However, there’s very little evidence to support this claim — at least, according to historian Richard Howells (as reported by The Culture Trip).
Howells claims that these gates seen in the blockbuster weren’t meant for shipwreck necessarily, but rather the prevention of diseases from spreading above.
While James Cameron strived to tell a realistic account, there are some details that appear to be based more on theories pertaining to the Titanic than anything that can be confirmed as accurate and/or official.
For instance, there’s a noteworthy sequence where many of the third-class passengers are barricaded against their will below the deck, preventing them from reaching the lifeboats and upper deck, in a stark bit of socioeconomic commentary.