Some remarkable numbers are possible in pumping water without electrical power. While it may not seem important to a developed world’s reader – the ability to reduce fuel use or increase incomes in less developed regions makes great sense. But even a thermal solar kit rigged to a home under floor water heating system with the electricity off could be toasty warm for a whole winter with a minimum of effort.
Jon Leary, 24, a mechanical engineering student in the University of Sheffield’s Department of Mechanical Engineering, took his bicycle machine design from a Steel City drawing board to the heart of Guatemala as part of his dissertation, which required him to `make something useful out of rubbish’.
Mr. Leary’s first try yields a rubbish sourced pump that can achieve a 40-liter per minute flow rate — equal to about four U.S. specification normal showers running, which is more than 10 U.S. gallons. At 26 meters (85.3 feet) of head or lift, a flow rate of 5 liters per minute can be achieved, still more than a gallon.
Leary spent four months time in Guatemala improving the design for his bicibomba movil — a mobile bicycle-powered water pump to be used for irrigation and general water distribution — by working with the Guatemalan Non Governmental Organization Maya Pedal, who designs and builds a variety of weird and wonderful bicycle machines using abandoned bikes sent from the U.S. and Canada.
Maya Pedal´s aim is to produce machines that can improve the daily lives of locals, without them having to resort to expensive electrical or environmentally damaging fossil fuelled machines. Their machines, which are human-powered sustainable energy sources, range from the bicilavadora (bicycle washing machine) to the bicimolino (corn grinder).
Mr. Leary created the water-pumping machine using a normal bike, which is mounted into a frame with an old electric pump converted to a friction drive attached to the back wheel. The back tire of the bike makes direct contact with the exposed armature of the motor, which is then covered with rubber from an old tire to give better grip. The machine was tested to a range of heights, with no head or lift making 40 liter per minute flow rate and the reported 26 meters lift making 5 liters per minute. Just like pedaling a bike. It’s a surprise what the human under ¼ horsepower output can accomplish.
The bike-mounting frame can be built quickly and easily using only basic workshop tools and materials, including a few lengths of angle iron, some flat lengths of metal, bicycle seat posts and seat tubes, and a scrapped standard electric centrifugal water pump.
Before Leary´s design became available, Maya Pedal had already produced a popular machine capable of drawing water up from 30 meters (98.4 feet) below the surface. Many Guatemalan farmers work on steep inclines and wanted to distribute the water once it had been extracted from the well. As a result, unlike Maya Pedal´s other static designs, Leary’s pedal pump is completely mobile — when a person is done pumping, they can simply flip the pump frame upside down and it will rest above the back wheel like a bike rack. The mobility enables users to pump from the bottom of the hill to a mid-way tank until full, and then continue pumping from the mid-way tank to the top of the hill. The number of mid-way tanks can be increased indefinitely, effectively making the pumping distance unlimited. Sounds like a bunch of work, but compared to carrying water by the bucket – superbly easy – as one isn’t carrying oneself along during each trip.
The pedal pump is now in regular production in Guatemala and at least six more models have been made since Leary´s departure from the country last summer. Mr. Leary has since produced an open source construction manual for the machine, which is freely available on Maya Pedal´s web site. The manual was recently sent to Malawi by students from the University of Strathclyde involved in a rural irrigation project aiming to address some of the agricultural problems that the developing nation is facing.
Leary said, “When I was asked to design a novel product from waste material for my Master’s thesis, I never would have expected that I’d end up welding together bicycle machines in the highlands of Guatemala! Working at Maya Pedal was like being on Scrapheap Challenge – there is a storeroom full of stripped down bicycle parts, a workshop full of tools and the only limit is your own imagination. There was never a dull day, the volunteers came from all around the world to be there and everyone in the local town was so friendly – it’s certainly an experience I’ll never forget.”
Jon will return to Guatemala in two months or so with a team of three more of the University’s recent graduates from the Department of Mechanical Engineering to design, build and test a wind turbine. The turbine will be designed specifically for Maya Pedal and as a result will be constructed from disused bicycle parts and other scrap materials.
We can join with Dr. Steve Bradbury from the Department of Mechanical Engineering at the University of Sheffield who said: “It is gratifying to see that the design expertise that we foster in our students can be utilized in worthy projects such as this. It is a result where everybody wins; Leary, the University and most importantly, the people of Guatemala.”
The human’s ¼ horsepower isn’t much. But when used effectively a wee bit of energy can go a long way. 10 gallons, two full five gallon buckets in a minute would be 80 pounds – if just moving the water to extract heat – properly put to work human power looks very strong.