Abstract
Model tests of a high-speed midwater rope trawl were made to estimate the optimum ratio be-tween headrope flotation and wingtip weights. The weights were secured to the bottom of each wingtip. The model has some new design features. i.e. it is a variable type of rope trawl, has a long tapered body and a codend without flapper. The vertical mouth opening was measured in an ex-periment tank at towing speeds of 3-5 knots using various headrope flotation, wingtip weights and rigging. The proper wingtip weights can be determined from the height of the mouth opening. Based on the height of the mouth opening divided by the sum of the wingtip weights and the static buoyancy of the floats, the proper wingtip weights were estimated to range from 5 to 8 tons within the range of buoyancies of 0.5-1.0 ton. These weights were heavier than those normally used on midwate trawls of a similar size to the scaled up value of the model.
