1. The cables rely on the deck for horizontal anchorage
2. The cables are too flexible to install before the deck
3. The towers cannot support the cable loads alone
4. The deck provides access for cable spinning operations

Explanation

Explanation: In a self-anchored suspension bridge, the main cables are not tied to ground-based anchor blocks like in a conventional suspension bridge. Instead, the tension in the cables is resisted by the deck structure itself, which acts as the anchorage. Therefore, the deck must be constructed first so that it can carry the horizontal components of the cable forces. This contrasts with conventional suspension bridges, where the main cables are constructed first and anchored directly into the ground before the deck is suspended.

Learning Resources:
• Bridge Engineering Handbook – Construction sequencing of self-anchored vs. ground-anchored suspension bridges
• Case Study: Self-Anchored Suspension Span of the Bay Bridge (San Francisco)
• Mola Visualization: Build a suspension bridge using the Mola Kit. First simulate a conventional suspension system by anchoring cables to fixed points outside the towers. Then model a self-anchored system by attaching cables directly to the ends of a rigid deck structure. Compare how the load path changes and observe that in the self-anchored case, the deck must be in place to resist horizontal cable forces.