through the supplier network.
Are rubber wheel chocks OK for outdoor industrial use?
Rubber chocks are fine for sheltered outdoor use — depot yards, covered loading docks, partly-protected fleet parking. They're not the best choice for prolonged direct UV exposure (workshop floor sun, open mining pit), hot bitumen contact, or chemical/fuel exposure. For harsh outdoor industrial conditions, step up to polyurethane — 20-50% lighter, much better UV/chemical resistance, and higher load rating. For ultra-extreme applications (foundry, rolling mill, transmission worksite), aluminium or steel-faced chocks are the right call — but check the conductivity issue first if electrical work is involved.