Totness Lock

[DHutch]

I received the below email during the week and post it here for the forums attention.

 

Dear Administrator,

 

I am not very competent at using blogs etc so please find attached two files relating to what may be the last major standing flash lock feature in the West Country.

 

It joins the tidal River Dart, at Totnes, Devon, to the freshwater river above.

 

The site is to be developed as a Hydroelectric power scheme with a pair of Archimedes Screws. Requests to list or schedule the lock have been turned down but it is hoped that an archaeological survey, during the construction, will be undertaken.

 

The Planning application can be viewed on :-

 

http://www.southhams.gov.uk/spec_planning_apps_list-m3.htm?AppNo=6%2F1419%2F11%2FF&Applicant=&Address=&selectparish=None&startday=-&startmonth=-&startyear=-&endday=-&endmonth=-&endyear=-&Submit=Search&show=0&show2=1

 

Any pressures on the local District Council planning committee by interested members of the Canal Forum could be very valuable in helping with the recording of this unique feature.

 

Yours sincerely

 

Totnes Lock

 

 

Two attachments:

 

 

Daniel

[Pluto]

I would not expect to find a flash lock at the head of a tidal river, as a conventional lock gate would be all that was required. Flash locks were used where the river below the lock was shallow, the flash of water let down by the flash lock allowing boats to sail over the shallows. On a tidal river, this would not be necessary as you would only have to wait for the tide to cross any shallow sections. With a simple lock gate, the bed of the river below would not need to be sloped and it is much more likely to have been level. The whole structure, from the photos, is typical of a water mill installation.

[magpie patrick]

Need to be a little careful, as a "flash lock" is a modus operandi rather than the actual structure. Fenland staunches, for example we closed behind boats ascending and the reach allowed to fill, rather than the opposite: their default position was open rather than closed. and such locks did give access to tidal water

 

Is there any evidence that the structure at Totnes was a navigation structure, even if this was only incidental to it's main function? Did boats pass through it? It would be interesting to know.

[Pluto]

The structure, as illustrated, would not be useable for navigation. To make a more detailed assessment, it would be necessary to get the tidal levels, to compare high tide levels with the level of the river bed upstream, and thus the cill of any lock-type structure. The slope of the river bed upstream would also be needed, to see what effect holding back the fresh water would have. On fenland areas, holding back water would give quite lengthy navigable sections, but where the land slopes, there would be a need for further weirs to maintain navigable depth. The other factor is where would goods be carried to and from. The obvious place would be Dartington Hall, though that is where local knowledge would be useful to identify other possibilities. The local archaeologist probably has it right, in proposing checking the site for any remains during the construction of the generating station.

[Derek R.]

Looking at the aerial maps of the area, the illustration in plan form would appear not to relate to the old photograph. The reference to the Brunel railway bridge alludes to the area which is quite covered by trees in the aerial shot, (zoom out to see the weir to the N.Nor.W.) and appears not to be the site referred to for development. The "Site address", gives the Dairy Crest establishment adjacent to the Totnes railway station. That is not where the weir is located.

 

The course of the river nearby that appears to be beneath the railway, continues hidden beneath trees until disappearing under a development and joining the tidal River Dart.

 

The old photo shows the site that is to be developed. This, and the plan in greater detail is available here;

http://www.southhams.gov.uk/PlanningDocs/1/00/25/62/00256244.pdf

http://www.southhams.gov.uk/PlanningDocs/1/00/25/62/00256245.pdf

 

A letter from the Historic Environment Service of Devon C.C. showing some concern is here:

http://www.southhams.gov.uk/PlanningDocs/1/00/25/71/00257171.pdf , and has some historical content.

 

The sluice and weir do not seem likley to have been in any way navigable.

 

Comments on this development have a deadline of 6 July 2011.

 

EDIT to add: Apart from typo's, the old shot clearly shows a 'fish ladder', which is where the Archimedes screw turbines would be located. What kind of facility is currently in use for fish is not given.

Edited June 27, 2011 by Derek R.

[Pluto]

Looking at the aerial maps of the area, the illustration in plan form would appear not to relate to the old photograph. The reference to the Brunel railway bridge alludes to the area which is quite covered by trees in the aerial shot, (zoom out to see the weir to the N.Nor.W.)

 

 

I think the site is a little to the north. The sketch map refers to a bridge made from Brunel-type bridge rail and not a railway bridge. Check the road names in the deposited plans to give a better location.