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A visit to Dudgrove locks, a derelict double lock on the disused Thames and Severn Canal

By Vieve Forward

15th February 2012. It was already late in the day when I set out to nab SU1997. I’d had to come to Lechlade on business, but that would only take a couple of hours, so I’d decided to mop up a few tpoints at the same time. The first was SU1893, where I had to run the gauntlet of angry farmers by walking quarter of a mile down a lane to take a photograph, I hoped, of the place where that lane petered out: a photograph of nothing, in effect. As it was, I found some piles of wood to add interest to the picture. SU1893 : Farm track near Bydemill Farm by Vieve Forward
I beat a hasty retreat, having been spotted by a horse rider just as I was about to have a pee. Luckily, I’d seen her dog just in time. I carried on to Lechlade, fulfilled my obligations there, then went and parked up at the garden centre in order to take a walk down the main road in order to tick off a couple more tpoints. This trip proved hazardous, but at least more interesting. I was able to bask in some winter sunshine next to a flooded gravel pit that was now a nature reserve with a sailing club in it. SP1800 : Bowmoor Sailing Club, Coln Country Park, near Lechlade by Vieve Forward
Back at the garden centre, I had a cup of tea, and debated what to do next. I was already tired. There was a choice. I had been going to carry on to Fairford where three more tpoints were available, but there was still one square I hadn’t done near Lechlade. I said to myself, which would you rather do? Do three squares badly or one properly? The Lechlade square was the only tpoint outstanding in that corner of the outer limit of my “territory”, so I plumped for that. I really didn’t want to do it, but I resolved to make myself.
It promised to be another very dull square. The only things I could see in it were a track, a disused canal bed and an enclosure. I wasn’t going to get my hopes up regarding the enclosure, because in my experience, Highworth enclosures (if that’s what it was) were invisible except from the air. So it looked as if I was doomed to walk quite a way in order to take a photograph of just another farm track.
There was also the problem of how to get there. The only public footpath going anywhere near the square would take me to Dudgrove Farm and no further. Even though that seemed to be how my predecessor had got there five years earlier, I did not fancy climbing over a five-barred gate on to a private track in front of a farmer and his wife who were probably sitting down in their parlour having tea. You couldn’t attack it from the east either, because there was the minor inconvenience of the Thames being in the way, with no bridges marked above Inglesham. The only alternative was to go at it from the north: leave Lechlade by the lane to the Roundhouse, then nip over the river Coln there, where it flowed into the Thames, presenting another barrier, borrowing the Roundhouse’s bridge, and head off across country. But when I got there, having had to park back in Lechlade, there being nowhere to park in the lane, I found the gate to the Roundhouse was so heavily fortified with barbed wire that even a skinny urchin would have had trouble getting through.
It didn’t look as if the cottage beside the Roundhouse was inhabited at that moment. I’d noticed on a recent trip that they were renovating the Roundhouse: that was probably the reason for the fortifications, to protect the plant on site. Luckily, I had brought my 1:25,000 scale map (something I frequently do not do), so I could just about make out a bridge over the Coln a little way from the confluence. I retraced my steps to the beginning of the field it was in, then checking to make sure the coast was clear, strode purposefully towards it.
I crossed the bridge, which was made of sleepers, SU2098 : River Coln, Lechlade by Vieve Forward just in time to glimpse a car pulling up at the gate to the Roundhouse. Damn, I thought, wishing I wasn’t wearing my bright green hat. But I carried on, hoping I wouldn’t be noticed, and succeeded in getting out of sight of the Roundhouse when my course took me along the eastern edge of a block of trees. By that time, the Roundhouse was hidden by the trees that surrounded it, and from then on, the course of the old canal was hidden in an over growth of young trees. Further on, my path was blocked with electric fencing, so I crossed over the field, to a gate that was beside the canal. I could see no water in the canal, though a rivulet ran alongside it. Some of the trees had been cleared: later I realised that the restoration of the Roundhouse was continuing this far along the canal, to give a stub that was navigable.
I could see Inglesham Farmhouse to my left on the other side of the river; I wanted to avoid being seen from there, so I carried on down the next field keeping the canal on my left. At the end of the field, a track crossed over the rivulet and canal bed, and I decided to follow it, for fear of getting trapped on the wrong side of the water. So I crossed the canal bed, which at that point was nothing to write home about, and started to follow the line of weed-trees that were covering it towards my goal.
At the end of the next field, a drainage ditch was in my path, and in order to avoid getting diverted away from the canal along its course, I had to cross over on a narrow plank bridge with only one handrail, which nonetheless I grasped with both hands. SU1998 : Footbridge next to disused Thames and Severn Canal by Vieve Forward Back in the dry canal bed again, I found my way out of the overgrowth and followed the field edge, keeping the canal on my right. Along its length here, at the edge of the trees, was a broken down old stone wall. SU1997 : Drystone walling alongside disused Thames and Severn Canal by Vieve Forward
At a point not much further on, seeing a vague path heading into the undergrowth, I decided to go and have a look at the canal bed to see if there was any water in it here. What I saw came as an unexpected and exciting surprise: a pair of old lock gates, complete with some brackish water at their foot. The gates were very decrepit, and I set about photographing them. SU1998 : Derelict lock gate, Thames and Severn Canal by Vieve Forward I followed the path, if you could call it that, up past them, and beyond was a deep canal bed and another set of gates. This next set was more intact, and one half still had its balance beam and its winding gear. SU1997 : Derelict lock gate, disused Thames and Severn Canal by Vieve Forward Trees were growing out of the canal bed here, one growing out of a square hole at the bottom near the gate on the other side. SU1997 : Derelict lock gate, disused Thames and Severn Canal by Vieve Forward I snapped away happily, in my element amongst the derelict.
Above the second pair of gates, the canal became narrower and even deeper and was lined with fine brickwork. SU1997 : Canal wall, disused Thames and Severn Canal by Vieve ForwardHere, I had to lie on my stomach to photograph it. The weed-trees were growing everywhere, and I was terrified of tripping and falling, for here no-one would hear me scream. This part of the canal was filled with rusting sheets of corrugated iron and skeins of wire. At the top end of this part of the channel was a finely made shelf (or cill as I discovered it was called), upon which was more undergrowth, and then a low concrete wall truncated the canal. SU1997 : Inner wall of disused Thames and Severn Canal by Vieve Forward
I made my way gingerly out from the trees, then dutifully walked up to the track and photographed it, SU1997 : Farm track alongside canal bed, near Dudgrove Farm by Vieve Forward just to make sure of my tpoint, because I couldn’t be sure which grid square these locks were in, being virtually in the crosshairs of four. Then I returned to the locks, and began photographing them first from the top end, then walking down the other side.
I use the word “top” advisedly, after hours spent back at home trying to make sense of my photographs without the aid of any prior knowledge of canals whatsoever. It took me a good few hours to figure out that there must have been two consecutive locks here, not just one. The area around the concrete wall and cill looked like the start of a lock from which the gates were missing. If that was the case, the gate which was most intact must have been a middle gate, and the first one I saw the bottom gate. After long examination of my photographs, I eventually confirmed that it was a double lock by the simple expedient of looking it up on Wikipedia. LinkExternal link There, I also discovered that the locks were on the Thames & Severn Canal, were named after the farm I had been avoiding (Dudgrove Farm), and were numbered 42 and 43. Double locks, according to Wikipedia are ones where two narrowboats can enter side by side, although it does concede that the phrase means different things to different people. LinkExternal link At Dudgrove, the arrangement was like a string of sausages, the uppermost lock being the narrowest. I found I could also tell which lock was the highest not only from the contour lines on the map, but also from the fact that the gates opened towards the higher ground, so that when filled, the water would keep them shut.
Walking back to the low concrete wall, then, having photographed the track, I could see that it had been built relatively recently and had a drainage hole in the bottom. SU1997 : Derelict lock, Thames and Severn Canal by Vieve ForwardPerhaps it had been put there to protect what was left of the lock gates from flooding. Just inside it on either side were culverts shaped like the top half of a D. SU1997 : Culvert, disused Thames and Severn Canal by Vieve Forward Inside the one on my right was what looked like the remains of a sluice. SU1997 : Culvert, disused Thames and Severn Canal by Vieve ForwardThe arches and linings of these culverts were built with brick. Almost on a level with the concrete barrier there were vertical, square-sectioned grooves carved into the stone. SU1997 : Culvert, disused Thames and Severn Canal by Vieve Forward
I stepped over the low concrete wall in order to get a better look at the culverts and to photograph the upper chamber, looking down towards the middle gate. SU1997 : Derelict lock, disused Thames and Severn Canal by Vieve Forward Beyond the culverts, there was a great deal of ivy forming another low barrier before the drop into the upper chamber. Whether there was anything but ivy, I didn’t think to check, although at the time I guessed that this must have been the location of another gate because of the semi-cylindrical grooves carved in the stone on either side which would allow the gates to swing freely. SU1997 : Walling, disused lock, Thames and Severn Canal by Vieve Forward
I climbed back over the wall. Above it, the canal bed was a mere groove with a trickle of water in it. SU1997 : Course of old canal, near Dudgrove Farm by Vieve Forward I made my way back down the other, north-western side of the locks, photographing as I went.
The half of the middle gate on this side was the best-preserved of the lot, and still had its balance beam and winding gear. SU1997 : Winding gear, disused Thames and Severn Canal near Dudgrove Farm by Vieve Forward SU1997 : Winding gear, disused Thames and Severn Canal near Dudgrove Farm by Vieve Forward I also had a better view of the other, more derelict half, which I photographed. SU1997 : Derelict lock gate, disused Thames and Severn Canal near Dudgrove Farm by Vieve Forward
A little further on, near my “path”, was a hole in the ground through which I could see stones: this may have been an exposed culvert, but again, it was difficult to tell.
Below the middle gate the fine brickwork continued for a few metres on either side and continued at the higher level parallel with the lock gates as a revetment wall, holding up the earth on either side of the lock gates and canal walls. SU1998 : Walling, disused Thames and Severn Canal near Dudgrove Farm by Vieve Forward On the side I was on, there was a slit in this revetment wall, though whether it was a deliberate feature or whether the brickwork had just weathered into a split there, I couldn’t tell. Below this level, there was a step down in the canal walls on either side; here the brickwork petered out and the walls of the lower chamber were built out of stone. SU1997 : Walling, disused Thames and Severn Canal near Dudgrove Farm by Vieve Forward It was hard not to notice the marked difference between the two chambers (of which more below). SU1998 : Stonework, disused Thames and Severn Canal near Dudgrove Farm by Vieve Forward
There was more brickwork around the bottom gate, SU1998 : Derelict lock, disused Thames and Severn Canal by Vieve Forward and below it, I came across another brick culvert, this time U-shaped, which would have emptied into the canal below the bottom gate on my side. SU1998 : Culvert, disused Thames and Severn Canal by Vieve ForwardThere was some stagnant water in the canal below the bottom gates, but I was able to walk into the middle of the canal bed to photograph the bottom gates from below. SU1998 : Derelict lock, Thames and Severn Canal by Vieve ForwardThe light was starting to fade, and my camera was telling me to use flash, although the pictures I took without it turned out better.
I had lost track of time wandering around the locks, and when I emerged from the trees, I decided I’d better get a move on if I didn’t want to drive home in the dark. I retraced my steps, careless now of being seen, and got back to my car at about half past four.

Back home, I soon realised that I needed to study the photographs very carefully in order to understand what I had seen. My lack of any knowledge of canals didn’t help. I struggled to upload the photographs, changing my titles and descriptions several times, until I came to the interpretation I have set out so far. There is very little on the internet regarding Dudgrove Locks, but the comments of Ken Burgin, on the Stroudwater website LinkExternal link were interesting: “Dudgrove Double Lock is one of the strangest structures on the T&S Canal. Its top chamber is identical in design to many of the other T&S locks being of mainly brick construction with stone quoins. There is even an overflow weir outlet in the wall below the middle gates. Its fall is similar to those at Siddington, South Cerney and Latton.
“The bottom chamber is very different and has all the feeling of an afterthought. It is about 135 ft long and 27 ft wide. The bottom gates are situated in brick narrows of the normal width but the rest of the chamber walls are of dry stone.
“At the time of writing [2002], the lower and middle gates are still in situ and one of the middle gates is more or less complete with paddle gear and balance beam in place - it will even open and close but is now getting very fragile with age. The upper gates have at some point in the past been replaced by a low concrete wall but due to the infilling of the canal bed upstream, water no longer comes down this part of the canal and the upper paddles are no longer in place although until recently, one of the top ground paddle racks was still there.
“This lock is very overgrown and therefore difficult to photograph but remains one of the most complete T&S locks with much of its timber work still in place. Its remote location on private land has largely been responsible for this.”

I later found some useful information in Michael Handford and David Viner’s book, “Stroudwater and Thames and Severn Canals Towpath Guide”, published by Alan Sutton in 1984. Though out of date, much of the information is still valid, and I quote in full the paragraphs on Dudgrove locks. The authors describe approaching from Dudgrove Farm, from where “with permission [their italics] it is possible to walk on down the track to the site of Dudgrove Bridge, now levelled for agricultural access.
“Above this bridge the canal line survives from Hamfield Bridge to the west although now very overgrown. A swing bridge still remains but it has now settled onto the canal bed [I saw no trace of this, but don’t think I walked far enough up the track], so that access to the canal is now by a track alongside it, which soon ends just short of the Dudgrove Double Lock [the track now curls off to the south-east]. Access to this isolated and dangerous spot must be obtained from Dudgrove Farm [their italics again – I should have read this book before I left]. The milepost just above the locks still survives [I did not see it] and its mileage plate WALBRIDGE 28 INGLESHAM ¾ was removed in 1959 to the Waterways Museum at Stoke Bruerne. There are no other points of interest on this section which makes its way across isolated land, devoid of houses and road, in a north-easterly direction to reach the lock.
“Dudgrove Double Lock is the only example of its type on the whole length of the Thames & Severn. The upper chamber is a normal red brick deep lock with a 9’ fall and typical of so many locks along the line. However, it leads directly into a roughly-built lower chamber constructed of loose stone walling with only a 2’6” fall. The story behind this is an interesting one. The canal had been built this far by the early months of 1789 but this final section to join the Thames had yet to be agreed or even marked out on the ground. The cause of the dispute was the state of the upper reaches of the river, a notoriously ill-kept section and difficult for navigation. Fearful of achieving so much and then running into problems of this kind, the canal proprietors sought alternative solutions, including even a direct cut from Dudgrove to Abingdon. This reminds us very forcibly of the solution later offered to this same problem by the alternative North Wilts and Wilts & Berks routes to Abingdon, and helps to explain the willingness of the Thames & Severn authorities to dispense so readily with the whole of this eastern section in due course. But the problem in the year in which the canal was opened was indeed a pressing one, and the only solution was to cut the approved line to join the river at Inglesham. This meant that at Dudgrove a further fall was required, hence the afterthought which the lower lock represents. The nature of its construction also suggests that perhaps hopes lingered for a better solution and a new line in due course.
“At this point the river is very close and remains so as far as Inglesham. The actual point of contact with the river was also under discussion; a junction at Inglesham avoided the shallow stretches known to exist immediately above, and was also of course the junction of the rivers Coln and Thames, thus ensuring deeper waters. At the upper chamber remains of the gates include the bottom pair almost closed, but they are very decayed and the balance beams have collapsed onto the lockside. In the lower chamber the rough unmortared sloping sides are in complete contrast to any other lock masonry along the canal; again the bottom gates are still in position but very decayed. It must be said that both chambers remain in good condition.”

I add to this Ken Burgin’s comments on the Stroudwater website LinkExternal link
“The lock here [at Inglesham] has a fall of only 6ft 2in but may have originally been intended to have a 9ft fall to match that of the conventional upper part of Dudgrove Double Lock. This last part of the canal was started very late in the project and it may simply have been the case that the canal builders found that they would have had to import a lot of additional material to build the slight embankment to maintain equal falls - but not until after they had already built the upper chamber at Dudgrove. Another theory is that the Proprietors were expecting to extend the canal eastwards to Abingdon to bypass the upper part of the Thames. If this was the case, crossing the Thames at anything other than on the level would have proved an interesting problem as a right of navigation did, and still does, exist on the Thames to Cricklade. Thus a low headroom aqueduct would not have been permitted and the higher level of the canal which would have been caused by the omission of the lower chamber at Dudgrove would not have made much difference.” The website also has two pictures of Dudgrove locks in the 1940s and 1980s, which I am unable to reproduce here. LinkExternal link

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