The nitrogen generator arrived at Pike River about 1.30pm today.
The machine had been trucked to Greymouth after landing in Auckland yesterday afternoon.
This afternoon work began to unload the machine and prepare it for operation.
It is not yet known when the machine will begin pumping nitrogen into the mine.
It is hoped the nitrogen will help cool the environment inside the mine.
Meanwhile the GAG machine continues to pump water vapour into the mine to maintain a stable environment and preparations are under way to complete the next bore hole.