Queensland Coal Mine – Sound Attenuation

New Acland Coal operates a 24/7 open-cut coal mine in Queensland under some of the most stringent acoustic regulations in Australia. The site must maintain compliance with boundary noise limits below 42 dB(A), with even tighter thresholds at night, while continuing to meet production targets. To support increased material movement, the mine introduced a Caterpillar 993 wheel loader, supplied by Hastings Deering, which required a compliant sound attenuation solution prior to commissioning. Minetek was engaged to deliver a solution that aligned with both regulatory requirements and OEM performance standards from day one

At OEM specification, the Caterpillar 993 generates sound levels exceeding 116 dB(A), creating immediate pressure within a site governed by cumulative noise limits. Any increase in mobile equipment noise reduces the available compliance margin across the entire operation, limiting deployment flexibility near boundary zones and during night-time periods. The machine could not be commissioned and adjusted later. It needed to meet acoustic requirements immediately while preserving airflow, backpressure, and thermal performance to protect reliability and warranty. The challenge was precise. Deliver measurable noise reduction without compromising machine integrity or delaying delivery timelines.

Minetek engineered and installed a customised M-STEALTH™ Sound Package specifically for the Caterpillar 993 platform. The solution was designed to reduce noise at source while maintaining full OEM performance across airflow, thermal dynamics, and backpressure. Detailed assessments of the machine’s configuration enabled the integration of purpose-built acoustic components without impacting serviceability or reliability. Delivered within a 10-week window aligned to equipment supply, the solution was fully integrated prior to commissioning, ensuring the machine entered operation compliant with site requirements.

Post-installation testing confirmed a reduction from 116 dB(A) to 110 dB(A), delivering a measurable 6 dB(A) improvement in sound output. This reduction translated into a significant increase in operational flexibility, allowing the machine to operate up to 450 metres closer to boundary receptors under standard conditions. The quieter acoustic profile improved compliance margins, supported continuous 24/7 operations, and reinforced regulatory confidence. The outcome extended beyond technical performance. It enabled sustained production while protecting community relationships and long-term operational continuity.