Four Motion Australia business units – CMA, CRAM, SMS and CBC – have combined to design, build, install and commission a hydraulic guillotine gate for the ore crushing cycle at one of Australia’s leading iron ore miners.

The gate is designed to shut off the bottom of the feed hopper and prevent any ore from dropping onto the crusher feed belt. It is specialised equipment which ensures the site’s maintenance teams can safely carry out any work necessary.

By installing this gate, the maintenance team can isolate a feed hopper and do the maintenance work on the belt feeder and crushers downstream while the rest of the plant keeps operating.

The mechanical design work of the gate was completed by a Perth-based consultancy who called in CMA to assist with the hydraulic design for the operation of the equipment. This design collaboration, and a long-term professional relationship with the miner, led to CMA being awarded the full project.

The input of the four Motion Australia business units took this project from being a design on paper to ultimately installed and commissioned in an iron ore mine in the Pilbara.

CMA was responsible for the design of the hydraulic system including the HPU (hydraulic power unit), the SMS heavy fabrication workshop at Unanderra manufactured the gate and its infrastructure and CRAM supplied, manufactured and fitted the necessary hydraulic pipework including the fail-safe lockout system. A Perth-based CBC engineer was able to provide technical support at site during commissioning – an important aspect of the project given that a pandemic had meant interstate travel was not possible at the time.

Although working to detail drawings the technical expertise and experience within the business units involved allowed for on-the-run improvements to the gate as the job progressed.

CMA was able to overcome an issue with the clevis ends on the hydraulic cylinders. The specified pins were sized correctly for their material property however the load rating of the clevis itself hadn’t been taken into account. When this was discovered a quick consultation with the customer, the hydraulic cylinder supplier and the engineering consultants saw the clevis and pin resized to suit the load in the application. A minor change and rework which possibly avoided some unplanned downtime.

SMS engineers found that the weld-on trunnion mounts for the cylinders didn’t leave any room for any adjustment of the mounting points – an important consideration on such a long-welded structure as the gate. A new design was proposed – trunnion mounts which would bolt on to the structure and give the flexibility needed. The variation was approved, and new mounts quickly manufactured, and the project stayed on track

The project had a three-month schedule – from paper plan to commissioned gate – however the cooperation and involvement of the business units meant the job was completed on budget and ahead of time. Ironically, the early completion of the fabrication allowed for minor improvements to the finished gate in Perth prior to its final transporting to the mine. Improvements that had been identified would improve operation and which will be included in the second gate for the project.