While reading about Saturn launch vehicle family, I read that Saturn 1 third stage used 2# RL 10 engines, producing a total thrust of 30K Pounds.
But each RL 10, individually produced approx 25K pounds of thrust. If two of these were used in Saturn 1 third stage, why total thrust of 3rd stage is said to be only 30 K pounds and not about 50 K pounds.
Similar is the case with S1 second stage. It used 6# of RL 10 (@ 25 K Lbf each), but total thrust of 2nd stage of S1 is only 90K Lbf and not 125 K. WHY so?