Fiber-Optic LHD Pilot — Open Vehicle Deck, 6 Weeks

The operator wanted to know whether they should be running distributed fiber-optic LHD on their open vehicle deck or whether the per-vehicle grid generalised across both deck types. We ran both, side by side, on the same vessel for six weeks. The answer was less either/or than the question implied.

What fiber did well on the open deck

• Continuous coverage along the run — no blind spots between vehicles.
• Immune to wind-driven thermal mixing that defeats point smoke sensors.
• Single interrogator unit, simple cabling, low maintenance overhead.

Where the per-vehicle grid won

• Per-vehicle localisation — fiber gave deck-section coordinates, grid gave bay coordinates.
• Earlier detection on staged cell-level events (smaller deltas resolvable at narrow FOV).
• Coherence check across cells suppressed solar gain that fiber alone could not isolate.

Recommendation back to the operator

Fiber on weather decks and open ramps as a continuous coverage primary; per-vehicle grid on enclosed decks as the localising primary. Both, not either. The cost delta between the two architectures across a full vessel is smaller than the coverage delta.