Pedal Power-In Work Lesiure and Transportation

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Leisure, andTransport

. How to produce yourown enerav from a stationarvbicycle! US ---- -- ---- J0 Perform kitchen tasks usingpedal-powered equipment!

0 Watch TV from electricity producedat home!v 0 Actual building instructions for a newlydesigned energy dycle!

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lnW~r~~ leisure and TrmsprttiionHow to produce your own energy from a stationary bicycle- with actual buildinginstructions for a newly designed energy cycle!

l Perform kitchen tasks using pedal-powered equipment!e Watch TV from electricity produced at home!y Operate many household machines without plugging into household outlets!This unique new book explores the potential for pedal-driven devices in theworkshop, in the kitchen, on the farm, for transportation-anywhere, in fact, whereinexpensive energy to run simple machines is needed. It tells you why weneed to develop the potential for human power and how to do it inan inexpensive and healthful way.In PEDAL POWER youll read about

l The use of human muscle throughout history from hand cranking to capstans,treadmills, treadles and pedals. el The broad range of pedal power apparatus particularly useful in developingcountries as transportation, water pumps, borehole pumps and winches.l The invention and development of the Rodale Energy Cycle.* The use of the primemover to operate a trash can washing machine,water pumps, and a wood saw.l The advantages of a treadle band saw and other treadle workshop equipment.0 The future of pedal power: the recumbent bicycle, pedaled lawn mowers,boats, tire pumps, saws, sewing machines, typewriters, cooling fans,railbikes, delivery vehicles, and personal rapid transit systems.

PEDAL POWER is like no other book ever written. Its never-before published buildinginstructions and designs for new pedal-power inventions make it well worththe price aione.

O-87857-1 78-7


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Edited byJames C. McCullagh

With Contributions From: DavidGordon WilsonStuart S. WilsonJohn McGeorgeMark BlossomDiana Branch

RODALE PRESSEmmaus, PA


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Copyright @ 1977 Rodale Press, Inc.All rights reserved. No part of this publication maybe reproduced or transmitted in any form or byany means, electronic or mechanical, includingphotocopy, recording, or any information storageand retrieval system without the written per-mission of the publisher.

Printed on recycled paperLibrary of Congress Cataloging in Publicatibn Data

Main entry under title:Pedal power in work, leisure, and transportation.Bibliography: p.Includes index.1. Pedal-powered mechanisms. I. McCullagh,James C. II. Wilson, David Gordon, 1928-TJ1049. P4 621.4 77-6422ISBN O-87857-178-7

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ContentsACKNOWLEDGMENTS ..........................INTRODUCTION ................................CHAPTER ONE:Human Muscle Power in History-David Gordon Wilson ..............................The Manpower Plow of Shantung .......................Handcranking ........................................Levers Actuated by Am and Back Muscles ...............Capstans ............................................Treadmills.. ........................... . .............LegsonTreadles .....................................Leg Muscles Used in Cranking ..........................Pedal Power in the Workshop ..........................

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CHAPTER TWO:Pedal Power on the Land: The ThirdWorld and Beyond-Stuart S. Wilson . . _ . . . . . . . . . . . .-Transportation . . . . . . . . .._............................Stationary Pedal Power. . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . .The DynapodThe Winch

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Pedal Drives for Irrigation Pumps . . . . . . . . . . . . . . . . . . . . . . .Pedal Drives for Borehole Pumps . . . . . . . . . . . . . . . . . . . . . . . . .

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............... vii............... ix

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......... 10......... 13......... 13......... 15......... 15......... 25

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............. 45................... 48........... ....... .51

CHAPTER THREE:Multiuse Energy Cycle: Foot-PoweredGenerator-Diana Branch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............ 57The Energy Cycle . . . . . _ . . . . . . . . . . . . __ . . . . . . . . . . . . . . . . . . . ............ 58Genesis of an IdeaTesting ProgramRefinements in DesignWinch......................................,............ . . .......... 67Homemade Foot-Powered Generator.. . . . . . . . . . . . . . . . . . . . . . . * . .......... 71MaterialsBuilding InstructionsRear-wheel Bicycle Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80MaterialsBuilding Instructions

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Pedal PowerCHAPTER FOUR:American Tinkerer: Further Applicationsof Pedal Power--John McGeorge __ . . _ . . . . . . . . _ . . . . . . . . . . . . . . . . . . . .87TheFrame....................................................................89TheJackshaft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...89The Flywheel . . __ . . . . . . . _ . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . .90MakingaFlywheel .._............_......., . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..gOTheV-beltPulley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...90PossibleApplications..................................................,........91Trash Can Washing MachineThe Wood SawWater PumpingThe Pitcher PumpLog SplitterCider Press

CHAPTER FIVE:Treadle Power in the Workshop-Mark Blossom .................................. .97Hand-MadeToys ............................................................ ..9 7Construction.. ............................................................. ..lO 0RenaissanceofHandCrafts....................................................lO 4

CHAPTER SIX:The Future Potential for Muscle Power-David Gordon Wilson ..................................................... .106High-PowerDevices ........................................................ ..lO 7Low-Power Special-Feature Devices ........................................... .107Low-Power Convenience or Status Devices .................................. .107Need for Improved Muscle-Power Delivery Systems .............................. .108ARecumbentBicycle ....................................................... ..lO 8APedatedLawnMower ..................................................... ..lllPedaledBoats ............................................................. ..113Yacht Battery-Charging Generator ............................................. .114Irrigation Pumps ............................................................. .114TirePumps ................................................................ ..117Saws ..................................................................... ..117Sewing Machines, Typewriters ................................................ .117Cooling Fans. ............................................................... .118DeliveryVehicles.............................................................ll 8Raitbike ................................................................... ..119Personal Rapid Transit (PRT) Systems ......................................... .122

CONCLUSION ...................................................... .124POSTSCRIPT ...................................................... .125APPENDIX ......................................................... .126BIBLIOGRAPHY .................................................... .127fMDEX ............................................................ ..12 8

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Acknowledgments

In many respects this book is an outgrowth ofthe good work done by Dick Ott, Lamar Laubach,and others who developed the Energy Cycledescribed in Chapter Three. I am deeply gratefulto them for their technical assistance and advice.

I am also grateful to the hundreds of readers o fOrganic Gardening and Farming who providedvaluable suggestions concerning possible ap-plications of pedal power.My special thanks to David Gordon Wilson,Stuart S. Wilson, John McGeorge, Mark Blossom,and Diana Branch who have considered the useof human power from new and interestingperspectives.And my appreciation to Diane Gubich for hergood research.

James C. McCullagh

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Introduction

In this age of lasers and deep spaceprobes, much of the muscle in the industri-alized world sags like a rag doll.In this rich technological age much of thepopulation, particularly in developing coun-tries, has been displaced from the workplaceby inappropriate technologies. The leap isfrom bullock cart to jet plane.Thus the paradox. Part of the worlddreams of the likelihood of a workless stateripe with leisure time; the other part is tryingto catch up. And the catching up is some-times written in bold letters. On any givenday, London, Lagos, and Tokyo canexperience traffic jams of simiiar proportisns.The industrialized nations, especiallyAmerica, have given birth to certain assurnp-tions which are rapidly gaining currencyaround the globe: cars are better thanbicycles; processed foods are bet:ei* thsnnatural ones; living in a city is better thanliving in a rural area.Ironically, because developing countriesmust live by the rules of a capital-intensive economic order, they are oftenobliged to accept the above assumptions.The retreat, then, is from the town, fromthe bicycle, from the land. The result: a deathof simplicity, both in life-style and machine.Mothers milk is no longer in fashion.Interestingly, at the time when the appro-priateness of technology is being ques-tioned daily, the bicycle, which is perhaps the

most appropriate and efficient machineever invented, is making a rocky comebackin many countries. A compelling example ofthis renaissance is in Dodema, the newcapital of Tanzania, now under construction.The master plan for Dodema calls for a com-plex network of roads that will encouragemaximum use of the bicycle Furthermore,the plan decrees that the ratio of bicycles tocars will be 70:30, thus assuring this ma-chine a major role in an enlightened trans-portation system.In addition, the bicycle has come underclose scrutiny by those who believe it offersgreat potential for performing stationary workand for goods transportation.The literature is filled with examples ofpedal- and treadle-driven machinesdesigned to perform all types of useful work.However, with the decline of the bicyclecame the decline in pedal-power devices,with the notable exceptions of apparatusused in Chlna and other Asian countries.Partly because of a general critique oftechnology, there has been in the lastdecade a renewed and vigorous interest inthe potential of pedal power for bothdeveloping and developed countries.Professor Stuart S. Wilson of OxfordUniversity, Professor David Gordon Wilsonof the Massachusetts Institute ofTechnology, the Intermediate TechnologyDevelopment in the United Kingdom, the

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Pedal Power

Rodale Press Research and DevelopmentDepartment, and many inventors, scientists,and tinkerers have brought new and valuableinsights to the science of pedal power; andfrom these minds has come this book.Pedal Power is a philosophical work inthat it explores the full human potentialinherent in the use of the bicycle for work. Onthe other hand, it is a very practical book, asit suggests scores of tasks which can beeasily and effectively accomplished withpedal devices.In Chapter One David Gordon Wilsoncharts the use of human muscle in historyand explores the singular display of pedalequipment invented at the end of thenineteenth century. In Chapter Two StuartWilson discusses a whole range of pedal-power apparatus which could be particularlyuseful to developing countries.In Chapter Three Diana Branch offers adetailed account of the Rodale EnergyCycle. The author not only gives a descrip-tion of this complete machine, but also

provides a full set of building instructions forthose who desire to construct it. Further-more, the author offers a host of suggestionsabout how the Energy Cycle can be effec-tively used around the house, garden, farm,and homestead.The possible uses for pedal power are sig-nificantly extended by John McGeorge andDavid Gordon Wilson in Chapters Four andSix, respectively. And in Chapter Five MarkBlossom considers Treadle Power in theWorkshop.Overall, the book is ripe with plans,models, prototypes, and possibilities. It ishoped the reader will be moved to developpedal equipment of his own.Above all, we hope this book will bringabout a reconsideration of the bicycle andpedal-driven machines. We feel these aresubjects worthy oKadditional study.Perhaps an interface between East andWest is the bicycle, the machine whichmakes us all brothers and sisters.


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Human Muscle Power in HistoryBy David Gordon WilsonThe sweat of the brow is daily expendedby millions, and daily millions of sighs arewrung from the tormented frame of the bentand weary in the pursuit of providing food.Rudolf P. Hommel wrote this after living foreight years in China in the 1920s studyingChinese tools and crafts. His aim was togive a fairly complete picture of Chinese life,as lived by millions of people today, a life in

which there has been no considerablechange for thousands of years.

five-gallon cans of water and the manure.The fork, the spade, and the hoe were theprincipal tools; and they used, or misused,our bodies painfully. We could utilize only asmall proportion of the energy output ofwhich we were capable because of the twist-ing contortions which these implements de-manded of us. How different from the relativecomfort of a bicycle, with a choice of gearratios to suit the load and the terrain.

That picture is, I believe, one which we allhave of our forebears in any culture except,perhaps, those few tropical paradises wherewe are taught to believe that the inhabitantsjust sat under the banana trees and coconutpalms eating their fruits whenever theywished. My remembrances of growing up inEngland in the thirties and forties are cer-tainly closer to the Chinese model than tothat of the Pacific islands. During World WarII we all had large vegetable gardens carvedout of tennis courts and the like, and I lookback without longing at the back-breakingweeding, watering, and the double-digging(double-depth trenching the plots, withmanure in the lower part of the trenches).The only mechanization we had was myhomemade bicycle trailer which carried the

I have worked on farms in England, Scot-land, and Germany and have lived amongfarmers in Nigeria. In all these places thetractor was beginning to take over thosetasks which could be most easilymechanized. But this meant that the manuallabor which was left to be done wasgenerally the least susceptible to relief givenby the application of mechanical aids. Weshoveled endless quantities of manure; wehoed the weeds from almost invisible crops;and we picked up potatoes from the mixtureof earth and stones thrown up by a speedingtractor with a rotary digger. We did not feelthat we were much better off than our moreancient ancestors.What is remarkable about the historicaluse of muscle power is not only how crude itgenerally was, but that when improved

SHANTUNGPLOWTwo sticksare matches for strikingsoil at mans fertility,sweat at his crotchhis sun.

James C. McCullagh

CHAPTER ONE


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Pedal Powermethods were tried, they were generally notcopied and extended. There were threeways in which the application of humanmuscle power could fall short of the op-timum. first, the wrong muscles could be in-volved. We find time and again that peoplewere called upon to produce maximumpower output, for instance in pumping or lift-ing water from a well or ditch, using only theiram and back muscles. It seems obvious tous nowadays that to give maximum outputwith minimum strain we must use our legmuscles, not incorrectly called our secondheart.Second, the speed of the muscle motionwas usually far too low. People were re-quired to heave and shove with all theirmight, gaining an occasional inch or two. Amodern parallel would be to force bicycliststo pedal up the steepest hills in the highestgears, or to require oarsmen to row boatswith very long oars having very short inboardhandles.Third, the type of motion itself, even if car-ried out at the best speed using the legmuscles, could be nonoptimum in a ratherabstruse way. Here is the best example Iknow of: Dr. J. Harrison of Australia took fouryoung, strong athletic men and a speciallybuilt ergometer-a device like an exercisebicycle in which the power output could beprecisely measured. He wanted to settle thecontroversy as to whether oarsmenproduced more or less power than bicyclists,and he reproduced the leg and arm motionsrequired for rowing racing boats (or shells)and pedaling racing bicycles. He found(somewhat to his surprise, no doubt) thatthere was negligible difference between thepower output produced in these twcj very dif-ferent actions by the same athletes after theyhad practiced long enough to become ac-customed to each.Then he tried some old, and somepossibly new, variations. He fitted ellipticalchainwheels in place of the normal circulartypes to the cranks of the bicycle-motion

devices. These chainwheels were made inEurope in the thirties to reduce the ap-parently useless time spent by the feet at thetop and bottom of the pedaling stroke in bicy-cling, and correspondingly to increase themore useful time when the legs are goingdown in the power stroke. He found thatsome of his subjects, but not all, couldproduce a little more power with the ellipticchainwheel than they could before. Then hechanged the ergometer so that, instead ofthe rowing motion usually found in racingboats where the feet are fixed and the seatslides back and forth, the seat was fixed andthe feet did the sliding. This time all his sub-jects produced a perceptible increase inpower output. The reason was apparentlythat they did not have to accelerate so high aproportion of their body mass at each stroke.In normal rowing, after the oarsman hasdriven the oars through the water bystraightening out his legs and body, he mustthen use muscles to eliminate the kineticenergy produced with such effort in the body.Harrison investigated the effects of usingmechanisms which automatically conservedthis kinetic energy. He used various types ofslider-crank motions, like those of a piston inan automobile cylinder. He called theseforced, as opposed to the normal free,rowing motions; and he found that all hissubjects produced a substantial increaseover their previous best power outputs inrowing or bicycling. What is more, thisimprovement held for as long as the testswent on. One subject, apparently Harrisonhimself, could produce no less than 2horsepower (1.5 kilowatts of mechanicaloutput) for a few seconds, and a more-or-less continuous output after five minutes of ahalf horsepower, still 12 percent or so abovehis best output by other motions.This careful, scientific work enables us tolook with a better perspective at the use ofhuman muscle power in the past. Until Har-rison did his work, no one could agree as towhich muscle action was best to use for rac-

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ing or for steady, all-day work. Even now, sixyears after wide publication of his results, noone to my knowledge has grasped the sig-nificance sufficiently to apply this ne;w in-formation to ease the lot of anyone who hasto use muscles in his daily work or toincrease the speed of people who race. And,incidentally, other research by Frank Whitt inEngland has shown that power outputmeasured by ergometers may be sub-stantially lower than that produced by thesame persons using the same muscle ac-tions when bicycling or rowing because theabsence of the self-produced cooling windresults in dangerously overheating the body.As pointed out earlier, few of the motionsused historically to harness human musclepower incorporated any intrinsic cooling ac-tion. They were mostly of the slow, heavingvariety, so that our unfortunate forebearshad to cope with heat stress on top of the useof usually inappropriate muscles movingagainst resistances which were too large atspeeds which were too low. If in the futurewe run out of the earths stored energy andhave to resort to that of our bodies, weshould be able to look forward toconsiderably greater comfort while we areworking-if the results of Todern researchare applied.

The Manpower Plow of ShantungThis was, and possibly still is, a plowoperated by two men, one pushing and onepulling. Rudolf Hommel found it still beingused in China in the twenties. Shantung isvery much overpopulated, and poverty istherefore much in evidence. . . . [I]t is

therefore not surprising to find today a primi-tive plow, which for lack of draft animals hasto be served by man to pull it. There is abaseboard with a cast-iron share at one end.Two uprights are firmly mortised into thebaseboard, the rear one of which, farthestfrom the share and bent backward, resem-

Human Muscle Power in History

Figure l-l The Shantung plow

bles the handle of one of the ancient one-handled European plows, but is not so used.Instead of grasping the upper end of this up-right in his hands, as in the old western plow,the plowman, leaning forward and down-ward, presses his shoulder against it, whilehis two hands grasp the two projecting endsof a cross peg-handle driven through thelower part of a curved upright. Thus in a veryingenious manner, he not only guides butpushes the plow.For this arduous task, both plowmen usedtheir leg muscles, which are the most appro-priate muscles for the duty. The motions aretoo slow to be efficient (in engineering wecall this a poor impedance match), andmost of the other muscles and body frame

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Pedal Power

are strained painfully to apply the forceproduced by the leg muscles. One hopesthat it was used only in soft ground. In therocky soil of New England its use would beexquisite torture.I have started with this plow because wehave so good a description of it, completewith a knowledge of how it was used. In mosthistorical cases, we have just old illustrationswhich were made for purposes other than forshowing the details of the mechanisms or theprecise way in which they were used. Wecan usually guess intelligently enough. Butbefore we leave the manpower plow,consider how you would perform the sametask today. I know of no purchasable alterna-tive to the fork and spade-for either ofwhich my back has no great affection. Cer-tainly the Rodale winch described in Chapter

Three is a solid advance. W e will be discuss-ing various other alternatives in the chapteron futuristic uses of manpower.In the examples which follow, I am not at-tempting historical completeness: I havechosen them as interesting illustrations ofhow muscle power has been usedin the pastfor a variety of tasks. I am grouping them bythe muscles and motions employed.Handcranking

This is perhaps the most obvious means ofobtaining rotary motion, and man has beenusing i t for centuries. The earliest knownhandcranked device was a bucket-chainbilge pump found on two huge barges usedby the Roman emperors and uncoveredwhen Lake Nemi was drained in 1932.

Figure l-2 The bucket-chain bilge pump (Reproduced by permission ofDoubleday & Company, Inc.)


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Figure t-3 Bucket-chain water lifter (Courtesy of Friedrich Klemm)


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Pedal Power

Figure 1-4 Chinese endless-chain water lifter (Courtesy of Martha Hommel)Agricola, writing in 1556, showed a compli-cated handcranked transmission for driving asimilar bucket-chain water lifter. He alsoshowed a bucket-chain being assembled. Anendless-chain water lifter was also used inChina in much later times. It was different intwo respects. Instead of buckets, the waterwas trapped by boards sliding in a trough.One would think, however, that this would beless efficient because of friction and leakage.In addition, levers were attached to thecranks, with all the lost motion and top-dead-

center problems they entailed. Presumablythe levers were used to give a more com-fortable working position for the ground-mounted trough.Leonardo da Vinci shows concern for thecomfort of the user in his drawing of a textilewinder with a handle at a convenient heightand with a winder-drum of a diameter givingwhat will presumably be a near-.3ptimum rateof action. Leonardo uses gearing for thesame reason-obtaining a good impedancematch-in his design of a file-cutting ma-

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chine in which the crank is used to raise a One can imagine the difficulty of si-weight at a speed to suit the operator, and multaneously turning a high-resistance loadthe weight subsequently delivers energy at with a small crank in one hand while trying toan optimum rate to the drop-hammer cutter. control the cutting process with the left hand.An earlier crank-driven screw-cutting lathe Two much more modern examples ofwas obviously not designed by Leonardo. handcranking are taken at random from the

Figure l-5 Leonardos fiie -cutting machine (Courtesy of Friedrich Klemm) 7


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Figure 1-6 Screw-cutting lathe (Courtesyof FriecirichKlemm)

Science Record of 7872: the air pump for anundersea diver and what looks like a multiplestirrer for a nitro-glycerine-manufacturingprocess. These seemed to be low-torque ap-plications of muscle power. A high-torqueapplication which scarcely needs illustrationwas the old hand-wringer, which I used totry to turn for my mother. This was rathersimilar to the fifteenth century screw-cutting lathe in that while the right hand

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turned a heavy and fluctuating load, the lefthand had to perform a difficult andhazardous control function.A variation of the handcrank was used inChina in the form of a T-bar attached to thecrank. The use of this simple connecting rodenabled the use of both hands and/or oneschest or belly to contribute to overcoming theresistance.


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/ . .. .-. :; .. ..A

READY TO 00 DOWN.Figure 1-7 Air pump for undersea diver

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Pedal Power

Levers Actuated byArm and Back MusclesUntil the arrival of the sliding-seat scull,oars were moved predominantly through theaction of the arms and back. Battles amongwarships were won by the boat which could

pack in the most oarsmen. Ameinokles ofCorinth in about 700 B. c. built boats to ac-commodate three rows of oarsmen in a stag-gered arrangement on each side; with al-most 200 oarsmen, it could travel at sevenknots and became the standard battleship ofthe Mediterranean.

Levers Actuated byArm and Back MusclesUntil the arrival of the sliding-seat scull,oars were moved predominantly through theaction of the arms and back. Battles amongwarships were won by the boat which could

pack in the most oarsmen. Ameinokles ofCorinth in about 700 B. c. built boats to ac-commodate three rows of oarsmen in a stag-gered arrangement on each side; with al-most 200 oarsmen, it could travel at sevenknots and became the standard battleship ofthe Mediterranean.

At the other end of the warlike scale werethe pipe organs designed by Ktesibios inAlexandria in the third century before Christ.The air pump was a rocking lever whichcould be operated with two hands. Therewas little difference in the external ap-pearance, at least, from the hand-pumpedorgan used in our church in England when Iwas a boy. (My father fitted it with one of thefirst electric blowers used for the purpose, atleast in our area of the country.)Some tricycles were designed for leverpropulsion by the hands, the arms, andpossibly the back. Sharp showed a drawing

At the other end of the warlike scale werethe pipe organs designed by Ktesibios inAlexandria in the third century before Christ.The air pump was a rocking lever whichcould be operated with two hands. Therewas little difference in the external ap-pearance, at least, from the hand-pumpedorgan used in our church in England when Iwas a boy. (My father fitted it with one of thefirst electric blowers used for the purpose, atleast in our area of the country.)Some tricycles were designed for leverpropulsion by the hands, the arms, andpossibly the back. Sharp showed a drawing

blAE;lX'; h-ITIZO-GLTCEI:INli.Figure1-8 Nitro-glycerine factory


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Figure 1-9 Pipe organs (Reproduced by permission of Doubleday & Company, Inc.)


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Pedal Power

Figure l-10 Singer Velociman

Figure l-11 Erection of a massiveobelisk at the Vatican (Courtesy ofFriedrich Klemm)


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of a Singer Velociman. The arms pulledtwo levers which pivoted on swinging armsand operated the cranks of a transverseshaft. This drove the wheels through a chaindrive. The driver steered by pivoting the backrest. With this type of drive, the legs could at-rophy, as has been predicted if modern au-tomobiles become any more automatic. Thisvehicle flourished in the 1880s and 1890s.Much earlier than that, in 1821, Louis Gom-partz made a velocipede in which propulsionand steering were supposed to take placethrough swinging a lever over the frontwheel. The lever carried an arc with a rackgear that engaged a circular gear, pre-sumably on a free-wheel, on the front hub.

CapstansThe windlass or capstan represented anenormous improvement over most of theforegoing devices when maximum workoutput was to be given by human musclepower. It involved the large muscles of thelegs. The motions were those of walking,which must be at least reasonably efficient;and the motion speed could be varied simply

by using a smaller or a larger winding-spooldiameter. It seems likely, however, that infact slow, high-force pushing was used moreoften than the fairly rapid light-force walkingwhich modern research would show to bemuch more efficient.Capstans have probably been in use al-most as long as there have been ropes. Aliterally monumental use of capstans was inthe erection of a 360-ton obelisk at theVatican in Rome by Pope Sixtus V in 1586.Forty capstans were used, as well as 140horses and 800 men, in a military-typeoperation.

TreadmillsOf the devices so far discussed, treadmillsare the nearest approach to true pedal

Human Muscle Power in Historypower. They seem to be at least as ancient.Varieties of treadmills were in use in Meso-potamia 1200 years before Christ. Theycontinued in use in Europe at least until1888, when the last treadmill crane on thelower Rhine ceased operation, but they werestill being used in China at the time of Ru-dolf Hommels stay there in the 1920s.Treadmills had the same advantages ascapstans. The motion was walking, and thegear ratio could be easily adjusted to be nearoptimum (but probably seldom was). Sometreadmills shown in Agricolas 1556 book onmechanics and mining looked exactly thesame as capstans except that the radialhandles were fixed and the circular walkwayrotated. No doubt this improved comfort andperformance in long-duration work becausethe power plant was less likely to becomegiddy.A variation of the capstanlike treadmill wasone with the rotating footwheel inclined.Rather than continually pushing on a bar toforce their feet back, the men on an inclinedtreadmill moved as if they were climbing anendless ramp or flight of stairs. Their weightwas usually enough to carry the wheelaround, and the horizontal bar was less forpushing against than for steadying theoperator(s). One disadvantage of the in-clined treadmill was that, whereas in a hori-zontal mill several men could all push atonce as on a capstan, only one person couldbe located in the optimum position of an in-clined treadmill.Most treadmills were of the squirrel-cagevariety, and, in fact, various animals fromdogs to horses were frequently used. Butwhen tasks requiring close control, such aslifting weights in a crane for buildingconstruction, for instance, were called for,men were more usually employed. Thus menworked treadmills in winches and cranes,and animals were used in devices poweringirrigation pumps or forge blowers.Leonardo da Vinci, as usual, has the lastword on ingenuity. He designed a treadmill to

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Pedal Power

fKotlI1oyfz~e, l?,5ctline pow la x;n-~uc SUf .!nvutlL*c cFigure 1-12 Handcranked machine used in marking metal coins(Compliments of Lehigh University, Honeyman Collection)

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bend and cock four crossbows mountedradially on the inside of the wheel. A singlearcher loaded and fired each in turn: it was atype of Gatling gun or revolver. The wheelhad unidirectional, comfortable-appearingsteps on the outside of the wheel for theseveral people to use when supplying themotive power. This must have been a supe-rior position to being cooped up inside awheel in an often-cramped position. Leo-nardo took pains, too, to protect the workersas well as the archer with armor. Most ofhis designs were never made; we dontknow if this repeating crossbow was, but itis doubtful.We can see from the accompanyingexamples from The Encyclopedic desPlanches (1751) by Denis Diderot and JeanLerond DAlembert that the European work-shop of this period used handcrankingdevices to a considerable extent. While insome cases the method appears to fit thetask, in others, such as in the scenes from anopticians studio and from a knife-cuttingshop, handcranking appears to be woefullyinadequate. On the other hand, theeighteenth century workshop had some verysensitive machines, such as the one for en-graving fine stone. Note the application ofthe treadle and the flywheel.

Legs on TreadlesThe application of leg muscles to treadlescan be roughly divided into two categories:that where low power was required and thehands were required to perform an accuratetask, such as in treadle sewing machines,and those in which maximum power outputwas desired, as in certain types of cycles.Treadles often provided energy in the low-power category in a reciprocating manner.We have, for instance, illustrations of abowstring boring machine used for drillingpearls for necklaces and a foot-operatedlathe with bowstring and overhead cantileverspring, both dating from the fourteenth

century. The Chinese used treadles to obtaincontinuous motion for cotton ginning andspinning, but the treadles were almostcranks. One end of the treadles wasmounted in a universal bearing at near floorlevel, while the other was fitted in anotheruniversal bearing eccantrically on the drivewheel. Apparently both feet would be usedon on& treadle, because the wheel wouldgenerally be inc!ined to give a favorableangle to the treadle on one side and wouldmake ihe use of a treadle on the other sidevery difficult.The use of treadles for maximum poweroutput has been principally in their applica-tion to cycles. They were generally con-nected to cranks on the driving wheel. Thefirst pedaled bicycle, made by AlexanderMacmillan in the period 1839-l 842, was ofthis type. Tricycles and four-wheelers oftenused this system. But the American Star,which was introduced in the 1880s as a saferversion of the ordinary or penny-farthing,used a strap going from the foot-levers to aspool on the wheel. The spool was mountedon a one-way clutch or free-wheel, with aspring tending to wind up the strap. The ridercould push down on the levers together or al-ternately to propel the bicycle forward. Thediameter of the spool controlled the gearratio, so that there was, in fact, no need forthe manufacturers to use a-dangerous highwheel at all. The American Star was apromising development which was, however,eclipsed by the small-wheeled chain-drivenpedal-and-crank safety bicycle.

Leg Muscles Used in CrankingJust as the high-wheelers were eclipsedby safety bicycles, so the lever propulsionsystems which some of them used disap-peared, and during the 1890s the pedal-and-crank drive became almost universal. Theessentials of the safety bicycle in almost allits aspects had been developed by the turn

15


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Pedal Power

f.i.7 .i lid - + 5 P&J I lb I..4 -- .\

---+ _ -. -a- .-.9-.s ,.e-

H H n I\

- - ------------ ---- - -a. A .:, &K 1. .i

Figure 1-13 Opticians studio (Compliments of Lehigh University, Honeyman Collection)

16


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II_-.- -

1 z 3 ; ILLr IIIL -11n,.v./ ,,Figure 1-14 A machine for cutting and sharpening knives(Compliments of Lehigh University, Honeyman Collection) 11


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Pedal I

Figure l-15 A machine for engraving fine stone (Comp liments of Lehigh UtIiVerSity,Honeyman Collection)18


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-- -hZ% /l 1 i.___~--_- ---. - - --- .n. I). d I, d

Figure l-16 Treadle-powered lathe for making spoo!s of thread (Compliments GfLehigh University, Honeyman Collection)19


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Pedal Power

of the century-even derrailleur gears hadarrived-and it has reigned almost un-challenged since then.One can believe, with the benefit ofhindsight, that so obvious a system as ped-als and cranks must have been used formuscle-power applications before the adventof the bicycle, but I have been able to find norecord of them. It is possible that the designof a cantilevered pedal with low-friction bear-

ings to take the large forces which can be ap-plied by a heavy, muscular man was too dif-ficult for the low-strength materials whichwere available earlier.Once pedals and cranks had beendeveloped for bicycles, however, they beganto appear in many other applications. Racingboats were built and were easily able to beatthose manned by trained oarsmen. Pedalswere applied to tools like lathes, saws, and

20

Figure 1-17 Bowstring-operated boring machine for preparing pearls for necklaces(Courtesy of Friedrich Klemm)


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pumps. Many attempts have even beenmade to fly a man-powered airplane. Thepropulsion system in every known case hasbeen by standard bicycle-drive components.Whether the standard bicycle arrange-ment is optimum is often a matter of heateddebate. The proponents of the standardsystem reject all challengers. In 1933 a so-called Velocar was introduced in France. Itwas a bicycle in which the rider sat, or lay,

behind rather than over the cranks. It brokeall cycling track records according to a newsstory but was later banned by the Interna-tional Cycling Union on the grounds that itwas not a bicycle. We are lucky to havepeople whose minds are more open nowa-days. Dr. Chester Kyle, running what has be-come an annual world speed-record event atLong Beach in California, allows any type ofhuman-powered vehicle to enter. The variety

Figure 1-18 Foot-powered lathe (Courtesy of Friedrich Klemm)


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Pedal Power


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Figure l-20 The American Star

Figure 1-22 Velocipede powering a sew-ing machine (U.S. Bureau of Public Roads,Photo No. 30-N-41 -356)

23


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Pedai Power

24

BICYCLE EXEBCISES AT LEIPZIt3.Figure 1-21 Bicycle exercises at Leipzig (U.S. Bureau of Public Roads,Photo No. 30-N-33-44)


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Figure l-23

Figures l-23 and l-24 Renditions of two of the numerous patents forrailroad bicycle attachments

of the initial contestants machines has beenextraordinary. Out of these contests theremay emerge methods of using the legmuscles with greater effectiveness, not onlyfor superathletes competing for the glory ofbeing fastest, but also for those who labor atmore mundane intensities.

Pedal Power in the WorkshopWith the invention of the bicycle came averitable avalanche of pedal and treadle ma-

chines. The bicycle influenced all aspects oflife: work, sports, leisure, and transportation.Errand boys, policemen, and post officeworkers discovered that the bicycle madethem mobile or more efficient, Women, solong tied to the home and garden, foundsome liberation in the two- and three-wheeler. And the sports world, which wor-shipped the speed of the trotter and racehorse, turned to the bicycle racer, whopromised undreamed-of speeds.Resourceful Americans and Europeanstried to adapt the principle of the bicycle to all

25


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Pedal Power

Figure l-24

Figure 1-25 Rendition of a patentfor a treadle grinding wheel

___. ._.,,.__ ..


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Figwe 1-26 Primitive cotton factory in Alabama-ca. 1890 (Culver Pictures, Inc.)

parts of the home and workpiace. Some ap-plications, depicted in the etching of anexercise velocipede, were fanciful. Butothers were not. Consider the drawing of avelocipede powering a sewing machine. Theartist, who was perhaps parodying the high-riding racer, reveals quite accurately thework potential of the bike. And consider thepatents for railroad bicycle attachments, aconcept which is being revived today (seechapter six). The patent office was alive withdesigns fo r countless applications for pedalpower.

Ail in ail, the bicycle seemed to present thepossibility of humanizing the workplace, ofrelieving men and women ,f some of thedrudgery associated with arduous tasks.it is unlikely that we will ever know the fullstory of pedal power at the turn of thecentury. We do know, however, that nationalmail-order companies, including H. L.Shepherd 81 Co., W. F . Barnes & Co.,and the Seneca Fails Machine Company,lost little time in applying features of thebicycle to uses in the home and workplace.The accompanying catalog reproductions of

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Pedal Power

NO. 1 AMATEURSAW.

NO, 6 AMATEUR SAW.We otfcr this mnchine, believing it to embodyall tl1:i.t thr rnt,& r.ritic::tl (~11&%irla. It, will cut

pint* of ;111yl~ic*ltnr++ 111, 0 I):W il1t.h. :~ucl harder~oo~lr 111~~q~c~~ion;ttr thic.knr+$. It admits aswill of Iti in(.lies :tr~a~nd thea I~ladr, ~111 \vill&;LWant1 drill ivory. lbonr. metal, shells, etc.

Tht? bl;~cle II;M h;udenell +tt!el clamps OKI lideswhir.h move in l)rrm:lnr*nt qidew:r)-s. ahove;tutl heloW the table. giving x positive aIld &C-ctnxtr motion.

Thr tnblr has iL beveled adjustment, wherebyit can l)r srt for inlaying. mosaic and otherwork.

The pricy 111he Ill:t~.hint~ unuplete is $12. Theprice w?thrmt ISr,riny Attachment is 810.It weighs -lib pouncls. Boxed ready fnr ship-

ment it wr-righs W~~M~WI~~C.We int.lrltlt~ alp tlrcwn 111;u11*~vith f.:lr.ll Ill:L-

chiue.

This machine will cxt pineof any thickness up to 11;inches, and h:trdtbr woocis ofproportionate thic.knrssrs. Itadmits a swing of 18 inchesnrcnmd the hliltlr. and nc-complishes every br:lnc,h ofsawil1.q xithin thrb range ofgeneral ;unnteur nnrk.

The table does not tilt. asin No. B Aniateur SiV . lblltsawing for inlay work rxn 1~done by plnrinr: :I I~vrlr~l .strip nnder the stuR beingsawed.The price of thr machine(aomplete is bl0.W.The price of the machinewithout Borinfi Attachment

is WOO.It weighs -ll~poumlr;.Boxed ready for shipmentit weighs NJ ~~UIXIS.

Figure l-27 Amateur saw, 1892 (Eleutherian Mills Historical Library)

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SGROLLSAW NO. 7 IMPROVED,4Formerly Called Large Size Scroll Saw.

Price, $xg.oo.

Figure 1-28 Scroll saw, 1892 (Eleutherian Mills Historical Library)


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Pedal Power

VELOWEDE SGROLLSAW NO, 2,--improved.Price, Complete, $23; Without Boring Attachment, $20.

b-----

-

-- /Figure l-29 Velocipede scroll saw (Eleutherian Mills Historical Library)

30


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FOOT OWERORMER,--Ivroved.

Price #20.00. Knives Extra.

Figure I-30 Grinding wheel (Eleutherian Mills Historical Library)


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Pedal Power

Lathe No, 4,7cInch Swing.Price, $40.00.

32

When ordering lathes, be particular to state clearly whether wantedwith foot power or counter-shaft; if with foot power, state whether veloci-pede or treadle.Figures 1-31 through 1-34 Pedal-powered lathes and descriptions(Eleutherian Mills Historical Library)


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Lathe No, 4,7-Inch Swing.

HIS lathe is designed for turning both wood and iron, and for boringdrilling. polishing, etc. It is a desirable tool for small work, antihas many important advantages in the construction and arrangementof its parts. It swings 7 inches and takes 90 inches between centers. Ithasour patent velocipede foot power, which is the best power ever applictlto a foot-driven lathe. The speed can be varied from 1,000 to 2,000 revolu-tions per minute, and the motion can be started, stopped or reversedinstantly, at the will of the operator. Greater power can be applied onthe work than with any old-style foot power, and with greater ease. Thelathe is made entirely of iron and steel. The bed is solid, and hasV-shaped projections, over which tht head and tail s tocks and hand andslide rests are fitted. The lead screw for the carriage is operated byhand; by it the carriage can be traveled 20 inches, the entire distancebetween centers. The carriage can be engaged or disengaged instantlyfrom the lead screw. The cross feed way on which the tool post moves canbe set at any desired angle for taper turning and boring. The tail stockcan be moved and set at any point desired by the simple turning of thehand-wheel; or it can be taken off entirely, thus leaving the bed free forface-plate or chuck work. The head stock spindle is hollow, size ofhole 3ss nch. The head stock spindle has taper bearings, and is capableof very nice adjustment. The tail stock center is self-discharging.The price of the lathe is $40.00; this includes face-plate, two pointedcenters and one spur center, hand rest, wrenches and necessary belting,as shown in cut.The lathe weighs 210 pounds.

Boxed, ready for shipment, 265 pounds.

The above cut represents a countershaft for No. 4 and 4% lathes.The pulleys on countershaft are 7x1s inches, and should be speeded250 revolutions.Price of countershaft, $15.00.We can furnish lathe with countershaft in place of foot power at sameprice as with foot power.Figure l-32

33


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Pedal Power

Screw Cutting Lathe No, 4/,,9-Inch Swing.

Price, $65.00.

When ordering lathes, be particular to state clearly whether wantedwith foot power or countershaft; if with foot power, state whether vrloci-pede or treadle.

Figure 1-33

34


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Screw Cutting Engine Lathe No, 6,13-I&h Swing.

When ordering lathes, be particular to state clearly whether wantedwith foot power or countershaft; if with foot power, state whether veloci-pede or treadle.

Figure 1-34

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4

I\: REFERESCE TO TIIE $54 SCREW Cl.TTISGL.\TIII?.PORT I!I.R~s, AI ICI:., Dee. 26. :S;6.

MR. Il. L. SHEP.\RD, .Dmr Sir: I have delnrd writing to Lou hefore as I wishedto trr the Lath-z hefore aayb;1:: anything ahout it. It nnswerfi allmu &wcttltions and is that best Lathe I ever GI\Y for the money.Scvrml mechanics (h raring I had the Lathe) have c;tlled to reeit and all speak farombly of it. You RF expect 3 lOW ordrrss000. Resptxztfullv vouwc.\i-. l),\SGER.L. S. Survey, Port IIuron, !Uich.

SIR. II. L. SIIEPARD,ACSTIS, ILL., Dw. 26, ISib.

I an ver+v bully disappointed in *ny Lathe. Taking thePrice into consideration. I expected to get n light build shakymachine. but in?;trxd I have a reallv wad rmall size EngineLathe. The Self Feed for Metal T&i%g is n qrcnt feature. andwork?; splendid!!. I prett!- thoro!l;qhIy tested iis vnlue in turnin:out a Spur Center from a piece ot rnch steel. which I did withoutdifficulty. I cowidcr it n hcttcr Tool than I ever saw before fortwice the money. and am entirclv ?;nti&.i with it. You nutsuse ny name in any wan yoo &tie. end rcfir to me and I wiilbe happy to an.wcr hy mail an?- intluirie~ that may be made. andwill elao exhibit the Lnthcto ROY one calling cm me. llopin:: Imay influence othera to pntroni;e you. and wishing for your en-tire success in J-our enterpriw. I remain pours ver! trulr,Austin, Cook Co., Iii. AL J. F.\RRcLLI:, P. M.

Figure 1-35 Letters from users of foot-powered machines (Eleutherian Mills Historical Library)foot-powered lathes, saws, and grinding was not improved; few explored additionalwheels reveal a remarkable simplicity of pedal-power possibilities.design. Some of the machines seem very For close to a century in the industrializedmodern in design. The screw-cutting world the application of human power tolathes represent a genuine maturity of transportation and useful work was seldomdesign which is not far removed from that of contemplated. However, decades ofthe machines used in countless workshops mechanization and pollution have led us totoday. reconsider human muscle potential.If the bicycle represented a revolution of Ironically, as developing countries strain tosorts, so did the manufacture of foot-power give up their bikes and pedal-power equip-tools which inaugurated, in a small way, the ment, industrialized countries are givinghome workshop, where even the unskilled more and more attention to these items.could perform certain machine tasks with ac- Hopefully, all countries will reconsider thecuracy. enlightened use of pedal power. The highUnfortunately, the internal combustion costs of energy and the failure of our trans-engine retired, for the most part, bicycles and portation systems make such reconsidera-pedal-power machines. The bicycle design tion imperative.

36

5l..\lK 1l:sl11Io~l.\i,li \\1IICll .slI.:.\K 101;1III~:\I~I~:I.\ 1-h.

--1. ., $ cc .\ RC I; 1.Y ,I


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ARCHIMEDESSCREWTurn the riveron its backdig a peep holeto China.

James C. McCullagh

CHAPTER TWOPedal Power on the Land:The Third World and BeyondBy Stuart S. Wilson

It is arguable that the most imnortantdevelopment, technically and socially, in thenineteenth century was the bicycle. Pre-bicycle technology was heavy and ineffi-cient-typically the steam locomotive-butpost-bicycle technology became lightweightand efficient, both structurally andmechanically. Witness the lightweighttubular steel frame, wire spoked wheel, bushroller chain, ball bearings, and pneumatictire. All these, developed specifically for thebicycle, led to a triumph of ergonomics-matching the machine to the human being-which explains why the bicycle has suc-ceeded so widely in providing cheap and ef-fective personal mobility for all, worldwide.Unfortunately it also led to the develop-ment of the automobile, which has had sucha disastrous effect on our way of life in thetwentieth century, yet the signs today arethat the automobile has passed its peak

while the bicycle continues its steady upwardtrend-a tortoise and hare situation.In energy terms the reason the bicycle isso efficient is that it uses the most powerfulmuscles in the body-the thigh muscles-inthe right motion, a circular pedaling motion,at the right speed, 60-80 revolutions perminute, and then transmits the power effi-ciently by means of a sprocket-and-chainmechanism and ball bearings.The torque or turning effor t exerted by thefeet on the crankshaft and therefore on thesprocket and chain are not constant, beingappreciably smaller but not zero at the topand bottom positions of the pedals.This minimum torque is achieved partlyby ankling (tilting the top foot upwards andthe bottom foot downwards), partly by frictionof the shoes on the pedal rubber, or by theuse of toe clips. The minimum torque varieswith individuals but is of the order of one third

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Pedal Power

of the maximum. On a bicycle this variationhas little effect because of the inertia of therider and machine; but if we consider drivinga stationary machine, for example a pump ora corn grinder, then the motion becomesjerky and it is desirable to even it out, eitherby incorporation of a flywheel or by othermeans, such as the use of an ellipticalsprocket, which in effect varies the gear ratiotwice during each revolution of the crank.How much power can we expect to be ableto supply by pedaling? Tests done underlaboratory conditions do not relate too well toexperience on the road, but tests at Oxfordon a bicycle with a built-in dynamometerconfirm that 1 lO horsepower or 75 watts is areasonable figure for the sustained output ofan average rider at a road speed of 12 mph.On the other hand, V4 horsepower, or nearly200 watts, is produced at 18 mph, whichmany riders can achieve at least for a limited

time; and up to 1 horsepower or 750 watts ispossible for a second or so.These figures reveal a remarkable over-load capacity of the human body-theability to exert 10 times our normal outputwhen required. The question is how to applythis muscle power to useful ends other thanpersonal transport as with the usual bicycle.In particular, how can we develop ways andmeans of helping people to help themselves,in rich and in poor countries, by their own ef-forts, without depending on expensive oilfuel?

TransportationLet us first consider extensions of bicycletechnology to goods transport. The carrierbicycle with a large basket over the frontwheel is effective for loads of up to 100 lb. or

Figure 2-l Tricycle used for transportation of goods in Taiwan38


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-... -

Fii ure 2-2re 2-2Yii Bicycles remain a popular transportationicycles remain a popular transportationvee lcle in Taiwan and many other countries.cle in Taiwan and many other countries.

:_>-~ ., ..>.,I.,. .._ -.,:

Pedal Power on the Land: The Third World and Beyond

so. Beyond that, however, three wheels arebetter than two and have been in use sincethe nineteenth century, but have hardlyevolved. A modern attempt to rethink thedesign is shown in Figures 2-4 through 2-P Itwas designed by the author and built at Ox-ford with support from Oxfam, the well-known international charity. Named the Ox-trike, it is designed as a basic chassis with achoice of bodies to carry a variety of goodsor people up to a payload of 330 Ibs. (150 kgor 3 cwt). It incorporates a number of novelfeatures in order to overcome some of thelimitations experienced with existing designsof cycle rickshaw (pedicab, becak, or trisha)in current use in India, China, Indonesia, andSoutheast Asia. Although a variety ofdesigns have evolved in these different loca-tions, there is little evidence of radicalredesign in order to improve performance.The main defects of existing designs in-clude the use of only a single gear ratiowhich is often too high, so that starting on the

Figure 2-3 Foot-powered trolleys are a common form of transportation in the Philippines.39


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Pedal Powerlevel or climbing a gradient imposes a severestrain on the driver; usually only one wheel isdriven, while braking also is confined to onewheel-a dangerous defect. The use of stan-dard bicycle parts often results in insufficientstrength for the far greater loads imposed,leading to the collapse of wheels or forks un-less specially strengthened. The frame itself,of tubular construction on bicycle lines, canbe regarded only as a less than optimumdesign with regard to strength-to-weightratio.Despite these defects, the various types oftricycle have established themselves widelyin Asia, though not in Africa, but they arefighting a losing battle in some of the biggercities, such as Singapore and Jakarta. Someauthorities wish to banish them on thegrounds of lack of safety, causing conges-tion, and lack of a modern image. To abolishsuch a useful , low-cost, low-energy, low-

Figure 2-4

noise, and low-pollution vehicle would de-prive the poor and middle classes of a mosteffective means of transport and causeconsiderable unemployment amongstdrivers and associated trades.Since the tricycle holds exciting promisesfor both developing and developed countriesalike, it seemed worthwhile to rethink thedesign with a view to maintaining or extend-ing tricycle use. The authors first experiencewith tricycle building was the design andconstruction of the cycle rickshaw. This in-corporated a simple form of differential gearto allow both rear wheels to be driven but forthem to turn at different speeds when round-ing a corner; it also showed up the commonproblems of weakness in the wheels andfront forks and lack of braking.However, it helped to convince Oxfam ofthe potential for an improved tricycle designand resulted in their financing a technician to

Oxtrike chassis


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build two prototypes of the new Oxtrike.What follows are some of the major featuresof the Oxtrike.(1) The wheels chosen were of 20inches in diameter, largely for the sake ofgreater strength. The rear wheels are Ra-leigh Chopper type (20 x 21/s), thestrongest wheels made by that firm. They areespecially strong against side load, a re-quirement which does not arise on a bicyclebut is a very real problem on a tricycle. Thefront wheel (20 Y 13~6) and fork are of thecarrier-bicycle type and are designed tocarry a large load which is forward from theframe over the front wheel.

Figure 2-5 Up-ended view of Oxtrike chassis showing abilityto park in a small space, easy inspection of transmission andbrakes, and ability to tip out the load. Note Sturmey-Archerthree-speed hub gear with double adjustment for primary andsecondary chains.

Further advantages of the 20-inch rearwheels are a general lowering of the centerof gravity of the load (but giving adequateground clearance), easier access by elderlyor infirm passengers, and a full-width rearseat without an increase in the overall ve-hicle width, which is only 36 inches. The useof small wheels also reduces the overalllength of the tricycle to just over 6 feet 7inches.(2) A three-speed gearbox is incor-porated into the transmission system; thisgearbox is a standard Sturmey-Archer humgear, a well proved, reliable design. It is usedas an intermediate gearbox, as on many mo-torcycles, with a primary and secondarychain. The sprockets are so chosen that theoverall gear of the Oxtrike is 311/z nches inbottom gear, 42 inches in middle, and 56inches in top. These compare with 661/2inches for a normal bicycle with 26-inchwheels and greatly improve the driversability to start with a heavy load and to climbat least a slight gradient, thus improving therange and mobility.(3) Since good brakes are essential forsafety, particular attention was paid to thisproblem; the front brake is the standard pull-rod stirrup type, but the rear brakes are in-board band brakes applied by a foot pedal.This is a powerful and effective method ofapplying a braking force: each wheel has itsown brake drum, mounted at the inboard endof the half-shaft, and the braking effect is ap-plied equally by means o f a balance bar. Thislocation of the brakes ensures that they areprotected from the rain, essential for safety inwet weather. The brake pedal can be helddown by a lever catch to act as a parkingbrake, a very necessary feature on a tricycle.(4) Since the construction of a normalbicycle frame is a fairly complex matter,involv ing thin-walled tubing brazed into spe-cial sockets, it is not really suitable for small-scale local manufacture except by the im-portation of the tubing and sockets. Suitablesockets for tricycle construction may well not

4.1


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Pedal Power

Figure 2-6 Back axle drive of Oxtrike

be available. For this reason the Oxtrike wasdesigned to use mild steel sheet of a stan-dard thickness. This can readily be cut on afoot-powered guillotine, folded on a hand-operated folding machine, and joined by al-most any method of welding, brazing, orriveting.(5) A variety of bodywork types havebeen designed, including a two-passengerrickshaw with a multiuse body having ahinged tailboard. When lowered, the

tailboard allows two passengers to sit facingbackward; when raised, it provides for threechildren to sit facing forward or for the car-riage of goods. Larger loads may be carriedwith the tailboard horizontal.The chassis can be fitted with a simpleopen truck body or an enclosed box body forcarrying parce!s, etc. A hopper body withsloping ends would be suitable for carryingsand, gravel, or other loose material; the sizeof the hopper would be restricted to prevent

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Pedal Power on the Land: The Third World and Bevond

Figure 2-6 Oxtrike with temporary seat

Figure 2-7 Hand-powered machine formaking rolling section

Figure 2-9 Neo-Chinese wheelbarrowwith 4-foot-diameter wheelof sandwich construction


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Figure 2-10 Rotary hand pumpconnected to pedal operation,mounted on fully adjustable slid-ing-seat (Courtesy of AutometrucPumps, Ltd.)

overloading. Finally, a 40-gallon drum can befitted for carrying liquids.For rougher going, where a four-wheel-drive vehicle such as a Jeep or Land Roverwould normally be required, a vehicle is be-ing evolved named the Pedal Rover. Itconsists of four large-diameter wheels ofabout 44 inches, each directly pedaled byone of the crew. The front and rear halves ofthe vehicle are articulated to allow bothsteering and twisting of the two halves as inmodern dumper trucks. It is expected that apayload of 500 to 600 lb. could betransported in such a vehicle.Even simpler and more versatile is a new-Chinese wheelbarrow, using a single large-diameter wheel under the load rather thanthe usual small-diameter wheel in front,which leaves too much load on the handlesand makes tipping difficult.Two-wheeled garden carts are availablewith a 26-inch wheel on either side. Theseare adequate on smooth ground but tend toyaw badly on rough going; a single wheelcannot be thrown off course and enables

Figure 2-11 Two-man dynapod built by Alex Weir44


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even the narrowest of footpaths to be used.Rolling resistance is reduced by using areally large diameter wheel. Figure 2-9shows a 48-inch wheel in a prototype built forthe Rev. Geoffrey Howard who later crossedthe Sahara, 2000 miles from north to south,pushing a load of up to 350 Ibs.singlehanded and averaging over 20 milesper day.For general garden use, a simple and ef-fective design can be built with a 26-inchdiameter bicycle wheel and tire underneath athree-sided tray-type body. Although higherfor loading, unloading is easier, especially ifa brake can be incorporated to stop the bar-row running forward when tipping.

Stationary Pedal PowerTurning to stationary uses for pedal power,three approaches are possible. A hand-cranked device such as a corn mill may befitted with pedals and arranged with a suit-able seat for direct pedaling. Figure 2-10shows a rotary hand pump of the sliding-vane type mounted on a low wooden trestle

or horse which is fitted with an adjustableseat; normally only horizontal adjustment isneeded for varying lengths of leg. Thoughnot quite as efficient physiologically as thenormal saddle above the pedals, this ar-rangement may prove convenient for manypeople.

The DynapodThe second approach is to design a basic

stationary pedal-power unit or dynapod(from the Greek for power and foot)which can then be hooked up to any devicethat needs to be driven. A design for such adynapod was put forward in 1968 but wasnot built at that time, although Alex Weir fromEdinburgh University built one-man and two-man units at Dar-es-Salaam in Tanzania. He

used as a flywheel an old bicycle wheel inwhich the whole of the space between thespokes was filled with cement. Later AlexWeir made other types of pedal units in Dar-es-Salaam, using square-section tube for theframework. He used them to drive corngrinders and a winnowing machine.Among the machines which could bepedal driven by means of a dynapod is notonly a wide range of hand-driven machines,pumps, corn grinders, forge blowers, grind-ing machines, etc.-many of which may bebetter converted to direct pedal drive-butalso a great number of machines such aspotters wheels, drilling machines, and hori-zontal grinding wheels, which are not nor-mally hand driven.Figure 2-12 shows a commercially avail-able maize sheller which is driven by a verysimple but effective form of bolted-on pedaldrive unit. It is sold in several countries inAfrica and can shell two cobs at a time. Aheavy cast-iron fan serves both as flywheeland as a winnower to blow away the husks.The problems of optimizing pedal powerfor stationary use are several. The prob-lem of the cyclic torque has been mentioned,but another is the need for a rigid strutbetween the driving and driven sprock-ets to take the pull of the chain, which can beroughly twice the riders weight. There mustalso be some provision for adjusting thechain. A less obvious need is to keep therider cool in the absence of forward motion.The Chinese, who have used a simple formof pedal power for hundreds of years, usuallyprovide a roof over the pedalers for shadeand to keep off the rain. It might actually beworthwhile to use a small part of the power todrive a fan to keep the rider cool.The Winch

The third approach to using pedal power isto design the equipment from the start forpedal drive. An example of this is the pro-totype of a two-man pedal-driven winch


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Figure 2-12 Commerc ial maize sheller (Courtesy ofRansomes Sims & Jefferies Ltd., Ipswich, England)

Figure 2-13 Commerc ial maize sheller in use in avillage in Africa (Courtesy of Ransomes Sims &Jefferies Ltd., Ipswich, England)

shown in Figure 2-15, which is based on theuse of two automobile flywheels. The lowerone carries the winch drum and is driven bymeans of the starter gear ring meshing with astarter pinion on a shaft above. This shaftcarries two small fixed sprockets, each con-nected by a chain to a normal bicycle-typechainwheel and pedals, arranged in such away that the two sets of cranks are at rightangles to each other in order to smooth theoutput.The shaft also carries a second flywheelwhich rotates sufficiently fast to store appre-ciable energy in order to overcome any sud-den snag in the load being winched. Thegear ring of this second flywheel can be fittedwith a pawl to form a ratchet mechanism andprevent the load running backward. Forlowering a load the pawl ring may be disen-gaged and the load lowered under control bymeans of the braking action of the pedalsand also of a caliper-type brake acting on thesecond flywheel.The whole unit is mounted on skids so thatit can be moved sideways when the ped-alers dismount; but when they are ped-aling, their weight helps to anchor the winchfirmly so that the cable can exert a powerfulhorizontal pull. Apart from the obvious usesfor such a winch in excavations and load lift-ing, the major use on the land is for cable-cultivation, an old principle in which the mo-tive power for plowing or other cultivation isstationary and only the implement movesacross the field. (See the Rodale winch inchapter three.)Advantages are as follows: a saving inenergy, since the motive power-human,animal, or machine-does not have to wastepowe; in moving itself over the soil; avoid-ance of soil compaction, one of the worstfeatures of using a big tractor; the ability towork even waterlogged ground, as can beseen in China, using an electrically drivenwinch. For nearly 100 years steam cableplowing was the only mechanized method ofagriculture. Small engine-driven winches are

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Figure 2-14 Early prototype of a dynepod, w!ichcould be geared down for something hke a winchor geared up for a winnowing fan.

Figure 2-15 Prototype for two-man pedal-driven winch

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Pedal Power

used on small steep plots in France and Italyfor hauling a plow up a slope, the plow thenbeing dragged down again by hand. At theNational College of Agricultural Engineeringat Silsoe in Bedfordshire, a recent develop-ment is the Snail, an engine-driven mobilewinch which is driven along on two wheels,paying out the cable. The winch then stopsand hauls in the cable and the process isrepeated.The pedal winch should be capable oftackling much the same type of work, andwhere manpower is plentiful, as in most less-developed countries, a two-man winch canbe used at either end of the plot. The ped-alers could have a rest in the shadebetween spells of hard work! Hand-pushedplows, cultivators, and hoes are availablewhich would be suitable for cable tractionwith little or no conversion.

Figure 2-16 Foot-operated diaphragm pumpdeveloped by the International RiceResearch Institute

Pedal Drives forIrrigation PumpsIn Bangladesh and other parts of the ThirdWorld a requirement exists for pumping

water from a river to the fields. The foot-powered pump developed by engineers atthe International Rice Research Institute inthe Philippines can lift large quantities ofwater several feet using only moderateamounts of labor. The operator simplystands on two foot rests at either end of thepump and rocks back and forth. That effortcompresses a diaphragm which forces waterfrom the outlet va lve. By operating the pumpin a rhythmic manner, a continuous flow ofwater is pumped. This is quite an efficientunit.Efficient as the bellows pump is, it isperhaps possible to propose a pedal-drivenirrigation pump, particularly one that couldleave water at considerable heights. Furtherrequirements would be:(a) low cost but long life with minimummaintenance,(b) use of local materials or standardbicycle parts,(c) portability (the pump must not onlyaccommodate to varying river levels but becapable of being moved to different sites as

\--Handlebar

II1Water-I-- ^.

line--Inlet valve

Figure 2-17 Schematic drawing o f a bellows pump

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required and perhaps dismantled and storedduring flood times),(d) use of pedal power rather thanmanual operation, since it is two to threetimes more effective, and(e) if possihle, a two-man operationrather than one, for increased and smootheroutput as well as for social reasons.

Figure 2-18 Chinese tric cle water pump inwhich wheels also serve as lywheels

Figure 2-21 shows a proposed design oftwo very traditional elements in a new way.The pedal unit is of a type used in China forhundreds of years and still in use for a varietyof purposes, including low-lift pumping bymeans of a square pallet chain pump. Thistype of pump is not altogether suitable forBangladesh and similar areas because at

Figure 2-20 Close-up of Figure 2-l 3

Figure 2-19 Chinese wooden water pump used for raising sea water into salt-evaporation beds


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Water level_ -. . ._., .:- .. ,,,. .

Flexible shaft

Figure 2-21 Prototype for a pedal-driven Archimedes screw

low-water levels the distance from the bankto the water may be 10 meters or more; also,the construction is complicated and difficultto transfer successfully.Hence another very traditional device issuggested, the so-called Archimedes screw,which probably originated in Egypt beforethe time of Archimedes and is still in use boththere and in developed countries for certainspecial purposes. It is said to be up to 80percent efficient.One method of constructing an Archi-medes screw is to coil up a circular sectionpipe into a cylindrical helix. It is known thatthis form was used long ago, but it is notclear what materials were used. A modernversion could be made using thin-walledplastic tubing; a particular type has recentlybeen evolved for field drains, in which thetubing is corrugated with a fine pitch tostrengthen it and to allow coiling to a smallradius. Although this is normally perforatedwith a multitude of fine holes, if it could beobtained unperforated, it could form thebasis of a simple low-cost pump, since therest of the construction could be done locally.

For example, a stout bamboo could serve asthe main axle and the coils of pipe-probablyin two-start or three-start thread form-couldbe held in place by lashing with rope, cord,tape, or any suitable local fiber, using longi-tudinal strips of bamboo or other wood toform a cage on the outside of the coils. Al-though the pipe corrugations would giveincreased friction to the flow of water, theirother virtues may outweigh this disad-vantage.The possible dimensions of this type ofpump are such tha? it is almost certainlysuitable only for slow speeds, which couldenable it to be driven directly from a Chinesetwo-man pedal unit at up to 30 rpm.The pump is connected to a pedal unitsituated near the top of the river bank. Sincethe maximum slope of an Archimedes screwof any type is about 30 degrees, a length of20 feet (6 meters) is needed and should bepossible with all types. This leaves a gap of13 feet (4 meters) or so to be bridged to thehorizontal shaft carrying the pedals. A simpleand effective method is to use a steel rod ofsuch a diameter that it will transmit the


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torque but will bend over its length to accom-modate the 30-degree difference in slopebetween pump and pedal unit. A suitablediameter is about 314inch (18 mm). By mak-ing the pedal shaft with a full-length axialhole to accommodate the rod and providinga coupling at one end which can clamp therod firmly, e.g., by use of two cotter pins ofcycle type, adjustment to length can readilybe made. The best method may be to insertthe rod alone into the coupling on the pump,then to thread the pedal shaft over the upperend of the rod, then pull down the pedal shaftonto its supports, finally clamping the rod atits upper end.These supports may conveniently betripods made from three bamboo poles, oneof which is larger and extends upward to helpsupport a stout horizontal pole for use as aseat and an upper horizontal pole acting as ahandlebar. The three poles forming a tripodare lashed firmly together, leaving short ex-tensions to provide a three-point support fora spherical wooden bearing, drilled across adiameter to accommodate the shaft of thepedal unit. It may be necessary to hold downthe bearing to its tripod, which could be doneby use of a metal ring on top of the housing,the ring being then lashed to each of thethree poles. Such an arrangement wouldgive a self-aligning bearing; the diametricalhole may be lined with a brass or plastic tubeto provide a better bearing surface if theparticular wood used is not adequate, but inmost cases wood should suffice. A methodused by Alex Weir is to boil the wood in oil(e.g., old engine oil) for 12 hours to providebuilt-in lubrication.

Pedal Drives forBorehole PumpsThere is widespread need in India,Pakistan, Bangladesh, and many othercountries for a reliable form of pump which iscapable of lifting water from depths of from20 to 330 feet (6 to 100 meters) or more. The


normal pump used for such purposes is awell proved design and gives good reliableservice in engine-driven and windpump in-stallations. There is evidence of widespreadfailure in hand-operated village use;therefore, it seems worthwhile evolving apedal-driven version on the grounds that it isup to three times as effective as hand opera-tion, enabling greater quantities or greaterdepths to be achieved with minimum energyexpenditure.Figure 2-22 shows an arrangement basedon a traditional Chinese method of pedalingand used for hundreds of years for operat-ing pumps, windlasses, etc. A horizontalwooden axle is fitted with two sets of pedals,each set consisting of four arms spaced 90degrees apart with a short cylindrical pedalat its outer end. The two sets of pedals arearranged at an angle of 45 degrees to evenout the pedaling torque. The shaft has bear-ings at either end supported by crossedpoles. One pole at either end extends up-ward to cross a second horizontal pole at aconvenient height to serve as a seat for thetwo pedalers, who may also hold on to a thirdhorizontal pole in front of them and leanbackward against a fourth pole.

The main pedal shaft is extended at eitherend by means of a steel shaft which passesthrough the bearing and overhangs a shortdistance at each end. A standard bicycle left-hand crank and pedal is fitted at one end andat the other is fitted a standard chainwheeland crank or a wooden pulley with adiameter of 12 inches or more.The left-hand pedal is connected to a wirecable or a rope which passes upward andover a bicycle wheel used, without a tire, as apulley wheel. The wheel is supported by therear part of a standard bicycle frame sus-pended from the two upper horizontal poles.The other end of the cable is connected tothe upper end of the pump rod; a leatherstrap may be used to line the wheel rim toprevent damage to rim or cable. The strapcan be joined by a thong at the bottom of the

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Pedal Power

/A A- Cables adjustfor chain tension

re or rope to pedal

1 1 To pumpI II

wheel, since the wheel will reciprocatethrough an angle of only about 60 degrees. using a standard 46-tooth chainwheel andThe chainwheel or pulley at the other end the smallest standard fixed sprocket of 15of the pedal shaft drives a flywheel at a teeth, a ratio of about 3 to 1 is available, giv-higher speed by means of a step-up drive; ing a flywheel speed of about 90 rpm for apedaling speed of about 30 rpm (half the

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normal bicycle pedaling speed, since thereare four pedals per revolution). With a 12-inch pulley and a flat leather belt drive to apulley o f 2- to 3-inch diameter, a ratio of 4:lto 6:l could be obtained, giving a higherflywheel speed.The flywheel itself could be made from anold bicycle wheel with the space between rimand hub filled with cement and/or the rimwound with whatever type of wire is avail-able. The v.Yeel is supported from the upperhorizontal poles in such a way that the ten-sion in the chain or belt can be adjusted. Apossible method is to use a front fork pivotedto one pole and a Spanish windlass (a dou-ble rope twisted by a piece of wood to tightenit) attached between the other pole and ashort yoke connected to either end of theaxle. Such an arrangement is suitable forchain drive but a different arrangement isneeded for belt drive, since a longer axle isrequired. Possibly a wooden fork could re-place the bicycle fork. The use of a flywheelshould considerably improve the smoothoperation of the pump by helping to lift thepump during the operating stroke.Some improvement may be achieved alsoby partially counterbalancing the weight ofthe pump and operating rod; the counter-balance could be attached below the crankpedal, between the pulley wheel and thecircle swept by the crank, or to one side ofthe pulley wheel.The pump as described should have thefollowing performance with two men ped-aling at 30 rpm:

Pumphore.inches 1% 2 2% 3 4Lifffeef 204 108 75 51 27Delivery.gella&~ur 135 240 373 540 OS0

Figure 2-23 shows an alternative arrange-ment for one man pedaling in the normalbicycle mode. There is a T-shaped woodenbase carrying a tripod on which is mountedthe saddle and the pedals. From the chain-


wheel the chain is taken forward to drive abicycle rear wheel, modified to form aflywheel by pouring cement into the spacebetween hub and rim. The freewheel isretained but should have a 22-tooth sprocketinstead of the normal 1Stooth sprocket.Such larger sprockets are obtained and areused, for example, in Bangladesh on cyclerickshaws. On the other side of the wheel isfixed a 15tooth sprocket-this may be themost difficult part of the construction, butsome rear wheels do have threads on bothsides of the hub; with other wheels someother method of attachment could probablybe devised.A second chain conveys the drive from thel&tooth sprocket to a second chainwheeland pedals vertically above, giving a speedof about 45 strokes/min when pedaled at 66rpm, with a flywheel speed of about 140 rpm.The second chainwheel carries a normalcrank and pedal to which is connected a ropeor wire cable running over a bicycle wheelused as a pulley in the same way asdescribed for the first pedal unit except thathere the wheel may be supported on twoposts and braced to the pillar supporting theflywheel and second chainwheel by meansof a strut. The tension of the first chain isresisted by a compression member consist-ing of a bicycle front fork. The threaded topportion of the fork enters a hole in the saddlepost and a threaded nut may be used toadjust the tension in the chain. The tension inthe second chain may be adjusted by meansof a screw which raises one end of the hori-zontal member carrying the pedal shaft, thefront end of which is hinged to a lowermember mounted on top of the left-handedpost. The upper member may also be usedto carry a wooden bar or metal tube for useas a handlebar.The upper pedal shaft may also be fittedwith a normal left-hand crank and pedal SOthat both it and the right-hand crank may beused as handles to assist the pumping effortby an extra person on either side. A balance

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Pulley-bicycle wheellined in rim with leather -Pedals retained as auxiliary handleshain tension adjusting screw

Flywheel-cement filled bicycle wheel

Front fork used to adjust chain tensi

Figure 2-23 Pedal drive for low-lift borehole pump (prototype)

weight may be hung from the pulley wheel toreduce the dead weight of the pump and itsoperating rod.Figure 2-24 shows a further arrangementwhich is better suited to deeper boreholes.The stroke is shortened, to as little as 5inches, and the speed reduced to about 20rpm. These changes are effected by usingan old automobile flywheel with its startergear ring meshing with a starter motor pinionto give a large reduction of about 13:l; thepinion is driven by a sprocket-and-chaindrive from a standard chainwheel and ped-

als to a 15-tooth sprocket on the same shaftas the pinion. This shaft also carries a ce-ment-filled bicycle wheel to act as a flywheel.There are almost certainly many other ar-rangements possible for pedal-drivenborehole pumps, as well as hand-drivenvariations, but the ones described here areprobably worth trying as they appear to offera solution to the main problems of operationand can be built readily from local materialsor easily obtainable parts. The bearingsthroughout are standard bicycle hub or pedalshaft bearings; in some cases a 3-inch

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-. -~..--~_


Other end of axle carries starter motorpinion and small sprocket -

/ rank pin fixed to flywheel atdesired radius to give best strokeFlywheel-cementfilled bicycle wheel

\-

To pump

Figure 2-24 Pedal drive for deep borehole pump (prototype)

length of 1 S-inch diameter tube is used, parts or made by a small manufacturerthreaded internally with left-hand and right- possessing the necessary taps. A woodenhand threads to take the ball race cups. member, e.g., 3 inches square, may beThese tubes may be obtainable as standard drilled with a 1 M-inch diameter hole to ac-

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cornmodate the tube, or the tube can bewelded or brazed to a plate bolted orscrewed to the member.To reiterate the main advantages of theseforms of pump drive:(1) A fixed pump stroke should give along, trouble-free life.(2) Pedal operation is much more effec-tive than hand operation, especially with aflywheel.(3) Bicycle parts, as well as the requiredconstructional and maintenance skills, arewidespread.A major obstacle to this type of simpledesign has been the lack of any unit dedi-cated to the design and testing of prototypes.There is little incentive for commercial firmsto undertake such work, since there is no ob-vious financial return. Not insignificantly, thewhole idea of solving re

Pedal Power-In Work Lesiure and Transportation

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