Rope guide modifications

The rope guide has been modified so that the 7th rope now falls better in the rope circle. Previously it was somewhat closer to the window and the ringer of the 7th had to have their heels on a rather uneven part of the window sill at floor level.

This also makes room for a seating area in the window.

The 6th (left) and 7th (right) now have ceiling bosses as well.

You can see on the right of this photo, against the wall, one of the square rope chutes from the original medieval installation. There's another square hole (minus the chute) to the left of the 6th rope. The larger square hole that's covered up on the far left is another interesting feature as it was for the weights of a church clock which is long gone.

The positions of these holes, and three more in other places, give a clue to the number of bells (5) and the layout of the frame as originally installed.

We do know that in 1552 there were just 3 bells which came from Bordesley Abbey which had been dissolved in 1538. About 10 years prior to the 1552 date, the bells which had been in the tower were sold to pay for new pews in the church.

These c1540 pews still exist, but the Bordesley Abbey bells don't, since in 1704/5 five new bells were cast in Gloucester by Abraham Rudhall I, and the frame rotated 45 degrees.

Here's a reminder of the current frame layout.

Diagonal frames are fairly unusual, other local examples are at Powick (also 1705) and Croome D'Abitot on the NT Croome Estate just up the road. There's also another nice example at Brailsford in Derbyshire, also by Rudhall in 1717.

Swing time targets

After playing with the swing time figures, I've now calculated the target times for each bell and what is needed to achieve this.

Slow down the treble by 25ms, the 6th by 10ms and the 7th by 7ms. This will be done by fixing 

 counter weights at the top of the wheel.

Speed up the 4th by 14ms and the 5th by 6ms. This will be done by fixing ballast weights at the bottom of the wheel.

There are no changes to the 2nd, 3rd or tenor.

Compare this graph with the one in the previous post.

The amount of correction for each bell seems very small but there is a good reason for setting them up as accurate as this. Experiments I have done in the past indicate that the human ear can detect errors in rhythm down to about 20ms, ie +/-10ms.

Setting up the swing times is the only the first part of getting the bells set up. The second part is to get the average clapper swing times set up, and the third and final part is to cancel out any oddstruckness.

So in order to achieve this +/-10ms target, it's important to get the swing timings as good as possible so that the accumulated errors across all three stages are within limits.

The results will be well worth the effort!

Measuring the bell swing times

The first job tonight was to measure the swing times of each bell. To do this I used one of the Oddstruckness Meters I make.

This shines a light at a reflective tape on the wheel, and when the bell is swung gently from side to side, the meter measures the swing each way, and then adds them together to display the period of swing.

 The figures for each bell are then entered into a spreadsheet which produces the above graph. The blue line is the raw data, and the black line is a 2nd order polynomial which helps analyise the results.

From this, it is possible to see that the bells 1, 3 and 6 need slowing down, and this will be done with counterbalance weights which will be bolted to the spokes at the top of the wheel.

It is possible, but much harder to speed 2 and 4 up as there are no spokes in a suitable place for mounting any weights.

This will be an iterative process to get the line as smooth as possible.

The other job was to install a temporary rope spider to hold the ropes up out of the way. This will be replaced at some point with a bespoke one made by my Nephew who is studying to be a blacksmith.

Visiting ringers

Word is starting to spread about Strensham's bells!

Here is a visiting band, mainly from the Worcester area, but there were also people in the group from Reddich, Guildford and Basingstoke.

A fantastic sound, which will only get better when everything in the belfry has been accurately set up.

So far, there have been 3 ringing sessions on the new eight, and the total head count is 58!

It's nice to be appreciated!

After all our hard work in the tower at Strensham over the last 2½ years, it was wonderful to see this in the service sheet for the Carol Service on 15th December.

Happy Christmas!

We rang for the Christmas Service today which was the target we were hoping to reach.

If you haven't see the video on the last post, then do so before looking at this video which was taken before the project started.

What a difference!

Over the next few weeks, we will work our way through the snagging list. There's nothing too large, just some tweaking and tidying up, but it all needs doing to make the bells as good as possible.

Trying the bells out!

Last night 22 people gathered by invitation at Strensham to try out the new ring of eight bells.

This included David Kelly of the Keltek Trust from whom the bells were obtained, and Matthew Higby who not only supervised the job, but did much of the offsite work.

The overall result is excellent!

Here is a short clip of the bells ringing.

The try-out highlighted a few more minor jobs to do, mainly with the internal acoustics and the clapper timings. These will be looked at over the next few months, but for the moment we can rest assured that Strensham now has a magnificent ring of bells!