|A. Arnold Gillespie in his waders in the MGM Lot 3 tank during the Ben Hur sea battle miniatures shoot.
The hero foreground ships were built at 1/6th scale and had molded rubber figures with poseable wire armatures populating the decks. A few of the figures were made to mechanically "walk the decks" while others were mounted to springs to effect some movement. There were motorised mechanisms inside to move the galley oars.
Distant ships were built at a smaller scale while the most distant were photographs of the models mounted on flat board cutouts pulled on tracks outside the tank.
The camera shot at three times normal speed, 72 frames per second while the ships were made to move at around 3 feet (1m) per second. The sinking ship was pulled down into the deeper well part of the tank by two cable and pulley systems.
There are some very interesting detailed layout drawings and photographs of the tank set up in the book The wizard of MGM Memoirs of A. Arnold Gillespie. There is also an interesting and detailed blog article by the author about the planning and filming of some of the miniature shots for Ben Hur on the Wizard of MGM book site. http://www.wizardofmgm.com/2016/12/ben-hur-1959-miniature-ships.html
The photo below shows one of the 1/6th scale models as it is displayed in the Baltimore Convention Center.
One other of the larger ship models was reported to be on display in a Ripleys believe it or not traveling exhibition, in this case at the San Diego Air and Space museum.
In 2012 nineteen smaller models came up for auction. According to the auction description the models were originally built for the 1925 silent version of Ben Hur and refurbished and modified for the 1959 version. They were between 5 and 9 feet long (1.5m - 2.7m) and made of wood with copper hulls. Some still had the rowing mechanisms inside in various states of disrepair. Another auction site has a single model of this series with an intact rowing mechanism and a description stating its use in 1925 but no mention of re-use at all.
Another of these 1925 models in somewhat better condition, can be seen in the National Museum of Ship Models and Sea History, Sadorus, Illinois, USA.