Strengths  The prototype effectively uses cardboard, dowels, and simple mechanisms to represent the structure and functionality of the underwater train concept. Including a propeller element demonstrates an understanding of how propulsion might work for underwater vehicles, simulating movement through water. The train’s design incorporates a simple, streamlined shape, which aligns with the concept of minimizing drag underwater.

Suggestions for Improvement Incorporate wire or foam elements to create a more rounded, hydrodynamic frame Use translucent materials (e.g., plastic bottles) to simulate viewing windows, which could enhance user experience. Add LEDs for lighting elements to represent headlights or interior illumination.