Challenging route completed with innovative bridge engineering and Trojan trucks
In-house logistics expertise
ALE has negotiated steep gradients, bridges and other challenges to complete the transportation of two transformers. From the port of Inverness, the transformers, weighing 193t each, were transported along a complex route to Tomatin Substation in Scotland, UK, where they were successfully installed.
The transportation was performed using ALE’s AL34 girder frame with 24 axle lines of conventional trailer, two Trojan trucks and an additional prime mover. There were numerous structures on the route, including three onsite bridges, and ALE selected this equipment to reduce the axle loadings, enabling safe transportation over them all.
All the bridges were assessed during the planning stages to ensure they could support the transport loads. However, the capacity of one bridge could not be sufficiently determined and therefore an efficient alternative had to be found. ALE’s creative solution was the installation of an overbridge. A crane needed to be positioned a suitable distance from the centre of the bridge, so ALE utilised a 100t capacity mobile crane to install the 12m bridge raft over the bridge’s 9m span.
Another challenge on the route was the range of steep gradients, both up and downhill, that the convoy needed to negotiate. ALE transported the transformers over gradients of up to 14% and this was further complicated by road surfaces made up of loose materials. It was an opportunity for the Trojan trucks to demonstrate the strength of their capacities as they operated at their maximum gradient.
As there is no limit to the number of prime movers that can be added to a convoy with the Trojans, ALE was able to further utilise the capabilities of the innovative trucks by adding a third prime mover for the transportation through Farr Windfarm. This route between the public highway and the substation spanned almost 18km and its constant bends and varying gradients made it the most complex part of the transportation. On the Trojan trucks, steering, braking, electrics, engine, and transmissions are synchronised by a computer, enabling each to be matched across the vehicles and numerous elements to be controlled identically. This made them the most efficient vehicles to assist with traction during this section of the transportation.
ALE transported the transformers over 35km before installing them at the substation with the operation being completed in 12 days. ALE’s innovative solutions and the unique abilities of the Trojan truck ensured that this challenging operation could be completed as efficiently as possible.