Victoria Bridge, Mar Lodge Estate

Taziker was contracted by the National Trust for Scotland to undertake major maintenance and refurbishment at Victoria Bridge, a lattice girder bridge built in 1905 over the River Dee. The Category B listed bridge is located at Mar Lodge Estate, which was awarded National Nature Reserve (NNR) status in 2017, making it the largest NNR in the UK.

The challenge

The paint on the structure had reached the end of its life span, with areas of steel beginning to corrode. One of the pier’s within the water was also being exposed to damage and at risk of undermining, due to previous floods in the area causing re-alignment of the river flow.

The team on site faced several challenges, including the planning around our works, due to the delicate landscape of the bridge’s location. Prior to the commencement of scour protection, we were issued a Controlled Activities Regulation (CAR) licence.

Weather conditions also played a huge factor, major disruption was caused by Storm Arwen, Malik & Corrie in the local area, with several trees falling as a result of the heavy storm. This restricted roads around the town and stopped essential travel to and from site during our works, as well as causing heavy damage to site.

The solution

A bespoke hanging scaffold design with full heated encapsulation was erected, meaning the team could access underneath the bridge deck with ease. This design for the scaffold factored in the roof having allowances for adverse weather conditions, with the Scottish Highlands being susceptible to heavy snow fall in the winter season.

A Geo-dam was put in place to allow access for our scour protection works in the water, vital works to protect the structural integrity of the bridge. Once scour protection to the north pier was completed, the entire structure was grit-blasted. Steel repairs were carried out on site by our specialist engineering team, who did a like-for-like aesthetic repair on all structural defects found. 257 Victorian balustrades were carefully removed, tagged and transported to an off-site coatings facility to be blasted, before the application of a protective paint system was applied to the whole structure.

Using a hi-ab mounted crane, the 1905 cast irony entry portal was removed before being blasted and repaired off-site and receiving a full coat painting. The existing brickwork pilasters and wing walls were dismantled and rebuilt using an approved heritage limestone mix and colour matched mortar.

Following on from Storm Corrie, the site team offered their services to the local maintenance teams to help with the safe removal of the trees which had fallen due to the extent of the storm.

The environmental impact

Daily visits by the onsite Ecologists were made prior to works commencing to ensure no trace of wildlife were within the dam area. All fish and eels were safely removed by the ecologist team during the dee watering process and let go further downstream.

Bat surveys were undertaken and our Site Manager worked alongside the National Trust ecologist daily, reporting on wildlife that may have entered the dam as it was being dry pumped. Plant entering the dam was equipped with biodegradable hydraulic oil to safeguard the fragile environment. Following the embankment works, deer fencing was erected to prevent the free roaming herds of deer from entering the water course.

Where possible, battery powered tools were used to cut down on cables and diesel-powered generators. The switch to HVO fuel was implemented on plant and machinery to cut down on emissions, lowering our carbon footprint on site.

Surplus material from hardstandings and the road surfacing plannings were delivered to the Mar Lodge estate groundskeeper’s yard, where it was all recycled and re-used as footpaths and other uses throughout the 113 square miles of land. We left compound hardstanding, which is now used as a car park for the equestrian vehicles utilising the area.

The result

Despite the extreme weather conditions, the team were able to adapt quickly and efficiently, making vital repairs to the steelwork and breathing new life into the structure with a full paint system that will stand the test of time.