Title
Boat
Description
Year 7 Modified Curriculum
Key Stage 3
Area Designing
Objectives
To introduce the students to further shaping of materials and streamlining.
Equipment Required
Blocks of timber 80x45x22 approx., coping saws, rasps, glasspaper, drawing pins, varnish, brushes turps, a waterfilled gutter and a power supply and lego winch. ?...Would polystyrene be better no varnish required and it could be loaded and tested, reshaped and tested more easily
Richard Murray
Abbey Hill School Technology College
Plan
Introduce the students to various shapes of boat hull e.g. barge, liner, dingy and speedboat. Discuss the different uses of each type of hull and the speed it would be expected to move through the water. The students have to design a shape which will move efficiently through the water, possibly carrying a small weight.
It is especially important to have an efficient shape in a gutter as a large bow wave is produced and with it a considerable amount of drag. The levels of water in front and behind the model can be quite surprising. There is also the problem of spillage and this testing is best performed somewhere where spillage will cause no problems.
The students should sketch a number of shapes and then choose the one they think is best. This can be cut from the block and the result smoothed with glasspaper. The hull should then be sealed with varnish and allowed to dry.
The hull may be fastened to a thread connected to the lego winch which is powered from a stabilised power supply through long low voltage leads. The power supply should be turned low and the winch geared quite highly so that there is a very noticeable difference in dragging efficient and inefficient shapes along the gutter. The trip is timed with a stop watch and the results of these noted.
The hull may then be reshapes and tried again, the results noted once more to see what effect the change has had.
The students should note down the changes they made and the difference this made to the results, perhaps commenting on these with regard to the reasons for the result, if they can.
