TESTING
All our work and time spent on the project so far was in aim of testing this scale model in similar conditions that the construction would face in the North Sea. However, before we could begin this level of experiment, we had to first test our completed and sealed model on a smaller scale to see whether it would float unaided. There was much dispute among the team’s hypothesis as to the result of this experiment, and after all the bets were taken, we set to work in testing the buoyancy of the model in our very ‘elegantly sourced’ rubbish bin. The aim of this test was to simply find the level at which the base would float and so allow us to know where and how we would have to construct the flotation device which would improve the stability of the base, and would be needed irrespective of the buoyancy. Therefore, this fairly simple test was a major part of the rest of our testing, and fortunately for us, the next parts of our project were made simpler when we discovered that the model, and thus the scaled up construction, would float at a reasonable level. Quite conveniently we found that the model alone floats so that the water level is 16cm above the base, which is 8m on the real construction, and lies right on a seal, meaning that positioning the floatation device was relatively easier than previously thought. However, the model was unstable and would always topple over unless held upright. This proved the need for a stabilising device as we had already anticipated.
This meant our plans for a floatation device could then be implemented and suited to our model to enable stability in the water. The process of construction of this floatation device meant that we would have to create and estimate the size of the floats before we could work out their effectiveness. A decision was made and the size and material of these floats (Styrofoam) were decided and therefore remained through to the end of the project. This meant we proceeded into the testing phase with a limited number of variables. • •
The height of the floatation device The mass (of water) that the model held so to influence the position that it sat in the water.
The location of the experiments we had chosen to undertake had been decided on the basis of ease of access and to some extent, similarity to the conditions that the real construction would undergo. This meant that a handily located private swimming pool became our experimental ground and site of all further testing on our completed model. Having attached a suitable length of rope to act as our tug, completed a few preliminary runs to adjust the force needed to pull the model and then set up our recording equipment in the form of both camera and video we were ready to proceed. Aiming for a valid set of results, we implemented our knowledge of the sciences to conduct a reasoned experiment where only one variable changed at a time. This meant that throughout the experiments we tested different masses of water at one height, before changing the height and then repeating said experiment. This order was very much chosen due to the accessibility of the floatation device. Changing the height of such a major component took ill-afforded time, Engineering Education Scheme: The Report | Testing
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