Boom Repair Criteria

4-i

4

SECTION 4BOOM

TABLE OF CONTENTSBoom Stop Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Automatic Boom Stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1Maximum Operating Angles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3Physical Boom Stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Boom Angle Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5Adjusting Angle Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5Sensor Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Pendulum-Type 120 Potentiometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5Solid State Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Ordering Boom and Jib Lacings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7Purpose. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7Boom or Jib Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7Ordering Lacings from Lacing Drawings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7Ordering Lacings without Lacing Drawings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8Welding Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

Boom, Jib, Tower, and Mast Inspection/Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9Extent of Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9Ordering Lacings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9Inspection Intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9Inspection Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10Replacement Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

Dents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10Gradual and Sweeping Bends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10Kinks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11Cracks and Breaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11Corrosion and Abrasion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12Chord Straightness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13Welding Electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14Replacing Lacings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15

Boom, Jib, Tower, and Mast Inspection List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16Using Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16Record Keeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16Identifying Sections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16

Servicing Boom Hoist Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18Boom Hoist Cylinders Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19

Before Welding on Crane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19

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4

777 SERVICE MANUAL BOOM

SECTION 4BOOM

BOOM STOP ADJUSTMENTSThis section contains instructions for both types of boomstops the crane has: automatic and physical.

Automatic Boom Stop

Maximum Operating AnglesA limit switch (Figure 4-1, View B) automatically stops theboom hoist cylinders when the boom is raised to one of the

following preset maximum (MAX) operating angles,depending on boom configuration: 83 for Boom without Luffing Jib. 88 for Boom with Luffing Jib.

OperationWhen the boom is below the MAX angle (Figure 4-1, ViewC), the limit switch is closed and its LED (light-emitting diode)is on. The boom hoist can be operated as long as the switchis closed.

When the boom is raised to its MAX angle (Figure 4-1, ViewB), the actuator opens the limit switch and the LED goes off.Boom hoist operation stops automatically because the openlimit switch turns off power to the boom hoist electric circuit.The boom hoist pump shifts to neutral and the holding valvesclose to stop boom movement.

MaintenanceAt least once weekly, check that the automatic boom stopstops the boom at the specified MAX angle. If not, replaceany damaged or worn parts and/or adjust the boom stop.

WARNINGFalling Attachment!

Do not operate crane unless automatic boom stop isproperly adjusted and operational. Do not adjust MAXoperating angle higher than specified. Boom can bepulled over backwards or collapse, causing death orserious injury.

FIGURE 4-1P436 View A

View B

View C(switch closed)

(switch open)

LimitSwitch

Cap Screws

ActuatorBracket

Actuator

LED(off when switch

is open)

A990

Left InboardSide of Boom

1/16 in.(1.59 mm)

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BOOM 777 SERVICE MANUAL

FIGURE 4-2

#78 Boom without Luffing Jib

Boom Lengthft (m)

Dimension Aft-in. (m)

60 (18.3) 8-6 (2.6)70 (21.3) 9-8 (3.0)80 (24.4) 10-11 (3.3)90 (27.4) 12-1 (3.7)100 (30.5) 13-5 (4.1)110 (33.5) 14-7 (4.4)120 (36.6) 15-10 (4.8)130 (39.6) 17-0 (5.2)140 (42.7) 18-2 (5.6)150 (45.7) 19-6 (5.9)160 (48.8) 20-8 (6.3)170 (51.8) 21-11 (6.7)180 (54.9) 23-1 (7.0)190 (57.9) 24-4 (7.4)200 (61.0) 25-7 (7.8)210 (64.0) 26-10 (8.2)220 (67.1) 28-0 (8.5)230 (70.1) 29-2 (8.9)240 (73.2) 30-5 (9.3)250 (76.2) 31-8 (9.6)260 (79.2) 32-11 (10.0)270 (82.3) 34-1 (10.4)

#78 Boom with Luffing Jib

Boom Lengthft (m)

Dimension Aft-in. (m)

60 (18.3) 3-4 (1.0)70 (21.3) 3-7 (1.1)80 (24.4) 4-0 (1.2)90 (27.4) 4-4 (1.3)100 (30.5) 4-8 (1.4)110 (33.5) 5-0 (1.5)120 (36.6) 5-5 (1.6)130 (39.6) 5-8 (1.7)140 (42.7) 6-1 (1.9)150 (42.7) 6-5 (2.0)160 (48.8) 6-10 (2.1)170 (51.8) 7-1 (2.2)180 (54.9) 7-6 (2.3)190 (57.9) 7-10 (2.4)200 (61.0) 8-2 (2.5)210 (64.0) 8-6 (2.6)220 (67.1) 8-11 (2.7)230 (70.1) 9-2 (2.8)240 (73.2) 9-8 (2.9)250 (76.2) 9-11 (3.0)260 (79.2) 10-4 (3.1)270 (82.3) 10-7 (3.2)

View A

Dimension

Front ofRotating Bed

P472

LoadBlock

A

A990

Center of Freely Suspended Load Block

or Single-Part Line.

Dimension A is measured from front of rotating bed to centerline of load block freely suspended from lower boom point.

If a single-part line is used over lower boom point, add 14 in. (357 mm) to dimension in table and measure to centerline of freely suspended single-part line.

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AdjustmentThe automatic boom stop was adjusted and sealed at thefactory. Readjustment is required when the boom stop fails tostop the boom, when parts are replaced, and each timeluffing jib is installed or removed. The seals must beremoved to allow readjustment.Travel crane onto a firm level surface or level crane byblocking under crawlers.1. Loosen capscrews retaining actuator to actuator

bracket.

2. Rotate actuator out of way so it does not contact limitswitch roller when step 3 is performed.

3. Raise boom to Dimension A for corresponding boomlength and angle (see Figure 4-2 Tables).

4. Check position of limit switch with relation to actuatorbracket. If necessary, loosen screws and adjust limit

switch up or down in slots to obtain dimension inFigure 4-1, View C. Securely tighten mounting screws.

Limit switch will not trip open if it is too far from actuatorbracket. Limit switch could be damaged from over-travelif it is too close to actuator bracket.5. Rotate actuator against limit switch roller until limit

switch just clicks open and hold. The LED should go outwhen the switch opens. If it does not, troubleshoot theelectrical system.

6. Securely tighten cap screws for actuator.7. Lower boom several degrees.8. Slowly raise boom. The LED should light when the

switch closes. If it does not, troubleshoot the electricalsystem.

9. Boom must stop at specified Dimension A; if not,repeat adjustment steps.

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Physical Boom StopThe physical boom stop assembly (Figure 4-3) serves thefollowing functions: Assist in stopping the boom smoothly at any angle

above 81.

Assist in preventing the boom rigging from pulling theboom back when traveling or setting loads with theboom at any angle above 81.

Assist in moving the boom forward when lowering theboom from any angle above 81.

Provide a physical stop at 90.

OperationSee Figure 4-3 for following procedure.1. When the boom is raised to 81, the springs in the boom

stop tube begin to compress.2. As the boom is raised higher, spring compression

increases to exert greater force against the boom.3. If for any reason the boom is raised to 90, the boom

stop springs will fully compress to provide a physicalstop.

RemovalNormally, the boom stop tubes are not removed unless theyneed repair or replacement.

FIGURE 4-3

A991

81

81 Start ofSpring Cushion.

Solid at 90

32 inchOverlap Boom StopUpper Tube Spring

Boom StopLower Tube

Use care when handling boomstop tubes. Lower tube is not

retained in upper tube.

Boom Butt

ShippingPosition

90

WARNINGFalling Load Hazard!

Physical boom stop must be installed for all craneoperations. Physical boom stop does not automaticallystop boom at maximum operating angle. Automatic boomstop must be installed and properly adjusted.

WARNINGFalling Load Hazard!

Use care if boom stop tubes are removed for any reason.Lower tube is not retained by upper tube and they mayseparate when detached.

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BOOM ANGLE INDICATOR An ang le sending uni t mounted on the boom but t(Figure 4-4) monitors the boom angle.The sending unit houses a sensor which sends an electricsignal to the cranes programmable control ler. Theprogrammable controller converts the electric signal into anangle which can be monitored on the digital display in theoperators cab.

Adjusting Angle IndicatorPerform following adjustment steps at initial installation, afterinstalling a new sending unit or potentiometer, and at leastmonthly when boom is lowered to ground (Figure 4-5).1. Locate punch marks on line through centerline of boom

butt as shown in Figure 4-5. If necessary, scribe a linethrough punch marks.

2. Hold a protractor-level along scribed line.3. Record angle indicated on protractor-level.4. Scroll to boom angle on digital display in operators cab.5. Angle shown on digital display must match angle

recorded in step 3 plus or minus one degree.6. If necessary, loosen mounting screws and rotate

sending unit in mounting slots until reading on digitaldisplay matches angle on protractor-level.

7. Securely tighten mounting screws to lock adjustment.

Sensor ReplacementReplacement sending units can be either the pendulum-type120 potentiometer (past production) or solid state sensor(current production).Pendulum-Type 120 Potentiometer When replacing parts in the pendulum-type potentiometersending unit, take the following precautions (see Figure 4-6,View A):Mount potentiometer at angle shown.Connect black, green, and white wires from receptacle toproper terminals on terminal strip.Connect wires from potentiometer to proper terminals onterminal strip.Make sure all parts are securely fastened to their mountingposition.

Solid State Sensor When replacing existing pendulum-type potentiometer withcurrent production solid state sensor, take the followingprecautions (see Figure 4-6, View B):Identify all input wires to existing potentiometer.Cut existing input wires near terminal strip (if used) to allowfor splicing.Remove existing potentiometer and terminal strip (if used).Mount new sensor in existing holes at 52.5 as shown inView B.

Refer to wiring chart in View B and parallel splice sensorwires to existing input wires with crimp, solder, and heatshrink tubing.Seal green wire on sensor with heat shrink tubing and coilup.

Angle Sending UnitBoom Butt

(left inboard leg)

Boom Stop Limit Switch

Receptacle

FIGURE 4-4P437

Punch Mark (typical)

Scribed Line

Boom Butt (right outboard leg)

Protractor Level

Angle Sending Unit (left inboard leg)

FIGURE 4-5

A990

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FIGURE 4-6

O-Black52.5 REF.

Boom Angle Sending Unit

Pendulum-Type Potentiometer

87FA-White

82BA-Green

3- Pole Receptacle with Protective Cap

(+)3

2

(-) 1

A990

52.5 REF.

O-Black

87FA-White

82BA-Green

3- Pole Receptacle

Solid State Sensor (+/- 60)M.C.C. #A09716Vendor #CS17

VIEW B

Input Wires Color

Sensor Wires Color

Operation Code

From ToBlack Black GroundGreen White SignalWhite Red 10 Volts DC

Green N/C

A1294

VIEW A

Black

GreenRed

White

Position Sensor Like This

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4


ORDERING BOOM AND JIB LACINGS

PurposeThis topic is divided into two sections: Ordering boom or jib lacings from Lacing Drawings

contained in Section F of the Parts Manual furnishedwith the crane.

Ordering boom or jib lacings when lacing drawings arenot available.

Boom or Jib IdentificationAll parts orders for lacings must contain the boom or jibidentification number and the component part number: Past Production (View A):

Boom or jib number, component part number, andmanufacturing code stamped into two connectors(diagonally opposite) on both ends of each insert and onend of top and butt.

Current Production (View B):Boom or jib number, component part number, andmanufacturing code stamped into a plate mounted on allfour chords of each section.

Ordering Lacings from Lacing DrawingsThe parts order must contain the following information toensure that Manitowoc provides you with the correct lacings:

1. Crane serial number (can be found on builders platedecal in operator's cab.)

2. Boom or jib identification number.3. Quantity of lacings.4. Component part number and lacing identification

number (from lacing drawing in Section F of PartsManual).

5. Component name.

EXAMPLE: Assume you have a number 22 boom and thelacings with circled letters in Figure 4-8 are damaged.Your parts order should be similar to the followingexample:Crane Serial Number: 00000 (from builders plate decal).Boom Identification Number: #22 Boom

Required:1 each 48153-9 (N) for 30 ft Butt1 each 33426-3 (B) for 20 ft Insert1 each 33426-3 (D) for 20 ft Insert1 each 50453-2 (C) for 40 ft Top

Quantity Component Name

Component Part Number

Lacing Identification

Number

Manufacturing Code

Boom or JibNumber Component

Part Number

FIGURE 4-7

X-X-XX

ZZZZZZ-Z#YY

A524

View APAST PRODUCTION

Chord

View BCURRENT PRODUCTION

Component Part Number

Manufacturing Code

Boom or Jib Number #YY Z-ZZ-ZZ

XXXXXX

A524

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Ordering Lacings without Lacing DrawingsThe parts order must contain the following information toensure that Manitowoc provides you with the correct lacings:1. Crane serial number (can be found on builders plate

decal in operator's cab).2. Boom or jib identification number.3. Quantity, lacing location, and lacing number.4. Boom or jib component name (butt, insert, or top) and

part number.NOTE: To obtain the lacing location and number, view the

boom or the jib from the butt end looking forward.Identify the side on which the damaged lacing islocated: left side, top side, right side, or bottomside. Count each lacing up to and including thedamaged lacing, starting with first lacing nearestbutt end of the component as shown in Figure 4-9.Do not count a diagonal lacing as the first lacing.Identify diagonal lacing separately; lower enddiagonal lacing or upper end diagonal lacing.

AssistanceIf you are in doubt as to which lacings to order, do notguess. Contact your nearest Manitowoc distributor for

assistance; doing so may prevent the wrong parts from beingshipped.

Welding InstructionsSee Welding Electrodes topic in this section.

FIGURE 4-8

D(Diagonal)

(Diagonal)B

ED

B B

BA

EEBEE EA

B

E EA

B

CAC

A

Y (DIAGONAL)

40 ft Top

R (DIAGONAL)Q

V(Diagonal)

P

NN(Diagonal)

30 ft Butt

QP

XM

LKWV

SR

ON

UT

FDC

BA

JIHG

AA

FF

JJHH

BBDD

KKIIGG

EECC

MM

U

TS

XWY Z

J

ON

ML

IHG

FD

CBA

B

E

LL

K

E

SAMPLE ONLYDO NOT USE LETTERS ON THIS SAMPLE WHEN ORDERING LACINGS. USELETTERS ON LACING DRAWINGS IN PARTS MANUAL FOR YOUR CRANE.

A924

20 ft Insert

EXAMPLE: Assume you have a number 22 boom and thelacings with circled numbers in Figure 4-9 are damaged.Your parts order should be similar to the followingexample:Crane Serial Number: 00000 (from builders plate decal).Boom Identification Number: #22 Boom.

Required:1 each Top Side Lacing (1) for 30 ft Butt 48153-91 each Right Side Lacing (5) for 30 ft Butt 48153-91 each Bottom Side Lacing (3) for 20 ft Insert 33426-31 each Bottom Side Lacing (6) for 20 ft Insert 33426-31 each Top Side Lacing (2) for 40 ft Top 50453-2

Quantity Component Name and Part

Number

Lacing Location

Lacing Identification

Number

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4


BOOM, JIB, TOWER, AND MAST INSPECTION/REPAIRCrane owners are to use this section as a guide for properlyinspecting and repairing boom, jib, tower, and mast sectionsin the field.

For inspection or repair procedures not covered in thissection, contact your Manitowoc Cranes distributor.

Extent of RepairField repair is limited to replacing damaged lacings, but onlyif the following conditions are complied with: The lacings are ordered from Manitowoc Cranes. The welding is done by competent welders qualified to

work with the types of steel involved. We recommendthat welders be qualified per Section 5 of AWS D1.1Structural Steel code or an equivalent code.

The welding procedures and specifications contained inthis section are followed.

Ordering LacingsLacings are made of various high strength materials. Toensure that replacement lacings are of the proper type andsize, lacings must be ordered from a Manitowoc Cranesdistributor.

Inspection IntervalsRegular inspection is necessary to ensure that theattachment can safely lift its rated load. Inspection should beperformed by a qualified person at the following intervals: Weekly (this interval can vary depending on operating

conditions, application, and crane history). Prior to initial use.

After transport. After an overload or shock load condition has occurred.

If the attachment has come into contact with anotherobject (power lines, building, another crane).

If the attachment has been struck by lightning.

Diagonal Lacing

Diagonal Lacing

Lower End Diagonal Lacing

Upper End Diagonal Lacing

Bottom Side

Left Side Top Side

Right Side

Bottom SideBottom Side

Left Side

Left Side Right Side

Top Side

Right Side

Top Side

FIGURE 4-9

A924

5

3

3 4

2

2

1

1

21

1 2

543

6

40 ft Top

20 ft Insert

30 ft Butt

WARNINGComponent Failure!

If damage was caused by overload or shock load or ifthere is damage to other major structural components, werecommend that a thorough inspection be made by aqualified person. A nondestructive test of all criticallystressed members must be made.

WARNINGComponent Failure!

No welding shall be done to chord members or plate work,except to attach lacings. No chord member or plate workmay be replaced in whole or in part. Complete sectionmust be replaced if chord members or plate work do notcomply with specifications given in this section.

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Inspection Guidelines1. Position the crane on a level surface.

2. Block the attachment so it is level; blocking should beplaced under each connection point to eliminate all sag.

3. Thoroughly clean the attachment of all dirt, grease, oil,etc. so a thorough inspection can be made.

4. Visually inspect the entire attachment looking for thefollowing types of damage:a. Dents in lacings, chords, and plate work.b. Corrosion or abrasion in lacings, chords, and plate

work.

c. Bent, kinked, or distorted lacings, chords, and platework.

d. Cracked lacings, chords, and plate work.e. Cracked welds.f. Twisted sections.

5. Closely examine those areas where the paint is chipped,wrinkled, or missing and where faint rust lines or marksappear.

6. Fill in the Boom, Jib, Tower, and Mast InspectionChecklist and make a detailed report of the type anddegree of damage found.

7. Repair or replace damaged sections.

Replacement Specifications

See Lacing Drawings in your Parts Manual or contact yourManitowoc Cranes Distributor for the wall thickness of thelacings and chords on the attachments for your crane.

DentsSee Figure 4-10 for following procedure.For tubular lacings or chords, dents must not be deeper thanthe lacing wall thickness or 1/8 in. (3.2 mm), whichever isless.

For angular lacings or chords and all plate work, dents mustnot be deeper than 1/8 in. (3.2 mm).

Gradual and Sweeping Bends See Figure 4-11 for following procedure.For tubular lacing, gradual and sweeping bends must notdeviate from straight more than 5 percent of the lacingdiameter.

For angular lacing, gradual and sweeping bends must notdeviate from straight more than 5 percent of the angle leglength.

Gradual and sweeping bends in lacings can be straightenedby cold bending them back into alignment. Take extremecare not to kink or further damage the lacings.

WARNINGStructural Failure!

If damage not within specification is found, do not operatecrane until appropriate section has been properly repairedor replaced.Operating crane with a damaged section may result instructural failure or collapse of boom, jib, tower, or mast.

CAUTIONLacing Replacement!

Damaged lacing must be replaced if it meets replacementspecifications contained in this section. Entire section ofattachment must be replaced if any chord or plate workdoes not meet replacement specifications.

FIGURE 4-10

P322

Dent

Dented Lacing

FIGURE 4-11

B231

Straight Line

Bent Lacing Bent Lacing

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KinksSee Figure 4-12 for following procedure.Kinked lacings must be replaced; do not bend kinkedlacings back into alignment.The entire section must be replaced if any chord or platework is kinked; do not bend kinked chords or plate workback into alignment.

Cracks and BreaksSee Figure 4-13 for following procedure.Cracked and broken lacings must be replaced; do notattempt to repair cracked or broken lacings.The entire section must be replaced if any chord or platework is cracked or broken; do not attempt to repaircracked or broken chords or plate work.

FIGURE 4-12

P323

Kink

Kinked Lacing FIGURE 4-13

P324Lacing Broken Away from Top Chord

Broken Lacing

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Corrosion and AbrasionSee Figure 4-14 for following procedure.Corrosion and abrasion must not be deeper than 10 percentof the wall thickness, the angle thickness, or the platethickness.

FIGURE 4-14

P325

P326

Not AcceptableAbrasion from handling with

chain exceeds allowable limit

Not AcceptableSurface is badly pitted;exceeds allowable limit

AcceptableSurface is relatively smooth:

within allowable limit

Corroded Chord

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Chord StraightnessSee Figure 4-15 for following procedure.If visual inspection indicates that a chord may not be straight,proceed as follows:1. Remove the suspect section from the attachment.2. Place wood blocks or steel plates having the same

thickness against both ends of the section (X1 and X2).3. Stretch a line (string or wire) over the outside of the

wood blocks or steel plates.4. Stretch the line as tight as possible and tie it off at both

ends.

5. Measure the distance from the chord (on either side oflacing intersection) to the line as shown in Figure 4-15.

6. Measurements must be take in two planes at each chord(dimensions A and B). To eliminate the effect of sag inthe line, take all measurements in the horizontal plane.

7. Take the first set of measurements, then roll the insertover 90 degrees, and take the second set ofmeasurements.

8. Tubular and angular chords must not deviate fromstraight more than plus or minus 3/16 in. (4.8 mm) at anylacing intersection (dimension A). Deviation betweenany two adjacent lacings must not exceed plus or minus3/16 in. (4.8 mm).

9. On angular chords, waviness at toe of chord(dimension B) must not deviate from straight more thanplus or minus 1/4 in. (6.4 mm) at any point. Furthermore,waviness between any two adjacent lacings must notexceed plus or minus 1/4 in. (6.4 mm).Gradual and sweeping bends in chords can bestraightened by cold bending them back into alignment.Take care not to kink or further damage the chords.

FIGURE 4-15

B231

X 2

Line

X 1

B

A

AB

A

A

A

ALine (black dot)

Typical

Chord Measurements

Tubular Chord and Lacing

Angular Chord and Lacing

Angular Chord and Lacing

A = Measurement to Determine StraightnessB = Measurement to Determine Toe Waviness

Measurement(chord to line)

Wood Blockor

Steel Plate

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Welding ElectrodesThe welding electrodes must be high quality low hydrogentype. Use 3/32 in. (2.4 mm) diameter electrodes for allwelding positions; 1/8 in. (3.2 mm) diameter electrodes maybe used for horizontal welding only. See Table 4-1 forelectrode and preheat specifications.

Electrodes must be purchased in air tight containers andmaintained in their as manufactured condition until use.

Once the container is opened, the electrodes must be storedin an oven at 250 300F (121 149C).Unheated electrodes will absorb moisture over a period oftime. Remove only the quantity of electrodes from the sealedcontainer or the oven that can be used in 30 minutes.Electrodes that have been out of an oven for 4 to 8 hoursmust be baked at 700F (371C) for 1 hour before use.Do not use wet electrodes; scrap them.NOTE: When used for welding ASTM 514 (T-1) steel,

electrodes of any classification lower than E100Xmust be dried for at least 1 hour before use,regardless of the type of electrode container.

All welding shall be done with a 200 300 amp D.C. motorgenerator or D.C. rectifier.

Table 4-1Electrode and Temperature Specifications

NOTE 1: No substitutions for E9018-M are allowed.E9018-M welding rods must not be out of ovenfor more than 1 hour before use.

Sealed packages of E9018-M can be purchasedfrom MCC by ordering Part No. 409758 for 1/8 in(3.18 mm) rods or 409759 for 3/32 in (2.38 mm)rods.

NOTE 2: Preheat chord and lacings uniformly to preventspo t bu rn ing wh ich causes excess iveoverheating and may cause steel to lose itsrated mechanical strength.

NOTE 3: AISI 4130 or 8630 chord and/or lacing must bepreheated in the weld area for both tacking and

we ld ing ; app ly p rehea t even ly. Use atemperature crayon to check.

NOTE 4: In an interpass or multiple pass weldingoperat ion, this is the temperature of thedeposited weld metal before the next pass isstarted. Example: 450F (232C) maximummeans that if 450F (232C) crayon meltsslightly on contact, it is too hot for welding. Letmaterial cool until crayon shows white whenmarked.

A 400F (204C) minimum means that 400F(204C) crayon must melt on contact to be readyfor welding.

CAUTIONStructural Failure!

Do not use electrodes larger than 1/8 in. (3.2 mm)diameter; larger electrodes may burn through lacing.

Lacing Material Trade Name AWS Electrode No. Preheat Interpass Temperature

A514 T-1 StroloyRQ100A

E9018-M -For all lacing material.

(See NOTE 1)

125 150F(52 66C)

(See NOTE 2)ERW 90 YS-T80 MAXI-FORM 80

AISI-4130 400F (204C) Minimum (see NOTE 3)450F (232C) Maximum

(see NOTE 4)ASTM-A242ASTM-A441*ASTM-A572GR 42 through 50ASTM-A440AISI-1018AISI-1020ERW 60 (see NOTE 3:)

COR-TEN TRI-TEN EX-TEN

MANTEN

MAXI-FORM 60YS-T60

125 150F (52 66C)

(see NOTE 2)

* MEC 850 replaces A572 for material up to 4 in (101.6 mm) thick, but should be treated the same as A572.

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4


Replacing LacingsAll new lacings are shipped with Form 00SPFM006 whichidentifies the lacing and chord material being welded.1. During inclement weather conditions, move the boom

section to be repaired into a covered area or build ashelter over the section.

2. Measure the exact position of the damaged lacing withrelation to the chords as shown in Figure 4-16. Recordmeasurements, as any marks on the chord will beremoved during grinding.

3. Cut out the damaged lacing with a burning torch or saw.Cut 3/8 1/2 in. (9.5 12.7 mm) above the chord toprevent overheating the chord.

4. Carefully grind the remaining lacing and weld from thechord to provide a smooth gouge-free surface. Takecare not to overheat the chord.

a. If the chord is straight, damaged lacings should beremoved one at a time. If the chord is bent or bowedslightly, cut loose damaged lacings first, and thencheck the chord straightness.

b. Always replace the center lacing first in a series ofdamaged lacings. This will assist in maintaining thecross sectional dimensions of the section. Thenreplace the remaining lacings, first on one side ofcenter and then on the other side of center.

c. Always replace diagonal lacings first. Diagonallacings run from one corner to another (for example,from upper left chord to lower right chord).

5. Inspect the ground areas with dye penetrant or amagnetic particle test to determine if any cracks exist inthe chord. Section must be replaced if cracks exist.

6. Make sure all welding surfaces on the chords andlacings are free of dirt, moisture, oil, paint, and rustbefore welding. If necessary use emery cloth to polishthe surfaces.

7. Fit the new lacings into position using themeasurements recorded in step 2. The gap between thechord and lacing must not exceed 1/16 in. (1.6 mm) ateither end.

8. Tack weld the new lacing into position at both ends witha 3/32 in. (2.4 mm) electrode. The tack welds should beapproximately 1 in. (25.4 mm) long on both sides of thelacing as shown in Figure 4-17.

9. Weld the lacing into place.

Whenever possible, weld lacings using a horizontal filletweld. The finished fillet weld must be the same size asthe original weld. Position the electrode so the chord willtake the major portion of the heat.Preheat and maintain the interpass temperatures givenin Table 4-1; use a temperature crayon to check thetemperature.The weld passes should be in as straight a line aspossible; do not weave electrode from side to side.

10. Remove all slag from the weld.11. Slowly cool weld by wrapping with an insulated blanket.12. Once the welds have cooled to the ambient

temperature, visually inspect each weld to ensure thatall craters are full (no porosity) and that there are noundercuts around the weld.


No welding shall be done in snow, rain, or high winds thatwill chill welds extremely fast. Ambient temperature inwelding area must not be less than 40F (4C).


Do not allow temperature of chord to exceed 400F(204C) during cutting or grinding (use temperaturecrayon to check).

FIGURE 4-16

B231

Lacing LocationMeasurements


Crater which forms at end of weld pass must be filled in;otherwise a crack may develop at crater.

FIGURE 4-17

B231

Tack Weld Locations

1 in (25.4 mm) Long Tack Weld (both sides)

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a. Determine if there are any cracks in the welds byperforming a non-destructive test on each weld notless than 48 hours after welding (per AmericanWelding Society Code).

b. Bad welds shall be ground out and rewelded.c. Do not use boom section during the 48 hour period.

13. Prime and paint all welds and replacement lacings.

BOOM, JIB, TOWER, AND MAST INSPECTION LISTBoom, jib, tower and mast sections (butt, top, inserts) mustbe inspected by a qualified person for the types of damageindicated in this check list.

See Boom, Jib, Tower, and Mast Inspection/Repair, forinspect ion gu idel ines, intervals, and replacementspecifications in this section.

Using Checklist

It is recommended that damaged areas be marked for quickidentification by repair personnel. Brightly colored tape workswell for this purpose. As a reminder, the type of defect can benoted on the tape.

Record KeepingA separate copy of this checklist must be filled out for theboom, jib, tower, and mast on each crane you own.Signed and dated copies of completed checklists must bekept on file at all times, as they may be required to verifywarranty or product liability claims.

Identifying SectionsOne of the connectors on the boom, jib, tower, and mastsections is marked as indicated in the below illustration.These numbers must be recorded in the checklist for eachsection inspected.

If no damage is found or the damage is withinspecif icat ion, check the box next to the itemindicating that the section is okay.If the damage is not within specification, indicate soin the box next to the item (for example: D to indicatedamage). Then make a detailed report of the typeand degree of damage found.

WARNINGStructural Failure!

If damage not within specification is found, do not operatecrane until appropriate section has been properly repairedor replaced.Operating crane with damaged sections may result instructural failure or collapse of boom, jib, tower, or mast.

Manufacturing Code

Manitowoc Part Number

of Component

Manufacturing Code

Identifying Boom, Jib, Tower, and Mast Sections

PAST PRODUCTION

Boom, Jib, Tower, or Mast Number

Boom, Jib, Tower, or Mast Number

X-X-XX

ZZZZZZ-Z#YY

#YY Z-ZZ-ZZXXXXXX

A524 CURRENT PRODUCTION Manitowoc Part Number

of Component

FIGURE 4-18

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4-17

4


Crane Serial No. Number

Inspectors Name

Boom

Signature

Jib

Date

MastTower

BUTT:

Dents

Manufacturing Code Part Number

Bends Kinks Cracks Breaks

Corrosion Abrasion Straightness Welds Other

TOP:

Dents

Manufacturing Code Part Number

Bends Kinks Cracks Breaks


Insert:

Dents Bends Kinks Cracks Breaks


Insert:



Manufacturing Code Part NumberLength ft


Insert:



Insert:





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SERVICING BOOM HOIST CYLINDER

1. Lower boom onto blocking at ground level (Figure 4-19).2. Fully lower mast and pin to boom butt as shown in

Figure 4-19.3. Move boom hoist control handle to off and park boom

hoist.

4. Stop engine.5. Exhaust pressure from cylinder valve blocks, as follows:

a. Slowly unscrew and remove vent plug from valveblock (Figure 4-20).

b. Slowly unscrew and disconnect pressure senderline from elbow in valve block (Figure 4-20).

6. It is now safe to remove holding valves, disconnectremaining hoses, and remove cylinders as required.

7. If boom hoist cylinders were removed, install them at thistime:

a. Pin head end of cylinders to rotating bed. Blockvalves on cylinders must face inward.

b. Securely block cylinder bodies on mast (seeFigure 4-19). Do not connect rod end pins to mast.Both cylinders must be free to extend and retractwhen bleeding air.

8. Install holding valves and connect hoses as required:a. Thoroughly clean all fittings.b. Make sure all O-rings are properly installed.c. Apply thread sealant to vent plug threads and

securely install vent plugs.d. Install and securely tighten holding valves, fittings,

and hoses.

9. Bleed air from boom hoist cylinders as follows:

a. Both cylinder rod ends must be disconnected frommast. Perform step 7b if not already done.

b. Start and run engine at high idle.

FIGURE 4-19

Boom HoistCylinder

BlockHere

Unpin Boom HoistCylinder Here

Mast

Pin Mast toBoom Butt Here

A1107

Crawler or Truck Crane

WARNINGFalling Boom Hazard!

Do not attempt to service boom hoist cylinders (removeholding valves or disconnect hoses) until following stepsare performed. Boom will lower uncontrolled.

FIGURE 4-20

ValveBlock

P986

Right Side Cylinder Shown(Left Side Cylinder Similar)

PressureSender Line

VentPlug

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4-19

4


c. Fully extend and retract boom hoist cylinders twice.Use care not to allow cylinder rod ends tocontact mounting lugs on mast.

d. Check for oil leaks at cylinder valve blocks ascylinders are operated. Stop engine and correctleaks if found.

e. Remove blocking and connect cylinder rod ends tomast.

10. Bleed boom hoist cylinder pressure sender and calibratepressure senders (see Pressure Sender Calibrationprocedure in Section 2 of this manual).

11. Disconnect mast from boom butt.

12. Slowly raise boom to desired operating position. Thenslowly lower boom approximately 20. Continue thisprocedure until operation is smooth in both directions.

BOOM HOIST CYLINDERS WELDINGWhen welding on the subject cranes, weld current can arcfrom the boom hoist cylinder barrels to the pistons or rods.

This action can cause damage to the pistons and rods,causing premature seal failure. Leakage will occur, and theboom may lower on its own.

Before Welding on CraneTake the following precautions to prevent damage to theboom hoist cylinders (and other crane parts such asbearings, swivels, slewing ring, computers, etc.): Disconnect all cables from batteries.

Disconnect output cables at engine junction box. Attach ground cable from welder directly to part being

welded and as close to weld as possible. Do not weld on engine or engine mounted parts (per

engine manufacturer).If weld arcing at the boom hoist cylinders is detected,carefully inspect the cylinders for damage: pitting in rods,leakage at rod seals, cylinder drift (internal leakage). Ifdamage is found, contact the Service Department atManitowoc Cranes for repair/replacement instructions.

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SECTION 4BoomBoom Stop AdjustmentsAutomatic Boom StopMaximum Operating AnglesOperationMaintenance

AdjustmentPhysical Boom StopOperationRemoval

Boom Angle IndicatorAdjusting Angle IndicatorSensor ReplacementPendulum-Type 120 PotentiometerSolid State Sensor

Ordering Boom and Jib LacingsPurposeBoom or Jib IdentificationOrdering Lacings from Lacing DrawingsOrdering Lacings without Lacing DrawingsAssistance

Welding Instructions

Boom, Jib, Tower, and Mast Inspection/RepairExtent of RepairOrdering LacingsInspection IntervalsInspection GuidelinesReplacement SpecificationsDentsGradual and Sweeping BendsKinksCracks and BreaksCorrosion and AbrasionChord StraightnessWelding ElectrodesReplacing Lacings

Boom, Jib, Tower, and Mast Inspection ListUsing ChecklistRecord KeepingIdentifying Sections

Servicing Boom Hoist CylinderBoom Hoist Cylinders - WeldingBefore Welding on Crane

Documents

Boom Repair Criteria