Four supergrid transformers will complete their journey to Blackhillock Substation near Keith over the next few weeks.
The transformers weigh about 245 tonnes each and will leave from Buckie harbour, where they were delivered by sea from Sweden.
Specialist haulier Allelys – working on behalf of Scottish and Southern Electricity Networks (SSEN) and its lead contractor ABB – will load the transformers onto multi-axle trailers and deliver them to the site with traffic management systems and police escorts in use where necessary.
SSEN project manager David Fraser said: “Every stage in the journey of these transformers has been carefully planned, going back to the earliest stages of developing plans for the new substation.
“Once they arrive and are installed on site, they are expected to play a key role in the network for decades to come.
“The arrival of these transformers represents a significant milestone in the Blackhillock development and the overall Caithness-Moray transmission project.”
The deliveries will be made over the four remaining Sundays in July with the convoys leaving at 8am in order to minimise traffic disruption.
Blackhillock substation is part of the Caithness-Moray project which will cost £1.1 billion overall.
It is the largest investment in the north of Scotland’s electricity network since the hydro development era of the 1950s.