A Tour Of The Futuristic Roof On California’s High-Speed Rail Station

As the landmark signifying an entirely new way to travel throughout the state, California’s first high-speed rail station needs to look firmly towards the future. Thanks to a material called ETFE that turns its roof into a giant plastic balloon, this Anaheim station showcases groundbreaking design and engineering as part of its progressive transit mission.

On a tour of the almost-finished Anaheim Regional Transportation Intramodal Center (ARTIC) this week, I saw how the station hopes to connect the 16-acre plot between Angel Stadium and the Honda Center with transit services and local businesses. And I got to get up close and personal with ETFE, the polymer named ethylene tetrafluoroethylene that arcs over its puffy exterior.

ETFE was selected by architects at HOK and engineers from Parsons Brinckerhoff precisely because of its sustainability qualities. It’s far more lightweight than most other materials used for roofing, meaning the rest of the structure doesn’t have to be bulked up to hold it. And it allows natural light to enter the cavernous space, saving on energy costs. If the building ever needs to be demolished, the roofing can be recycled.

But ETFE also has a few qualities that I can only describe as magic. It’s self-cleaning, meaning it doesn’t require any additional resources, like water, to wash it off — it’s slippery enough that dust doesn’t really cling to it. And instead of feeling like you’ve stepped into an airlock, the material is actually somewhat breathable so it doesn’t act like a greenhouse. Heating and cooling systems are installed in the floor to moderate the temperature only where humans will be walking. But on a 32°C day, the ETFE shielded enough of the sun to keep things comfortable inside.

With all these great qualities you’d think it would be stretching across every building in the country. But while it’s widely used throughout Europe and Asia — most famously on Beijing’s Olympic Water Cube — ETFE hasn’t been as embraced by U.S. architects. ARTIC is so far the largest application of the material in the U.S., with about 200,000 square feet, enough to cover 4.5 football stadiums. Coincidentally, the new Vikings stadium under construction in Minneapolis will use ETFE, too.

ETFE’s pneumatic panels are deceivingly strong. What looks like a single bubble is actually three sheets of thick plastic, the exterior sheet coated with a honeycomb pattern to reflect solar rays. A ventilation system pumps air into the pockets, keeping them separated from each other.

But of course, because ETFE transforms any surface into what’s essentially a giant inflatable, it can be punctured if you have a sharp enough object. That’s why the station design will keep passengers far away from the curving walls. But we got to touch them on the tour. The ETFE feels like a very thick, very firm pool raft.

Design services manager Rudy H. Emami demonstrates ETFE’s tensile strength

In addition to the striking patterns created by the catenary curves of steel arching over the station, tiny strips of LED lights run along each beam. These can be programmed to illuminate in four different colours, in any pattern or sequence.

The lights slowly transitioned from one colour to another while we were there during the day, adding subtle illumination. But at night, these lights work together for a seriously dramatic effect. The entire building can glow a single colour — like Angels red, to celebrate the victories over the freeway.

The station’s design has to work extra hard, pulling together many forms of transit under one roof: local and regional buses, Metrolink and Amtrak trains, and a heavily used bikeway and bike parking. Not to mention the increased pedestrian capacity needed for games and special events. Then, sometime in the next two decades, the station will add high-speed rail alignment, which will be laid just to the south of the existing regular-speed tracks.

While there’s no definite timeline for when the high-speed rails will arrive, the route will definitely originate here on its journey north. It’s fitting that the station is essentially this cathedral to the future, a striking sculpture easily seen from the traffic-clogged freeway that will encourage people to consider a new way to travel. Of course, it doesn’t hurt that it’s extremely Instagrammable too, encouraging passengers to share their journeys.

In a way, the quilted plastic roof almost feels like a very direct shoutout to the crystal palace train depots of 19th century Europe or the lost, lamented Penn Station in New York City. It’s bridging the traditional idea of train travel with an earth-shattering new paradigm for the state. And it’s doing it with beautiful innovation that demands people’s attention. [ARTIC]