Firstly the huge container ship Ever Given became wedged sideways in the Suez Canal, crippling much of global trade and causing a queue of hundreds of ships to form.
The Belfast project was relying on stone floor tiles, the supply of which was threatened by the blockage.
“We've had to navigate a couple of challenging times,” said Duane McCreadie, project director, employed by Spanish construction firm SACYR.
"It's funny how these things can impact your project. Following the incident in the canal, the shipping costs went from £2,000 a container up to £10,000 – which is a lot of money for all of us, but it's even more if you have 90 or 100 containers of a product.”
Thankfully the ship was dislodged after a week, prices came back down, and they were relieved of the need to go hunting elsewhere for their tiles.
Another headache was the massive steel frame for the main terminal.
"At that point the Ukraine war had just started, and we had massive challenges in trying to control the cost and the actual availability of the steel,” he said.
But after an initial spike in cost around the time of the Russian invasion (both Russia and Ukraine are major steel-making nations), it too tumbled back down.
"There's been some nice spin-off stories as well,” he said.
"There were actually Ukranian refugees that came to Northern Ireland who were employed by Walter Watson down in Castlewellan, who helped build this steel frame.”
Mr McCreadie has been involved in many of the major building projects in the city in recent years: he was project manager in the building of Grand Central Hotel, the redevelopment of Ravenhill rugby stadium, and was construction director for the later phase of the new Ulster University campus.
Asked how the Grand Central Station project measures up, he said: “I think this is massive for Belfast.
"This is a world-class multi-transportation hub. The surrounding areas are going to have 15, 20 years of investment.
"It's going to be an absolute game-changer for the city.”