Caterpillar has released a new longwall plow system for very low coal seams.
The GH800B system builds upon the previously released GH1600 plow system.
The machine is similar to the GH800 plow, but contains armoured face conveyor (AFC) modifications such as PF4 plow line pans with replaceable top trough, and a new plow guide made from a one-piece casting that provides extra strength and durability, while also being much lower in height that the previous welded version.
External dogbone connectors between the line pans and a very strong and flexible relay bar between the AFC and the roof supports further adapt the conveyor for very low seam operation.
To increase coal throughput, the engineering team widened the conveyor cross-section with extended side plates.
According to Cat the plow system has been developed to cutting heights ranging from a maximum of 1.55 metres to as low as .75 metres.
It has a cutting depth of 205 millimetres, and measures approximately 2.64 metres in length.
Optimised design at both ends of the body helps load more coal onto the face conveyor, and reduces the amount of cutting power consumed.
The GH800B also enables an effective horizon control system, which provides greater ability to follow the seam line without cutting adjacent rock.
It also utilises Cat low seam roof supports, which have shortened canopies that avoid collision with the plow, even in their lowest position.
The shield canopies are also 8 centimetres thinner, to create a more ergonomic environment for the face crew.
An additional canopy water spray sequence has been designed to synchronise with the cutting plow to minimise dust.
The machine has been tested underground at the at the Ibbenbüren coal mine, in Germany.
According to Cat tests at the site showed a reduction in operating and maintenance costs by about 50 per cent compared to a nearby coal face.
"An advance rate of as much as 10 meters (33 feet) per day reveals the enormous production capability of the system," it added.