| 49 / | HD | MOVABLE OR REMOVABLE CLOSURES |
| 73.1 | DF | CLOSURES INTERCONNECTED FOR CONCURRENT MOVEMENT {9} |
| 95 | DF | .~ Closures in spaced openings along barrier {1} |
| 96 | ![]() | .~.~ Levers acting between interconnector and closures {1} |
| 97 | DF | .~.~.~> Rock shaft interconnector |