MSHA - Interactive Training - JTA Spiders -Table of Contents

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	DBT Roof Bolter
	Contact: Palmer.Melvin@dol.gov

Cuts

Check white board and assistant notes

Tools needed

Supplies needed

Roof conditions

Equipment conditions

Mining cycle location

Obtain needed supplies

Obtain steels

Obtain wire

Obtain signs

Obtain bits

Obtain filters

Obtain nails

Obtain spads

Obtain hand tools

Hammer

Razor knife

Adjustable wrench

Channel locks

6 inch flat screw driver

Electrical tape

Allen wrench

Check in/Tag in

2. Pre-op mantrip

Check lights

Check panic bar

Check brakes

Check brakes second time on the ramp prior to going into pit

Check charge indicator, if applicable

Check for fire extinguishers

Two fire extinguishers

Check for jack and lifting bar

Clean reflectors

Clean off debris

3. Enter mine

Conduct travelway examination

Put safety glasses on

Observe for mobile equipment

Check roof conditions

Check for cracks, loose rock, taking on weight, water

Look for uneven bottom

Rough spots and bumps in the road

Soft spots/low spots

Look for roadway debris

Look for crib blocks, rock, banding material, cable, bolts and knocked out timbers

Check for damaged bolts

Correct and/or report any unsafe conditions

Exit mantrip

Be aware of crawling hazards

Obtain glue

Drop glue off at intake supply car

Travel to return supply car to drop off glue

Take canvas down

Anytime back check/line curtain is taken down, replace canvas after traveling through

Replace canvas

Travel back to intake and park mantrip in the intake

Restore canvas

Use only a permissible mantrip

Contact section foreman for bolting cycle

Load supplies if needed

Empty dust box

Face bolter inby

Stay out of this dust

Open box

Stay on the intake side of box

Tap the filters out

Replace filters if necessary

Once filters can not be tapped out, replace filters

Clean box out with hoe

Clean seal

Close door

4. Conduct workplace examination

Look for section foreman pre-shift date, time, and initial

Workplace exam must be conducted before a bolter moves into a new place

Check line curtains

Examine roof conditions

Start at outby corner of last open crosscut

Check for cracks, loose rock, taking on weight, water

Scale loose top with slate bar, if necessary

Spot bolt any area that can't be scaled

Check for loose ribs

Start at outby corner of last open crosscut

Cracks

Ledges

Spalling

Support or scale any loose ribs

Check for methane with spotter, and probe where necessary

1 inch from face/roof/rib

If magnet on head of miner is not used you must use a probe

Check for damaged bolts and wide bolt spacing

Correct and/or report any unsafe conditions

Ensure danger unsupported roof signs are hung where roof is unsupported

In low coal, it is very easy to accidentally travel unsupported roof. These signs make it much easier to identify unsupported roof.

5. Pre-op of Roof Bolter

Check cable

4 splices, 5 to end the shift

Adequate cable for the shift

Adequately hung

Nicks, abrasions

Pull from reel if necessary

Check for accumulations

Coal dust

Spilled oil

Grease

Empty boxes, garbage, etc.

Check fire suppression

One in kitchen

One in the front of the machine near the operator station

Do not activate

Check panic strips

Check all three panic strips

Start the machine and tap

Check controls

Ensure controls are self centered

On some older machine, the cable reel lever may not self center

Check for excessive play

Keep linkage free from obstructions

Check lights

Report any lights that are out to foreman or mechanic

Check tires

Look for missing tire tread

Check for tools

Rock bar

Hammer

Torque wrench

Probe

Check suction

6. Tramming/Place Change

Ensure everyone is clear

Check inch tram

Check ATRS

Raise ATRS and pressurize

Be observant for broken pins, cracks, and bleed-offs

Check for bleed-off

Bleed-off is when the ATRS will not stay pressurized when against the roof

Lower ATRS

Check boom

Check rotation

Check suction

Raise stab jack

Turning the machine right and left, pull ample slack cable from reel

Ensure gas tests have been made in face area before entering last open crosscut

See workplace exam

Get in kitchen

Ensure entire body is in kitchen

Keep all body parts inside kitchen

Check cable reel to ensure that it is off

Center machine in entry

Stay as low as possible in the kitchen

Beware this machine may teeter and roof out

Look ahead for obstruction on travelway

Overhead clearance

Bottom obstructions

7. Tramming Bolter from Inch Tram Controls

Ensure cable reel is disengaged

Locate last row of bolts

Make visual assessment of cut

Inch tram forward to last row of bolts

Tram bolter so that the right rear corner is closer to the right rib

Have roof control plan diagram showing the placement of the machine in the roof bolter cycle

Position the drill head of the machine so it is within 4 feet of the last row of bolts or closer, and within 4 feet of the rib or closer

Roof conditions will dictate the exact distance of the bolt spacings

8. Drilling Test Hole

Drill proper length test hole according to roof control plan

You can always drill higher than the roof control plan requires

Review approved roof control plan and/or mine policy for exact location of test holes

Watch for steel to jump

This comes with experience

Jumping indicates bed separation

Look, listen, and feel for changes in the roof

This comes with experience

Roof may sound drummy or hollow

Drilling sound will change as you go through different laminations

Measure test hole

Drag tip of tape measure against side of hole while withdrawing

Catches with the tip of the tape measure indicates separation or cracks

Install proper length bolt and identify

Mark test hole

Paint test hole or bolt installed in test hole

This allows people to know where test holes are located

Leave test hole open and identify

Optional, to install a correct size bolt

Notify section foreman of roof defects to determine supplemental support if you are unsure

Will determine course of action

Determine the length of bolts

All bolts must anchor in solid roof. See roof control plan

9. Drilling and Installing Bolts

Visually examine the roof

If roof is visually defective, do not sound

Look for dribbling, cracks, cutters, clay veins, horsebacks, etc.

Advance bolter not more than 4 foot from last row of bolts

Do not expose yourself to unsupported roof

Raise ATRS

ATRS must make contact with the roof

Properly position bolter

Within 4 feet from the rib and the last row of bolts

See diagram from he roof control plan on bolting sequence

Set canopy and stab jack

Make sure the canopy and stab jack are pressurized

Take assembled bolt, bearing plate, and resin

Sound roof

Unless obviously bad

Use suitable device to sound the roof

Listen for drummy or hollow sound

Keep all body parts away from the drill boom

Lower drill head to bottom

Place starter steel in chuck

Raise head until bit contacts roof

Drill steel must be straight or plumb to correctly drill your hole

Remove your hand from the drill steel

Slowly rotate steel until bit penetrates rock while raising the drill head

Increase drill speed

Increase up pressure so that steel penetrates rock without clogging

Drill starter hole to proper depth

Look and listen for changes in roof

Lower drill head to bottom with slow rotation and remove starter steel

Varies with type of steel

Insert finishing steel in existing hole

Insert pusher steel into chuck

Allow finisher steel to drop and couple with the pusher steel

Remove you hand from the drill steel

Increase drill speed and pressure to drill the maximum depth

Pusher steel must be marked to ensure the proper hole depth which is 1 inch deeper than the bolt to be installed

Slow rotation

Lower drill head to bottom

Remove steels

Do not put your hand or arm directly underneath a hole with steels in them

Place steels in steel quiver

Insert resin into hole

Insert bolt with plate already assembled

Using the boom, push bolt 1 inch from roof

No rotation should be used at this point

Drop boom

Insert wrench

Wrench may not be used with hex steels

Seat wrench firmly on bolt

Rotate maximum speed for recommended mix time

Over mixing can be just as bad as under mixing. Count by saying one thousand one, one thousand two, etc.

Stop rotation and push to roof with maximum thrust

Hold pressure for recommended hold time

Spin time and hold thrust time are on each box of resin

Drop boom with wrench

First bolt in each cut must be torque

See roof control plan

Follow roof control plan for bolting sequence

Following the pre-established roof control bolting sequence gives you maximum protection from your ATRS and already installed bolts

Set bolter so that the right rear corner is closer to the right rib

Have roof control plan diagram showing the placement of the machine in the roof bolter cycle

Make gas test at intervals not to exceed every 20 minutes

Extend line curtain as bolts are advanced

Normally it is acceptable to have curtain up to the rear of bolter unless concentration of methane requires the canvas to be closer

Keeping an unsupported roof sign behind the curtain

In low coal, it is very easy to accidentally travel unsupported roof. These signs make it much easier to identify unsupported roof.

Hang curtain to within 10 feet of face when bolting is concluded

Normally it is acceptable to have curtain up to within 10 feet of face unless concentration of methane requires the canvas to be closer

Makes the area safer for the scoop operator

Bending 6 foot bolts

Place bolt on slight angle with head end on bottom

Place knee on the crimp point

Press with your knee

Pull the end of the bolt upward until you reach 45 degree angle

Pick the head of the end of the bolt up

Place your knee on the crimp

Press with your knee

Pull the head end until you reach a 90 degree angle

The bolt when pulled properly will appear like a "U" shape

Install plate

Bending 42 inch or similar bolts

Place bolt end in square stock on the bolter designed for bending

Slide bolt in to the desired length

Push head end down toward bottom

Stop when you have about a 25 degree bend

Over bending will create drag while inserting bolt into hole. This makes it very difficult to get the bolt inserted, and may result in hangers

Install plate

10. Installing a Control Rod

Follow all procedures outlined in drilling and installing bolts, except using a bearing plate

Install control rod at intervals not to exceed 100 feet in solid roof

The installation of control rods are not required where full grouting can be observed at the intervals required in the roof control plan

Install control rods at 50 foot intervals in subnormal roof

Drill control rod hole to the same depth as normal roof bolt hole

Determines if there are voids in the roof into which resin is being lost

Drill control rod hole out of pattern

Install a normal length bolt without a bearing plate

This allows you to measure up into the hole for resin

Insert the bolt to within 1 inch of roof

Mix resin according to manufacturer recommendations

Look for a show of resin at the bolt head

Contact foreman if there is no show of resin

Adverse or unusual roof conditions must always be reported to the foreman

11. End of Shift Activities

Assure danger unsupported roof signs are hung

In low coal, it is very easy to accidentally travel unsupported roof. These signs make it much easier to identify unsupported roof.

Hang line canvas to the second to last full row of bolts outby the face

Tram bolter to supply cars

Hang bolter cable, if necessary

Check with foreman for further instructions

Let foreman know what supplies are needed

Inform foreman of any roof changes/machine problems

Load bolter with supplies

Gather and remove any damaged resins and used bits

Put bits in used bit container

Dispose damaged resin in garbage container

Review the MSDS sheet with the trainee

Go to mantrip and conduct head count

Travel outside

Look for hazards in travelway

See entering mine

Talk to cross shift bolters about conditions and bolter maintenance

This could be in the section, on the travelway or outside

Park mantrip in pit shop

Set panic brake

Shut light off

Place on charge

Go directly to shower house and tag out

Put your light on charge

Place methane spotter on charge

Make notations on white board as needed

12. Unusual/Non Routine Activities

Gas detection 1 percent or greater

Shut down

De-energize your machine

Notify foreman

Follow foreman's instructions to make changes in the ventilation system

Retest for gas prior to restarting

Gas detection 1.5 percent of greater

Shut down

De-energize your machine

Notify foreman

De-energize power to the entire section

Follow foreman's instructions to make changes in the ventilation system

Retest for gas prior to restarting

Installation of supplemental support

Identify signs of roof failure in which supplemental support is necessary

Danger area off

Get instructions from foreman

Start bolting 8 feet outby in solid roof

Position bolter to provide maximum protection with your ATRS

Install supplemental supports according to plan

Evaluate roof continuously during any supplemental support installation

Monitor areas where supplemental supports were installed

Areas inby or outby the supplemental area may need additional attention

Firefighting and evacuation

Roof bolter duties obtain; fire extinguishers, rock dust, and take to the intake side of the fire

Quick response in attacking a fire lessens the possibility of the fire getting out of control

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DBT Roof Bolter

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