The Hamilton Road / Motherwell Road Bridge which carries the 4 lane A273 across the River Clyde in North Lanarkshire is a vital link between the towns of Hamilton and Motherwell.
The 4 span steel structure required Grit Blasting and the application of an industrial paint system in order to halt the corrosive effects of heavy precipitation and the unpredictable rising of the Clyde.

Work got underway in the August of 2005, and was scheduled to last through the Christmas period and into the New Year. The bridge is constructed of 12,664m² of steelwork. As well as carrying the dual carriageway above it, high voltage electricity cables, water and gas pipes run through the substrate.

Great care must be taken when working alongside live lines such as those found within this bridge and once the bridge has been boarded out by the scaffolding contractor we must ensure that we do all we can to protect the pipework when working in it’s vicinity. The pipes are wrapped in insulating foam approved by our client, this allows for protection from the high pressure shot blast which may pepper the pipe during the blasting process.

During the Blasting phase of the contract 440 tons of expendable abrasive was used to clean the steel to a standard of Sa 2½. This was removed using an industrial vacuum, called a Monkebo, suitable for removing dried grit from the structure, through the vacuum and then into a hopper placed over an open top 8 yard skip. This gives us a rapid cleaning process; after the days blasting has been completed, regular cleaning shifts at night allow for the weight on the scaffold to be kept to a minimum and in turn the benefits to the sites Health and Safety performance are enormous as there is a clear walking route through the bridge maintained at all times.

Quality and productivity are increased through our day shift painters working in clean environments and our blasters being able to traverse the scaffold unimpeded thanks to the efficient clean up process. Once the blasting process has been completed and our clients inspector has approved that the surface profile is acceptable and the surface is clean from salts and contaminants then the painters are able to commence their work.

Using hydraulic spray pumps, lines and guns we are able to provide a quick overcoating to enable efficient protection of the steel once it has been handed over.
A specialist paint system was developed by our suppliers International Paints to ensure a strong finish was applied to protect the steel for up to 20 years. The paint system devised consisted of a 4 coat system, using 2 Epoxy coats, Intercure 324 (Item 111, Sand) and Intercure 384 (Item 112, Light Grey) and double Polyurathane coat of Interthane 870 (Item 168, Red) to give a strong protected finish to the steelwork.

A total of 9300 litres of paint were used to give the Dry Film Thickness the Clyde Bridge required across all areas of the substrate, the minimum DFT which we had to achieve was 350 Microns and this was tested by our clients paint inspector, our on-site supervisor using his
calibrated testing equipment and routinely inspected by one of our contracts managers who is an Institute of Corrosion Accredited Paint Inspector.

We all know every contract has its own unique challenges; it’s how you deal with them that determines the strength of a company in the face of adversity. During mid-October 2005 an unprecedented amount of rainfall fell in the Glasgow area, and the rivers feeding the Clyde deposited more water than had been expected into its course. This led to the level of the river rising by 3 metres so that it was flowing just 30cm below the bottom boards of the scaffold. The Scottish Environment Protection Agency were informed of our situation and they advised us that the bridge should be evacuated as their was no sign of the waters relenting. The water did continue to rise and the scaffold sustained some damage to the lower sections of its Standards, by floating timbers being carried down the stream colliding with the structure. Work was suspended until SEPA gave us acknowledgement that it was safe to return to work over the Clyde and our scaffolding sub-contractor had carried out a full inspection of the scaffold and any necessary repairs had been made to ensure the continued safety of all T.I. Protective Coatings operatives and our valued sub-contractors.
After the combined efforts of all our team and supply chain we were able to complete works by the end of January to leave the bridge with a bold and positive look for the future.