Library Workshop Review: Hydraulic Bridge

Our July 2026 Library Workshop challenged participants to become engineers by building a working hydraulic drawbridge. Using syringes, tubing, water, and a laser-cut bridge structure, participants discovered how water pressure can be used to create movement and lift heavy structures. By the end of the workshop, each participant had constructed a bridge that could be raised and lowered using a simple hydraulic system.

Through this hands-on activity, participants explored several important STEM concepts, including hydraulic systems, pressure, force, energy transfer, and mechanical design. Many participants were fascinated to learn that the same principles used in their model bridges are also used in real-world applications such as construction machinery, vehicle brakes, and large movable bridges.

Preparation Challenge

One of the biggest challenges during preparation was preventing air bubbles from becoming trapped in the hydraulic tubing. During our trial builds, we found that trapped air reduced the pressure transmitted through the system, causing the bridge to lift unevenly or not fully raise. To fix this problem, the team worked out the best way to fill the tubing and tested each hydraulic set before the workshop so participants could build bridges that moved smoothly.

On the Day

Participants were highly engaged throughout the session, especially when connecting the syringes and watching their bridges rise for the first time. They eagerly compared how high their bridges could lift and helped one another adjust the tubing connections to improve performance. It was wonderful to hear so many enthusiastic discussions and excited reactions throughout the room.

Participant Feedback

Year 3 participant said “I loved pushing the syringe and seeing the bridge go up. It felt like I was controlling a real drawbridge!”

Year 5 participant said “I learned that water pressure can transfer force through the tubes. Building the hydraulic bridge helped me understand how engineers use hydraulics in real life."