Reducing glare at mine sites

Image: HELLA

HELLA Australia has been brightening mine sites with its glare-free lighting solutions for some time now. Australian Mining speaks to HELLA Australia’s Stefan Kisser and Trent Launer to find out about how the company’s lighting is making mines safer.

Ensuring safety on mining trucks and haul roads is a critical part of an open cut operation.

Some iron ore sites in the Pilbara, Western Australia have more than 50 massive haul trucks operating around the clock.

This raises numerous safety challenges, particularly at night when vision can be impaired on the extensive haul road networks at these mines.

Lighting solution specialist HELLA responded to the lighting challenges in the mining industry by developing solutions to reduce potentially dangerous levels of glare from headlights.

This prompted HELLA to develop its Zeroglare range of work lights in 2015 following extensive research and development.

HELLA designed Zeroglare to introduce a headlight for mining vehicles that was more in line with the heavily regulated on-road lighting technology common to commercial fleet and road vehicles.

With the advent of improved lighting technology, modern on-road vehicles are generally capable of focusing the maximum possible amount of light on the road, while minimising wasted light and glare for oncoming traffic.

HELLA applied this design philosophy to mining trucks by introducing cut-off lines to prevent light leaking beyond the horizontal line.

Stefan Kisser, HELLA Australia’s applications engineer, is surprised that this innovation to eliminate glare wasn’t being applied to mining vehicles earlier.

“On passenger cars and trucks, glare is a problem that has been addressed for many decades now,” he explains. “Modern road vehicles use a low beam function with no light above the horizontal line to avoid producing glare for oncoming traffic.

“In mining equipment, those lights are completely different, with optics very similar to what you would find in a ceiling light in your home.”

Typical mining lights tend to produce circular beams that, while powerful, produce a lot of wasted light.

The headlights of a haul truck will light a dark road reasonably well, but their circular beam pattern means that half or more of the light produced points straight or in the air. This wasted energy can cause potential dangers for oncoming traffic, whether it is another haul truck or a light vehicle, due to issues with glare.

Two decades ago, mining companies didn’t consider light glare an issue, as lighting technology was not as bright. The headlights of a typical mining truck in the 1990s using halogen lighting may have produced 1000 lumens (lm) a bulb — a lumen being the standard measurement of light output — but more modern xenon high-intensity discharge (HID) and light-emitting diode LED work lamps can produce around 3000–8000lm.

These issues are exacerbated further as mine vehicle lighting is not held to the same Australia Design Rules (ADR) and Standards Australia (AS) regulations as road vehicles.

“Mining lighting falls into off-road lighting,” explains Kisser. “ADR is not directly applicable, but engineers do need to understand the purpose of the lighting when working on the designs.

“Our main product for haul trucks, the RokLUME 380, which has a measured output of 7500lm, has a total of five different optic setups (including Zeroglare) for example.”

Different types of mines can also affect the requirements for lighting output due to a factor known as ‘albedo’ – the proportion of light or radiation that is reflected or absorbed by a surface. Black coal for example, tends to absorb a lot more light than lighter-coloured surfaces.

The stopping distance is another consideration that needs to be considered when lighting mining trucks as opposed to road vehicles. The size and weight of mine trucks, in combination with their heavy loads, means they take longer to slow down, a reason why additional forward visibility is crucial for safe operation.

“What the Zeroglare does is put light where it’s needed,” explains Trent Launer, off-highway national sales manager at HELLA Australia. “The concentration of light is on the road in front rather than having stray light

“Hence the focus on ensuring that disability glare is removed from the top section of the beam, and that the line of brightness has a sharp physical cutoff to ensure full brightness all the way to the uppermost edge of the light beam.”

The RokLUME 280 and RokLUME 380 product lines, which use LED lighting, are the standard mining headlights with HELLA Australia’s Zeroglare. The RokLUME 280 can produce 4300 measured lumens at a power output of 55 watts (W), while the RokLUME 380 can produce up to 7500 measured lumens at a power output of 84W.

In addition, the smaller RokLUME 155TP and 190TP are also available.

HELLA’s work lamps include various optic patterns including Zeroglare, close-range, long-range, pencil beam and flood.

The RokLUME range (280 and 380) also offers an advanced NanoSafe surface coating.  NanoSafe is designed with an easy-clean, corrosive-resistant coating for the harsh conditions of mine sites. Amber lights, also called ‘turtle-friendly lights’, are designed for low visual sensitivity in coastal areas so the delicate breeding patterns of marine turtles are not disrupted.

RokLUME 190 TP and RokLUME 155 TP are developed specifically for mining applications and have a high-quality thermos plastic housing for heavy duty use – deliberately made to handle corrosive environments.

The lights are also designed to operate in a temperature range from negative 40C to 50C, ensuring they are suitable for the harshest weather temperatures. The diverse and adaptive lighting range allows HELLA Australia to develop customised solutions for its clients.

RokLUME lenses are comprised of high impact-resistant materials, with a stainless-steel bracket and a premium-grade, anticorrosion aluminium housing. Adverse effects caused by vibration are reduced through an advanced rubber dampening system.

HELLA Australia’s product range also includes lighting for fixed installations. Its HypaLUME light, designed primarily for lighting towers and excavators, is the company’s most powerful light for mining. It is capable of producing up to 25,000 lumen of light, around 31 times greater than an average 60W light bulb.

“Rather than use multiple lamps it gives operators the ability to use one large lamp,” says Launer.

“It uses a unique design where heat sources are separated to help create a high-powered lamp that’s proven to last in harsh mining environments. It has a high IP rating and is particularly well-suited to handling highly corrosive environments.”

HELLA Australia aims to customise the lighting needs of trucks by site and scenario, rather than simply replacing old lights with new ones.

“We work with the client to produce lighting designs before we go to the fitment stage,” explains Launer. “We want to solve the problem that they have, rather than just swapping out what’s currently there on the machine. It’s about providing a tailored solution for the client and their site requirements.”

“Sometimes the goal is to increase safety, sometimes the goal is to increase productivity,” adds Kisser. “If you can increase the light level to the extent that the average speed of the haul trucks can safely increase by even two or three kilometres per hour per night, that equates to a couple of extra trips per night, or a couple of hundred tonnes of additional ore.”

HELLA Australia uses computer-aided design (CAD) software to pre-visualise various setups for its clients and to ensure that they are using the optimum lighting required, with no wastage. CAD models of haul trucks allow demonstrators from HELLA Australia to reposition lighting in real-time simulations.

“Quite often we can reduce the number of lights and create the optimum amount of lighting,” explains Launer.

The HELLA optical lab measures light output. The measurements are loaded into the CAD based lighting software.  The data is used to design the safest and most efficient customised lighting solution for the client. The method is indicative of HELLA Australia’s bespoke approach to lighting design and technology.

“The computer-aided lighting design removes the guesswork from lighting,” explains Kisser. “We can predict the outcome before the mine site has to spend a single dollar.”

After the simulation has been carried out, clients are offered a trial period to test the lights preceding an agreement.

The process of attaching the lights is made relatively simple due to their use of standardised DT connectors, providing ‘plug-and-play’ efficiency, though power consumption does have to be taken into consideration, particularly when changing from older to newer lighting technologies.

“All HELLA mining products come with DT connectors, so if the harness comes with the right connector you can just plug it in,” says Kisser. “You may have to drill a new hole if the bracket is slightly different from the previous product but overall the changeover is easy.”

“The lamps are made with a variety of sizes to fit a range of applications and different cavities,” adds Launer.

This holistic, technology-led approach to mine lighting is indicative of a wider industry trend towards increased connectivity and smart functions. Kisser believes that ‘smart lighting’ common to road vehicles will become increasingly important for mining applications.

“I sometimes wonder why this didn’t happen 20 years ago, but the fact is nobody did it in the mining industry and as of today, there aren’t any products with the same level of performance as Zeroglare in the market,” says Kisser.

“If you look at some of the automotive applications on passenger cars, many vehicles come with LED lighting and automatic high-beam and low beam functions.

“As you drive, the car is always on high-beam when you are outside of a town and there are sensors in the vehicle that will dip areas of your vision into low beams when traffic is oncoming, minimising areas that would be affected by glare.

“There are so many other technologies that could be transferred from automotive applications into mining — perhaps too many to list — and I believe similar systems will most likely become available to heavy duty equipment found in mining over time.”

This article originally appeared in the September issue of Australian Mining.

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