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Designed for mining, earthmoving, and heavy transport settings, load support blocks are rated to securely hold components in place during maintenance. They’re an ideal solution for wherever a truck tray, dozer push-arm or similar component must stay elevated while work is carried out underneath or around it.
National Plastics & Rubber manufactures a range of load-rated polyurethane support products for these applications, including Stacko™ interlocking cribbing blocks, Timba™ solid support blocks, Tray Support Blocks matched to specific haul truck models, and Dozer Push-Arm Support Blocks. Each range is built to do a different job, and the right choice depends on the task, the required height or length, and the load involved.
Our Load Support Systems are meticulously engineered to provide reliable and secure support for a variety of maintenance tasks, ensuring a safer workplace environment.
Featuring innovative designs, our Stacko™ Blocks serve as a superior alternative to traditional timber blocks, constructed from high-quality UV-stabilised materials for long-term performance. Their interlocking design enhances safety while being up to 30% lighter than comparable products.
Complementing this, our Tray Support Blocks enable safe access under trays during maintenance activities, reducing service time and minimising potential hazards. These blocks support multiple simultaneous operations and are designed to facilitate hoisting cylinder changeouts, making them ideal for most trucks.
Additionally, our reusable Timba™ Blocks are crafted from durable polyurethane materials, offering an effective, long-lasting solution in all working conditions. Together, these load-rated support systems elevate workplace safety and efficiency, ensuring you have the confidence to tackle any maintenance task.
Stacko™, Timba™, Tray Support Blocks and Dozer Push-Arm Support Blocks are not interchangeable; each is engineered for different applications.
An interlocking cribbing block system for building a support stack to a required height, replacing hardwood cribbing, gluts and dunnage.
Designed to be sized and matched to specific haul trucks, tray support blocks provide workers with safe access underneath raised trays during maintenance.
A solid polyurethane support block supplied in set lengths, for applications that need a fixed block rather than a built stack. See the Timba™ products.
Purpose-built support and knuckle block assemblies for dozer push-arm maintenance. See Dozer Push-Arm Support Systems.
Stacko™ is an interlocking cribbing block system, manufactured from non-conducting, UV-stabilised virgin polyurethane, designed to replace hardwood cribbing, gluts and dunnage. Individual polyurethane cribbing blocks interlock to build a support stack to the required height, in single, double or triple configurations, plus a V-Block for curved loads. The range also includes top and bottom pads, packers, a Safe Build Trolley and a Start-Up Kit.
Each configuration is load-rated for a specific weight, provided the whole contact face is covered:
Stacko™ is tested to AS1170.0:2002 with a 3:1 safety factor, across a -50°C to +40°C temperature range, with less than 2% deflection at maximum load.
At up to 30% lighter than timber, Stacko™ removes much of the manual handling load of building a cribbing stack.
Full configuration details, dimensions and the Load Rating Matrix are available on the Stacko™ category page.
Timba™ blocks are solid, reusable polyurethane support blocks supplied in set lengths, for jobs that need a fixed block rather than a stack built to height — for example, supporting a component at a set clearance during a hoisting cylinder replacement. Timba™ is manufactured from rigid industrial polyurethane that doesn’t splinter or warp like timber.
The range covers seven sizes across three series, from 400mm to 1,800mm long, with load capacities from 18 tonnes up to 108 tonnes depending on size:
Size / Part No. | Length | Width | Depth | Weight | Capacity |
100 Series – 600mm (NPR02247-00) | 600mm | 100mm | 100mm | 3kg | 18T |
100 Series – 1200mm (NPR02249-00) | 1200mm | 100mm | 100mm | 5kg | 36T |
100 Series – 1800mm (NPR02248-00) | 1800mm | 100mm | 100mm | 8kg | 54T |
200 Series – 600mm (NPR02140-00) | 600mm | 200mm | 100mm | 5kg | 36T |
200 Series – 1200mm (NPR02246-00) | 1200mm | 200mm | 100mm | 10kg | 72T |
200 Series – 1800mm (NPR02142-00) | 1800mm | 200mm | 100mm | 15kg | 108T |
300 Series – 400mm (NPR02336-00) | 400mm | 300mm | 300mm | 13kg | 36T |
Timba™ is load rated at 30kg/cm² with a minimum load area of 100cm² (load rating = contact area x 30kg). It’s tested to AS1170.0 and ASTM D1621-10, and shouldn’t be used above 40°C or below -50°C.
Typical applications include hoisting cylinder replacements and general heavy-duty maintenance across mining and workshop operations. See the Timba™ product range for individual products.
Compare | Stacko™ | Timba™ |
Product type | Interlocking cribbing system | Solid support block |
Best suited to | Building a support stack to the required height | Applications requiring a solid block of a set length |
Available configurations | Single, double, triple and V-Block configurations, plus top/bottom pads, packers, Safe Build Trolley and Start-Up Kit | 7 sizes across 100, 200 and 300 series, from 400mm to 1,800mm long |
Material | Non-conducting, UV-stabilised virgin polyurethane | Rigid industrial polyurethane |
Load rating | 23,000kg (single) up to 60,000kg (triple/jack plate); 40,000kg for V-Block curved loads; tested to AS1170.0:2002, 3:1 safety factor | 18-108 tonnes depending on size (contact area x 30kg/cm²); tested to AS1170.0 and ASTM D1621-10 |
Selection method | Configure by required height and load | Select by required length and load capacity |
Factor | Polyurethane load support blocks (Stacko™/Timba™) | Timber cribbing |
Known load rating | Load rated to 30kg/cm² (AS1170.0; Timba™ also to ASTM D1621-10), with a 3:1 safety factor and less than 2% deflection at maximum load | No standardised testing or certification; load capacity varies with timber species, moisture content and condition |
Weight | Stacko™ blocks are up to 30% lighter than timber | Varies by species and moisture content; heavier to handle, particularly when wet |
Moisture and chemical resistance | Resists moisture, oil, salt water and most workshop chemicals | Absorbs moisture over time, contributing to swelling and decay |
Rot | Does not rot | Vulnerable to rot and decay from moisture exposure |
Splintering | Does not splinter or warp | Prone to splintering, creating manual handling hazards |
Reuse | Engineered for repeated reuse, with consistent size, shape and weight across units | Reusability declines as splintering, decay and moisture damage accumulate; conditions varied unit to unit |
Load ratings for the full range, verified through National Plastics & Rubber’s testing and Load Rating Certificate CER-A-230-V1.0.3:
Full load-rating matrices and load calculators are available in the Stacko™ Brochure and Load Rating Matrix, the Timba™ Brochure, User Guide and Load Rating Calculator, the Tray Support Brochure and User Guide, and the Dozer Push-Arm Support System Technical Data Sheet.
All load support blocks should be used on a flat, even, solid surface — never on a slope or a soft, compressible surface. The load should be applied to the full rated contact face; end faces are not load-bearing. Chassis and tray rails should sit parallel with block surfaces for full contact, and blocks shouldn’t be point-loaded.
Requirement | Product |
Build a support stack to the required height | |
Solid support block of a set length | |
Support a raised haul truck tray | |
Support for dozer push-arm maintenance |
Tray Support Blocks are matched to specific truck models:
The Dozer Push-Arm Support Block Assembly and Knuckle Block Assembly are matched to the CAT D10 and D11. If your equipment isn’t listed, our technical team can confirm the right fit.
Need help selecting the right load support system for your fleet or workshop? Request a quote or contact the National Plastics & Rubber team, and we’ll help you match the right Stacko™, Timba™, Tray Support Block or Dozer Push-Arm Support solution to your equipment and load requirements.
A load support block is a load-rated block positioned beneath a raised component — such as a truck tray, dozer push-arm, or other machine component — to support it during maintenance.
Yes. Stacko™ and Timba™ are designed as direct replacements for hardwood cribbing, gluts and dunnage. Both are load-rated to 30kg/cm² and tested to AS1170.0 (Timba™ also to ASTM D1621-10), and both resist moisture, oil, and most workshop chemicals in ways untreated timber does not. As with any load-support product, selection and use should follow the load-rating and configuration requirements for your specific application.
Yes. Stacko™ is tested to AS1170.0:2002 with a 3:1 safety factor and rated from 23,000kg (single) up to 60,000kg (triple/jack plate), with the V-Block rated to 40,000kg. Timba™ is tested to AS1170.0 and ASTM D1621-10, rated at 30kg/cm² with capacities from 18 to 108 tonnes depending on size. See the Stacko™ Load Rating Matrix and the Timba™ Load Rating Calculator for full details.
Stacko™ is an interlocking system for building a support stack to a required height, while Timba™ provides a solid support block of a set length. Choose Stacko™ when you need to configure height and load; choose Timba™ when you need a fixed-length block.
Tray Support Blocks are designed for this application and are available in sizes matched to specific truck models, including Caterpillar, Komatsu, Hitachi, Liebherr and Terex haul trucks. Selection should be based on your specific truck model – see the Tray Support Brochure and User Guide for the full fitment list.
Load support blocks should be used on a flat, even, solid surface – never on a slope or a soft, compressible surface. The load should bear on the full rated contact face; end faces are not load-bearing.
View individual Stacko™ Configurations to see load ratings.
