Manual

170
Model 10054 Rev 3/02
General Maintenance
Elongation
Double Extend Chains or Retract Chains:
When the original length (Figure 121, “A”) of 12.00" (305 mm) per foot
of new chain has elongated from wear to a length (“B”) of 12.36"
(313 mm), the chain should be discarded and replaced.
Single Extend Chains:
When the original length (Figure 121, “A”) of 12.00" (305 mm) per foot
of new chain has elongated from wear to a length (“B”) of 12.36"
(313 mm), the chain should be discarded and replaced.
It is important to measure the chain in the section that moves over the
sheaves because it receives the most frequent articulation. Measuring
the chain near its clevis terminals could give an inaccurate reading. The
ends of the chains, near the clevis terminal, will not have flexed as
frequently, if at all, as nearer the middle of the chains.
Double Extend Chains or Retract Chains: Measure across a span of
17 pins at the center of the extend chain. Measure from pin center to pin
center. Because the retract chain is inside the boom you will not be able
to measure the chain.
Single Extend Chains: Measure across a span of 13 pins at the center
of the extend chain. Measure from pin center to pin center. Because the
retract chain is inside the boom you will not be able to measure the
chain.
All Chains: The maximum measurement allowed is 12.36" (313 mm). If
the measurement is more than 12.36" (313 mm), the chain should be
replaced.
Figure 121
MM2120
“A”
“B”
170
Model 10054 Rev 3/02
General Maintenance
Elongation
Double Extend Chains or Retract Chains:
When the original length (Figure 121, “A”) of 12.00" (305 mm) per foot
of new chain has elongated from wear to a length (“B”) of 12.36"
(313 mm), the chain should be discarded and replaced.
Single Extend Chains:
When the original length (Figure 121, “A”) of 12.00" (305 mm) per foot
of new chain has elongated from wear to a length (“B”) of 12.36"
(313 mm), the chain should be discarded and replaced.
It is important to measure the chain in the section that moves over the
sheaves because it receives the most frequent articulation. Measuring
the chain near its clevis terminals could give an inaccurate reading. The
ends of the chains, near the clevis terminal, will not have flexed as
frequently, if at all, as nearer the middle of the chains.
Double Extend Chains or Retract Chains: Measure across a span of
17 pins at the center of the extend chain. Measure from pin center to pin
center. Because the retract chain is inside the boom you will not be able
to measure the chain.
Single Extend Chains: Measure across a span of 13 pins at the center
of the extend chain. Measure from pin center to pin center. Because the
retract chain is inside the boom you will not be able to measure the
chain.
All Chains: The maximum measurement allowed is 12.36" (313 mm). If
the measurement is more than 12.36" (313 mm), the chain should be
replaced.
Figure 121
MM2120
“A”
“B”