The extension of the longwall is planned to increase production and reduce costs. Already regarded as one of the most productive longwalls in Australia, the current system set a monthly production record of 1.057Mt in April. The mine will start mining its first 400m-wide panel in the second half of 2017.

Narrabri is operating a complete Cat longwall mining system including an EL3000 shearer, roof supports, AFCPF6 face conveyor and BSLPF6 beam stage loader with crusher and boot end. The order of Cat roof supports includes 43 face roof supports and seven gate road supports with 2.05m spacing, 2.25-4.7m height range, 450mm leg diameter and 13,000kN support capacity.

Last year the mine ordered a second EL3000 shearer based on the productive performance of the first machine. The EL3000 shearer features a one-piece mainframe that is engineered to optimise productivity while ensuring reliability and durability. The ranging arms feature cast hinge points designed to handle higher cutting and haulage forces, such as 860kW cutting forces with haulage capable of 32m/min while cutting.

According to Whitehaven, the mechanical availability of the second Cat shearer since its installation in September 2015 is very good. Advanced, state-based automation is boosting longwall productivity and reducing downtime. Functionalities such as horizon control and face alignment provide a consistent cutting process.

Narrabri established a new calendar year production record of 8.3Mt of ROM coal in 2015. Whitehaven’s June quarter production report explained further positive results: “As a direct consequence of the higher production levels, production costs have fallen with Narrabri confirming its place as Whitehaven’s lowest cost mine.”