Dragline Propel Stabiliser Links.

Dragline propel stabiliser links form part of the walking and propel system, helping control the position and movement of the walking assemblies while transferring loads between connected structures. They assist in maintaining alignment and stability as the dragline raises, advances and lowers during each propel cycle, withstanding high cyclic tensile and compressive loads, impact, vibration and changing load directions while maintaining secure pin and bush connections.

MEA was engaged by BMA's engineering teams to design and manufacture multiple dragline propel stabiliser links for use across its operating fleet. Due to the heavy plate construction and extensive welded sections, each stabiliser link was fabricated under controlled welding procedures before being thermally stress relieved in a furnace, reducing residual stresses and minimising the risk of distortion during final machining and service.

Following stress relief, the links were finish-machined to the required dimensional accuracy: connection bores machined to specification and mating faces slab milled to ensure correct fitment and alignment within the dragline propel system. Each stabiliser link was fitted with large cast phosphor bronze bushes incorporating internal lubrication grooves.

To assist installation, the bushes were cooled using dry ice to temporarily reduce their diameter before being shrink-fitted into the machined bores, then Scotch-keyed to the link structure to prevent rotational movement during operation. MEA has manufactured and supplied multiple sets of propel stabiliser links for BMA draglines operating at Caval Ridge, Saraji and Norwich Park mines, providing purpose-built replacement components designed for high cyclic loading and long-term service.