The Busy Shore: the Block and Tackle System

The author explains how a block and tackle system multiplies human strength and illustrates a number of uses for them.
By Jan Adkins
May/June 1973

The parts of a block and tackle system.
ILLUSTRATION: MOTHER EARTH NEWS STAFF
Slideshow


Content Tools

Related Content

Recycled Plastic Block Houses

Turn low value plastic trash into valuable building blocks with a $300 homemade press. Free plans fo...

How to Block Winter Winds in Your Kitchen: Make a Range Vent Cover

The author devises an inexpensive and very effective way to block cold winter winds from blowing int...

Heirloom Spotlight: The History of Beans

Read this excerpt about heirloom beans from Heirloom Vegetable Gardening: A Master Gardener's Guide ...

Spontaneous Bender Build

The full team from thePOOSH.org attended Over the Moon Festival last autumn in the UK and built a be...

In the matter of strength, a man's a puny creature. You cannot carry a deer in your jaw, you cannot fly two thousand miles or two feet on your own, cannot ant-like lift ten times your weight. Man's mind must multiply his trifling strength. But a race of men that has developed aerosol cheese spread leans heavily on its technology, and tends toward caterpillar tractors to move its garbage cans. A few people, watermen especially, rely more on clever thought and simple machines, and know that puny strength can be craftily applied to immense advantage. One of the oldest and simplest machines is the block and its tackle, an idea of such wonderfully spare reason that it seems magical, running uphill against the stream of nature. Its principle is just this: if one line suspends a weight, it bears all the load; if two lines suspends a weight, each bears half the load; if the lines are rendered movable, the weight can be moved with half the effort. There are a few cautions in using blocks. The sheaves must be of sufficient diameter and width for the size of the rope; too tight a turn will damage the fibre. Keep the pivot pin oiled. Figure a safely factor of five; the line you use should have a breaking strength of five times the expected load.







Post a comment below.

 








Subscribe Today - Pay Now & Save 66% Off the Cover Price

First Name: *
Last Name: *
Address: *
City: *
State/Province: *
Zip/Postal Code:*
Country:
Email:*
(* indicates a required item)
Canadian subs: 1 year, (includes postage & GST). Foreign subs: 1 year, . U.S. funds.
Canadian Subscribers - Click Here
Non US and Canadian Subscribers - Click Here

Lighten the Strain on the Earth and Your Budget

MOTHER EARTH NEWS is the guide to living — as one reader stated — “with little money and abundant happiness.” Every issue is an invaluable guide to leading a more sustainable life, covering ideas from fighting rising energy costs and protecting the environment to avoiding unnecessary spending on processed food. You’ll find tips for slashing heating bills; growing fresh, natural produce at home; and more. MOTHER EARTH NEWS helps you cut costs without sacrificing modern luxuries.

At MOTHER EARTH NEWS, we are dedicated to conserving our planet’s natural resources while helping you conserve your financial resources. That’s why we want you to save money and trees by subscribing through our earth-friendly automatic renewal savings plan. By paying with a credit card, you save an additional $5 and get 6 issues of MOTHER EARTH NEWS for only $12.00 (USA only).

You may also use the Bill Me option and pay $17.00 for 6 issues.