Developer and supplier of fail-safe braking systems and vehicles to the mining industry NCS Engineering reports that it is manufacturing its first pro- duction run of MaximB purpose-built, non- mechanised personnel-transporting trailers for black economic-empowerment group Imbawula Mining’s Msobo Coal at its facility in Nigel.

The order for these three trailers was received in January and was completed this month, says NCS Engineering director Jose Gil.

The MaximB nonmechanised low-profile trailers, to be towed by mine-ready tractors, are designed to carry up to 20 passengers. The trailer is about 6 m long, 2.2 m wide and 1.5 m high and is available in a low-profile configuration.

The trailers come standard with rear-axle- only mounted MaximB 300 Series M4 brak-ing systems.

In addition, NCS Engineering supplied South African precious metals junior Pan African Resources’ subsidiary, Barberton Mines, with six MaximB 200 Series LH 201 brakes for LH201 underground load-haul-dump (LHD) vehicles, six MaximB 500 Series EJC 65D systems for EJC 65 D underground LHD vehicles and four MaximB 200 Series Hino Moto tractor fail-safe braking systems in December last year.

Since then, the mine placed an additional order for five MaximB 200 Series Hino Moto tractor fail-safe braking systems. The order will be supplied to the client’s gold mine in Barberton, in Mpumalanga, next month.

Fail-Safe Braking Systems
Gil notes that there was a need for a braking system in the market that not only delivered from a braking performance point of view, but also offered benefits relating to the high maintenance and overall life-cycle costs of conventional braking systems.

These braking systems were typically installed on material-hauling vehicles; how- ever, the increased need for the safe trans-portation of personnel prompted the drive to design a system for modified commercial vehicles – the transportation of choice in underground mines.

To supply a complete solution for under-ground-mining commercial vehicles, which are fitted with fail-safe braking systems on the rear axle, and an original-equipment manufacturer’s (OEM’s) braking system on the front axle, NCS Engineering is in the final stages of developing a comprehensive MaximB 200 Series four-wheel fail-safe braking system.

The four-wheel system comprises either a brake for each wheel-end to provide service and fail-safe braking, or fail-safe brakes for only the rear wheel-ends. The hydraulic requirements for the braking system are supplied from the vehicle transmission.

NCS Engineering’s MaximB fail-safe brak- ing systems are fitted only to vehicles used in mining applications, specifically in under-ground and opencast mining applications.

The company’s range of braking systems, specifically larger braking systems, is aimed at trackless mining vehicles, such as LHD vehicles. However, the company recently focused on developing braking systems for smaller commercial and trailer-type vehicles.

Gil adds that, in the past, the company successfully commissioned customised braking systems for local and international markets.

The fail-safe brake design is modular to enable it to be customised for a wide range of vehicles, with only slight modification to the brake itself. The installation of the braking system is simple, quick and relatively cheap and eliminates lengthy installations owing to axle modification.

Innovation and upgrades to the original NCS Engineering brake design include improved seals and friction materials and additional electronic safety features, such as coupling the vehicle’s speed to the automatic actuation of the braking system through a purpose-design speed-control unit, as mine safety is key, says Gil.

This development will enhance the safety features of the braking system and will also have a positive effect on the maintenance requirements of the braking system.

Further, NCS Engineering is also in the testing phase of a comprehensive braking system for towed trailers in underground and opencast mining applications, adds Gil.

All MaximB brakes are tested individually and in-house on a brake test dynamometer, after which each brake receives a serial number and a corresponding test certificate.

How It Works
The MaximB braking system is a wet and fully enclosed disc braking system that works on the principle of oil shear. The brakes have separ-ate, hydraulically applied service and spring-applied fail-safe brake pistons, which function on a common friction disc pack.

It is designed to keep contaminants out of the braking components and to automatically actuate, subsequent to a loss of energy in the braking system, should the vehicle experience electrical or hydraulic failure.

As a result of the brakes being used under-ground, the braking systems are rated for low-speed operation, as governed by mining regulations.

The MaximB modular braking system was developed because of the need to meet braking performance without having to per- form any modification to other OEM-sup-plied componentry to reduce potential risks associated with modification.

“Most of the fail-safe braking-system com- ponents are manufactured in South Africa and only a limited amount are imported. NCS Engineering aims to supply an affordable system, with added benefits, which is manu- factured under its control, to ensure quality and the cost effectiveness of the product,” says Gil.

Maintenance and Repairs
“A challenge experienced at South African mines, which may result in accidents, owing to the inadequate braking capabilities of underground vehicles, is the lack of a proper maintenance system or adequate preventive maintenance scheduling,” says Gil.

This can be caused by cost-saving measures and a singular focus on production. To over-come this, NCS Engineering MD Charles Davis suggests that braking systems be certi- fied, which entails regular testing of the sys- tems to ensure that they still meet under-ground braking specifications.

Brake performance verification is done on underground trackless mining vehicles with a Simret-type brake tester in accordance with the SANS 1589 specification for braking systems, and diversified miner Anglo American’s AA23600100 specification for the deceleration distance for rubber-track vehicles.

The braking system itself is once again tested when the brakes are fitted to a trailer, says Gil.

This certification ultimately tests the brake’s static and dynamic functionality. It indicates the braking torque achieved, the brake’s ability to fulfill its function under load and its ability to operate at specified speeds to prevent the occurrence of an accident, owing to brake failure, explains Gil.

It also helps to reduce maintenance costs through regular checking and repairing of brakes, as opposed to replacing brakes as a result of poor maintenance.

Further, Gill notes that the decision by mining companies to have their vehicles’ brakes repaired by non-OEM-certified com- panies generally leads to the use of sub-standard replacement parts, which will affect the ability of the brake to fulfill its design purpose to brake a specific load travelling at a specific speed within a specified time.