Jon Eppell is a busy man. As lead bridge engineer at Halifax Harbour Bridges, he’s been hard at work on The Big Lift project for over six years.
Find out more about Eppell’s passion for bridge-building, along with some interesting details about this exciting, challenging project.
What made you decide to become an engineer?
JE: I was always good at math and science. They came to me naturally. I was also that kid that would disassemble things and put them back together, just to see how they worked. I had started on the path of a science degree when my father suggested I consider engineering, which I did. I completed a diploma in engineering, followed by a Bachelor’s degree in civil engineering. I focused specifically on structures where I could.
I began my professional career as a consulting engineer in Halifax. The owner/president of the firm, Dan O’Halloran, had been the site engineer for the MacKay Bridge, which lead to working with Hugh Pratley. Pratley, along with Roger Dorton, had been responsible for the design of the MacKay Bridge and had been a site engineer on the Macdonald Bridge construction. The Macdonald Bridge was designed by Pratley’s father, Phillip L. Pratley. I had the good fortune of being assigned to do work for the bridges, which grew to being one of the leads on the third lane expansion project in 1999.
What do you love about your job?
JE: I get to work on suspension bridges. They are amazing structures with such long spans. Not to mention the graceful curve of the deck. They are very aesthetically pleasing and, of course, pretty iconic for the Halifax/Dartmouth area. They are more complex than highway overpasses because of their length and because the load is being taken by a cable.
There are many interesting challenges with this sort of bridge structure and with the traffic we have to work around. I enjoy finding solutions to the many varied challenges that we face. I get to see my ideas develop from a thought to being on paper to being built. That is very satisfying. I also get to work with a team of people who I respect and like. We share the common goal of taking care of these bridges.
What’s the hardest thing about your job?
JE: I take the care of the bridges very seriously. With the Big Lift there are a lot of additional people and activities. As a result there are more things to track and make sure we are doing right. Obviously that adds a bit of stress.
A lot of effort has gone into preparing this project so it can happen safely and still be open for public use each day. This is an incredibly large project and there are a lot of people working behind the scenes to make it appear as seamless as possible. I work hard to make sure the bridge is well looked after, safe, and available to use for years to come The Big Lift project, which is very complex, adds another dimension. Right now the most difficult part of my job, and for the many other people involved in all areas of this project, is finding downtime. But we are also very excited to be part of such a tremendous project.
How long has the Big Lift been in the works?
JE: Planning/engineering of the project began back in 2009. As part of that process, internally we’ve been joined by engineers from all over the world and externally, we are working with consultants and contractors that are both local (where we could keep it local) and also from around the world.
What excites you most about the project?
JE: Taking apart and rebuilding a large suspension bridge while keeping it in service is pretty exciting. This project is very complex and the sheer size and scope should be considered intimidating. I think a lot of people still believe that this is a paving project, or something smaller that we have done before. But this is only the second time the suspended structure of a suspension bridge has been replaced while remaining open to traffic.
The project includes replacement of the road deck, floor beams, stiffening trusses and suspender ropes on the suspended spans (762 m of the overall 1,347 m length) of the Macdonald Bridge. Once complete, much of the bridge infrastructure will be new, leaving only the towers, main cables and anchorages on the suspended spans as original.
I think a lot of people will be surprised when they see the first of 46 deck segments get replaced as to how big an undertaking this actually is.
What’s the biggest challenge in the project?
JE: I think the biggest challenge is ensuring that the project is done safely. A lot of attention was paid to engineering this to be done safely in the design phase, and this carries on through the construction. We are not just concerned with worker safety, but also the safety of the structure and the safety of the public who are using the bridge while we are working on it.
The other big challenge is schedule. Because the project is complex there are a lot of dependencies on having ‘A’ done in order to do ‘B’, etc. We routinely have two deadlines per day – work that must be completed to allow for the work during the closures to proceed and completing work to allow the bridge to re-open. We cannot leave things undone and re-open to the public. The contractor has to deal with whatever Atlantic Canada throws at us in terms of weather. In spite of the massive amount of snow Halifax had blocking roads last winter, the work on the bridge had to proceed to keep to the schedule We have to balance the needs of the public users while remaining realistic about the necessity of the work.
In the spring of 2016, the International Cable Supported Bridge Operators Association (ICSBOA) will be holding their conference here in Halifax. Why is this a big deal?
JE: There are unique challenges to operating a suspension bridge, and we don’t have a lot of close neighbors who do. ICSBOA provides an opportunity for these operators from around the world to come together and share best practices in the unique challenges we face as long span structures, including engineering, maintenance, repairs, and new approaches or technologies. We need to stay abreast of what is working best, and apply it for the benefit of our bridges and users. It is great timing for the conference to be held here because they will get to see the Big Lift up close and personal.
What’s one awesome fact about the Big Lift project that people probably don’t know?
JE: It has taken six years to get to this point in the project and we have another 2.5 years to go. There are 46 segments to be replaced, the heaviest weighing about 130 tonnes. The segments are being fabricated in Halifax and will be painted and pre-paved before they are delivered to the site. Once all of the segments have been replaced the deck will be lifted up to provide an additional 2.1 m clearance for ships.
The name the Big Lift was chosen because it fits well with the size of bridge segments being lifted into place, lifting the bridge up to increase the shipping clearance.
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