Seas Your Future perceives sail training aboard tall ships as a route to personal development and unique arena to inspire young people to engage with environmental and ocean science. This year, our Scientists in Residence engaged hundreds of sail trainees in STEM outreach and citizen science activities on board, as well as during maritime events ashore. Our workshops around wind and power illustrate the nature of our work with young people, which is aligned with a range of the United Nations Sustainable Development Goals.
When she is under sail, Pelican is powered by the wind, its force is harnessed by setting and adjusting up to 11 sails according to wind direction and strength. This requires the experience of tall ship-seasoned mariners, as well as the strength of a well-coordinated team of crew heaving on the lines. It is an obvious choice to transform the physics of sailing into a STEM activity, one example of which are the block and tackle, or pulley systems, we operate daily to set, adjust and hand sails.
During STEM voyages, our Head of Science Charly Braungardt, runs workshops that got small groups of trainees to look more closely at the pulley system used for bracing the yards of the square sails. They are were then given a set of smaller blocks and rope to replicate this pulley system, and to measure the force and length of rope required to lift a 4 kg weight using two, three, four and five supporting rope sections. After also calculating the theoretical values, the potential sources of discrepancies and errors were discussed, bringing in concepts, such as friction and quality control.
Figure 1: Extract from the Pelican’s STEM education curriculum, including a schematic of the ship’s bracing of the yards and theoretical considerations relating to the pulley system operating the bracing rope. The photographs show young sail trainees constructing a block and tackle and measuring the length of rope pulled (Sp) and required force Fp to lift a lead weight a certain distance.
Leanne Hughes, geologist at the British Geological Survey, converted some key principles of her recent work into an outreach activity for young children on board the Pelican of London. At the Bristol Harbour Festival 2022, the children constructed simple paper windmills and mounted them on paper straws. The different engineering conditions on the seabed were simulated by placing the windmills into pots filled with various materials akin to substrates found offshore. Potting compost was used to mimic peat and submerged organic matter, sand and pea gravel simulated sandbanks and areas of gravel and boulders, clay represented glacial overridden diamict and a rock stood in for a bedrock outcrop at the surface.
The stability of the substrates was tested by blowing on each of the windmills, which either tipped over, tilted or stood fast. Based on the outcome of this experiment, the young participants used geological charts of the seabed to select sites where potential windfarms could be placed for best ground conditions. Given the additional task to consider water depth and distance from the shore, they went on to factor in construction, connection and maintenance cost. Finally, information on marine conservation zones narrowed down the number of suitable sites even more. Leanne spent two weeks on board and engaged sail trainees in similar exercises, adding sediment collected during the voyage to the experiment. As they cruised in the Irish Sea and Scottish waters, they also discussed the visual impact potentially affecting local opinions and tourism income.
While this activity provided young people with an insight into the parameters affecting decisions about the placement of offshore wind farms specifically, it also highlighted that multiple constrains affect any large infrastructure project in general and showcased the multi- and interdisciplinary nature of large-scale developments.
Figure 2: Young participants taking sediment samples while on anchor and examining it under the microscope, constructing windmills and testing sediment stability in an exercise find suitable locations for the placement of offshore windfarms.
The wind turbine design competition is a playful way to explore the interplay of rotor diameter, blade shape and number, stability of construction, rotational speed and resource economics. In this favourite STEM education activity, trainees construct a wind turbine rotor onto a slice of cork from a wine bottle, using an offering of diverse materials that includes toothpicks, tissue paper, cardboard, glue, string and pins. The briefing includes the design constrains with respect to size and materials, as well as the type of ‘wind’ used to test the turbines - a hair dryer.
Questions about the difference between the wind speed and flow in real-life wind farms, compared to the narrow jet from a hair dryer are discussed in the context of desired rotational speed, and what rotor blade size and arrangement would be advantageous in either case. The teams also have to be mindful of the resource intensity, innovation and aesthetic appeal of their design and nominate a communicator who will present the design concept. They know that their efforts will be judged by the panel in three ways:
The prize award ceremony is followed by a discussion about the design process, prototypes and optimisation, which often leads several teams to make changes and test the efficiency of their improved design. The workshop highlights the interdisciplinary and iterative nature of industrial design and the importance of presenting concepts to stakeholders.
Figure 3: Teams working on their design and construction, presenting their ideas. Bottom centre: The wind turbine is mounted onto the axis of the dynamo, which is wired up to the voltmeter and is being put to the test by Charly with the hairdryer.