Catalyzes the transfer of the carbamoyl group from carbamoyl phosphate to the delta-amino group of N(2)-succinyl-L-ornithine to produce N(2)-succinyl-L-citrulline. Is essential for arginine biosynthesis. Has no activity with either L-ornithine or L-aspartate as substrate. Has also no detectable AOTCase activity, being unable to convert N(2)-acetyl-L-ornithine to N(2)-acetyl-L-citrulline. carbamoyl phosphate + N(2)-succinyl-L-ornithine = H(+) + N(2)-succinyl-L-citrulline + phosphate Amino-acid biosynthesis; L-arginine biosynthesis. Homotrimer. Belongs to the aspartate/ornithine carbamoyltransferase superfamily. SOTCase family.