Why falling ice leads to closing the Mackinac Bridge

On this week’s Talking Michigan Transportation podcast, questions and explanations about the increasing frequency of melting ice falling from the Mackinac Bridge cables, creating hazards for motorists and the need to close the bridge for many hours at a time. This video illustrates the danger. 

First, Joe Shampine, maintenance supervisor for the Mackinac Bridge Authority, talks about the dangers the heavy ice presents to travelers below and the decision-making process for closing and reopening the bridge. He also offers praise for maintenance staff members who have to explain to frustrated drivers why the bridge has to be closed during these events.

Later, Matt Chynoweth, the former chief bridge engineer at the Michigan Department of Transportation (MDOT) and now bridge practice leader for the consulting firm RS&H, returns to the podcast to offer broader perspective based on his research and conversations with other bridge owners across the country and world.

Transcript

Why Falling Ice Forces Closures

Jeff Cranson 0:07

So welcome to the Talking Michigan Transportation Podcast. I'm Jeff Cranson. This week I'm revisiting an issue that I first talked about on the podcast four years ago, just about the same time of year, and that's falling ice that leads to closures, sometimes hours long, of the Mackinac Bridge. This is a really big deal because it's a major inconvenience for the people who live in the Straits area and have to cross back and forth for work or other reasons. But it's also an incredible danger, and closing is the best way to keep everybody safe. Those decisions don't come easily. And I wanted to talk about that with the head of maintenance for the Mackinac Bridge Authority, Joe Champagne, who explains what goes on, what goes into that decision-making process, and why it's so dangerous to have these heavy chunks of ice falling from those kinds of heights. So after that, I spoke with Matt Chinawith, who is the former chief bridge engineer for the Michigan Department of Transportation. He is now the bridge practice leader for RSH, a national consulting group. And Matt offers some perspective, as he did uh a few years back, on how this issue is dealt with in other states and even other countries. Um there aren't very many suspension bridges at at the latitude that the Mackinac Bridge is at. So in terms of climate, uh it's a somewhat unique challenge, but others do deal with this, um ice forming and falling. And so he has some some perspective on that. I hope you enjoy the conversation. So, first, as I mentioned, I'm talking to Joe Champagne, who is the head of maintenance for the Mackinac Bridge Authority. Um, he's had to deal for a number of years with these ice falling issues and closings of the bridge, which is very frustrating and nobody understands it more than he and his colleagues who live and work there. Um, Joe, I'm guessing you probably hear about it all the time from friends and family, right?

Joe Shampine 2:22

Oh, absolutely. You know, main thing is, you know, they always call or text or whatever. When's it gonna open? When's it gonna open, you know? And I wish I had that magic, you know, number, but we never do, you know, it's all up to Mother Nature for sure.

Jeff Cranson 2:38

I've noticed uh more lawmaker requests this year. I wasn't sure. Um, I get the text alerts, and I hadn't really picked up that it was more frequent than in recent years, where we always, I mean, in the past probably seven to eight years, it seems like every spring has had an abundance of these, but it turns out this year has had more. Um, is that does that track with what you know and and what you see anecdotally?

Safety Risks And Reopening Calls

Joe Shampine 3:05

Yeah, for sure. You know, it all consists of, you know, we've had more, but like I said, again, it's all depends on Mother Nature. You know, we've had that ice up there for over a week, you know, or more. Mother Nature don't let it drop at that time, you know. So it takes a long time for that ice to fall off that bridge. We don't have the temperatures or the sunshine or whatever, you know, and then we do get it for a brief moment, starts falling, we've got to close it down, then sun goes away, temperatures drop, and everything, you know, tightens back up. And then there we are again, waiting for another closure again when the weather permits.

Jeff Cranson 3:43

And if you've never seen the photos or the videos and you've never been there to personally witness it, I think you're not gonna appreciate how heavy this is and what kind of destruction it could create. Um, so talk about that a little bit.

Joe Shampine 3:58

Yeah, absolutely. We had a this year, and you know, me and uh a couple other, you know, my chief engineer and my uh um assistant engineer Matthew and Kim, and you know, we all end up going out there watching the you know the ice fall, you know. So what we do usually is go to center span where the cables are low, so we can watch both ways, you know, with binoculars and everything else, making sure everything's falling and what hasn't fell and everything. And then it gets to the point where it starts falling really bad, and then we just get right off the bridge. And that's happened to me this year once, and it uh ended up coming down on the roof of my truck and scared the wow, you know, out of me. And then once I got back to the shop, got out and assessed the damage and ended up then in the side of my box of my truck. Yeah, if that would have hit the windshield, it would have shattered it.

Jeff Cranson 4:49

Yeah, and you're you're talking ice falling from what kind of heights?

Joe Shampine 4:53

Who knows when I was coming across because I didn't even see it come down, it hit the roof of the truck. You know, it was coming down all around me, but uh, you know, so it could have been 100 feet, 50 feet, it could have been 200 feet. I don't know.

Jeff Cranson 5:05

Yeah, either way, yeah, heavy ice falling from any of those heights is gonna do some damage. Absolutely. One of the questions that we get a lot, and there are several that are included. Um, the the your counterparts, uh, your colleagues at staff are very good about helping compile these FAQs, but one of them is about the paint. There seems to be a a faction of citizens, helpful citizens, that that think it's all about the paint on the bridge, and that if you used a different kind of paint, that would prevent this. Can you talk about that at all?

Joe Shampine 5:38

Yeah, I mean, is there studies out there for you know lights not sticking to certain paint? I guess there is out there being feasible for us, you know. I mean, everybody, you know, why don't you have uh heat tape out there? Why don't you have this out there? You know, everybody makes their comments, you know, and for how much the bridge actually closes a year, it's not really, you know, in our best interest for that cost to do all that stuff. And you know, and that's obviously we just stuff we cannot do. But the paint-wise, you know, I mean, if it's out there available, if they can prove it, you know, that would be something different. And we, you know, maybe we'd look into it.

Jeff Cranson 6:15

So yeah, I've talked to uh Matt Chinawith, who's the former chief bridge engineer, about these issues and his kind of national, even international perspective, and and he's said the same things um that you have about you know, weighing the cost of this versus the inconvenience. And so far, that's a pretty easy calculation to make. But are there are there little things in the meantime that you've learned from this that have that have helped in the the maintenance process and decision-making process? For like closing it down mean or yeah, or just yeah, just just any mitigate mitigation.

Joe Shampine 6:51

You know, I mean closing it down is the easy part, is opening back up is the hard part. Um, right. You know, once we see a fall, and you know, we obviously we shut it right down for you know everybody's safety. And you know, this last time that we did it, you know, it was you know, over probably a couple weeks, and that ice has been up there. We left our lane set up on the north and south end of the bridge. So all we had to do was get our guys over there. As soon as it started falling, we could shut the bridge down immediately. So that helped this year a lot. Once we have the ice out there and it's not all falling, we just keep our lane closures up to where we can uh slow people down and turn them around.

Jeff Cranson 7:29

Yeah, if you haven't spent time in northern Michigan, let alone the straits with its own, you know, heavy winds and climate, you might not be aware that it could uh it could be drizzling, you know, maybe a a light mist in the afternoon. That night it clears up and gets down to 10 degrees, and then the next morning, you know, by 10 o'clock it's 30 degrees, right? All this happens really quickly.

Joe Shampine 7:56

Yep. It happens really quick. I mean, the last time, excuse me, we were out there, you know, we uh anticipating, you know, it was gonna fall. And you know, we're out there and it was 32, um, then went out there a little, you know, it's 36, you know, and then I took one ride across, and all of a sudden it hit 37, 38 degrees, and that started falling like nobody's business, you know, and it happens quick, really quick. So that's the hard part is you know, closing it down is the you know easiest part, but we want to get the people off the bridge safe as possible, too. And uh opening it back up is another it's it's hard to open it back up, you know. When we're out there, we're all kind of like, boy, you know, I mean, we have the right temperatures and stuff, but then once we get the traffic back on it for the vibration, you know, that the traffic causes out there is any more gonna fall, you know, and that's just that's a tough call. Knock on wood has been good for us lately. We've been, you know, making the right calls, but you know, there's a chance that this year we already had to shut it, we opened it and we shut it down 20 some minutes later because the traffic got on it and started shaking more stuff loose. You know, you just never know.

Jeff Cranson 9:02

Yeah, I uh I appreciate that uh you guys are so diligent about this that you and Kim and the entire staff take this take this very personally and know how you would you would feel if you felt like you made the wrong decision and something horrible happened.

Joe Shampine 9:18

And so Yeah, that's what we go through.

Jeff Cranson 9:22

Right, right. And I I I yeah, I I appreciate it, and you know, everybody in the state that travels that bridge should. So so thanks. Is there anything else you want to say, Joe, about this?

Joe Shampine 9:34

Basically, you know, I mean, our workers, you know, are on the north and south end, and they're they're the ones that take the brunt of it because they got to turn the traffic around and you know, when is it gonna open or you're inconveniencing me? I gotta do this, I gotta do that, I gotta get across. And they take the brunt of it, you know. And I just want to do a big shout out to the maintenance staff here that are stationed on the north and south end, you know, because they do one heck of a job and they take the brunt of everybody's, you know, for the most part, everybody is really cordial about it, they understand, but then you have the few that don't. So it's on them, you know, and then we go out there at times where we have a little bit of ice left out there, we load up our trucks, our sand trucks, you know, with sand. We'll go out there and we get the we we we try to shake the the ice off the bridge with our trucks, you know, and it has worked in the past, you know, for certain weather conditions, you know, to get the rest of the ice off the bridge. But uh so we try our best. We're just main thing is we want to keep everybody safe. And it's just uh that's the main part, you know. We want to keep everybody safe and want everybody to understand that.

Jeff Cranson 10:41

Yeah, I know. I'm I'm glad you you mentioned that the people that are on the front lines and have to to deal with these questions and people saying, you know, I I know, I know, you gotta close it, but just let me go. Right. So yeah, that that's gotta be difficult. And um, and everybody needs to understand that even if you don't travel the bridge very often, um, how important it is as a symbol to our state. I mean, we put it on our license plates, candidates put it on their campaign signs. I mean, it's just it's I I know that you guys all have a lot of pride and you appreciate that it's kind of it's our it's the most iconic thing in Michigan. Absolutely. Yep. Well, thank you, Joe. Thanks for talking about this, and thanks for to you and your your staff for doing what you do. Okay, we appreciate it. Thank you. Please stay tuned. We'll be back with more talking Michigan transportation right after this.

MDOT Message 11:31

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Jeff Cranson 11:58

No, so back. Once again, I'm with Matt Chenoweth, who is the National Bridge Practice Leader for RSNH. He was formerly the chief bridge engineer at MDOT. How many years did you have in at MDOT all together, Matt?

Matth Chynoweth 12:12

Just under 20.

Jeff Cranson 12:13

Okay. So Matt and I have talked about this before. Um, this issue has really become much more front of mind the past uh, I'd say seven or eight years for a long time. There were occasional closures, but in the last several years it's really taken off. And so I wanted Matt's perspective on you know what he knows from both his work at the national level and from talking to counterparts across the country, really across the world, um, about how they deal with this. First of all, Matt, from my research, there aren't a lot of suspension bridges at this latitude or higher in the world. Is that right?

Matth Chynoweth 12:51

You're correct, Jeff. There's a there's a few that experience some of the icing that uh we do at Mackinac. Um, believe it or not, some of the suspension bridges in New York, the the George Washington Bridge, uh, they have regular ice there. And I read an article that their way of dealing with it is sending someone up in a man lift and beat the hangar cables with a baseball bat to get the ice off. They can get a man lift high enough to do that? Or or they they walk the cables and they yeah, hit it with a bat, but yeah, they use some sort of access. And yeah. Um, another one that that has been in the news, maybe not so much in the US, but over in Europe, is the the Great Belt Bridge in Denmark. Um, I read that that bridge closes about 12 times a year due to due to ice accretion and ice falling. And they've conducted a bunch of studies on, you know, what what can we do? What can be done both actively and passively? And uh they still haven't figured it out yet, to my knowledge.

Jeff Cranson 13:49

So if that's Denmark, I'm guessing that bridge probably includes a cycling lane. Probably. Yeah.

Matth Chynoweth 13:54

It's the second longest suspension bridge in the world, so it's a pretty big deal.

De-Icing Tech And Cost Reality

Jeff Cranson 13:58

Wow, yeah. No my gosh, being closed 12 times. Yeah. So let's let's reset on this. We last talked about this on the podcast four years ago when you were still at MDOT. Um, I've talked to the Mackinac Bridge Authority, uh, Kim Nowak, the bridge director, Joe Shampine, who's the head of maintenance there. Um, they they've heard everything. They've heard every question, they've heard everything that could come up, every every idea. I wanted you to to talk based on your experience about why there's just no easy solution to this problem.

Matth Chynoweth 14:32

Yeah. So years ago, as you mentioned, we did sort of a synthesis of what is cutting edge, what is being done, what is being proposed, uh, what's being done at other bridges. And we really we came up with, you know, three main three main activities that can be done. One is some sort of mechanical removal of the ice, uh, the other is thermal removal of the ice. And then the last one is like a passive system. And I'll I'll go into what each of these mean. So any one of these systems would obviously have to be retrofit on the bridge. And given the size and the scale of the bridge, none of it would be easy because we have ice coming from three locations, right? We've got the towers, we've got the main cables, and then we've got the hangar cables. All of those experience ice buildup or ice accretion. So there's a bunch of technologies out there that you could install, but it's cost prohibitive for the most part. Uh, there's electromechanical expulsion de-icing, electromagnetic impulse de-icing, and then ED current de-icing. All of these things involve you know installing a machine in the ice-prone areas, and it either it excites the metal from vibration or it sends pulses through through like the cable, energy pulses to blow the ice off. So those have um those have pros and cons, right? Number one, you have pretty expensive equipment up there that you have to maintain, you have to attach to power. And even if these devices can't remove the ice, it's still a safety issue. You still would have to close it to traffic to have these systems remove the ice, right?

Jeff Cranson 16:18

Which I assume they do on the George Washington Bridge when they do the baseball method.

Matth Chynoweth 16:23

Yeah, because it's still falling from a great distance. There's wind, and these pieces of ice can weigh a decent amount. The other system are our thermal systems, and those are exactly what they sound like. You're going to heat an element of the bridge uh to prevent ice from forming. Um, there's electrical resistance heating systems, which basically you're putting a small current through the bridge. Um, there's indirect heating where you can have a device that puts pressurized heated air right on an ice prone uh location. Uh, and then there's infrared radiation. Again, all of these things are systems that would have to be installed in the ice-prone areas. Uh, these might be a little better than the mechanical systems because they're gonna melt the ice instead of break it up so it melts and you may not have to close to traffic, right? But again, all of these things are systems that are gonna require power, they're gonna require maintenance. And considering the Mackinac Bridge is 100% a steel structure, meaning the towers are steel, the main cables are steel, the secondary cables or the hangers are steel, stray current could be an issue because that could accelerate corrosion, right? So any one of those systems that uses a current or something to heat the bridge or heat the element um is just, you know, it's it's it's just tough to consider on a structure of this size.

Jeff Cranson 17:45

So that would rather counter to everything that you do in terms of paint and maintenance to try to protect corrosion, right? So yep.

Matth Chynoweth 17:54

Yep. We even we even looked at um there's an interesting vehicle that's used by the agriculture industry. It's a it's a vibrator on a truck, and the vibrator wraps around an orange tree and it shakes the orange tree and all the oranges fall off, right? We looked at doing something, you know, very preliminary. If if the bridge authority could fashion a truck with a with a vibrating system on it and hook it up to the tower and vibrate the tower. But again, you would probably have to close the bridge to do such a thing. And and I we never got to the point, nor am I knowledgeable of you know what is the maximum vibration you could put in that without worrying about damaging the tower, right? Which is a serious consideration. Absolutely. Yeah. To say the least. Yep. So so the the third option, which is called passive uh ice mitigation, has to do with how things are shaped. So unfortunately, um, you know, the the main cables, the the hangers, those are perfectly circular. Uh so water's gonna hit and it's gonna run down and it's gonna collect at the bottom. On Gordy Howe, we actually shaped the sheaths for the um for the stay cables with the spiral wrapping so that even if the water hit and went around and froze, it would be broken up by these spiral rovings. So that's a passive system. That's easier to do on a cable stay bridge where the stays are straight as opposed to a suspension bridge where the main cables are in a kind of parabolic shape.

Jeff Cranson 19:24

But should talk about that just a little bit because I remember we we talked before, and I think that there was consideration, but you and your counterparts at the Windsor Detroit Bridge Authority and Bridging North America about other mitigation that could be built in to the Gordy Howe International Bridge. And and yes, basically what you said is is about it in terms of ice, right?

Matth Chynoweth 19:44

Yeah, what's going to be on the Gordie Howe Bridge is a passive system, meaning the stay cable sheathing is shaped in a way to prevent accumulation of ice. But we did look into active systems up to and including robots that would crawl up and down the stay cables with little blades on them and break up the ice. Um, the stays are designed for some future implementation of active de-icing, but we looked at several options. Uh, there are manual options where it's a chain, it's a ring of a chain. Uh the portman bridge in British Columbia has this. Uh, but an operator has to stand at the bottom and move the chain up and down. But that will break up ice. We looked at the robots, which was really, really cool, but also very expensive. Uh, so they may be able to implement something in the future on Gordy Howe.

Jeff Cranson 20:34

So just I guess not to go too deep into this, but what are the advantages? I mean, why are we seeing more cable stay bridges as opposed to suspension bridges in this era?

Matth Chynoweth 20:44

No, yeah. So on Gordie Howe, um, when we did the uh initial RFQ, one of the teams did propose a cable or a suspension bridge, excuse me. So everybody but one team proposed a suspension bridge. Um and ultimately that wasn't selected. It has to do with cost. So a cable stay bridge. So you've got a beautiful rendering of Gordie Howe behind you there. If you think about a cable stay bridge, it it generally has the same number of cables in the back span than in the main span, and that's called self-balancing, meaning a load that's in the main span is carried by the cables and then balanced out by uh the tailspan. On a suspension bridge, the main cables are not self-anchoring. They have to anchor into a massive concrete block, right? Every suspension bridge has at least two anchors. And what happens is those big cables they go into the vault and they break out into the individual cables, and those attach to an I bar that is then embedded in a massive amount of concrete. So those giant concrete vaults, they're massive, cost prohibitive when it comes to competing against the cable state bridge. Um, so that's that's that's why. The last suspension bridge that I'm aware of that was built in the US. New was the Tacoma Eroos 3 bridge in 2007. And I believe that one was built as a suspension bridge. I don't know the back details on it, but I believe it was built as a suspension bridge to kind of match and mirror the Tacoma Ero's 2 bridge, which was built in the 50s. No and has its own history. Yeah, that was the second bridge that was built in that location. The first one, obviously, Gallup and Gertie, which collapsed in 1940. Yeah. Yeah.

Jeff Cranson 22:26

Well, that video still makes the rounds and probably is part of every curriculum and civil engineering classes, right?

Coatings Design Choices And Line 5

Matth Chynoweth 22:33

I show it in my I show it in my bridge design class. Yeah, every semester, Gallup and Gertie.

Jeff Cranson 22:38

So do you see that there's talk among some lawmakers about seeking a study, perhaps. Um I mean, certainly everything is open to review, and uh the Mackinac Bridge Authority people are always open to ideas and everybody wants to be open-minded. But how do you know that you're not just throwing away money, I guess?

Matth Chynoweth 22:59

Right. I do think that a formal kind of synthesis of the art of the practice for ice mitigation would be a good idea. Some of the more cost-effective things they could look into from a passive perspective, again, are there's coatings out there, there's thermal absorbent coatings that you could put on, meaning they're gonna absorb heat um and prevent you know ice buildup. There's hydrophobic coatings, right? Stuff that is very the water just runs off it. It's basically um like a like almost like a frictionless surface and water runs off. There's solid ice phobic coatings. I don't know much about those. I just I remember reading about it. Um, and then there's also uh viscous products such as anti-icing grease, right? So you have a grease buildup and the ice can't form. All of these things, again, though, would still have to be maintained. They would have to be part of what we inspect when we inspect the bridge. Um, but I do think that a uh, you know, uh a synthesis of the art of the practice is uh is probably good because then that can also inform everybody as to if there is something out there, how much does it cost, right? What does it cost to maintain to know yeah?

Jeff Cranson 24:12

I mean, you have to weigh that that cost against the cost to the economy, you know, the the gross domestic product um between the two peninsulas, uh what goes across the straits and commuters, obviously, too. Um, but yeah, I think when you when you frame it that way and think, yeah, this is an inconvenience when it happens, but weigh that against the cost of some mitigation or you know, building a second span.

Matth Chynoweth 24:39

That's just yeah, not a consideration. Keep in mind too, you know, Kim and and her folks up there on the Mackinac Bridge, they're part of a group of, you know, cable stay and suspension bridge owners that meet, I think, on an annual basis. So I would assume that there's a lot of discussion about this in in the areas where they do have, you know, ice falling from these big bridges, and that different authorities are talking to each other, kind of trying to come up with ideas, what can be done? Have you guys tried this, you know? Definitely, definitely. Yeah.

Jeff Cranson 25:11

No, I think they're open-minded and they're looking at every possibility. Um, I think the only other thing I wanted to to hear from you is um, you know, because you're with the department 20 years before you left a few years ago, so you kind of tracked this too. I mean, was this even on your radar uh in your earliest days of the department? The idea that the Mackinac Bridge would have to close because of falling ice?

Matth Chynoweth 25:34

No, it wasn't on my radar until it was, right? Until I heard about the first the first uh closing of it due to ice. So yeah, no, but when it did happen the first time I heard about it, I'm like, well, yeah, that makes sense. You know, those again, we're talking about huge elements. These towers are 500 feet in the air, and you know, when ice forms on them, it's gonna be big pieces of ice. So it's a it's a safety issue.

unknown 25:57

Yeah.

Matth Chynoweth 25:58

It's an inconvenience, yes, but it's it's also they're being very safety cautious when they do that.

Jeff Cranson 26:04

Yeah, yeah. Well, real quickly while I have you, um you've got some involvement now with the uh the proposed line five tunnel. Um talk about that a little bit and how that uh I know you get really excited and geek out and you're just like you do about bridges, about this. So talk about that a little bit.

Matth Chynoweth 26:26

Yeah, no, I was I had the pleasure of of being part of that project when I was still at MDOT. Um, we worked with with Enbridge to develop joint specifications to make sure that it would be built to something that that crossing authority could accept. Um so yeah, we're excited. Um RSNH is is going to be MDOT's uh owner's rep uh for the project and help MDOT uh make sure that that all of the requirements of the tunnel agreement, which was um you know executed, I think, in 2019, there's a lot of requirements in there about you know how they how they build it, how they maintain it. And uh we're going to, you know, obviously we're here to assist MDOT and enforcing the you know all the requirements of that and making sure that it's uh it's it's built properly and uh serves its function.

Jeff Cranson 27:17

Yeah, and there's still some things that have to wend their way through the courts, and we'll keep an eye on that. So we'll be interested to talk more about that when time allows. But in the meantime, thanks, Matt, as always, for taking time to do this and help explain this issue, which uh to a lot of people that don't travel, um, you know, the population centers in Michigan that aren't up north for several months of the year, it doesn't seem like a big deal. But if you live there or if you need to get uh from one peninsula to the other for any reason, it's a it's a huge deal. So yeah. Thanks.

Closing Thanks And Credits

Matth Chynoweth 27:48

Thank you, Jeff.

Jeff Cranson 27:49

Who posts the podcast to various platforms and transcribes the audio to make it accessible to all. I'd like to thank you once more for tuning in to Talking Michigan Transportation. You can find show notes and more on Apple Podcasts or Buzz Sprout. I also want to acknowledge the talented people who helped make this a reality each week, starting with Randy Debler, who skillfully edits the audio, Jesse Ball, who proofs the content, and Jacke Salinas.