The cover is green & black & you really need to know about it. Engineers call it Roark & Young, sometimes just Roark. If you're in N America you use the older issues but revision 6 onwards is allegedly metric. For laymen it also carries the superfluous title "Fomulas for Stress and Strain". Who would dare to suggest that a correct title should be "Formulae...."??? certainly not me.

Also you need to cross reference to the applicable crane code to be sure, to be sure. That's the Irish Code!

Less seriously Roark's Formulas for Stress & Strain...by Warren C Young...McGraw Hill....ISBN 0-07-072451-1. The copy I have before me cost AU$59.95 whereas the local bookshop is selling the newest edition for AU$39.95. Buy now while stocks last. If the price is coming down it looks like some looney might take it out of print. ■

Ah Roark, what would I do without it (not being a Timoshenko myself). ■

I could never fathom out Tim O'Shenko either. ■

:-)) ■

we can supply SLEWING BEARINGS ■

Timoshenko lived in Germany, where he died in 1972.

Stephen Prokofyevich Timoshenko was known as a teacher, author of numerous publications and books, researcher and scientific consultant. S.P.Timoshenko is considered to be the founder of the technical mechanics scientific school in the USA.

S.P.Timoshenko has developed the theory of beams and plates bending with taking in account shear strains (in modern structural mechanics terms “Timoshenko plate”, “Timoshenko element” are widely used), published numerous works on torsion, thrust and pivot vibration, solved the problem about stresses concentration near holes (Timoshenko problem). ■

and .... ? ■

Hi tabojuex,

To solve a problem you have to find out what is the question.

1 - A chain hoist for a 5 ton lift is a stock standard item. What sort of trolley do you want, and what controls?

2 - A reach of 5 m is not unusual. But how will it be supported? Does it have to swing through 120 deg, 180, or 360?

3 - Does it need a mast, or can you bracket it off some exisiting steelwork? Does the steelwork have to be reinforced to take the 25 ton-m of leverage?

4 - What deflections can you accept on the crane beam? Any idea?

5 - I would suggest textbooks like Roard and Timeshenko are a bit complicated for your application. Call up a qualified structural engineer. He can design a crane beam and support system for you. It is not that expensive, and a lot safer than hoping for an instant solution in the internet.

Regards - John.rz ■