“It’s a confined space and a strange experience,” says Doug Megran, a final-year mechanical engineering student, when asked to describe what it’s like to pilot the Mayflower. On the screen next to him runs a silent video of the sub being tested in the Plymouth Life Centre, with Doug diving down and jimmying his way into the hull. As the door is sealed, you could be forgiven for giving a little shiver. “I mean, scuba diving itself can feel a little weird, but when they close the hatch and you’re lying there in the sub…it’s not for the claustrophobic!”
A little under nine feet in length, and constructed from woven cloth, epoxy resin and carbon fibre, the Mayflower clearly hasn't been built with comfort in mind. But that it’s been built at all is testament to the vision and skill of the staff–student team behind PULSE – the Plymouth University Legpowered Submarine Engineering.
The project originated with Dr Keri Collins, who joined the University in 2012 as a Research Fellow. A graduate from the University of Bath, she’d seen the way her Alma Mater had integrated it into its programme and wanted to do the same at Plymouth.
“We have this great marine tradition at the University, and there’s the naval dockyard in the city, so it just made sense on a thematic level,” says Keri. “But initially it was difficult to show people what we were trying to do, and at the outset we couldn't even be sure we’d have the funding to do it. So it wasn't an easy ‘sell’ to the students.”
But sell the idea Keri did, and at the beginning of the 2013/14 academic year a team with “zero experience” embarked on the project. The submarine was designed through dissertation projects and it was that first version that Doug, dive lead Daryl Oosthuizen, Mike Prest and Matthew Merrett took to the European International Submarine Races at Europe’s largest freshwater tank, QinetiQ’s Ocean Basin in Gosport. There, they achieved a remarkable third place overall around a demanding slalom course, reaching speeds of 4.6 knots despite effectively losing their hatch early on.
With students John Cima, Oliver Powlesland and Nicholas Arthur joining the project at the start of 2014/15, and the support of staff in the School of Marine Science and Engineering, including Dr Richard Cullen, Adam Kyte, Alastair Reynolds and Matt Brown, the focus switched to refinement and improvement for the International Submarine Races (ISR 13). Held biennially at the Naval Surface Warfare Center (NSWC), in Carderock, Maryland, the event places an even greater emphasis on speed, requiring the teams to make a straight run down a 100-metre course – in a facility so long that the designers had to take into account the curvature of the earth.
Daryl, who is on the masters programme in Mechanical Engineering, said: “This year, we made a number of modifications to the design, addressing the hatch problems, adding a new nose cone, modifying the control system and making the sub more rigid. These have all been designed to improve the hydrodynamic performance and reduce drag.”