There is a tradition that the first bridge was founded by two maiden sisters , one of whom had seen her lover drown while fording the river. The effigies of two women are reputed to have been carved on a stone on the east parapet and the faded remains could still be seen in the 19th century.
Morris ('The Brig of Ayr and something of its story') notes that the first written mention is in a 1236 charter of Alexander II, along with provision “ad susten. pontis” ; this wording indicates maintenance rather than construction. In Treasurer Rolls for 1491 (James IV ) is found the entry “XVII Nouembris , to the massonis of the bryg off Ayre Xs.”: that is 10 shillings to the masons of Ayr bridge. There is no evidence that this is a new construction, but do we know that in the same year James was ferried over the river on his way to Whithorn. It has been generally assumed that the present masonry bridge is from this time . The single remaining Gothic arch is compatible with this date (in reality, it may be a slightly broken segmental arch.) An old ford preceded the bridge, a little distance away. A date stone with ‘1232’ is clearly a later addition.
Between 1585 and 1588 the arches were ruinous and very major repairs were carried out – possibly a complete rebuild : "Ye bowis of ye brig yt ar ap-perend ruynous”. Tolls were imposed. In 1597 carts and sledges were temporarily banned, on penalty of five pounds. In 1687 further tolls were charged in the streets as well as the harbour and bridge, in order to pay for essential bridge repairs.
The north arch collapsed in 1732 along with the abutment on the north bank. Masons were appointed for the repair . The whole bridge was examined and still considered insecure. It was decided that henceforth the nearby ford should be used at low water to spare the bridge as much as possible. More patching and repairs are recorded in 1754, 1779 and 1782. In 1785 an extensive report condemned three of the arches; however, all repairs were set aside in favour of building a new bridge at the location of the old ford. This required an Act of Parliament.
In 1788 the new bridge of Ayr was opened, thanks to the efforts of Provost Ballantyne and the design of Robert Adam. It was 100 yards downstream where the old ford used to be. The old bridge became a pedestrian crossing.
The New Brig and the Auld Brig are commemorated in Robert Burns's poem The Brigs o' Ayr. The poem describes an argument between the two bridges, in which the Auld Brig predicts that it shall remain standing long after the the New Brig has gone.
The New Brig claims-
There's men of taste
wou'd tak the Ducat stream,
Tho' they should cast the very sark and swim,
E'er they would grate their feelings wi' the view
O' sic an ugly, Gothic hulk as you.”
The Auld Brig replies-
puff'd up wi' windy pride!
This mony a year I've stood the flood an' tide;
And tho' wi' crazy eild I'm sair forfairn ,
I'll be a brig when ye're a shapeless cairn!
Burns’ prescient suggestion became fact. The New Brig had to be demolished after a severe storm in 1879. The present New Bridge is a complete rebuild. The Old Bridge of Ayr is still standing.
In 1879 an Ayr watchmaker, Robert Templeton bequeathed his entire estate of £10,000 in trust for the rebuilding of the old bridge. Twenty-eight years passed before the estate was settled and the decisions were completed. No one knew what ‘rebuilding’ meant. Administrators and engineers, having inspected the bridge, declared it irreparable and suggested knocking it down and starting again. Lovers of history, supported by Burns enthusiasts, wanted to preserve, renew and renovate. The next-of-kin challenged the will and stood-by ready to claim the bequest for themselves if the trust was not properly carried out. It was largely thanks to the campaigning of James Morris, an Ayr architect, that the final decision was taken to preserve, in 1907.
bridge turned out to be even more insecure than had been thought. Scouring had completely undermined the
piers which had been founded on oak branders (see Structure section). These had to be underpinned as did the
cutwaters. Shafts were
bored down through the infill and the piers and through to the foundations and below. These shafts were filled with
concrete, effectively to pin the structure to the clay below. The voussoirs
were carefully repaired and the arches strengthened and pointed. Stonework was
replaced and the superstructure strengthened internally by pumping in more
concrete to replace the infill between the spandrels. Morris
reports particular attention given to the ‘distorted’ south arch (left) It was
decided not to dismantle and rebuild it, but rather to infill it with concrete
and underpin the foundations, thus preserving its distortion. Since elsewhere he describes “ four
beautiful segmental arches”, it appears that his view was that this south arch
was originally segmental rather than pointed. Certainly the voussoirs match the other arches and there is visible damage and sagging of the northerly spandrel. This issue is important for dating. Hume (RCAHMS 1977) describes three segmental and one
pointed arch which rather implies a 15th century date. I think he was wrong; this is a broken or hinged 16th century segmental arch.
Today the Auld Brig of Ayr is a pedestrian pathway and historical monument, mainly dating from around 1585. There may be some foundation remains from the 15th century. There are four arches, each of differing masonry, reflecting many rebuilds over the centuries. The depressed voussoirs are in dressed stone and the spandrels are in rubble. There are massive cutwaters but no refuges. The old lamps have been preserved. Parapets are stepped upwards at both ends and come from a later period.
The Auld Brig appears on Roy's survey and on Blaeu's Atlas. Pont did not cover Ayrshire but Gordon’s map from the same period does include Ayr Bridge.