Fletcher

The Fletcher CHDDR-4 is a four-mast feed roof drill. The bolter is run by two operators, each working two separate drill masts. With operator slide-out platforms, operators can use detented controls to bolt the inside, outside, and toward the rib. Because the masts operate independently from each other, operators can simultaneously perform separate tasks, maximizing production time.

• Walk-through chassis design element eliminates the need to walk between the machine and the rib
• With four mast-style drill rigs on the front platform, operators can drill four holes simultaneously
• The two outside masts can rotate a total of 100 degrees front to back, 95 degrees towards the rib, and five degrees in. The mast also has the capability to rotate five degrees side to side
• The two inside masts can rotate a total of five degrees front to back and 2.5 degrees in both directions. The masts can also rotate a total of 7.5 degrees side to side, 2.5 degrees in, and five degrees out.

Standard equipment includes:

• Fletcher crawler drive system
• Automatic spring set, hydraulic release brakes
• MSHA-approved temporary roof support (ATRS)
• Cable reel
• High-pressure filters
• Platform lift
• Fire suppression system
• Front and rear stabilizers
• Certified drill canopies
• Walk-through chassis
• Hydraulic disconnect at operator's stations

Specifications

Upgrades

• Towing package
• Methane monitors
• Rotary impact drillheads
• Wet drilling system
• Venturi or motor oil fill
• Hydraulic power take-off
• Latch drilling circuit

The Fletcher Model HDDR brings greater flexibility than ever to your high seam operation. Heavy-duty boom swing from 4' to 20' allows several bolt installations from a single chassis position. Booms allow operators to drill over rubble, near ribs and over loose bottom areas. The bolting pattern is established relative to the roof, not the floor.

Standard 90º mast tilt allows angle and rib drilling. The Fletcher ATRS (Automated Temporary Roof Support) eliminates the need for temporary posts and jacks in most applications.

• Walk-thru chassis reduces miner exposure to rib hazards
• Operates in seam heights of 6' to 17' (custom heights available)
• Dual heads install a full row of bolts from a single chassis position
• High-strength elevating booms drill without direct support from floor below

The mechanized mesh rack and mat rack, as well as winch on material pods, facilitate loading, storing and operator access to the supplies. The mesh is delivered to the rear of the machine where the bolter operator winches the shift's supply of mesh into place using the radio control. the materials pods are vendor-loaded above ground and delivered to the rear of the machine. The operator uses the radio control to winch that day's supply of consumable materials onto the bolter. The empty pods are then offloaded and returned to the outside to be reloaded.

Specifications

Electrical system

• Dual 50 HP AC motors
• Horizontal access cable reel
• Strip-type panic bars with start switches at all control stations

Dust collection

• Vacuum system for hollow-shaft drill steels
• Blower
• Rotary lobe type: 62 cfm
• Vacuum at drillhead: 12" Hg, separate system for each drill unit

Hydraulic system

• Maximum working pressure: 2500 psi
• Reservoir capacity 180 to 200 US gallons
• Filtration: magnetic in-tank, Pall high pressure
• Hand-operated fill pump with screened intake
• JIC hose fittings
• Dual pumps

Drive system

• 4-wheel chain drive
• Tractor-type steering
• Turns within length
• Staffa tram motors with motion control valves
• Automatic spring set, hydraulic release disc brakes
• Tram speed: 0-1.5 mph
• Foam-filled tires

Drilling system

• Linear sumping booms
• Telescoping mast feed
• Thrust: 0-7000 lbs (optional 10,000 lbs)
• Feed length: 70" to 90" depending on mast size
• Torque: 0-300 ft. lbs
• Drill rotation speeds: 0-560 rpm
• Feed rate: 0-36 fpm
• Boom extend up to 24"
• Minimum drillhead separation: 4"
• Maximum drillhead separation: 20"
• Adjustable bolt torquing valve
• Two stabilizers jacks on front of chassis

Upgrades

• 10,000 lb. thrust drill mast
• Auto dump precleaners
• Dust collection bags
• Crawler drive system
• Hydraulic power take-off
• 105" feed mast
• Load sense hydraulic system
• Wet drilling system
• Hydraulic flow meters
• Mat holder, mesh clamps
• Hydraulic extend ATRS beam
• Mast swing
• Tram intensifier circuit
• Independent platform lift
• Material handling system
• Exhaust water conditioner
• Radio remote control tram
• Rock duster
• Rotary impact
• Automatic drilling controls
• High performance blowers
• Intrinsically safe start system
• Hydraulic rear walkway ramp
• Rear chassis lift