The 1959 movie was 3 1/2 hours and the new one is only 2 hours and 5 minutes. So they must have left a lot of scenes out.
The original was 2:23 so maybe 1959 was with added scenes.
By the way My friend and his parents took me to the Egyptian in Hollywood to see Ben Hur 1959. It was unbelievable. I was 12.
Yes, one big difference was Ben-Hur’s rescue from the shipwreck. In ‘59 he saved the general and prevented him from committing suicide. The general thought they had lost the sea battle, but found out they (the Romans) had won. So he adopted Ben-hur and there was a great deal of development leading to the chariot race.
In ‘16 version, BH, by himself, washes ashore right where the arabs are training for the races. So the sequence from slave ship rower to chariot racer was greatly reduced.