Trussmere: Bridge Building Puzzle

A bridge-building physics puzzle: build from road planks, wooden beams and steel cables on a budget, then watch every member strain green to red as a cart, a hay wagon and a stone wagon cross. 12 gaps. Free, no ads, no tracking.

A string of highland gaps needs bridges and the money is tight. Drag road planks, wooden beams and steel cables between joints, then send the cart across and watch every member flex.

Each member glows from green to red as it takes load and snaps past its limit. Steel cables only pull, wood both pushes and pulls, and a deck that sags too far tips the cart off. Leftover money earns stars.

• 12 gaps: from a narrow millrace to a fifteen-square crossing with rock spires
• Three materials: road planks, wooden beams and tension-only steel cables, each with its own cost and strength
• Real stress: a mass-spring solver measures the force in every member while the cart drives
• Heavier loads: a hand cart, then a hay wagon, then a stone wagon
• Stars for thrift: the less you spend, the more stars you earn
• Keyboard or touch: build by dragging or with a cursor; designs, progress and stars are saved

Code and text written with AI assistance; checked by PN Scripts with automated tests. Every shape is drawn and every sound synthesised by code; there are no AI-generated image or audio files.

Controls

• Mouse / touch: drag from joint to joint to build, tap a member to remove it
• Arrow keys / WASD: move the cursor, Enter: start or finish a member (members chain on)
• 1 / 2 / 3 or Tab: road, wood or steel
• Z / Backspace: undo, X: remove a member at the cursor, C: clear
• Space or the Test button: run the cart, again to go back to building
• [ and ]: switch between unlocked gaps; P / Esc: pause, M: sound

Made by PN Scripts.