The official opening ceremony took place on Monday at the Belfast shipyard.
A new fabrication hall has been added to the existing site following extensive refurbishment work.
This extension provides an additional 5,000 square metres of manufacturing area for construction activities.
The facility is equipped with upgraded cranes, robotic plasma-cutting systems and a mechanised panel line.
Three vessels intended for the Royal Fleet Auxiliary are scheduled to be built using this new capacity.
Navantia UK confirmed it is funding the project as part of a broader £157m investment across four UK shipyards.
The other sites involved in the deal include Appledore in Devon, Methil in eastern Scotland and Arnish on the Isle of Lewis.
Harland & Wolff was established in 1861 and reached an employment peak of 35,000 staff during World War Two.
The company was acquired by Navantia UK last year, a British entity connected to Spain's state-owned shipbuilder Navantia.
Belfast Docks management described the new hall as the centrepiece of the overall investment strategy.
Local industry observers have noted the presence of historic yellow cranes known as Samson and Goliath undergoing similar upgrades.
The firm behind the funding initiative stated it views Belfast as central to a wider shipbuilding revival in the region.
No specific completion dates for the three support ships were provided during the announcement.
The project does not include any immediate changes to workforce numbers beyond the creation of apprenticeship opportunities mentioned by local media outlets.