From patch of sand to the outline of a masterpiece
The great sweep of the dome is there, casting its shade over the galleries beneath. It is a real, a visible presence now on the city's landscape, the shape of things to come.
Barely 12 months ago this was a patch of sand and an architect's drawing. To see more required a leap of the imagination and perhaps of faith. Since then, the pace of construction has been astonishing. The satellites that feed Google Maps sent their last images of Saadiyat Island some time in early 2013 and they still show only an outline in the desert.
Faster, then, than even Google can manage, the Louvre Abu Dhabi moves towards its completion next year. As that date moves ever closer, so the museum seems to rise to met the challenge. Yesterday came formal confirmation that the first gallery is complete, although work is far more advanced than that.
Step back to March 2013, and the site is little more than a depression filled with thousands of concrete stumps and steel rods. This is how the museum was left after the initial foundation work was completed three years before.
With the awarding of a new contract by Abu Dhabi's Tourism Development and Investment Company to a consortium headed by Arabtec and with Constructora San Jose and Oger Abu Dhabi, work was able to resume a year ago.
Those first weeks were unspectacular but essential. A waterproof skin was installed on what would become the building's lowest part. The site, several metres below sea-level, is protected by a temporary dam that will eventually be removed to allow the Arabian Gulf to wash against the museum's exterior.
Along with the waterproofing came the cranes, five of them by May and a sixth shortly after. For a while they towered over the site unchallenged. Then, as the basement and ground floors were laid down, four concrete towers rose up; the piers to support architect Jean Nouvel's vision of a dome.
In November Nouvel made one of a number of visits to the site, on this occasion to coincide with Abu Dhabi Art. Torrential rain slowed but did not halt progress on the museum. Less than three weeks later, an 87-metre crawler crane, specially assembled for the task, lifted the first section of the dome into place.
Attempting to reconstruct those first weeks of construction today is all but impossible. Even locating the first piece of the dome, a 43-tonne steel frame known as Super-Sized Element 63, is a challenge.
Since the start of the year, another 15 pieces have been installed and connected, out of the 85 needed to complete what is technically known as a space frame. The pieces are being placed counterclockwise, meaning that a large section, facing south-west to Mina Zayed, gives the illusion of being almost complete.
"You can see the dome is taking shape," says Peter Armstrong, the project manager for Turner Construction, who are effectively TDIC's eyes and ears on the site while the museum is built.
He runs through some of the numbers. "It's 180 metres in diameter; the total weight of the dome is going to be over 12,000 tonnes.
"What we see here is the structural steel frame for the dome. That's about 7,000 tonnes."
The space frame alone has more than 11,000 beams. To complete the roof, many more thousands of aluminium strips will be laid across the top and underside of the frame to create a criss-cross pattern that will fall on visitors in what the architect has called a "rain of light".
The outer walls of most of the galleries are now almost complete, and while a forest of temporary towers that support the dome until it is weight bearing partly obscure the museum's interior, the effect, once limited to architects' drawings, is becoming visible.
Most obvious is a long concrete structure peeking out from the completed rim of the dome facing the sea. This will be the cafeteria and restaurant, a place to appreciate the museum's architecture as well as savouring its culture.
"We need to take advantage of the location on the sea because it is a destination," explains Armstrong, "When visitors come to this museum they're going to be seeing the exhibits but they'll also have the restaurant and the cafeteria and be able to sit out on the water and experience the Arabian Gulf."
The view from the landward side of the site, if not quite as visually dramatic, is just as significant. Work is now well advanced on an access tunnel that will provide the entry point for many of the works of art as well as a dropping-off point for the museum staff. A deep trench has been cut parallel to the back of the museum turning to the already-completed underground entrance where security checks will take place.
When completed, a network of tunnels will serve all the museums on Saadiyat's cultural district - including the Guggenheim and the Zayed National Museum - with visitors entering through a dedicated floor underneath a still-to-be built shopping mall.
By July, the tunnel should be finished. Underneath the rapidly advancing dome, the galleries, their exterior structures completed in April, are ready for the complex process that will transform them into structures to display precious and often delicate works of art.
Construction, says Armstrong, "is proceeding at an extremely fast pace". Yet the atmosphere on site is one of calm and order that makes it hard to appreciate how rapidly the structure is advancing.
"We're not yet at the halfway point of construction and you can see that a significant amount of the work has been done," he says. "It won't be long now before all the structures are complete and we still have a year to go to finish it off."
At the front of the Louvre Abu Dhabi what looks like a terrace surrounded by two-metre walls is in the final stages of construction. These are the tidal pools, designed to keep seawater around the museum even at low tide, essential for Nouvel's vision that the building should appear to float on the sea.
At present the water is held back by a retaining dam. While the structure should be sufficiently complete to take down the dam by the end of the year, the reclaimed land it creates has proved invaluable for moving construction machinery around the site and it may be left in place longer. But by next May it must be gone.
Much of the work left in the coming 18 months or so is on the interior. "The mechanical systems, the electrical systems and the finishes - they have to be done properly and we have to focus on quality," says Armstrong.
The drive, he says, is "making sure that the quality is preserved and that we have the highest quality building at the end of the project,
"There's no point in rushing to get finished exactly on time if the quality is not there. So we have to balance the quality with the schedule."
Nevertheless, he is confident enough to say this: "We are on track to finish on time and the quality of the workmanship is of the highest level."