Bulk materials handling

[greenlaneman]

Thinking about a future layout involving large trains of bulk material such as chalk destined for a rail side site without bulk materials handling facilities other than dumping by gravity or offloading by grab crane or front end loader.
Scenario is flooding causing damage to track embankments similar to floods of 1953 between Reculver and Birchington or the recent landslips on the East Coast mainline (or was it West Coast?).
I'm interested in the wagons that would have been used in the 60s or 70s and currently.