We have designed similar brige connected lines for offshore platforms and follow the guidelines as below.

Generally, for the bridge lines, one side is fixed at one platform and other side is allowed to slide freely as per bridge movement and the first anchor or restraint shall be suitably located in second platform to allow for free movement.( inherent flexibility in the line without any expansion loops in the bridge). Also, the bridge movement shall be checked for both positive and negative directions and the expansion stresses shall be checked for worst condition.

Generally the fatigue bridge deflection shall be furnished by Naval architect depending on the wave heights and cycles and in the absence of the data, it is safe to to assume 60% of the operating bridge movement as fatigue movement. The fatigue analysis can be done using the Caesar fatigue option considering only bridge deflection.

In your case, I feel if it is possible to introduce new anchor on the second platform which can allow free bridge movement, without affecting the flexibility of the lines on the second platform, it is the best option. In such case you can remove the faulty anchor on the bridge after the expansion loop.

However a careful study shall be made before introducing the new anchor. Since I am available in KL/Singapore, if possible, I can have a look at your system and suggest some remedial actions.

You can contact me at krsrini@pacific.net.sg

regards,

K.R.Srinivasan.