[Dsg-rich] RICH winch used for detector rotation

[Tyler Lemon]

Hello, 




We have found that the label on the winch included in Box 1 for RICH assembly does not match the winch specifications given in the manufacturer’s manual. The label on the winch (picture attached) states that the maximum load for the first layer of rope is 1480 kg. The manual (attached) states on page 3 that the first layer has a maximum lifting load of 1300kg. Which would be the specifications to follow? 




JLab safety coordinators will not allow us to exceed 1000 kg for the load test, as that is the specified maximum capacity of the winch if the rope is on its fourth layer. However, if we can work with just the first and second layer of rope on the winch, there might be a chance we can still use the winch we already have. 




As a contingency plan, we have started looking at hand winches that will handle a higher load. The price of these winches are ~$2,000. 




Another contingency plan would be to use the winch we already have for only the assembly of the detector shell. For this plan, we need to know the weight of just the detector shell components that will be rotated in March. We also need to know the final, fully assembled weight for RICH as a different winch will be needed to lower the RICH from the rotated position before it is installed in Hall B if the total weight of the detector exceeds 750 kg (safety margin of 25% is required). 




The above issue needs to be addressed as soon as possible. If we cannot use the winch that arrived in Box 1, we will have to buy a new winch. 




We hope to use the winch we have to at least rotate the detector shell, which by our estimate would only weigh ~500 kg. 




Best regards, 


Tyler 
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