Heartbreak Hill Duplicate Locks

[pearley]

Coming up the last few days, why is this bit behind the bottom gate in wood? It is only the duplicates and always on the side closest to the original locks. The top ground paddles are also different. Those on the original locks sloping back whilst the duplicates are upright. 

[AndrewIC]

I believe there were additional  inter-chamber paddles, allowing the locks to be used as side ponds. Only ever seen one picture of them though.

[David Mack]

They were built at different times, so the later locks followed the style of the day, rather than being identical to the originals.

[magpie patrick]

The lower picture looks like it allowed water to weir past the tail gates, that doesn't explain building the recess out of wood though 

[1st ade]

The last picture would tempt me (very carefully...) to put my hand through the gap with a phone and snap a few pictures looking downwards...

[Boater Sam]

You won't see anything but water.

 

Cross paddles to use other lack as a side pound, the wood keeps the rubbish out of the paddle chamber and bywash.

[pearley]

13 hours ago, Boater Sam said:

You won't see anything but water.

 

Cross paddles to use other lack as a side pound, the wood keeps the rubbish out of the paddle chamber and bywash.

My first thoughts but why is there no sign on the other, original lock? 

[X Alan W]

13 hours ago, Boater Sam said:

You won't see anything but water.

 

Cross paddles to use other lack as a side pound, the wood keeps the rubbish out of the paddle chamber and bywash.

As said interconnecting the 2 locks the paddle gear was mainly half way width wise between the locks when it was 2 locks in use it was unwritten to use half a lockfull from the adjoining lock if it was set full & your lock was empty

[mayalld]

1 hour ago, pearley said:

My first thoughts but why is there no sign on the other, original lock? 

Because two cross-paddles were fitted to the duplicate lock end of the cross-culvert.

 

If you dewater the original lock, all you will see are the ends of the culverts

 

On some of these cocks, you can still see two holes in the top timber, with the paddle rods in place.

[Heartland]

Trent & Mersey Records being minimal, the duplication of locks is difficult to date accurately, I mentioned in Silent Highways that these were done in the 1830s. Since writing that book, I have considered the issue further. It is quite possible that this work was done gradually under the directions of Trubshaw. The fact that two locks at Pierpoint, 55 and 56 remained single, is another issue to be determined as is another at Lawton Treble. Were  55 & 56 the last of a plan to duplicate locks from both ends meeting at the Middle? The period of construction if done in house would have taken time to do and time may have run out as ownership changed later on, or the canal proprietors lost interest in further expenditure.

 

With Lawton the issue is further complicated it appears Brindleys original triple staircase was replaced by John Rennie as three single locks and these locks 50 -52 were duplicated in the later scheme.

 

How  all the locks between Wheelock & Kidsgrove were duplicated is another question to be resolved, as records have yet to be found. The wood lined recess may have been part of the process of construction rather than an operational facet. It will be of interest what other people can say on this observation,   

[mayalld]

8 hours ago, Heartland said:

Trent & Mersey Records being minimal, the duplication of locks is difficult to date accurately, I mentioned in Silent Highways that these were done in the 1830s. Since writing that book, I have considered the issue further. It is quite possible that this work was done gradually under the directions of Trubshaw. The fact that two locks at Pierpoint, 55 and 56 remained single, is another issue to be determined as is another at Lawton Treble. Were  55 & 56 the last of a plan to duplicate locks from both ends meeting at the Middle? The period of construction if done in house would have taken time to do and time may have run out as ownership changed later on, or the canal proprietors lost interest in further expenditure.

 

With Lawton the issue is further complicated it appears Brindleys original triple staircase was replaced by John Rennie as three single locks and these locks 50 -52 were duplicated in the later scheme.

 

How  all the locks between Wheelock & Kidsgrove were duplicated is another question to be resolved, as records have yet to be found. The wood lined recess may have been part of the process of construction rather than an operational facet. It will be of interest what other people can say on this observation,   

I am fairly convinced that they are an operational facet.

 

It is pretty clear that the paddle rods passed through the top plank of the wooden structure, and they are too well built (with cast iron braces) to be temporary.

 

The standard explanation for Pierpoint (small fall, so less time to transit) doesn't seem far fetched.

 

I had always assumed that Lawton Treble were initially constructed as singles, then duplicated. I would need to look at the "racing line" for which are the duplicates here, as the turn going downhill (particularly from the offside lock at 49) is horrible.

 

The duplicates are often on a poor alignment with very little effort made to make them easy to use, and it would be interesting to check whether the canal after Rennie replaced the staircase had a good line (the best line being N/S 49 then O/S 50-52). The offside lock at 49 is a pig to exit downhill (although would have been OK towards the staircase), and the track from either lock at 49 to the nearside lock at 50 isn't great

[Heartland]

The duplicate locks were built for a different age when fly boats, horse drawn and normal boats also horse drawn would pass both ways. Those who worked horse boats were used to poling their craft into basins and places where a motor boat had less opportunity to turn into.

 

Could that be an explanation, I wonder. Yet would an experienced engineer like Rennie allow such a situation, or was the new construction dictated by space and land availability?