The internal forces and deflections of a segmented locking ring inserted in an annular slot in a cylindrical vessel, andsupporting its bottom while the vessel is subjected to high internal pressure, are studied.The behaviour of the ring sectors is described in terms of a curved beam of rectangular cross section resting onelastic foundations.A closed form solution is obtained. The results presented show that the reaction force between the ring sectors andthe cylindrical vessel exhibits peaks at the sector ends, and that the maximum value of the bending moment for thering sectors is noticeably higher than that for a complete ring.