Narrow Bench Highwall System

Prior to 1977, it was not mandatory that highwalls in the U.S. be reclaimed. Hence, there are considerable highwall reserves that are readily available for mining. However, the benches that provide access to these reserves are quite narrow. This is because the equipment used for mining prior to 1977 was much smaller than today’s, and these reserve areas are located primarily in the coalfields of the eastern U.S. which are quite mountainous.

Hence, ADDCAR is developing a narrow bench machine to address this market need/opportunity. The overall machine length will be radically reduced from 90 to 45 feet. The time-tested fundamentals of the ADDCAR technologies are preserved—just arranged more compactly and in parallel rather than in a linear manner.

The central module of the ADDCAR Broad Bench system is the launch vehicle. This is the main structure of the highwall system, housing the electrical and hydraulic systems, hosting the operator’s compartment and other control functions, launching the miner into the seam and supporting the coal handling systems. First, the launch vehicle is lined up perpendicular to the coal seam at the desired location. A crawler-mounted continuous miner presses into the highwall, cutting the coal and feeding it onto the unique ADDCAR conveyor cars, which are placed at the back of the production line as the miner advances. This method of extending the production string means uninterrupted coal flow. The conveyor cars feed the coal car-to-car without use of an auger, which can increase fines. When it reaches the last conveyor car, the coal dumps off onto a final conveyor, which sends it to a stacking conveyor in back of the vehicle. The miner can drive an entry up to 1,000′ into the wall. Support equipment includes a stacker conveyor and wheel loader with forklift attachment. The deck crew remains under an FOPS canopy; and operators work in climate-controlled compartments.

This Narrow Bench System has particular appeal in trench mining applications as well. The two major benefits are: (1) the reduced length allows for highwall mining in conjunction with advancing the box cut because there is space for the rock and coal trucks to pass behind the launch vehicle and (2) the overall volume of rock to be removed is less.

narrow-bench-system-thumb

Features

  • Recovers coal from 2.5′-15′ seams
  • Penetrates up to 1,000′
  • Produces up to 200,000 tons/month
  • Cascading conveyor cars result in higher through put and fewer fines
  • State-of-the-Art horizontal & vertical steering

Specifications

Length (ft)

Overall (Assembled)
45.0
Canopy
40.0
Launch Base
41.0

Width (ft)

Moving – in Pit
21.0
Trucking
16.0
Across Skids
42.4

Height (ft)

Height
28.2

Compartments

Operators Compartment
12 x 12

Weight (tons)

Assembled Launch
175
with Miner on deck
215 – 225

Ground Pressure (psi)

Nominal
23.0
Maximum
34.5

Canopy Load (tons)

Load
185

Conveyor Belt

Width (in)
54
Speed (fpm)
500

Installed Horse Power (HP)

Main Belt Drive
75
Incline Belt Drive
75
Stacker Belt Drive
100
Main Hydraulic
400
Main Water
40
Total
690

Sump Force (tons)

Mining
151
Retract
92
Maximum Retract
226

Sump Pressure (psi)

Working
3000
Maximum
4500

Sump Speeds (fpm)

Mining
33.0
Maximum
72.5
Maximum Retract
86.5

Penetration Rate (ft/hr)

Rate
100 – 125

Input Voltage (v)

Voltage
4160 or 7200