How to do a proof load testing of 100-ton offshore crane…?
Prior to the load testing of crane by water bag and digital dynamometer , we have to assess whether the hook is single hook or double hook. If its a single hook you might require digital dynamometer load cell, shackles, water weights or water bags with discharge hose, water supply, Wire ropes etc. If its double hooks, we might require additional slings to manage the load testing inspection by water bag, digital dynamometer load cell, shackles, discharge hoses etc.Second thing is Barricade the area; adjacent to fitting to be tested should be open and clear of any other equipment and associated personnel. Accomplish all work operations in accordance with the standards identified in Hazard Identification. Life jackets will be worn by employees working over or near water, where the danger of falling into the water and/or drowning exists.
Third step is accessing the areas for filled water weights or water bags for the appropriate capacity. Height and Width at filling condition of water bag is very important and it needs to identified/determining as per the data sheet of water bag which we provided. For a single hook crane, connect the lifting accessories of shackles, Digital dynamometer load cell and water bags and setting up the filling /discharge hose to the valve in the right position. Carefully handle the water bags from sharp edges while during connecting water bags and lifting accessories. Install a pulley or wire rope sling on the top of water bag with master link and shackle assembly. Rope should have enough length to control far away.For a double hook crane; preparation of water bag and connections are same but carefully settle the sling between hook and shackles to avoid twisting of rope assembly. Also it will help the hook to bear equal weights/balancing the weights .After connection, slowly lift the water bag from the ground position and to avoid any friction/sharp edges at the ground level .When the water bag is away position from the ground and its in the right position as per the crane balance/drainage facilities; perform functional testing of water bag to ensure the valves function properly by pulling ropes and/or open &close the valves of water bags. We can ON the digital dynamometer load cell if all the connections are made. If we feel water bag function properly, start filling of water and have to ensure close discharge hose valves of water bag & control the discharge hose far away from the ground .Rope connecting with the water bag should be tied in a proper manner. Assess the total weight by the help of digital type dynamometer load cell and connect the filling hose to the water supply. Monitor the load in every seconds while filling water bags and with rigging and crane operator we can control the water filled weights at boom radius & as per the load chard as indicated in the crane.
Handling of water bags and Digital Dynamometer load cell after load testing of Crane:
Open up the ball valve in the central discharge area water bag and drain the water from the water bag. After the complete drain out of water ,pull down the discharge hose of water weight bag. Lower the crane boom by lowering the water bags and disconnect the entire water bag assembly from the crane.
Storage and Demobilize the Water bag and its accessories:
Storage should be in a DNV 2.7-1 offshore Container with sufficient vent/protection from Direct sunlight.