Replace timber excavator load pads with polyurethane

Collaboration Case Study: Excavator Load Pads

March 31, 2023

National Plastics & Rubber continuously works with clients to address new and emerging challenges across heavy industry. We specialise in creating a safe work environment, improving ergonomics, and providing engineered responses to critical incidents. Our problem-solving ingenuity along with commercially viable solutions have been utilised by a range of industries including aviation, manufacturing, construction, hydraulic and automotive.

We recently worked with a large Mining Client in Western Australia to develop Polyurethane Excavator Load Pads in response to a critical safety hazard.

The Problem

The client had been using timber slabs on their Excavator Lift Platforms which, when the machine is in place, tensions and raises the top of track to enable easier access to perform underbody maintenance.

The timber product on the platforms posed significant safety risks to employees. The weight of the machine and tracks chewed into the timber creating splinters, cracks, and extreme wear rather quickly. Maintenance crews were also faced with the cumbersome task of manually handling the timber into position, prior to performing maintenance tasks on the Excavator while relying on the slabs to support the machine.  Despite timber being a common ‘easy choice’ for cribbing, machine support, and chocks, its composition is unknown, is not load-rated, or undergone extensive testing.

Timber excavator load pad platform     Damaged timber cribbing load support

The Solution

Through our existing relationship with the client, we were approached for an innovative solution to replace these timber slabs. Our product design team proudly took on the challenge to develop safer, durable alternative. The solution involved four load-rated Polyurethane pads specifically manufactured to suit the client’s platform. The pads are stable enough to support an excavator, while being portable enough for two persons to move into position. The design features our patented High Traction surface and lifting eyes with polyurethane handles to improve ergonomic handling.

Polyurethane excavator load pad platform    Lightweight excavator load platform pads

NPR has developed a range of products aimed at replacing the use of timber in workshop environments, including for example, our Stacko™ Block System. This is another example of NPR’s commitment to our client’s continuous improvement and is a testament to our refined product design process. If you have a safety, reliability or productivity concern on site and believe an innovative polyurethane, rubber, or industrial plastic product is the solution – contact us today and work with the industry innovators!

Contact NPR to discuss collaboration opportunities.

earthmoving dozer ripper arm frame cover - dozer maintenance

Dozer Ripper Frame Cover

March 15, 2023

National Plastics & Rubber are proud to launch our new Dozer Ripper Frame Cover

dozer ripper frame arm cover - lightweightOEMs, mine site maintenance crews, and workshop employees face the risky task of dozer maintenance on the daily. Safety managers are continuously seeking new ways to reduce hazards and the severity of the risks they present. Our new Ripper Frame Cover aims to create a safe work platform on the ripper arm.

Take the risk out of dozer maintenance with our load rated and lightweight Dozer Ripper Frame Cover. The ripper cover sits over the hole in the ripper frame and allows workers to perform all maintenance tasks without the hazard of falling through the hole.

Maintenance teams are currently using timber blocks and steel coverings to plug the hole. These “quick fixes” create additional risks for employees – they are heavy to manoeuvre, become a hazard for hand and finger injuries, as well as, crushing incidents.

earthmoving dozer ripper arm frame cover - dozer maintenanceAs a result, we developed a lightweight polyurethane Ripper Frame Cover designed to suit both Caterpillar (CAT) D10 and D11 dozers. Our cover allows you to perform all maintenance tasks without worrying about dodging the hole. Safely reach any overhead areas, hydraulics, and engine systems without risking a serious injury – crouch, lay, sit, or stand – it’s got you.

The cover features a number of benefits making it the superior choice for a safer workplace. Extra grip is provided with our patented high traction surface on the top of the cover. Independent and field tested, the cover is load rated up to 120kg – remaining stable with you and your tools on it.

Eliminating the risks associated with using steel coverings, our polyurethane cover is light enough (14kg) to be lifted overhead and slid into position by the maintenance crew before climbing on the ripper arm.

earthmoving dozer ripper arm cover


Lead the way for safety across your site – inquire today about our Dozer Ripper Frame Cover! Give us a call on 07 3279 3066 or email

PART NO: NPR08051-00

Wheel Chocks for haul trucks & large vehicles.

Chocks that stop!

February 17, 2023

National Plastics and Rubber wheel chocks have evolved to meet changing industry demands. An increase in regulation and mine site safety requirements drove the innovation of our range of lightweight wheel chocks. 15 years ago, NPR used to manufacture and supply a heavy range of chocks to national and international mining companies. Due to the desire for companies to embrace safety and an incident free culture – we replaced this range with polyurethane lightweight wheel chocks. Plastic and rubber wheel chocks do not present the same safety features as our innovatively designed wheel stoppers. The aim of our chocks is to directly address the health and safety risks associated with manual lifting on site.  Our entire range of wheel chock sizes from light vehicles (size 1.5) to even the heaviest of mining trucks (size 7) can be stopped with NPR’s Australian made wheel chocks.

Our chocks feature a unique design unlike any other chock on the market. All wheel chocks in our lightweight range, except size 4/3, incorporate the “toe” design. This design ensures the tire engages with the toe of the chock before it engages with the face of the chock; locking the chock and preventing it from slipping in extreme conditions. The success of this design is demonstrated by its adaption to our range of aviation wheel chocks – AerochockTM.


To compliment our wide range of wheel chock products, we have developed a size 4/3 wheel chock. This chock features the angled design of the size 3 on one side and size 4 on the other. We anticipated the different operational areas that chocks will be used across mine sites -from workshops to extreme remote locations. The 4/3 wheel chock was designed for service trucks to take with them when going out to service vehicle breakdowns. Instead of carrying multiple sized chocks, the mechanic will only need to take one chock with them. The chock may appear “double sided”, however you are only required to use one side or the other depending on vehicle and tire size. The chock covers all vehicles that wheel chock size 3 and 4 suit – this is the widest range of commonly used mine trucks.

How to use wheel chocks

All company and site specific safety requirements, policies, and procedures must be adhered to. Users are reminded to consider the number of variables that could affect a wheel chock’s performance.

Before using your heavy duty wheel chocks, it is important to check the chock for damage or missing components – like handles or cracks on the face of the chock. If you identify any kind of damage, discard the chock as it will be unsafe for use.

When chocking a vehicle on level ground, whether loaded or unloaded, we recommend using a minimum of two wheel chocks. Place one wheel chock in front, and one behind, of the front tire of the vehicle.

Where a vehicle is parked on a gradient, mine safety authorities have indicated that wheel stoppers are only required to be placed on the downhill side of the tire only. Chocks placed on the uphill side of a tire have no effect on securing, stabilising, or preventing unwanted movement of a large vehicle. If a haul truck is loaded on a gradient, four chocks placed on the downhill side, front and rear tires. When chocking an unloaded vehicle, we recommend using a minimum of two chocks depending on chock size. Place a chock on the downhill side of the left and right side tires on the downhill side of the vehicle.

Importantly, you must always ensure that the chock is fitted square in the centre of the tire.

Only remove a wheel chock it is safe to do so.

What is the workshop wheel chock?

We were recently approached by a large mining company to develop a purpose designed wheel chock product for the workshop environment. The features of our standard range of lightweight wheel chocks are reflective of the harsh conditions chocks face on site, including up to a 10% gradient. This conditions simply do not exist in a workshop environment, therefore altering the product requirements of a workshop chock. NPR’s workshop wheel chock features a unique design with wheels and handles to easily manoeuvre the chock around the workshop – reducing manual handling risks and eliminating the need to go under the footprint of the truck. Tilt the chock onto its back wheels to push chock to vehicle – when you get to the vehicle simply tip onto front wheel and use handles to help position chock square against the tire. Watch our instructional video.

Recognising its contribution to safety in the mining industry, the workshop wheel chock won both the Innovation Award and Peoples Choice Award at the QLD Mining Health & Safety Conference 2022.


What are bearingless rollers?

December 12, 2022

National Plastics & Rubber are the proud manufacturer of bearingless roller systems used across draglines, shovels and other mining equipment. Our innovative system was created in response to the numerous disadvantages presented by traditional roller systems.

Traditional roller systems consist of polyurethane bonded to a solid shaft that rotates on bearings. There are many disadvantages to this system:

1.      Wear out easily

The systems can wear out easily due to rope wear patterns, requiring consistent maintenance. As the polyurethane is bonded to the shaft along the whole length – and the rope generally wears on one section – the whole system needs to be restriped and lagging replaced, although wear has only occurred to one section.

2.      Cost of replacement

The cost of replacing a traditional roller system is unnecessary and unsafe. As the polyurethane is bonded to the shaft, when a segment needs replacing due to wear, the entire roller system must be removed and replaced. This is an expensive task requiring a crane or other lifting equipment to get the system out.

3.      Cost of having spares in stock

To keep machine downtime low, the system needs to be replaced almost immediately after it has been removed. That means numerous spare roller systems, in different sizes, need to be held in stock. There is also often a long turnaround time and lead time if you have stock and need to wait for a replacement roller system.

4.      Bearings can seize up

The bearings can seize up and the roller will then stop turning – causing the rope to wear through.

In response to these concerns, National Plastics & Rubber designed, tested and manufactured our now globally trusted bearingless roller systems. These systems pose many benefits to the mining community – improving safety, machine uptime and site productivity:

1.      Easy replacement

Our bearingless roller segments are manufactured from lightweight polyurethane and can be handled by hand (avg. 8kg) – eliminating the need for a crane or other lifting equipment.

2.      Standardisation

We encourage you to have the same segment across all areas of your machines. This will eliminate the need to store and stock multiple segment sizes and roller systems – a problem encountered when using traditional roller systems. Here, if you are using the same segment, no matter what length shaft or aperture you encounter, you only need to stock one segment – no need for different bearingless roller segments.

3.      Segment rotation

Bearingless roller systems provide you with the ability to rotate out segments that are experiencing wear. The worn segment can be rotated out and used as a spacer – and a new (unworn) segment can be shifted into the wear area. As a result, all of the material can be used, compared to a standard roller where if one section is worn out the whole roller system will need replacing.

4.      Bearing free

Of course one of the main benefits of our bearingless roller systems is that they are bearing free! Therefore eliminating the need for maintenance of the bearings as the segments simply rotate on the shaft. The bearingless roller system comes greased as well to ensure smooth rotation.

At National Plastics & Rubber we strive for continuous improvement, always seeking new innovation opportunities to meet customer inquiries and challenges. We possess state-of-the-art product design facilities to advance our current product range through customisation. Recently we designed a specific roller system to ensure continuous movement and free flowing spin of segment rollers.

National Plastics & Rubber looks forward to the opportunity to supply your site with bearingless roller systems. Give us a call on (07) 3279 3066 or email for more information or to arrange a shovel or dragline inspection Australia.

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