Specialists have carried out a rope access examination of the Templand Viaduct in Cumnock.
Also known locally as the Woodroad Viaduct, specialists from SAS Rope & Rail Ltd had the task of undertaking the examination of the structure, which carries the railway line between Kilmarnock and Dumfries, for Network Rail.
Cumnock History Group says the viaduct opened on May, 20, 1850 and is one of the great engineering feats on the Glasgow, Paisley, Kilmarnock and Ayr line.
The highest arch is believed to be 175 feet above the Lugar Water, which would have been the height the workers would have been examining at.
To make it even more impressive, they carried out a section of their work during the night to minimise disruption to trains.
A spokesperson for the SAS Rope & Rail Ltd team said: "In April 1971 the structure was recognised as a category A listed building.
"The examination was completed over six railway possessions and was examined using rope access methods, allowing the examiners to be in touching distance of all elements of the structure.
"A full report of the structure will now be completed and submitted to the client."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here