The Tower Handbook

14.9 Bell

a: Do the bells themselves need maintaining?

Bells need virtually no maintenance, and when they do it is always beyond the scope of a DIY job. If they crack, they may need recasting, though these days cracked bells can be welded reliably using a very slow heating and cooling process before and after the weld. If they are out of tune that too is a professional job.

b: How are bells tuned?

They are mounted on a very big lathe and small amounts of metal are removed very carefully from the inside. The bell vibrates in a complex way and the different components of the sound (partial tones) are affected by the thickness of different parts of the bell. Removing metal from one area may have a big effect on one partial and very little effect on another, so they can be tuned separately by taking metal from different places. It is not quite this simple, because each change has a small effect on several other partials as well as the one it mainly drives. See The Sound of Bells

c: What is quarter turning?

The repeated impact of the clapper on the soundbow wears a pit at the point of impact. This process is very slow, but if left the pit could eventually become deep enough to risk damaging the bell by starting a crack. The cure is to take out the bell and re-hang it turned through 90_ (ie a quarter of a turn) so the clapper strikes on a fresh pair of surfaces. Sometimes, when the second lot of pits has been worn, a bell will be 'eighth turned', ie 45_ to find yet another pair of undamaged places for the clapper to strike. Obviously these are not DIY jobs, and the complications of drilling new holes etc to fix the bell can be considerable. You can tell whether any of your bells has been quarter turned by looking for impact pits other than where the clapper now strikes.

d: What can I do about an odd-struck bell?

It is worth trying to cure odd struck bells since they have a big impact on the quality of striking that you can produce. Odd striking [243] is caused by misalignment or imbalance between the bell and the clapper (see section 5.1b). What you can actually move to improve the situation depends on your bells and how they are hung.A drastic solution for odd struck bells – see picture?

The things above have all found some success, but there is no guarantee that you will be able to make enough adjustment to cure your problem. These are not simple maintenance tasks, so get advice before trying them.

e: How can I tell whether a bell is odd struck?

By ringing it. If the ringing rest of the ringing is even, a competent ringer will notice the need to apply extra correction at one stroke or the other to maintain even striking. If no one has a problem, then the bell is not odd struck enough to matter. If you decide to try correcting an odd struck bell, as above, you will need a method of measurement that can be used between adjustments. There are two ways.

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