m there are two type movements between riser 18 and the jacket leg and particularly the stiffened section 42 this could be a vertical motion i e longitudinal with respect to the axis of these members or it can be a pivoting type motion this bearing arrangement takes care of each the vertical movement can be between the bearing housing and the outer wall of floating bearing 48 this permits one to slide with respect to the other rotational movement between the riser and the jacket can be permitted or accommodated between the inner surface of floating bearing 48 and the outer surface of spherical bearing 49 thus inasmuch as these bearings are the spherical self aligning type they will allow riser rotation without forcing secondary forces and moments into either the riser or jacket structure the importance of using both upper and lower horizontal bearings is indicated in fig7 and 8 the lateral deflection of riser 18 without upper horizontal bearing 26 would be as indicated in fig7 assuming riser sleeve 30 were not in place fig8 indicates a changed and limited deflection of riser 18 between lower horizontal bearing 32 and vertical support bearing 22 the mathematics for determining lateral deflection of a vertically suspended pipe.