High rate of failure of mooring chains used in the offshore industry necessitates improved understanding of phenomena correlated to the fatigue life of these chains. Although fatigue damage models and methods for lifetime predictions have improved in recent years, the issue of residual stresses (RS) still is a “black box”. An improved model combined with little knowledge of actual residual stresses is sub-optimal and does not bring the fatigue assessment methodology much further. Hence, providing quantitative information of residual stresses in safety critical components is of high scientific value. The ENGIN-X has been capable of measuring RS in depth in steel materials and, thus, is ideally adapted for RS measurements in the case of large-scale mooring chains. The data will be compared to other measurement techniques and used to validated our numerical models.