The lowering down of spreader/container and twist locks operations must always be done manually. Whilst the hoisting up of spreader/container may be done semi-automatically subject to the following conditions: i) a learn cycle has been done to set the clear height: and ii) the learn cycle is still valid: andiii) the operator have manually hoist up the spreader/container to a preset height after performing the twist lock operation: andiv) the operator have selected the automatic operation mode.