Darling Downs Coal Mine – Caterpillar 993 Sound Attenuation

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Turn-key M-STEALTH™ sound attenuation package to reduce the noise output of the Caterpillar 993 Loader

The Caterpillar 993 is a large-scale wheel loader engineered for demanding mining operations. This machine is equipped with a powerful Cat C32B engine, delivering gross power of 775 kW / 1,039 HP and net power of 726 kW / 974 HP, incorporating advanced management systems and optimized efficiency. With an operating weight of approximately 133,668 kg / 294,687 lb and a bucket capacity ranging from 12.2 m³ / 16 yd³ to 23.7 m³ / 31 yd³, the Caterpillar 993 features an advanced operator cab that safeguards against dust and noise while providing superior visibility in challenging mining environments. With its robust engine, advanced hydraulics, and comprehensive monitoring capabilities, the Caterpillar 993 wheel loader stands as a dependable solution for large-scale mining loading tasks.

Minetek’s turn-key M-STEALTH™ package effectively reduced the noise levels from 115 dBA pre-attenuation to 110 dBA post-attenuation, achieving a sound reduction of 5 dBA. This enhancement enabled the machine to operate 450 metres closer to site boundaries while maintaining full regulatory compliance by maintaining sound noise levels on site below 42 decibels during daylight hours, and even lower at night.

Industry – Mining
Mine type – Open-cut
Mineral – Coal
Location – Darling Downs, Queensland, Australia
Product/Scope – Turn-key M-STEALTH™ Package on the Caterpillar 993 Loader

Breve

The client required a robust sound attenuation solution to meet stringent asset-level noise requirements for their Caterpillar 993 Loader. The goal was to reduce the cumulative sound power generated by surface operations while minimizing emissions, without compromising performance or payload.

Desafio

Faced with some of the strictest noise regulations in Australia, the client required a sound attenuation solution for their Caterpillar 993 Loader that could meet sub-42 dBA site limits during daytime operations, and even lower at night. The mine operates under constant scrutiny, with nearby residents and sensitive noise monitoring receptors continuously measuring site emissions. Failure to meet these stringent requirements could impact production schedules and environmental licensing. As one of the first Caterpillar 993s to arrive in Australia, this project presented unique design and engineering challenges.

Scope

Minetek Sound was engaged to attenuate Caterpillar 993 Loader with a custom solution that:

- Achieved maxiumum noise reduction
- ensuring the machine’s warranty and service life remained intact.
- Used minimal componentry to preserve payload efficiency
- Maintained strict OEM backpressure, airflow tolerances and thermal performance

Minetek’s in-house team developed a tailored M-STEALTH™ Sound Package, purpose-built to accommodate the loader’s advanced configuration. Despite the complexity, design, engineering, and fabrication were completed in just 10 weeks.

Resultados

- Noise reduction: From 115 dB(A) to 110 dB(A)
- Compliance: The machine can now operate 450 metres closer to site boundaries while maintaining full regulatory compliance
- Efficiency: Completed ahead of schedule with no safety concerns during installation or commissioning.

This project exemplifies Minetek’s capability to meet extreme compliance standards while delivering fast, safe installations and maintaining machine integrity. By reducing noise emissions without compromising performance, Minetek enabled the mine to operate confidently within its regulatory limits, thereby protecting both productivity and community trust.

Pre attenuation

115 dBA

The Caterpillar 993 Loader registered a factory sound frequency level of 125 dBA prior to Minetek Sound Attenuation.

Post attenuation

110 dBA

The sound output of the Caterpillar 993 Loader was tested after installing Minetek’s turn-key M-STEALTH™ sound attention solution. This registered a sound frequency level of 110 dBA.