Right Side Boarding Stairs

BOARDING STAIRS

Access to the main frame and machinery house can be attained by using the boarding stairs located on the right and left sides of the machine. When lowered, the stairs allow boarding from ground level. These stairs must be in their raised and latched position to enable the operator’s controls.

Right Side Boarding Stairs

When lowered, the stairs allow entrance to the base frame and machinery house from ground level. To lower the stairs, press and hold the DOWN pushbutton on the control panel. The stairway will return to ground. To raise the stairs, press and hold the UP pushbutton. Release the button to stop motion.

NOTE: The stairs must be in the RAISED position to enable the operator’s controls.

Use the Emergency Stop pushbutton to stop stair motion in an emergency situation. When pushed, the power to the hoist is shut off and the button locks automatically. Turn the button to the right to release the lock.

A proximity switch and target magnet are located on the inside of the stair walkway. Adjust the proximity switch to actuate in the up position.

NOTE: The maximum air gap allowed between the proximity switch and the target is 0.35 inches (8.9 mm).

Generally, very little maintenance is required for the stairs. However, ensure that the two flanged bearings on the pivot shaft are lubricated and also that the proximity and target switches are in good working order.

RUNNING THE MACHINE

PRE-START INSPECTION

Visual inspection of the machine should be performed by the operator at the beginning of each shift. A potential problem may be prevented if discovered early.

The following checklists can be used to help with the inspection. General (all areas of the machine):

• Are guards, cover plates, and safety devices secured in place?

• Are all loose parts stored in proper compartments or removed?

• Check all hardware for missing bolts, nuts, pins, etc.

• Are all lube (grease) spills wiped up?

• Is the machine thoroughly clean?

Tub ~ Check for the following items:

• Cracks, broken welds on exterior;

• Hook shoe adjustment and condition;

• No obstructions in roller path;

• Trail cable in correct position.

Machinery House ~ Check the following items:

• Automatic lube system with adequate lube supply;

• All gearcases have proper oil level and all filters installed;

• Air compressor crankcase oil level and drive belts’ tension;

• Main house crane hoist is parked and pinned correctly and in a safe manner.

Front End ~ Check the following items:

• Bucket - for wear, worn, broken or missing teeth, loose or missing pins, weld cracks;

• Boom & Tri-Structure - for cracks, bent pipes;

• The condition of the boom support ropes;

• The condition of the hoist and drag ropes;

• The condition of the fairlead components.

NOTE: If any problems are found after going through the above checklists, notify maintenance at once so that corrections can be made.

TYPICAL STARTUP

To start up the machine from a complete shutdown, use the following procedure. DO NOT start this machine unless you are completely familiar with the various controls. Perform the Pre-Start Inspection given on the previous page.

1. All the circuit breakers for the applicable controls and equipment must be closed and the power on before proceeding with startup. These are located primarily on the outside of the Power Control Room (PCR) and in the Operator's Cab/Anteroom.

CAUTION: DO NOT use circuit breakers as ON/OFF switches. Make sure that all the circuit breakers are ON before starting the machine.

2. Go to the rear of the PCR and to the Starting and Metering Cabinet. Observe the various meters and the startup controls and that the PHASE CHECK light is on.

IMPORTANT NOTE:

During each component start up, always be ready to immediately stop it if there are any unusual sounds, smells, or visual effects. Always let the system being started come up to its normal operating speed before starting the next system. Any time a problem arises, check the OIT display in the Operators Cab for assistance.

3. Press the "MG Set Start" pushbutton to automatically start the MG Sets in sequence. Be sure that both green indicators are lit and that all meters are stabilized for all four MG Sets.

The individual buttons can be used to start each MG Set individually.

4. The motor blowers start automatically when the MG Sets are on. These blowers are used in cooling the DC motors. Check that the green indicator is lit and for the sound of the blowers.

IMPORTANT NOTE:

If the vacuum breaker for the synchronous motor on the MG set does not stay closed when the start button is released, repeated attempts to start the set should not be made. On a motor of this type, only attempt two successive starts if the motor is at ambient temperature. More that two attempts to start without success can damage the motor windings. Before attempting another start, the vacuum breaker starting circuitry or mechanism should be inspected by qualified personnel and its proper operation verified.

5. The Machinery House Intake Filter Fan units will start automatically once the MG Sets are on. These fans introduce clean air into the machinery house to cool the dragline operating equipment. They also maintain a positive pressure within the house to prevent dust entry if all the access doors are kept closed.

To start each fan unit individually, fully press and release the pushbutton for each unit. This will start the bleed duct fans. In approximately 5 seconds the main fans will automatically start and then the light will come on.

6. When the above systems have been started and are operating correctly, go to the operator’s cab and observe the air pressure indicator in the OIT. This indicator provides a visual reference for the air system pressure and should indicate from 95 to 155 PSI (650 to 1070 kPa) during machine operation.

7. Sit into and adjust the operator's seat.

8. Check the Hoist, Swing and Drag and Propel Brake selector switches. If they are not at their SET positions, put all of them there now, even if the red light in the switch is on.

9. Check to be sure that the hoist and drag controllers are in their NEUTRAL position and that there is no pressure applied to the swing pedals.

IMPORTANT NOTE:

This machine is equipped with an electronic rope limit control system. This system is designed to aid the operation in avoiding serious mechanical damage to the machine due to hoist or drag bucket overtravel or bucket tight-lining. However, the system is not a substitute for careful operating procedures. The rope limit control system should be verified for proper operation on a daily basis. It is EXTREMELY important that the system be recalibrated after any rope or bucket rigging changes have been made. Refer to the Electrical Service Manual for this machine for proper procedures.

10. Press the EXCITATION START pushbutton on the operator's console.

11. Turn the Hoist, Drag and Swing drag break selector switches to the RELEASE position.

DANGER: THE MACHINE IS NOW OPERATIONAL. DO NOT LEAVE THE OPERATORS SEAT UNLESS THE CONTROLLERS ARE DEENERGIZED AND THE BREAKS ARE SET.

THE OPERATOR CONTROLS THE MACHINE. PLEASE KEEP SAFE OPERATING PROCEDURES IN MIND AT ALL TIMES.

PREPARING TO DIG

Before preparing to dig, contact support equipment and personnel to ensure that they are prepared for digging operations and are clear of the machine.

Perform the following operations to start the machine and prepare to dig. Confirm your operations on the SCADA screen.

1. Check the SCADA screen to ensure that the air pressure is in the working range between 655 kPa (59 PSI) and 793 kPa (115 PSI).

2. Check that the swing pedals are in the neutral position.

3. Ensure that the hoist, swing, drag, and propel brakes have been set (SCADA screen).

4. Check that the hoist and drag joysticks are in the neutral position.

5. Transfer to drag mode on the right console.

6. Sound the horn twice to indicate movement.

7. To start excitation, press the Excitation Start button on the right console.

8. Release the hoist, swing, and drag brakes on the right console.

9. When the area is clear, check the boom protection by lifting the bucket to ensure the boom limits are operating.

10. The machine is now ready to dig.

NOTE: Transfer to propel on the right console if you are intending to propel the machine immediately.

TYPICAL DIGGING CYCLE

Start a digging cycle with the bucket on the ground, in the pit, and under the boom point. If the machine tends to rotate freely, apply just enough swing effort with the RIGHT pedal in the opposite direction of machine movement, to hold the machine steady.

Begin dragging the bucket in by pulling back on the drag (left) joystick. The more the joystick is moved from its neutral position, the faster the bucket will be pulled toward the machine. As the bucket is dragged in, take care to remove any slack from the hoist rigging. Do not allow the spreader bar to rest on the bucket. Additional hoist pull can be applied to reduce the cutting depth and wear on the bucket heel. Do not drag the bucket any further than necessary to fill it. Dragging a full bucket wastes time and energy.

With the bucket full, a correct combination of hoist and drag joystick movement will increase the hoist speed (right joystick back) and decrease the drag speed (left joystick forward) to lift the bucket out of the pit. Keep just enough tension on the drag ropes to prevent the bucket dumping. Too much rope tension tightens the “line of bucket carry” and positions the bucket close to the boom. This adds strain to the boom and slows down the hoist speed.

As soon as the bucket clears the digging face, slowly press the swing pedal in the desired direction of machine rotation. A correct combination of hoist and drag effort with swing motion added avoids any excessive bucket and rope swing. Swing the machine and lift the bucket at the same time so that the bucket reaches the dump height and spoil location at the same time.

CAUTION: USE EXTREME CARE WHEN SWINGING TO ENSURE THE BUCKET CLEARS ALL OBSTRUCTIONS AND THAT CLEARANCE EXISTS AROUND THE MACHINE.

Upon approaching the dump point, reverse the swing motion to bring the machine to a smooth and accurate stop. Coordinate the hoist and pay-out so that the bucket dumps as the machine stops swinging, and the bucket is empty as it starts back to the pit.

All the drives are “plugged” while digging to bring each motion to a stop and control the bucket as desired. There are no “operating” brakes on this machine. All the brakes on the drives are “parking” brakes only.

Release the drag rope tension by paying some rope out from the drum. This dumps the bucket. As the bucket dumps, move the left joystick just slightly forward of its neutral position. Be cautious - do not allow an excessive amount of drag rope to pay out.

Never hold the load any longer than necessary to complete the dumping cycle. Once the material clears the bucket, slowly swing the machine back over the work area and lower the bucket into the pit, using a combination of the hoist and drag motions to place the bucket at its new dig site.

CAUTION: NEVER LOWER A FULL BUCKET OVER AN EXTENDED DISTANCE. DOING SO COULD CAUSE SEVERE DAMAGE TO THE ELECTRIC DRIVE COMPONENTS ON THIS MACHINE.

While operating the machine, observe its components for problems. Look for loose bucket pins, broken or frayed strands on the boom support, hoist, drag, and dump ropes, and bucket and rigging damage or wear. Keep an eye on the boom and the boom point. Report any maintenance requirements promptly to the appropriate personnel for attention so that unnecessary downtime can be minimized.

GROUND PREPARATION

Ground preparation is very important. The walking dragline requires a properly prepared ground base for operation. The tub and walking shoes must have full contact with the ground when the machine is digging or propelling. With the machine weight distributed over the entire tub bottom, or the partial tub bottom and the area of the two walking shoes, the components are less stressed.

The ground supporting a walking dragline must be as near level as possible, firm, and dry. Sand, clay, and topsoil can be leveled easily with a dozer or grader. Sharp rocks and boulders cause point loading, which will damage the tub and shoe structures and should be removed if possible. Where this is impractical, cover the working area with fill dirt to a sufficient depth that will eliminate the effects of the rocks.

This walking dragline can be propelled up or down a grade or ramp. Ramping the machine (moving it from one level to another) requires exercising great care because this situation subjects the tub and revolving frame to stresses much greater than experienced while digging. For a new machine, ramping should be restricted to a maximum 5% grade; later after the machine has propelled approximately 250 to 500 steps this can be increased to a 10% grade maximum. It is possible to traverse (cross) a 5% grade with this machine; however, AVOID CROSSING ANY GRADE IF POSSIBLE.

When beginning to propel the machine, the transition from one grade to the next should be gradual, no more than 2% over the length of the walking shoes. For example, starting from level ground, the machine should travel a minimum of three shoe lengths before reaching a 5% grade.

This machine design incorporates a calculated balance between boom length, boom angle, allowable bucket load, machine weight, and ballast used. During normal digging cycles, the center of gravity shifts from the front to the rear within a specific area called the “kern”. The machine maintains stability and relatively even ground bearing pressure over the entire tub area. If, for any reason, the digging radius or load increases to cause the center of gravity to extend out of the kern to the tub perimeter, an undesirable rocking motion will occur due to the cone shape that will develop in the ground under the tub. This results in an unstable machine and concentrated ground bearing pressure at the center of the tub. This condition is very detrimental to the machine and must be eliminated. Contact the Bucyrus International, Inc. Service Department for consultation on this problem immediately.

CHANGING TO PROPEL MODE

Perform the following procedure if you need to move the machine during digging operations. Confirm your operations on the SCADA screen.

1. Set the hoist, drag and swing brakes.

2. Stop excitation by pressing the Excitation Stop button on the right console.

3. Transfer to propel mode using the Propel button on the right console.

4. Sound the horn three times to indicate your intention to move (walk).

5. Start excitation by pressing the Excitation Start button on the right console.

6. Release the propel brakes.

7. Pull the left joystick backward to propel the machine backwards. The joysticks must be pulled back during the entire propel operation.

NOTE: The machine can only walk backwards - not forward toward the boom direction.

PROPEL OPERATION

Two separate but identical propel machinery assemblies are located at each side of the revolving frame. The operations of the two assemblies are tied together electrically by encoders and a monitoring system to synchronize them during the step.

Each propel assembly consists of DC drive motors, shafts and gearing, an eccentric, a walking arm with a stabilizing arm, and a walking shoe. The walking arm connects to the shoe through a ball joint that allows the shoe to swivel in all directions. It also permits limited lateral movement. Consequently, each shoe can adapt to ground contour within its design range.

A walking step is created when the eccentric rotates. During a walking step, the top of each eccentric turns toward the rear of the machine (away from the boom). The eccentric turns the walking arm in a path restricted by its stabilizer arm that generates the walking step through the shoes. Hook shoes, attached to the underside of the revolving frame, lift the rear of the tub during the step.

The walking process can be separated into 4 distinct phases:

• During the first quarter turn of the eccentric, the walking shoe moves from its “top dead center” or parked position toward the rear of the machine and down until it contacts the ground. Refer to PHASE 1 on the previous page. Just before the eccentric turns into the second quarter of its rotation, the rear of the machine and the rear edge of the tub raise and move slightly forward. This movement raises the tub out of any depression formed while digging and breaks any suction between the tub and the ground.

• During the second quarter turn of the eccentric, (PHASE 2) the shoes cause the machine to move rearward, dragging the front edge of the tub along the ground.

• The third quarter turn of the eccentric (PHASE 3) completes the propel movement of the machine. Near the end of this quarter turn, the machine is slowly lowered and the tub settles down onto the ground again.

• The fourth and final quarter turn of the eccentric (PHASE 4) raises the shoes into their park position (top dead center). The shoe return mechanism on each shoe realigns it parallel to the revolving frame as it is raised.