The Wittpenn Bridge, a vertical-lift span that extends New Jersey Route 7 over the Hackensack River and connects Kearny and Jersey City, has reached another milestone in its steps to completion since construction began in 2011. The bridge passed inspection by South Plainfield, New Jersey-based Atlas Evaluation & Inspection Services (AEIS), and is scheduled to open in early 2023, pending completion of construction.

At the heart of the new bridge is the use of an orthotropic bridge deck, a type of platform that incorporates beams in longitudinal and transverse directions for strength, can make a project lighter overall and can extend a bridge's lifespan by 50 years. Experts say orthotropic decks may see more use in infrastructure projects in the future, particularly bridges. 

Here, Construction Dive talks with AEIS President Nagesh Goel and AEIS Project Manager for the Wittpenn Bridge project Greg Sowa to discuss the project, the technology that went into it and what it bodes for the future on similar infrastructure builds.

Editor's Note: This interview has been edited for brevity and clarity.

CONSTRUCTION DIVE: What is the inspection process like for a brand new bridge in today's age? Has it changed drastically in the past 10 years with advances in technology?

NAGESH GOEL: The inspection process typically starts in a fabrication shop where the bridge is fabricated. And a third-party agency is retained either by the owner, or the owner stipulates in the contract that the contractor hire the third party, because today, everything is designed well. This new design-build model, that's very common. And the third-party agency shows that the critical checkpoints are being visited, they are being looked at and the construction is done as per the approved drawings and the specifications on the project. 

So that's the first step — in the fabrication shop — because that's where most of the fabrication work is done. Thereafter, the bridge components are shipped to site, and at the project site, these are assembled together. And then there's a whole bunch of inspections there. In our case here, we were doing welding inspections, bolting inspections and such. 

So that process, per se, overall hasn't changed in the last 10 years. What has changed is some technology, wherein, we are able to use some of the advances in technology to better understand the joints or the wells that have been welded, in the past.

How long did the overall inspection process take for this bridge?

GREG SOWA: We were on the site for about eight months. We were involved early on with getting all of their procedures for welding and [getting] all of their welders also qualified for those procedures. Even before the fieldwork started, we were involved with preparing for the fieldwork as well. So all in all, we were on the project for about eight months.

Do you feel that time and effort is a bit of a mismatch with how people commonly view the inspection process?

SOWA: There's a lot more than just, you know, putting a weld down there. There's science behind it, there's certain parameters you have to follow to make sure that the weld that's being deposited can perform the way that the designer wants it to. And that's where we come in, by doing both destructive and non-destructive testing. So, it's a lot more behind the scenes than people realize.

GOEL: A perception of inspection might be [that inspectors] used to go [to the site] and just say, "okay, this is okay, and this is not okay." There might be some companies that do follow that approach. But you know, you cannot really be a contributor to the project, if you do not, right from the beginning, work hand in hand with the contractor and the construction personnel. 

I personally feel, as a metallurgist, that's really very wrong because you end up repairing work, which means you're inputting huge amounts of heat to cut the joint, and then additional heat to repair the joint, which essentially changes the metallurgy of the material. So the important thing is to make sure, right from the beginning, that our processes and all the variables involved are as close as possible to the perfect scenario that can achieve defect-free wells. Still, defects happen, and then we analyze why they are happening as we go along.

Can you talk to me a little bit about that orthotropic bridge deck? Why is it noteworthy?

SOWA: Orthotropic deck is mainly used to repair existing [bridges]. We've used an orthotropic deck to replace the roadway on the Verrazano [bridge in New York City]. We're currently redoing it on the Throgs Neck [bridge in the Bronx]. 

In this case, this orthotropic deck was attached to the main members of a lift span. So, this is one of those bridges where if a large boat comes underneath, the bridge will actually raise. I think that's the word he was getting at, that the orthotropic deck was the first of its kind for a lift-span bridge.

Is this kind of installation difficult to perform?

SOWA: Since these orthotropic deck panels came attached to the main members [on the bridge], these field joints were treated as such. So they were held to a much higher standard than typically what we're used to on orthotropic deck panels, [and] the accept/reject criteria was a lot higher. The welders themselves had to go through a stricter test to be certified.

With the infrastructure bill passing recently, we're going to see a huge investment in bridges and roadways and such. Do you think that this kind of orthotropic deck and this kind of lift is going to become more popular?

SOWA: Yeah, especially with the bridges in and around the five boroughs [of New York City]. They're aging, you know? I mean, you drive over bridges all the time and they're full of potholes. So the roadways are going to be replaced with a much lighter orthotropic deck, like we're seeing on some of these suspension bridges, and like on the Wittpenn. It's lighter, and it has a 50-year lifespan. I think it's going to be seen more often, yes.