A stretch of the A38 in Devon was closed for several hours overnight while a large load was transported to a new power station outside Plymouth.
The power station is due for completion in 2008
Lampposts were taken down and a central reservation dismantled between Devonport Dockyard and Plympton to make way for the transformer part.
The 580-tonne load was taken to the £400m Langage Power Station site.
Another seven closures are planned on the A38 at Plymouth over the next two months as more equipment is brought in.
The Centrica-run gas turbine power station at Langage near Plymouth is due for completion in 2008.
The plant will provide 885 megawatts of electricity, enough to power about a million homes, and employ about 800 workers during major construction.
A business park is planned on 80 acres surrounding the station.