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.
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
