Mr Dalton said the repair job would be fast-tracked however - "we don't give in to these sort of louts".
The glass barrier had allowed visitors to the platform an uninterrupted view out to sea and it had proved increasingly popular, despite earlier criticism that it did not extend out to sea far enough.
It was highly strengthened glass which Mt Dalton said would have required a lot of force to break.
It appeared the culprits had stood on the seaward side and used rocks from the shoreline.
As one maintenance staffer said - "you throw enough rocks at it and it'll break in the end."
Rocks could be seen strewn across the end of the platform.
The cost of the damage was still being assessed.