We now look at the Lifting capacity chart for the crane
. Here we can see that at 20m radius/28.04m boom extension the lift capability is 11.9 tonne. For a 22m radius with same boom extension the lift capability is 10.5 tonne. As are lift is 6.4 tonne the crane is suitable.
These instructions may also be used for shore crane operations. On the capability chart a darkline denotes the limit of stability and refers to lifting weights with the boom at right angles to the bed rather than over the cab. For shore operations the capability chart refers to full outrigger extension only and a separate chart must be in place if half outrigger extension is to be used
Effects of sea state
A set of Class approved Guidance charts indicate the effects of seat state on the lifting capabilities of the vessel. These supersede the lifting capability chart although they are for guidance and care must be taken to observe additional factors given by the crane manufacturer.
Fly Boom Extended
Extending the flyboom creates a special case. The flyboom is only used with all the sections at maximum extension. For this crane that is a boom extension of 42.76m. The lifting capacity chart now changes from a radius/boom length relationship to a boom angle/fixed boom length relationship. Again the required angle to check the capability of the crane can be found by either by use of graph paper or by calculation It should be noted that great care when operating with the flyboom extended must be taken to ensure that the crane is not overloaded something which is entirely possible even with no load on the hook when Gibbing downIn addition a Swing Away may be used which takes the form of a fixed boom that bolts to the jib head and generally sits at an angle to the boom.