I haven’t heard of bollards before but there are many stories of “mooring rings” in cellars in Bridge Street. I have looked in some cellars (one of which is extremely interesting but for completely different reasons) but have found nothing. I was told that the cellar below the insurance brokers (was Lowland) had such things but that the cellar has been lined with concrete and nothing can now be seen. Under Liquid Lounge where the bookshop had been is a cellar with rings apparently. But does this have anything to do with an early port?
The theory I have heard and can go along with, postulated by Adam Menuge from English Heritage, goes like this.
The original alignment of the river bank was along Bridge Street. Gillies Braes, the raised area above the New Road continues south; think of the raised area where the Maltings is behind and to the east of Bridge Street and also Devon Terrace above Pier Road. In this idea of early Berwick, the Palace Green area did not yet exist.
Look along the east side of Bridge Street from the bottom of Hide Hill. The buildings’ frontage “waves” about somewhat. Those on the west side are more regular. One has to understand the principle that the footprint of older buildings is often preserved in relatively modern buildings. So this “wavy” alignment may be because it was following the line of an organic form, such as a river. Archaeological findings from similar early ports on the east coast and in Scandinavia suggest that wooden jetties projected out into the river from the bank.
The theory continues that the spaces between the jetties become silted up naturally or perhaps deliberately filled in. The jetties are simply extended further out. This process continues until the reclaimed land in consolidated such that buildings can be constructed. But unlike those on the east side, these can be built in straight lines as they are not constrained by the line of the river. My own additional thought on this is that, if true, the cobbled lanes like Sallyport are likely to be on the lines of the jetties.
All this would have happened before the beginning of the 14th century as the town walls exist to the west of Bridge Street. A topographic map of about 1570 (and others) show a quayside with a harbour wall such as we have today near the Old Bridge, and a sandy beach where the car parks and Chandlery are now. In between the river is shown up against the walls.
So where does this leave our rings or in your question, bollards. I don’t believe they are anything to do with a quayside. For them to be part of an early quayside they would have to be on the east side of the street so that rules out the Liquid Lounge cellar. But it is not likely that they would have used mooring rings then anyway. Boats then were round hulled so that they could be beached at low tide and unloaded. This was fairly common practice into the 18th century.
Of course, there could be any number of reasons why there might be rings in cellars but without having seen them I cannot comment further.
A few years ago I knocked up a painting to illustrate a possible early port. Hope that answers your question to a degree. As always, if anyone can shed any light on this or have any photographs of these elusive rings, I’d love to hear from you.