The metal posts were put in place last week on the pier, which dates back to 1897 and is a category B Listed Building, meaning it is of regional importance.
Guidance from Historic Scotland states: “Listed building consent must be obtained where proposals will alter the character of the building.”
Applications for consent are made through the local planning authority – in this case the Argyll and Bute Council, which also owns the pier.
A council spokesperson said on Tuesday: “The council did approach our own planning officers in Helensburgh. They reviewed the proposal and said that it did not require a formal application.”
She added that the barrier had been installed after talks with SPT ‘to enable safe marshalling of passengers’.
It was reported some months ago that pier staff would lose their jobs as new contractors Clydelink did not require the pier to be manned, but the spokesperson added: “It is not as yet determined whether the pier will be unmanned or not, this is subject to a further review once the planned works are installed.”
The spokesperson added: “I regret that the contractor has affixed the barrier to the pier building (as pictured, right) but this is to be rectified in early course.”
Historic Scotland’s website advises: “Alterations which may seem minor, such as stonecleaning all or part of the property, alterations or replacement of windows or installation of roof lights may require listed building consent.”
Pictures by Kerr Gardiner