SkyTrak 10054 Operation Manual - Manual (Page 170)

168 Model 10054 Rev 3/02
General Maintenance
E. Boom Chain Inspection
(250 Hour Intervals)
Under normal operating conditions the boom chains will need to be
inspected every 250 hours of operation. The retract chains need to be
exposed and inspected every 1000 hours of operation. Refer to the Service
Manual for the proper procedure. Environmental conditions and dynamic
impulse/shock loads can drastically affect normal operating conditions and
require more frequent inspection intervals.
Environments in which material handling vehicles operate can vary widely
from outdoor moisture to temperature to mildly corrosive or highly corrosive
industrial atmospheres, in addition to abrasive exposures such as sand and
grit.
Following are some examples of dynamic shock loading which can impose
abnormal loads above the endurance limit of a leaf chain.
• High velocity movement of load, followed by sudden, abrupt stops.
• Carrying loads in suspension over irregular surfaces such as
railroad tracks, potholes, and rough terrain.
• Attempting to “inch” loads which are beyond the rated capacity of
the vehicle.
The above load cycles and environmental conditions make it impossible to
predict chain life. It is therefore necessary to conduct frequent inspections
until replacement life can be predicted.
The boom chain’s normal life expectancy can be expressed as a maximum
percent of elongation. This is generally 3% of pitch. As the chain flexes
back and forth over the sheave, the bearing joints (pins and inside link
plates) gradually incur wear due to articulation.
WARNING:
Worn pins, stretched or cracked links or corro-
sive environments can cause chain failure. A chain failure could
result in uncontrolled boom movement, loss of load or vehicle
instability and could cause death or serious injury and/or property
damage.
250
OH2710
OA1490
168
Model 10054 Rev 3/02
General Main tenan ce
E.B oomC hain Inspection
(25 0Ho urInte rv als)
Under nor malop erati ngco nditio nsthe boom chai nswi llnee dt obe
ins pected eve ry 250hou rs ofope rati on.T he retr act chain sn eedto be
ex posed andin spec tede ver y1 000ho urs of oper ation .R efer tothe Ser vic e
Ma nu alf or the proper pro ce dure .E nvi ro nmenta lc onditi ons and dyn amic
im puls e/sho ck loa dsca ndr asti cally affec tno rm alope ra ting co nd ition sa nd
re qu ire mor ef re quent in spec tion in terv als.
En vir onme ntsin which mater ial hand ling ve hic le so pera te can va ry wide ly
from outdoo rmoi stur et ot emper atur et omi ldl yc orr osiv eor highl yc orros iv e
indu strial atmos phere s, inadd ition toabras iv ee xposu res such ass and and
grit.
Fo llo win ga re so mee xam ples ofd yn ami cs ho ck loadi ngw hich can impos e
abnor mal loa dsabov et heendu ranc el imit ofa lea fc hain.
• High ve locit ym ove ment ofloa d,f ollo wedb ys udden, abr upt stops.
• Carr ying loads insu spens ion ov er irr egula rs urf ac es suc ha s
railr oad trac ks,po tholes, and roug ht erra in.
• Attem ptin gt o“ inch ”loa dswhi char eb eyo ndt her ated cap acity of
the vehi cle .
Th ea bo ve load cyc les anden vironm ental con dition smak eit imp ossi ble to
pre dic tc hain life .I ti st heref ore nec essa ry toc onduc tf re quent insp ection s
un til rep lacem entli fe can be pre dic ted.
The boom cha in’s norma ll ife ex pec tanc yc anbe ex pres sed as ama xim um
pe rc en to fe long ation. Th isis gener ally 3% ofpit ch.As the chai nf le xe s
ba ck andf ort ho ve rt he shea ve ,t hebe arin gj oints (pin sa ndi nsid el ink
plat es)gradu ally incu rwear du et oa rti cula tion.
WA RNING:
Wo rn pins, stre tched orcra ck ed lin ksor co rro -
siv ee nv iro nments can cau sech ainf ailur e. Ac hain fai lure could
re su lt in unco ntrol ledboo mm ove men t,l os so flo ador ve hicle
inst ab ilit yan dc ould caus ed eath or se rio us inj ury and /o rp rop ert y
dam age .
250 OH2710
OA1 490