Clapper failure information request

[billy_clarke03]

Having read an article in the RW Feb 24th 2006, page 171 (Worcester 
Cathedral Tenor Clapper, A Treatise by Bob Smith) I'm intrigued by 
the failure figure of 1.5% quoted therein.  I suspect that if 
specific data were available on the service life of clappers in 
bells weighing over 30 cwt, the figure might somehow be different. 

What is the average replacement cost of clappers for large change 
ringing bells (is it approximately £1000 UK?) I wonder how many of 
these bells have had their clappers replaced once, twice, three 
times etc...  There are at about 100 or so change ringing bells 
(over 30 cwts) hung world wide.  If people who know of details of 
failed clappers in heavy bells are willing to share some information 
it might be interesting to try and estimate the total sum of money 
spent in replacing shattered clappers over the last 30 years.  

Would this sum of money be?

1.	less than
2.	equivalent to
3.	greater than 

the cost of buying a complete new ring of 12 bells with a tenor of 
approximately 30cwts?

I've wondered what sort of data might be meaningful and useful for 
this purpose.  I have some information on 5 clappers which I know of 
that have failed, such as;

1.	Bell Weight (cwts)

2.	No. of Years in service (year in which failure occurred 
minus year of installation)

3.	Estimated no. of strokes  (based on a estimated weekly 
average value x 52 x no. of years service)

4.	* Replacement cost (sterling) 



* Note that in some cases the supplier has offered to replace the 
clapper at their cost where it has failed.  
 

If anyone with information on the above cares to send it to me in an 
email I would be willing to put it into spreadsheet format.

Regards,

Billy Clarke.