Mobile Heavy Diesel Mechanics at Crown Jewel Boorara.

Service Requirements at Crown Jewel Boorara

Diesel fleet preservation is the primary mechanical obligation at Crown Jewel Boorara during its current care-and-maintenance phase. With open pit earthworks having commenced in August 2024 and ore processing routed off-site to the Paddington Mill facility, the on-site equipment inventory — including haul trucks, excavators, and ancillary mobile plant — must be maintained in a preserved, recommissionable condition rather than driven toward production cycle targets. Horizon Minerals Limited holds this asset base against future reactivation, meaning mechanical scope must prioritise corrosion control, fluid integrity, drivetrain preservation, and scheduled statutory inspections over throughput-linked service intervals. The quartz dolerite geology and associated sheeted vein structures that characterise the Crown Jewel Boorara ore body drove the selection of heavy open pit equipment suited to competent hard-rock conditions; that same equipment class — with its high-torque drivetrains and hydraulic-intensive dig cycles — defines the diesel mechanical scope now requiring care-phase management. Scope documentation should specify minimum drivetrain preservation service interval compliance to OEM care-and-storage standards as a minimum performance threshold.

• Care-and-Maintenance Service Regime: Contractor must demonstrate documented delivery of care-and-maintenance mechanical programs on a minimum of two (2) open pit gold or hard-rock mine sites within the last five (5) years, with written evidence of asset preservation outcomes (recommissioning readiness reports or equivalent).
• Thermal Operating Competency: Demonstrated service delivery in sustained ambient temperatures of 40°C, with documented procedures for peak thermal events reaching 44°C — including engine cooling system diagnostics, hydraulic fluid viscosity management, and battery/electrical system protocols under high-heat conditions. Minimum 18 months Goldfields-Esperance site exposure required within the last five (5) years.
• Heavy Mobile Equipment Scope Coverage: Contractor must hold current OEM authorisation or demonstrated competency across at least two (2) of the following equipment classes relevant to open pit hard-rock operations: rigid or articulated haul trucks (≥100-tonne payload class), hydraulic face shovels or excavators (≥200-tonne operating weight), or graders and ancillary support fleet. Competency evidence must be submitted with tender response.

Site-Specific Operational Constraints

Conditions procurement must communicate to all bidders in tender documentation for Crown Jewel Boorara.

• Environment: The East Coolgardie district delivers sustained summer ambient temperatures of 40°C with recorded peaks to 44°C, combined with fine laterite and silica dust loading that accelerates air filter cycles and fuel system contamination. Diesel mechanics must carry site-rated PPE and heat management protocols; tender documentation must specify minimum fluid-change intervals adjusted for Goldfields thermal and dust conditions.
• Logistics: Crown Jewel Boorara sits approximately 563 km from Perth via the sealed Great Eastern Highway corridor, with the nearest regional logistics hub at Kalgoorlie-Boulder (~17 km). All parts, consumables, and tooling mobilisation plans must account for this distance; contractors must nominate a Kalgoorlie-based parts staging arrangement or equivalent pre-positioned inventory strategy within their method statement.
• Response SLA: Care-and-maintenance phase requires a scheduled preventive maintenance window model rather than continuous on-call coverage; however, unplanned breakdown response for any recommissioning-critical asset must be achievable within 4 hours from Kalgoorlie staging point, with full field crew mobilisation within 24 hours for extended fault rectification.
• Roster: FIFO access via Kalgoorlie-Boulder Airport and the Eastern Goldfields road network must be detailed in the contractor's method statement. Given the 563 km Perth logistics envelope, roster plans must nominate a Kalgoorlie-resident or Kalgoorlie-staged crew component to meet the 4-hour response threshold. Fly-in rosters from Perth are acceptable for planned maintenance windows only, with minimum 48-hour advance mobilisation notice built into the schedule.
• Camp/Facilities: Site infrastructure includes grid-connected power supply and reticulated water, reducing contractor dependency on self-generated utilities. Contractors must confirm whether on-site accommodation is required or whether Kalgoorlie-based accommodation with daily drive-in access is operationally viable; the method statement must address this explicitly for both planned and emergency attendance scenarios.

Contractor Capability Checklist

Minimum evaluation criteria for shortlisting Mobile Heavy Diesel Mechanics contractors at Crown Jewel Boorara. Each criterion must be verifiable via documentation submitted with tender response.

• Technical certifications: Current OEM authorisation for at least one heavy mobile equipment platform in scope (haul truck, excavator, or grader class); evidence of competency in care-and-maintenance or long-term asset preservation programs; AS 4024 machinery safety compliance awareness where applicable to field service tooling.
• Personnel tickets: All field technicians must hold a current WA Recognised Trade Certificate (Heavy Diesel Fitter or equivalent) or interstate equivalent with WA recognition. Surface mine site induction certification (MARCSTA Gold Card or site-equivalent) required for all personnel prior to first site attendance.
• Mobilisation SLA: Documented evidence of ≤4-hour emergency response from a Kalgoorlie-equivalent staging point, drawn from at least one prior Goldfields-Esperance engagement within the last three (3) years. Response time commitment must be supported by a logistics plan, not a declaration only.
• Public Liability insurance: Minimum AUD $20M per occurrence (Certificate of Currency required with tender response).
• Professional Indemnity: Minimum AUD $10M aggregate — mandatory where contractor scope includes technical specification of replacement components, service interval recommendations, or asset condition reporting that informs recommissioning decisions.
• Workers Compensation: Full statutory cover under WA law (WorkCover WA — Injury Management Plan required and must be submitted with tender response).
• Site exposure: Minimum 18 months cumulative experience on open pit gold or hard-rock mine sites within the Goldfields-Esperance region, within the last five (5) years. Exposure must be evidenced by reference contacts or site engagement records, not self-declaration alone.
• Safety systems: HSE management system certified to ISO 45001 or equivalent documented standard; demonstrated ICAM (Incident Cause Analysis Method) investigation capability required, given the care-and-maintenance phase obligation to maintain a low-incident asset preservation environment ahead of potential reactivation.

Regulatory & HSE Framework

All mechanical work at Crown Jewel Boorara is governed by the Work Health and Safety Act 2020 (WA) and the Work Health and Safety (Mines) Regulations 2022 (WA), administered by WorkSafe WA. Under the care-and-maintenance classification, the site's principal hazard management obligations remain active — contractors performing diesel mechanical work on preserved plant must maintain compliant lock-out/tag-out (LOTO) procedures, confined space protocols for fuel and hydraulic system access, and hazardous substances management consistent with the WHS (Mines) Regulations 2022 requirements, regardless of reduced production activity. Horizon Minerals Limited retains principal contractor obligations under the WHS framework for this site; all engaged mechanical contractors must integrate their safe work method statements (SWMS) into the site's principal hazard management plan prior to mobilisation. Supplier portal not publicly confirmed. Verify via Horizon Minerals Limited corporate procurement contact. All contractors must complete site-specific induction via Horizon Minerals Limited procedures before mobilisation.

Sourcing Qualified Contractors

No recent tender activity for Mobile Heavy Diesel Mechanics at Crown Jewel Boorara has been confirmed through publicly available procurement channels. The regional labour pool for this service in the Goldfields-Esperance district is centred on Kalgoorlie (~17 km from site), with approximately five (5) active providers identified as operating in the region. This is a constrained supply market relative to the specialised care-and-maintenance mechanical scope required; procurement must not assume standard operating mine service levels are transferable without scope adjustment. Shortlist criteria should weight Goldfields-specific site tenure and demonstrated care-phase program delivery above general diesel mechanical capacity. No incumbent contractor has been confirmed through available market intelligence; procurement must conduct a full open-market prequalification process. Given the limited regional pool and the need to validate care-and-maintenance program credentials specifically, allow a minimum of six (6) weeks for prequalification, capability assessment, and onboarding prior to first scheduled maintenance window.