I saw a program talking about the manufacturing of the Titanic, where they said that the rivets were done manually and the rivetors were paid per rivet therefore encouraging them to do a fast job so they'd be paid higher therefore making some of them possibly faulty but that's speculation. Welding techniques that could've made the rivets and plates stronger wouldnt come into play until years later.

There is an awesome show that airs frequently called "the Iceberg that sank the Titanic" which is quite facinating about icebergs in general. but does shed some light. there is also another program that is about the men who built her (Titanic not the iceberg, irpy der!!) , however i forget the name of it.