The historic 3526 Locomotive will be unveiled at the Thirlmere Steam Festival this morning at 11.
The Locomotive entered service back in 1917 and retired in 1966.
However over the past five years, Transport Heritage staff and volunteers have embarked on a massive restoration project to bring it back to its former glory.
THNSW CEO, Andrew Moritz is encouraging people to stop past.
It'll be available to ride at the Transport Heritage Expo at Central Station in June.