Hello Mr Ramesh Dharamarajan,
Thank you for the detailed explanation with an example.
The numerical example dispels whatever doubt that one would
have, while lifting the job with two cranes.
In the example given above, the combined SWL of both the cranes is
MORE THAN THE JOB WEIGHT ensuring Safety.
This aspect is satisfied in the pre lift and lift conditions.
However when you made the first posting you have mentioned
it the other way,perhaps due to oversight.
,if both swls of both cranes do not exceed the actual load of the material,
IN CORRECT
, if both swls of both cranes exceed the actual load of the material by about 15 %...
CORRECT
Please make the correction ( of the clerical error) accordingly in your first post.
V.Raghunathan
From India
1330Thank you for the detailed explanation with an example.
The numerical example dispels whatever doubt that one would
have, while lifting the job with two cranes.
In the example given above, the combined SWL of both the cranes is
MORE THAN THE JOB WEIGHT ensuring Safety.
This aspect is satisfied in the pre lift and lift conditions.
However when you made the first posting you have mentioned
it the other way,perhaps due to oversight.
,if both swls of both cranes do not exceed the actual load of the material,
IN CORRECT
, if both swls of both cranes exceed the actual load of the material by about 15 %...
CORRECT
Please make the correction ( of the clerical error) accordingly in your first post.
V.Raghunathan
From India
Dear Mr.Itsamals,
From the query it is clear that you are not conversant with crane rigging. For God’s sake don’t get carried away with the “I think…….” answers in rigging. Tandem lift is a serious and dangerous operation. For that matter every lifting operation need be considered as serious and dangerous. The history of crane failures says so. Consequences of a failure can be quite serious. However by following the set procedures every lift can be completed safely and relax at the end.
A tandem lift (using multiple cranes) is a critical lift. It requires a lift plan.
A competent rigger only will draw a lift plan.
A lift plan is required as part of any critical lift procedure and must provide the following:
1. Type and de-rated capacity of cranes to assess SWL of the cranes (load chart) in the configuration
2. Boom length
3. Crane radius
4. Weight and shape of the load, center of gravity etc.
5. Ground and site conditions
6. Placement of the crane
7. Swing and tail clearances
8. Necessary communication to be used
9. Explanation of hand signals
10. Rigging hardware
11. Rigging sketch.
12. Rated capacity of rigging components
13. Sling angles
14. Strain calculations
15. Wind velocity
16. Load moment indicator
17. Others
Your cranes as such cannot lift the intended load and no rigger/competent person will permit it..
Regards,
Kesava Pillai
From India, Kollam
From the query it is clear that you are not conversant with crane rigging. For God’s sake don’t get carried away with the “I think…….” answers in rigging. Tandem lift is a serious and dangerous operation. For that matter every lifting operation need be considered as serious and dangerous. The history of crane failures says so. Consequences of a failure can be quite serious. However by following the set procedures every lift can be completed safely and relax at the end.
A tandem lift (using multiple cranes) is a critical lift. It requires a lift plan.
A competent rigger only will draw a lift plan.
A lift plan is required as part of any critical lift procedure and must provide the following:
1. Type and de-rated capacity of cranes to assess SWL of the cranes (load chart) in the configuration
2. Boom length
3. Crane radius
4. Weight and shape of the load, center of gravity etc.
5. Ground and site conditions
6. Placement of the crane
7. Swing and tail clearances
8. Necessary communication to be used
9. Explanation of hand signals
10. Rigging hardware
11. Rigging sketch.
12. Rated capacity of rigging components
13. Sling angles
14. Strain calculations
15. Wind velocity
16. Load moment indicator
17. Others
Your cranes as such cannot lift the intended load and no rigger/competent person will permit it..
Regards,
Kesava Pillai
From India, Kollam
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