Name & Purpose Grand Spans is a fast-paced engineering challenge. Teams use a small set of odd materials to build bridges that span the gaps between cans. It pushes creative thinking, rapid communication, and cooperative decision-making under a time limit.
a.k.a. Bridge Builders; Span Challenge
Age Band / Group Size / Time / Space Ages 8β16. Teams of 4β6; run multiple teams simultaneously for groups up to 20. Allow 20β30 minutes total. Needs a flat indoor surface β a table works best, or a smooth floor.
Materials (per team)
- 8 unopened cans (same size per team)
- 10 drinking straws
- 3 mailing labels
- 5 paper clips
- One 3-inch (approx. 8 cm) length of string
- 2 pipe cleaners
- 1 rubber band
- 1 pair of scissors β for cutting only, not part of the structure
- Stopwatch or phone timer
Materials
- 8 unopened cans (per team)
- 10 drinking straws
- 3 mailing labels
- 5 paper clips
- One 3-inch (approx. 8 cm) length of string
- 2 pipe cleaners
- 1 rubber band
- 1 pair of scissors (for cutting only β cannot be part of the structure)
- Stopwatch or phone timer
Quick-Run Card
- Place 8 cans in a row on the table. Leave a 20-inch gap between each can.
- Place all other materials nearby in a pile.
- Read the Team Instructions aloud (see below).
- Start the 4-minute timer on “Go.”
- Teams build spans to bridge can-to-can gaps. Each span must reach from one can to the next without touching the table/floor.
- Stop the timer. Count spans and score.
- Debrief.
Setup & Boundaries
- Set up each team’s cans in a straight row on a stable table. Double-check spacing β exactly 20 inches between each can, measured from edge to edge.
- All materials except scissors can be modified, cut, bent, or combined.
- Scissors cannot become part of the structure β use them only to cut other materials.
- Each span must bridge exactly one gap (can to adjacent can) and must not touch the surface between the cans.
- No other materials from outside the kit may be used.
- Teams may not interfere with another team’s cans or materials.
How to Play Read this aloud to each team before the timer starts:
“Bridge builders use steel to span the distance between strong towers. You have some different materials to work with. Your challenge: span as many of the gaps between the cans as possible. Each bridge must reach from one can to the next without touching the floor or table between them. You have four minutes. You cannot use the scissors as part of your bridge β they are for cutting only. You will earn up to 10 points each for creativity, communication, and cooperation. You will also earn 5 bonus points for each complete span that holds on its own. Go!”
Teams work together for 4 minutes. After the timer stops, assess each span:
- Does it reach from one can to the next?
- Does it stay up without someone holding it?
- Count complete spans and award bonus points.
- Award creativity, communication, and cooperation points (facilitator judgment, 0β10 each).
I-OPt Roles Run at least three simultaneously:
- Designer (Analyst) β thinks through which materials can span 20 inches. Plans before acting. Proposes structures.
- Builder (Implementer) β assembles the spans. Hands-on. Acts quickly. May not stop to think as deeply.
- Materials Manager (Performer) β tracks what’s left. Allocates materials. Calls out when supplies are running low.
- Communicator (optional) β calls out time checks, relays the Designer’s plan to the Builder, keeps the team moving together.
No elimination. If a span fails, the team tries again with remaining materials.
Inclusion Supports
- Participants who cannot manipulate small materials can direct: they verbally guide the Builder.
- Participants with fine motor differences can cut pre-measured strips before the timer starts (allow 2 extra minutes for prep).
- Participants who are uncomfortable with competition can focus on the team’s creativity score rather than the total span count.
- If a participant needs to sit out the build, they can be the official scorer and timer for all teams β full debrief participation included.
Stewardship Action: After the challenge, disassemble all spans and sort reusable materials (pipe cleaners, rubber bands, paper clips) into a collection bag for future use. Discard bent straws and used tape.
30-second reflection: “Engineers have to work with limited resources. Think of something in your daily life that you use without thinking about it. What would happen if you had less of it?” Pause 30 seconds.
Consent Pre-brief: This is a fast-paced, slightly competitive activity. Tell the group: “There is a timer and a score. If competition makes this feel stressful, focus on your team’s creativity score β that is 10 points and it is just as valid as the span count. You do not have to ‘win’ to get full value from this.”
Mid-game check-in: No formal check-in needed given the short duration. If you notice a participant withdrawing, briefly say: “Everything good?”
Opt-out/re-entry: A participant can step back from the build at any time and take the timekeeper or scorer role. They rejoin the debrief with everyone else.
Risks & Mitigation
| Risk | Likelihood | Mitigation |
|---|---|---|
| Scissors injury | Low | Brief scissors rules before starting; enforce cutting-only use |
| Can rolls off table and hits foot | Low | Use unopened cans only (heavy and stable); set up away from table edges |
| Team conflict over materials decisions | Medium | Remind teams that communication is scored β disagreement is part of the game, handled respectfully |
| Participant frustration with time pressure | Medium | Normalize it: “Four minutes is short on purpose β see what you can do” |
Warm-Up Suggestions
- 1-Minute Tower (2 min): Give each person 5 index cards. Build the tallest freestanding tower alone in 60 seconds. Then debrief: “What worked? What would you do differently with a partner?” Primes the engineering mindset.
- Material Audit (1 min): Before the timer starts, give the team 60 seconds to look at all the materials and name one thing each material could be used for. Activates creative thinking before the pressure hits.
Debrief What?
- How many spans did your team complete? What was your highest-scoring category?
- Describe the moment your team made a key decision. How did you make it?
So what?
- What communication patterns helped? What slowed you down?
- How did the time limit change how you worked together?
Now what?
- Name one thing your team did well under pressure that you want to keep doing.
- If you had 8 minutes instead of 4, what would you do differently?
Cleanup & Reset
- Disassemble all spans carefully.
- Sort: rubber bands, paper clips, and pipe cleaners into a reuse bag.
- Recycle straws if clean, discard if bent or used.
- Return cans to storage.
- Reset time: 3β4 minutes.
