The transformer, which is coloured bright red, will progressively be installed in the coming weeks in a move which will see it and the other three operating transformers and one spare eventually represent the rainbow-coloured pride flag.
The journey to the dam yesterday was one that began in late 2020 and was marred with Covid-19 delays.
The culmination of that began in Timaru at 4am with the transformer arriving on site about 12 hours later.
Contact Energy projects manager Kirk Pritchard said the first snow of winter on the Lindis Pass meant the convoy transporting the 4m wide, 6.4m long, 4.65m high, 96 tonne trailer encountered two other trucks stuck in snow.
"It’s been quite an eventful day," he said.
He admitted to being a "bit nervous this morning" when one of the trucks in the transport party pulled the trucks out to allow the convey to pass.
The trickiest manoeuvre was negotiating the top of the dam and winding tight bends to reach the dam’s powerhouse.
Mr Pritchard said the transformer was needed after an inspection in December 2020 found the condition of the four transformers was poor and it was no longer safe to continue operating the transformer for the Unit 4 generator. The spare was also unusable.
Unit 4 transformer was shut down. The other units were assessed as safe but would be replaced as a precaution over the next one to three years.
Now on site, the new transformer would be pushed into the powerhouse and the transformer would be unloaded using the gantry crane.
Farra Engineering in Dunedin had designed and fabricated a lifting beam to allow it to be safely lifted.
Once unloaded, it would be reassembled, together with additional components shipped separately, filled with about 36,000l of fresh oil and installed over six to eight weeks, he said.