Assuring the Required Tip to Face Distance

For the longwall system at the Yalevskogo mine, SUEK combined Cat roof supports from other longwall faces. In total three different types of Cat roof supports were combined – with closed an extended heights ranging from 2200/4800 mm, 2400/5000 mm, and 2550/5500 mm.

The challenge for Caterpillar was to match the armored face conveyor to these different roof support types. This was necessary because of the tip to face distance – the distance between the canopy tip and the coal face.

The tip to face distance is a very critical measurement in order to maximize roof integrity and limit dilation. It should be less than approximately 0.6m. The smaller the distance the better the result. For Russian mines the national law stipulates a tip to face distance of  412 mm.

For the different roof support types, Caterpillar manufactured custom-specific clevis mountings – the connection between AFC line pan and roof support base - in order to assure that all face roof supports have the same tip to face distance, according to the national regulations.

Cat® Customized Longwall Roof Support Systems
Cat® Customized Longwall Roof Support Systems


The Cat longwall system at Yalevskogo mine is fully automated. All three types of roof supports were upgraded with a Cat PMC-R roof support control unit. The automation system also incorporates a Cat PMC-D drive control, a Cat PMC-V for visualization and parameter setup of the drive system and a Cat MCU2 master control unit for visualization and control  of the longwall operation with an explosion-proof underground computer. Through data transmission in real time via optical fiber cable/modem the whole system could be  controlled from a mining control center at the surface and allows maximization of the longwall performance.

The Cat automation system used the latest version of the Cat V-software, a suite of condition monitoring programs for the various control tasks for each of the core system components like roof support, drive system and cutting machine.

The electrohydraulic roof support control system for the Yalevskogo mine offers special operating modes to boost both productivity and safety. The system can reactivate some regions of the face and resume production even though the face has been put into a safe condition in response to detection of an electrical fault, sometimes caused by a broken cable between two PMC-R controls. Before reactivation, strictly defined conditions must be observed.

The Cat face automation system represents the cutting edge in longwall automation technology and facilitates full automation, monitoring and remote diagnostics for all face equipment. It provides remote control of all system functions and adjustments to enable high production rates, enhance operator safety and minimizes operating cost.


Read: Russian Mine Sets Production Record with Cat® Longwall System


Cat PMC-R Longwall Roof Support Control
Cat® PMC-R Roof Support Control

Cat® Roof Supports

Steep grades, very thick and very thin seams, unstable roofs and massive sandstone plates, soft ground and geological faults. These varying conditions require a high level of adaptation to specific requirements. Cat® Roof Supports are world-renowned for their reliability under the most extreme conditions. With superior availability and unparalleled quality in design and production, our roof supports set the standard in longwall mining.

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Cat® Longwall Automation Systems

Longwall Automation

What if you could improve your coal output by 90% or more without compromising safety or availability? These numbers are not fiction; these are production results from three mines running complete Cat® Longwall systems in Australia. One mine has set a production record by producing 330,000 tonnes (363,762 short tons) in a single week.

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