Hello Gareth..

I was called in to consult on some tripper conveyors where the belts were failing despite a reasonable safety factor.

The reasons for failure were:

- Cord damage due to loading impact being greater than 1000 Joules

- Coastal environment corroding cords

- Winch take-up response time too slow

- Material getting locked into the pulleys

- Unsupported length of belt into the tripper too long.

The last one caused alot of the grief, as in troughed formation combined with the sag over the long span caused the edge tension to dissapear. The conveyor was nearly 2km long to the tensions were high, and these tensions were being taken only by the middle third of the belt.

I did my own calculations based on the stress distribution across the belt using the known belt modulus. This was not that difficult, and showed very clearly why the belt failed down its middle, especially at the splices.

I generally however use the Goodyear simple formulae for vertical curves

Regards

LSL Tekpro ■

Dear Gareth,

I believe we have the Oehmen papers related to the strain field in steel cord belts in their idler transitions and horizontal curves.

The University of Hanover will have the library on this since father and son did their research there. I cannot remember if it was the son who did the work, which goes back 15-20 years or more.

This is again archived. I think Fluor did the German to English translation. Unfortunately, I think we found a flaw in Oehmen's reasoning when we made a study of the subject. I know its bad form to make comments that do not have the facts to back up the accusation. If I find the work in the near future, I can lend more light on it.

I know I still owe you for the pulley stress work. I am trying to prepare for a overseas trip and wish to keep my clients content (sic?). ■

I also note that you are digging into a lot of technical detail on a variety of sugjects germain to belt conveyor technology.

Are you not a now or gonna be competitor of CDI? ■

Delving into Oehmen's, Lange's, or Schmoltzi's work is on a Ph D level. Maybe, they train'em young in Oz.

We know who you are and many of your offices with whom we do business. We have the same goals.

Ahmen to the utilization of good information.

My level on interest is to observe a quiet lake, tumbling water or crashing waves. Conveyors are now secondary. However, if you embark on knowing the technicalities illustrated and beyond, it sounds ominous for CDI.

I thought you would'nt ask. By phone every day. By person about 4-6 times per year.

Sydney, Brisbane, Perth, Melbourne, and the outback

Koniambo

Curragh

North Parks

Cadia

Yandi

Channar; upgrades; Eastern range

Muja/Collie

German Creek

BHP Bi-way and under the sea

Gove

and many more. ■

The title is:

"Calculation of Strain Distribution in Belt Convyors by Troughing Transition, Belt Turnovers and Cord Disconnection (splices)"

Author: Dr. Klaus Heiner Oehmen, Hannover University

Published in Braunkohle (12) 394-402, 1979

It translates to 30 pages in English.

Carrot?? ■

Gareth,

1. I am still trying to locate the Lange papers.

2. I am curious about your multi-person login in question -can you explain?

3. I sometimes uses my wifes computer at home at night - handle snordell ■