Bellframes (was Conservation gone wrong (was Whitechapel charges))
George Dawson
george at oRtTx6f2vARx0tRW3GjlhzN3ExASmSzwAM-y4Hc85_07eJz-l-5Po4XjSlVlb3qeWNOP5pth-IogqKDWhTQ-FGpFhXLt.yahoo.invalid
Wed Mar 24 13:20:53 GMT 2010
I remember watching a very substantial H frame unit with bells weighing 42 ½
cwt & 30 odd cwt either side shimmyimg nicely when they were both rung!
George
From: bellhistorians at yahoogroups.com [mailto:bellhistorians at yahoogroups.com]
On Behalf Of Bickerton, Roderic (SELEX GALILEO, UK)
Sent: 24 March 2010 11:42
To: bellhistorians at yahoogroups.com
Subject: RE: [Bell Historians] Conservation gone wrong (was Whitechapel
charges)
Take up more space, how so?
They are not as wide as the necessary pit length, and not being deeply
ribbed allow very close spacing. They are the same height as equivalent
H sections.
Flexing is only a problem if they are subject to to much load.
That only gives rise to bad go in the form of suck and blow if one A
supports bearings from 2 bells, allowing interaction.
The worst flex I can remember seeing was the top frame at St Mary le
Towers, in the early 1980's. That's a low side.
I was not aware of any effect on go, but as I was measuring striking
accuracy, I was only ringing one bell at a time.
(As an aside they were so good as to need no adjustment, although it did
reveal the front bells to be very fast turning).
I have been up with a couple of 1/2 ton 6's on early A's and could not
see flexing.
Ribs don't stop flexing, they just reduce it at the expense of a wider
overall section.
They improve the strength to mass ratio.
In fact a solid section the same width as the ribbed section would be
much more rigid.
It would also be seriously expensive and extremely heavy.
"The castings in those A frames aren't very good - they have no ribs on
them so can flex too easily. Also take up a lot more space than H
castings.
David "
SELEX Galileo Ltd
Registered Office: Sigma House, Christopher Martin Road, Basildon, Essex
SS14 3EL
A company registered in England & Wales. Company no. 02426132
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