De Hef in Rotterdam carried trains until a tunnel opened in 1993. It is a now a national monument. Photo by the author.

As the principle symbol of Duluth, writing on the Aerial Lift Bridge often focuses on its uniqueness. Because it started as a transfer bridge, the top span makes it unusual for a lift bridge. But lift bridges themselves are not so unusual. Wikipedia lists 137 of them in the world.

According to the rather brief Wikipedia article on lift bridges, the design allows for heavier spans because the counterweights don’t require the extra leverage needed for drawbridges. Because the counterweights only need to be equal to the weight of the deck, this type of bridge is well suited for situations where the deck must be sufficiently reinforced to support heavy loads. For this reason, many lift bridges are railroad bridges.

Above is a Great Lakes harbor with a lift bridge. Play the challenge to find out where.

Of the more than 100 lift bridges in the world, 11 (including Duluth’s own) are on the Great Lakes and its connecting waterways. This challenge takes you to five of those of bridges. Because not all of them are in prominent places within cities like ours in Duluth, each round has a six minute time limit.

PDD Geoguessr Challenge #10: Lift Bridges of the Great Lakes

This week also includes a bonus challenge. During the pandemic when I had plenty of time at home, I made a Geoguessr map that features 95 of the world’s lift bridges. I include it as a bonus challenge because the difficulty level is a bit higher than most of the PDD challenges have been so for — some of these bridges are in rather remote locations. And even though this challenge is already more difficult than the one above, the time limit is set to five minutes per round.

Bonus Challenge: Vertical Lift Bridges Around the World

How to Play Geoguessr

GeoGuessr can be played on a laptop or desktop and on Android or IoS mobile devices with the GeoGuessr app. Just click on the link that fits how you play and create an account to start playing.

Every game consists of five locations based on a theme chosen by the game creator. You are shown a Streetview image stripped of all the informational labels that are normally overlayed onto the image. Unless the challenge specifically restricts it, you can move around and look for clues like street signs and business names to find out where you are. The image below shows a basic overview of the Geoguessr screen layout and controls.

Once you think you know the location — or are nearly out of time — you use the inset map to place your marker where you believe the round started. After you hit “Guess,” you will see how close you were to the correct location and how many points your guess earned. The closer you are to the location, the higher your score, with a maximum score of 5,000 points. On a map that covers a small area, like the Gary-New Duluth neighborhood, being off by a few blocks will cost you a lot of points. On a map that has locations from around the world, you will get nearly all the points just for finding the right city. The maximum error for a perfect score also changes by map size, but in general if you are within 50 feet (15 meters) you will always get the full 5,000 points.

Not often, but every now and then, GeoGuessr gets a little buggy. If the underlying Streetview imagery has changed since the game was made, sometimes it repeats the last round, gives a black screen, or doesn’t allow a guess to be made. If that happens, please let me know and I’ll update the challenge.

At the end of the five rounds, an overview screen shows your score for each round in addition to your guessing time and how far off you were from the correct location. The correct locations and your guesses are also shown on a map and you can click on any of the round numbers to review the locations. Additionally, the final screen in a challenge will show how you rank compared to the top scorers of the challenge. When choosing your user name, keep in mind that your user name and score per round will be visible to other players of the challenge.

If you have feedback on this challenge or ideas for future challenges, please share them in the comments below.