Ship Unloaders
Designing electrical systems for moving machines, stackers, reclaimers, ship loaders/unloaders, and conveying systems
always requires special design considerations. Compliance to AS:4024 requires a comprehensive risk assessment, as well
as a CHASOP and failure mode analysis.
Safety Integrity Levels (SIL) help in the selection of equipment and materials, and determine the level of redundancy and monitoring required.
For example, in 2014 Logitech Engineering joined forces with John Holland to commission the Wiggins Island Coal Export Terminal (WICET) in Gladstone. This included the giant gantry stacker, and coal ship loader.
Coal Gantry Stacker
The Gantry Stacker at WICET required a 1,100-tonne Transi-lift crane to lift into place in September 2013. The gantry stacker dumps coal transferred from the train unloader onto any one of the 12 stockpiles. The long-travel controls use a laser alignment system to ensure that the two long-travel legs move at exactly the same speed so as not to twist the main gantry frame.
Coal Reclaim Tunnels
There are two reclaim tunnels, each with a 6,900-tonnes per hour reclaim capacity, and a ship loader that can load 8,500-tonnes per hour. The coal terminal can blend and transport coal to the ship loader at over 5.9m/s.
This type of stacker is very unique (only three in the world built so far) but it requires significantly less maintenance compared to conventional radial stackers.
