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Single-day trawling is commercially practiced along Thoothukudi coast, involving a total of 275 trawlers of varying length range operated from Thoothukudi fishing harbour (8°47’N, 78°9.5’E). The trawlers can be classified in three categories: vessels with overall length (OAL) of 40–50′ (Type 1), OAL 50–60′ (Type 2) and OAL above 60′ (Type 3). Trawlers with OAL of 45′, 55′ and 65′ were selected for the study. Irrespective of the type of vessel, the power required for towing the net was found to be unnecessarily high. The excess power wasted due to faulty trawl designs in Type-1, Type-2 and Type-2 vessels was 55, 87 and 133 hp, respectively. While trawling with optimal trawl design would contribute only 28.67% of the brake horse power (BHP) of the Type 3 vessels, the existing design of trawl used in this type of vessels contributed as much as 50.83% of the BHP. The Type-1, Type-2 and Type-3 trawlers were found to operate with excess fuel consumption at the rate of 103, 212 and 418 L of diesel per cruise, respectively. Based on the annual fuel consumption, true total annual CO2emission was estimated as 458 tons. The study revealed that the total fuel consumption can be reduced by 40% by optimizing the trawl design and reducing the free-running speed, free-running duration and trawling speed. Further, vessels with an OAL of 60′ and above may be permitted for multi-day fishing in distant waters after suitably limiting the number of fishing trips/month in order to minimize the fuel loss through free running. [ABSTRACT FROM AUTHOR]

• A novel multi-objective evaluation model for mass housing is formulated. • The model optimizes construction costs, embodied energy and indoor thermal comfort. • Composite layer envelop constructions are investigated in warm humid climate. • Best alternative envelop solutions are proposed for free running buildings. • Lean wall and roof constructions make repeated appearances in the solution sets. This study evaluates and compares the performance of the commonly constructed mass housing envelops in India with alternative building envelop constructions. These alternative construction scenarios are created with a material library comprising of the available alternative roofing and walling system combinations including some common emerging construction technologies standardized and advocated by the Building Materials and Technology Promotion Council of India. The common trend of housing envelop constructions in the country involves ordinary burnt brick walls and reinforced cement concrete roofing and beam-column system which is referred to as the base case building envelop in our study. We consider initial investment costs, thermal comfort perception and the initial embodied energy in a multi-objective evaluation framework for assessing free running building envelops. Rat trap bonded brick walls, glass fibre reinforced gypsum construction, light gauge framed steel (LGFS) constructions, monolithic concrete (MC) construction system, reinforced concrete ribbed roof and compressed stabilized earth block (CSEB) walls and CSEB filler roof slabs make repeated appearances in the multi-objective optimal solution sets or Pareto optimal solution sets. CSEB construction has lowest initial embodied energy, LGFS gives minimal thermal discomfort whereas MC construction system reports least construction cost. A predominance of lean envelop constructions is observed in the Pareto optimal solution sets considering minimization of construction cost, thermal discomfort and construction embodied energy. [ABSTRACT FROM AUTHOR]