Laborers carrying cans of Grikote anti-corrosion paste on the south-side span catwalk in the fog, 2012. Ironworkers Butch Madsen, Eduardo Jimenez, Johnny Albourne and Chris Wilcox installing bypass chord, Yerba Buena Island, 2008. Marine superintendent Eric Edwards, pile drivers Cory Pakes, Dave Lang, Johnny Wong, Chris Puglisi, Jason Pleasants, and surveyor Terry Dennis installing final wale frame connector piece for E2 foundation, 2006. Ironworker Stan Dalie guides SAS OBG anchorage deck section #14E on the left coast lifter main fall hook, 2011. Ironworker foreman Carlos Valverde and ironworker Josh Galvan installing shear plate at tower foundation T1. ABF engineer Andre Markarian observes. 2010. Ironworker Jaime Barragan monitoring strand jack cable during the 4th lift, east shaft, 2011. Ironworkers Scott Greer and Anthony Volpe removing cable wrapping machine from south-side span at dusk in winter, 2012. Pile driver James Lewis lights magnesium thermal lance for pile driver Doug Ailes to use to cut off steel grillage falsework at E2. Pile driver foreman Gordon Crocker and marine superintendent Eric Edwards watch, 2007. Ironworkers installing northwest chimney on top of the tower, 2011. Pile drivers welding studs on E2 foundation, 2007. Pile driver Mel Begin welding inside E2 foundation pile, 2007. Ironworker bolting gang installing 4" diameter saddle tie rods, tower saddle, 2012. Ironworker foreman Tony Costa and ironworker Ricky Chouinard maneuver a shackle into position on saddle lifting device, 2011. Ironworker Joe Bell and partner checking rebar measurements inside the tower foundation T1, 2007. Ironworker erecting gang installing chevron truss on temporary tower, 2010. Ironworkers C.J. Biskner, Matt Cochran and Jerry Kubala connecting 600-ton shackles and heavy rigging to OBG deck lifting frame lug, 2010.

After 25 years as a boilermaker, shipfitter and welder, photographer Joseph Blum knows his way around construction sites. His remarkable photographs take us behind-the-scenes on the construction of the new eastern span of San Francisco’s bay bridge, and are on view at the San Francisco Arts Commission gallery through September.

This is no ordinary construction site — the bridge is the largest self-anchored suspension bridge (SAS) in the world, and it connects the East Bay with San Francisco. Footed in mud strata, with giant shock absorbing fuses embedded underneath the roadway, the bridge is designed to be a seismic neutralizer and provide a lifeline into San Francisco for emergency services even when the surrounding area is flattened. It’s also supposed to last for 150 years.

It better. The price tag stands at $6.3 billion, orders of magnitude above initial projections, and the final cost to taxpayers could surpass $12 billion when all is said and done. That dollar figure includes manufacturing giant portions of the bridge in China and transporting them by boat (though this was the less expensive option), not to mention the laundry list of costly setbacks over more than a decade of construction.

Joseph Blum has been there to see it all as the men and women on the bridge have worked in all kinds of conditions to make the blueprints a concrete and steel reality. He shoots with 25-30 pounds of equipment, climbing high above the water and dangling from sections of massive infrastructure. Blum has become accustomed to the conditions on the bridge: wind, rain, fog, cold and extreme heights. He’s also 72 years old. Blum spoke with WIRED last week after coming off the bridge where he was “tied-off” (in a harness) and hanging over 150 feet above the water as he watched parts of the falsework (the supporting bridge) being cut away.

WIRED: What was your particular interest in this project — how did it come about?

Joseph Blum: I wanted to give the perspective of the people that were building it — to give people a view of what it means to build a bridge over water. Every single day out there is about the work, and every day something extremely interesting happens — people solve problems, do something special, you can’t catch it all.

Every day I came away with a photo that was unique, that showed the stamina involved, the physical difficulty of the work. The best thing is the possibility of showing to the public something from behind the scenes — something that is built and taken for granted. I get the chance to show how this is accomplished.

W: What are some of the difficulties involved in shooting on a construction site of this scale?

JB: I have no difficulties with climbing, or with heights, but I do not like confined spaces. When I was a boilermaker, I had to go into small spaces, or lose my job. Photographing on the bridge, I could choose not go into those confined spaces for a long time. I climbed into some pretty narrow spaces, got my photos and got out. I cannot think of single day when I went out that that I did not have a good time. Workers have looked after me, befriended me. Often you have only five minutes of shooting, but building up to that takes hours.

W: What kinds of safety precautions did you have to take?

JB: On a day like today I was in a place you have to be tied off in full body harness, the same harness the workers and inspector use. It has a ring on the back with a dual lanyard so you can be tied on 100% of the time. And of course you wear a hard hat, gloves, boots, glasses and a flotation device if you are out over the water.

W: How were you able to get access to this project?

JB: I was 57 when I started this project. I’ve been photographing this thing for 15 years. In the middle of the project the contractors changed so there was a need to go through a process to continue — insurance, etc. — but originally there was none of that.

One of the companies was doing test piles for the skyway, and I went out on their rig, and got in touch with the superintendent. A website called NewBayBridge.org was looking for a black-and-white gallery, so we teamed up together, and Cal Trans signed off on it. But mostly you need the permission of the contractor. It helped that I had the blessing of the unions — I had gotten to know the iron workers — the Four Seasons hotel and several others. Being in the trade has helped me understand the work.