[nabbers] Bell Frames

Roderic Bickerton rodbic at ...
Sat Oct 29 10:50:26 BST 2005

I submitted this in response to the RW article.

I posted it in the hope that some of the engineers out there would read it
and come down on me if I have missed anything.

I had intended it to be the basis for an RW letter questioning the work at
Brasted, but wanted to "try it out" in a more restricted forum.
RW 28 October front and pages 1030, 1031.
>From the picture and content It would appear that the tie rods fitted to the
Brasted frame are entirely inappropriate. If so they will not help to
stabilise it much, and could easily severely overload it. the 1558 frame was
intended to support about 1 .25 T of bells generating of the order of 2.5 T
peak down thrust and 1 T horizontal.
A 3/4 tie rod tensioned to its normal working load would generate about 3T
of tension.
40 have been fitted, which would be capable of together applying 120T of
pressure to the frame. Sure that would stop the joints moving but a bit much
for timber near 500 years old and only intended for 2.5T.
The King and Queen post joints were never intended to stop horizontal
movement, that was the job of the angled braces between the king posts and
the lower sills (Please see my original post).
A worst case would be that this pre load together environmental effects,
will slowly crush and destroy the joints.
Timber in a tower is subject to large changes of humidity and temperature.
this causes timber to expand and contract. If it is unable to expand and
subject to excessive preload the timber will permanently crush at its
weakest point. Subsequent drying out would then shrink it. It would not take
many years of tightening in dry weather to do far more damage than has
occurred in the last 500.

>From: Brett masters

>I can't work out why the post was made, it has no back ground as to why it
was posted I.E a >response to another post nor does it explain why it was
sent. Was it in relation to this week >article in the comic???


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