Stonehouse to Bowbridge

[nebulae]

I understood that the origional paddle gear was on the gate and was in such a position that it would have been dangerous to operate by inexperienced crews. The new design has to be a compromise between safety and heritage. In my opinion,free running paddle gear is a safety bonus,having come close to losing two boats on the Wigan flight,this year(heavily geared bottom gate paddles very slow to close)

[IanM]

The original gate paddle gear had to be wound by standing on the walkways, you are right.  I have no problem with the extensions they've fitted to make them usable from the lockside.  It's the over engineering that in my opinion wasn't necessary.  There were surviving original examples which could have been copied at less expense.  

[magpie patrick]

11 hours ago, IanM said:

Unfortunately, in my opinion and having used it, it is so over-engineered with bearings, etc. it may look like the original but runs so freely it is quite dangerous. If ones hand slipped off the windlass the paddle would drop so much quicker than any other I’ve seen before.

There were several examples of original gear laying around for years but it was deemed old fashioned and could be improved upon so the original was ignored.

An interesting observation, and not one I can readily answer in full, certainly not the issue of being very free running, which is an unusual complaint against paddle gear, more commonly it's the opposite and the gear has to be forced down.

The process, a far as I was concerned was as follows

1 - I specified "authentic gear" as far as practical (the trust had a design for completely boxed in modern gear using off the shelf parts which was very clever but in no way heritage)

2 - SDC came up with Worcester and Birmingham gear

3 - I said NO to the W&B stuff

4 - They went away and came up with the designs that have been used.

I don't know about the older gear, save for the gear for the intermediate gates at Ryeford was reconditioned original gear, but it was (I am told) unique anyway. Older gear is most useful if there is enough of it: it can be used as the mold for a foundry to make more, but there would still be foundry costs involved. 

The extra cost of the new gear over buying W&B gear was a few thousand pounds - that includes ground paddles (which are at the head of every lock) I can't remember what was proposed for the ground paddles when W&B gear was proposed for the gate paddles. CCT now have a stock of the new gear and the molds to make more as restoration progresses

[IanM]

Don't get me wrong, I'm happy that the gear matches the originals in appearance.  I do recall the design they wanted to use and I could see no reason at all why it needed to be so complicated!

[magpie patrick]

1 hour ago, IanM said:

Don't get me wrong, I'm happy that the gear matches the originals in appearance.  I do recall the design they wanted to use and I could see no reason at all why it needed to be so complicated!

I think we're singing from the same hymn sheet Ian!

Without opening up a box file I can't recall whether re-use and recasting of old gear was one of the options discussed - I recall a report with various options which identified as a preferred option the gear which they now have. I found no fault in their reasoning or conclusion so gave it the okay. My job is to check their reasoning and the conclusion, a form of due dilligence I suppose

Or rather, my job WAS to check... It's a bit odd to think that my regular trips to Ebley Mill for project meetings are now a thing of the past!

[David Mack]

Any pictures of the paddle gear?

[Tim Lewis]

27 minutes ago, David Mack said:

Any pictures of the paddle gear?

Paddle gear at Bowbridge Lock

[ditchcrawler]

20 hours ago, IanM said:

Unfortunately, in my opinion and having used it, it is so over-engineered with bearings, etc. it may look like the original but runs so freely it is quite dangerous. If ones hand slipped off the windlass the paddle would drop so much quicker than any other I’ve seen before.

There were several examples of original gear laying around for years but it was deemed old fashioned and could be improved upon so the original was ignored.

O dear, I was hoping they had dropped those ideas and gone back traditional which is what I though from the photo

[magpie patrick]

6 hours ago, ditchcrawler said:

O dear, I was hoping they had dropped those ideas and gone back traditional which is what I though from the photo

 It's based on traditional gear, rather than being identical to it. As mentioned, the gate paddle gear was originally worked standing on the gates, but is now extended to be operated from the bank. 

[IanM]

Original:

Dudgrove Double Lock - Thames and Severn Canal by Ian, on Flickr

Reproduction (albeit taken from the opposite site but it shows the extension off to the right to allow them to be wound from the lockside)

Wallbridge Upper Lock - Thames and Severn Canal by Ian, on Flickr

However this was something I was tremendously happy about having lived near the lock for 18 years...

Original:

Paddle Gear - Ryeford Double Lock 1991 by Ian, on Flickr

Original:

Ryeford Double Lock - Stroudwater Navigation by Ian, on Flickr

Edited November 17, 2017 by IanM
Sort out Flickr formatting

[Tacet]

It looks to be low geared - but is the profile of the teeth such that at a constant rpm of the pinion, the rack has a non-constant linear speed?  Not sure what that is called (non-invloute?) but it gives a delightful, historical feel and sound, even if it is mechanically imperfect.   The type of paddle gear where the pinion has only a few teeth and, in order to achieve an adequate depth of engagement at all time is paired with an out-of-phase neighbour,  is good too.  The rack waggles wildly from side-to-side as the paddle is drawn.

To walk across a lock gate and then place your foot in the centre of a well-worn stone on the lockside, as testimony to generations who have gone before in the same routine, is one of my favourite canal experiences.

 

[pete harrison]

Just out of interest are the spindles to the original size or have they been re-engineered to fit a 'standard' windlass ?

It is good to see the progress being made on this canal as I was a frequent visitor when I lived just north of Bristol (1985 - 2008)