above chamber 59 to cause outer barrel 49 to move upward relative to inner barrel 45 this causes the load ring 35 and collet 23 to move upward from shoulder 15 collet 23 will ratchet on the wickers 19 during this upward movement once load ring 35 is a sufficient distance above shoulder 15 the operator will slack off the upward force on the inner barrel 45 this slacks off the tieback casing to release its lower end at the mudline hanger at the subsea wellhead the tieback string may then be removed fig5 illustrates an alternate embodiment with mandrel 17 39 and collet 35 39 being the same as in the first embodiment the load ring 35 39 differs in that it employs a different retainer ring 39 39 split retainer ring 39 39 has a sharp upward facing shoulder for engaging recess 41 fig4 recess 41 will be configured with a sharper downward facing shoulder than shown in the first embodiment retainer ring 39 39 snaps into recess 41 when the load ring 35 39 moves downward adjacent recess 41 a cam ring 67 locates above the retainer ring 39 39 and engages a tapered surface on retainer ring 39 39 cam ring 67 is pinned to retainer ring 39 39 by a shear pin 69 shear pin 69 does not shear during running of load ring 35 39 and cam ring 67 remains fixed to retainer ring 39 39 in a position to avoid interference with the outward movement of retainer ring 39 39 into recess 41 to release the retainer ring 39 39 the lower end 51 of.