One area of concern at APL was the long-term integrity of mechanical connections on Oyster 800, a device which included a number of bolted and flanged connections of various sizes and functions. Operational experience shows that mechanical connections are prone to both corrosion and loosening, caused primarily by vibration.                                                      

This document was produced by APL in 2014 to provide a single, standardised point of reference for bolted connection design calculations for the Oyster 800 device. The spreadsheet included data on a large variety of fastener types, materials, locking methods, lubricants, and tightening methodologies. 

Outputs from the spreadsheet include required fastener tension, % yield, force range expected from tightening method, preload, bearing stress, and an indication if the design satisfies design criteria.

This document was informed by experience gained through training, design activities, and practical implementation of bolted designs during the offshore maintenance campaigns on Oyster 800 in the summers of 2013 and 2014.

The data for fasteners, frictional coefficients and tightening factors was obtained from manufacturer data, standards, and experiment, and was valid as of summer 2014. It is up to the user to be satisfied on the current accuracy of the data and standards referenced.

The spreadsheet is intended to be used as a design aid, and no liability is assumed by WES for the use of this calculation sheet.                                                                                                                                            

Project Keywords: Bolting, Loading, Structure, Torque, Guidance