Cutting Landing-Site Fish Spoilage Without Ice: A Solar-Assisted Dryer and Raised-Rack Design Priced per Kilogram of Catch Saved

At tropical landing sites without ice or grid power, part of each day's catch spoils before it can be sold fresh or dried. This paper designs a combined raised-rack and solar-assisted enclosed dryer for a 100 kg wet daily batch (SIMULATED, NOT MEASURED; nothing has been built or used at a landing site) and tests it in simulation against open-ground drying under identical weather using a first-order thin-layer drying model run as a race against a Q10-style spoilage integral. At the 10 mm design thickness the dryer reaches the 0.20 kg/kg dry-basis target in 13.1 h (hot-dry sunny) to 33.9 h (cool-humid overcast), saving every batch in all four weather cases, while open drying fails on both humid cases because its equilibrium moisture (0.198-0.245 kg/kg) sits at or above target. Across an illustrative 120-day season the saved fraction rises from 0.75 to 1.00, an additional 3,000 kg, at $0.051 per additional kilogram saved on a $608 materials cost. The design wins only for fish split to 15 mm or thinner on sunny days and 10 mm or thinner on cloudy days; at 20 mm neither method saves the batch on any day tested.