Our Candy Bridge Building Competition

Candy CRUNCH: Root3 Labs' 2023 Holiday Bridge-Building Competition

As part of our 2023 Holiday festivities, Root3 Labs held a candy bridge-building competition! Our talented engineers split into 3 teams to put their skills to the test. The teams were all given identical ingredients and thirty minutes on the clock to build their best bridges!

We were looking for their bridges to span at least 12 inches long, and have the best strength-to-weight ratio. The bridges would be given another thirty minutes to “set” and then be up for weigh-in. We weren’t expecting much out of graham crackers and marshmallow fluff, but our industrious engineers were full of surprises. You won’t believe how much weight the winning team ends up being able to support!


At the red table, there’s “Team Bridge”! This team consisted of our Mech E’s, with a lot of confidence in their ‘maximalist’ strategy. According to them, if you aren’t using every piece of material allotted, you’re doing it wrong. Their plan to work with the ingredients, using them in ways they could perform best, was to be their path to victory.

And at the green table, we have the “Green Team”! Somehow, not a single mechanical engineer ended up on this team, but our electrical and computer engineers are not to be beat! These mad scientists were coming up with some unique mortar techniques with marshmallow and graham cracker crumbs that they were sure would give them the edge. Plus, with our prototyping technician, they were in good hands for this bridge building competition.

“Team Win” contained our senior engineers, and most of the confidence in the competition! They seemed to take on an early lead by focusing on aesthetics – “Perfect work looks good,” says Chad – and taking the time to formulate a plan before diving into creation. We’re always following the Product Development Process – even in candy form! They were collected and confident, feeling like the front runners based on looks alone. But, as many engineers may know – style won’t always be compatible with best design practices.

The Rules

30 minutes to build. All materials must be edible. The bridge must span at least 12 inches.

The Results!


Green Team:

The fishbowl on top of the bridges for holding our weight counters (glue sticks) is a lightweight plastic that did not bend the top of Green Team’s bridge. Unfortunately, it started that way due to some last-second rushing!
Ultimately, the Green Team’s bridge consisted of layers of pretzel rod ‘rebar’, graham crackers in alternating layers, marshmallow fluff, and fluff mixed with graham cracker ‘sawdust’ to serve as a ‘mortar’. As you can see in the video, the sturdy construction at the bottom – fortified with the candy mortar – held up well in the beginning, but finally developed too large of a fault line to continue.

The Green Team finished at 80 glue sticks, with a total bridge weight of 1.40lb. Their strength-to-weight ratio worked out to a little less than 1x it’s total weight.

3rd Place!


Team "Win":

They started out strong, and confidently, with their clean and aesthetic bridge design. They easily took home first-place for looks with the decorative peppermint rivets.
The self-named ‘Team Win’s confidence only grew as the weights continued to pile into the bowl. But, as the video shows, the bridge wasn’t strong enough to hold after a catastrophic fault line nearly snapped the bridge in two!

Despite some questionable last-minute weights, Team Win ended on an impressive 196 glue sticks. The remains of their bridge weighed in at 2.26lbs, giving them a strength-to-weight ratio of about 1.5.

Great showing, Team Win, but nobody could have competed with Team Bridge’s crazy freezer strategy!

2nd Place!


Winner! Team Bridge:

It’s true. Team Bridge’s strategy was building a solid mass of frozen graham cracker, pretzel rebar, and melted marshmallow fluff from the beginning. As some critiqued the build’s design by comparing it to a log, they simply retorted – isn’t a log the original bridge? Incredible stuff from Team Bridge.

As it quickly became clear that they would easily outpace our measuring system, we got to work figuring out the best way to test this bridge’s load capacity. Finally, we landed on the pull weight scale as the best solution. Aditi really took one for her team to take up that position, but with requisite safety goggles on, she was ready for the real test!

See for yourself how it all ends! Amazingly, Team Bridge came in at 38lbs of force to get that cookie to crumble! With the bridge weighing in at only 2 pounds, that’s a strength-to-weight ratio of 19!

First Place, Team Bridge!