An Early Morning Ride

Today I dragged myself out of bed, far too early for full consciousness, and on a rare day off, determined to go for a solo morning ride.

If you are hoping to find great technical detail, cranks length selections, tyre
choices, you will be disappointed. If you expect to find descriptions of my superbly skilled moments in the ride, then sorry, there were none. On fairly easy terrain I stopped counting the UPDs at 10. I could have probably stopped counting at 20, maybe even 30. Those looking at the accompanying pictures will only find a very basic cheap unicycle, so nothing to excite them there either. But I hope that those who enjoy a simple unchallenging ride in gorgeous surroundings will enjoy it. It contains so little unicycle specifics, that I wondered whether to post in JC.

I had walked the route before a couple of times, and now hoped I was finally good enough to be able to ride it. I wasn’t, as you will see. I was given a lift to the Ring o’ Bells pub, in Marple, Cheshire for the start of my ride, somewhat before 7.00AM. My driver was very kind considering his lack of sleep, complaining only that the pub was closed at this early hour. As I often do, I had chosen to ride a canal towpath and this pub is but a few yards from the Macclesfield Canal. I rode to the bridge and then descended the slope, walking. The bridge is a fascinating curly design, which in the past enabled horses to change sides of the canal without having to unhook the boat rope.

The slopes are steep, and cobbled, and I was neither daft enough and nor skilled enough to try to ride them, even in the dry. I was worried because as the car disappeared into the distance, some gentle rain had begun to fall, and I was totally unprepared for riding in the wet. But it eased and then stopped after a couple of minutes sheltering beneath the bridge.
Back round and across the bridge, and the towpath is a wide, flat section passing by some boat moorings. A few narrowboat owners are getting their first taste of the morning air and wish me a pleasant good morning. At the end of this section, the wall and the land behind it have collapsed across the towpath. A scattering of pebbles has been placed across the grass as a bypass pathway, and they cause my first UPD of the day. I rode across them nervously, and they rewarded me for doing so.

A few more yards and I reach the end of the Macclesfield Canal, for here it joins the Peak Forest Canal, completed in 1804 and used in those days to transport limestone from Derbyshire to Manchester. Derbyshire right ---->, Manchester left <----. The towpath and bridge is again arranged so as to allow barge/horse transit without needing to untie the rope.
I go left, which I know will take me past a long flight of downhill locks. I want to see if I can ride the slopes down past each of the locks. At the second lock there is a narrowboat, rising in the lock chamber. Each of these locks has one gate at the upstream end, and twin gates at the downstream end. I don’t know why, so I asked the guy who was opening the upstream gate. He said that, because the downstream gates were
three times the height, it mean’t that it was much easier to open the half width gates against the water pressure. I mumbled that it seemed to be a good logical explanation, and only realised two locks later that it was a complete nonsense: when you open the gates, the water level each side of the gate is the same, and so only the bottom 3 or 4 feet of the gates would be in the water. There must be a good reason for the added complexity of a double gate though.

The canal now passes below a road, the first of two , and I managed to ride through the oval tunnel ( horse shaped I believe ) below this road. The stone work gets very eccentric here. Why the tunnel? The barge rope still has to be undone. The horse could have easily crossed the road. And right next to it is a peculiar narrow tunnel with steps to allow a person to reach the towpath directly under the bridge. All a bit superfluous, and quite an intriguing bit of stonework. I didn’t get through the tunnel completely unscathed. My head and hair collected the homes of several spiders en route.

Shortly afterwards one of the home owners had to be evicted from another place he was finding comfortable. I fished him out and hope he also likes his new residence in the canalside dry stone wall. I continued on down and 4 or 5 locks later reached the second roadway, with a second barge and bargee. He didn’t know either. Crossing the road, the canal continues down through the locks, each with quite a large lock pound. The slopes between are all quite steep and either gravelly or cobbly or both. I UPDd on every single one, falling ungracefully flat on my face once, grazing the heel of my right hand and slightly hurting my right ankle.

Eventually I leave the locks behind, passing below the old stone and cast iron rail bridge. The stonework has a vertical crack for its entire height, but I suppose the cast iron structure above holds it safely in place. Soon after is the aqueduct: a 7 foot wide channel across an old stone arched bridge, carrying the canal high above the River Goyt. In the picture you can see that the other side of the aqueduct has no wall, no barrier of any kind. When I last walked along here, three teenagers were jumping across the canal, landing on this narrow strip, and stopping just before they fell over the edge and into the river. I dropped a stone over the bridge. It took two and a half
seconds to hit the water. Those of you who miss the MikeFule puzzle page could now calculate the distance a teenager would fall, assuming similar aerodynamics to my stone, before he hit the shallow water at the bottom of the ravine. For everyone else the aqueduct is 100 feet high. Crazy kids, but the view is spectacular, encompassing the railway bridge, which is even higher than the aqueduct. Riding is far easier now that I am on the flat, and although the UPDs do not stop, they are now caused through tiredness. I ride slowly and have even more time to watch the waterbirds: Mallard, Canada geese, and moorhens, one of which has two very newly hatched fluffy black chicks. Already they swim well. There are plenty of fish ringing the surface, mainly very small, and I see none more than about 4 inches long. They are hard to see because the water has been muddied by the passage of narrowboats. The canal continues through a stone cutting a hundred yards long, whose purpose I can only guess at. Soon after I have to leave the towpath, for the canal enters a tunnel that looks to be 3 or 4 hundred yards long. The towpath , in a fit of cowardice, does not follow the canal into the oblivion beneath the hill. I understand that, before diesel engines, the bargees would lie on the boat roof and walk along the tunnel roof to propel the barge through the tunnel. I pause to wonder if you could ride the unicycle along the tunnel roof to similarly propel a barge. Deciding not to wait for the next narrowboat and conduct the experiment, I shoulder the unicycle and walk over the hill, past the tea shop, to rejoin the canal the other side of the tunnel.

Once past the factory, the scenery is again very pleasant. The clouds have largely gone, the sun is now shining and that, with the gentle breeze ruffling the trees, makes a very pretty scene. A few houses started to appear as I rode nearer to Romiley, some use the canal bank to enhance their garden, and although they have done it very well, I would have preferred the wild look had it been left to grow just by itself. I was by then feeling tired and thirsty, my mouth very dry. I had not thought I would be out for quite so long. But I stopped to eat a few of the blackberries that grow in
considerable numbers along the towpath. Problem solved in a delicious way. The whole of this stretch, from the aqueduct onwards has woodlands sloping steeply down to the left, and might well be ideal for a more adventurous unicyclist, but I stayed on the towpath and tried to freemount. Bad idea, my ankle was now hurting considerably more and I would have to rest it. Journey’s end. I shouldered the unicycle, but as I walked, it made a regular clanking noise, once every two steps. On looking at it I could not see
any problem, and there is no noise when riding. Very strange. Kitchen table job later.

I walked my way back to the tea shop, and whilst drinking tea and eating scones, phoned for rescue. I expect the ankle will recover in a couple of days, and am not too annoyed with myself for failing to complete the journey. And UPDs: I always expect them and am never disappointed.

All in all a very nice trip out, I saw just three people the whole time, no silly
questions, no worries, decent weather.
There should be some pictures in the post.

aqueduct and rail bridge.JPG

Nice write up. Is the “puzzle” that you were be surprised by rain so near to Manchester?

The lock gates: all lock gates leak. This means that even when the top ones are closed, water leaks into the lock chamber. This causes a slight current that tends to close the bottom gates. The lock chamber then slowly starts to fill.

If a boat approaches from the lower side, and the difference in water level is only an inch or two, then the gate can be opened without the rigmarole of raising the paddle and equalising the water level. This is where having two small gates instead of one large one may help.

(The pressure is the same, whatever the size of the gate, but the pressure is acting on a smaller surface area if the gate is just over half size.)

The lock gates: all lock gates leak. This means that even when the top ones are closed, water leaks into the lock chamber. This causes a slight current that tends to close the bottom gates. The lock chamber then slowly starts to fill.

If a boat approaches from the lower side, and the difference in water level is only an inch or two, then the gate can be opened without the rigmarole of raising the paddle and equalising the water level. This is where having two small gates instead of one large one may help.


Agreed very entertaining write up. Nice pictures too.

Lock gates: suppose the last boat through had been moving up the lock. the leaks are now from the lower gates. The current ( or conscientious boatman ) closes the top gate. So now is someone wants to go down the lock, he has the inch or so of height difeerence across the full width of the canal because it is one gate. So would it not be just as useful to have the top gate as a pair?

Great write up Naomi. Looks like a lovely ride. D’you know how far it was?

Also, aren’t you afraid of falling in the cannal? I work in Chester at the moment and go home via a canal bridge. I have glanced down the canal occasionally and thought about whether I would like to ride the path or not. But it’s only about one unicyclist in width and is right next to the canal. I’m too afraid of falling in.


Nice description and beautiful scenery! Looks great for uni-ing. But why no pics of you? Maybe a shot of you & your uni with the nice scenic backdrop.

If the lock is empty, it will start to fill up because of the leakage. The leakage through the top gate is under more pressure than the leakage through the bottom gate.

So if someone approaches from the top when the lock is almost completely empty, they will need to use the paddles to adjust the water depth anyway. It is only physically possible to push a lock gate against an inch or so of water pressure.

If the lock is full, then the bottom gates will elak, but this will cause only a slight current, nowhere near the top gate. That means the top gate can stay open indefinitely. A boat approaching fromthe top can therefore drive straight in.

The lock is the narrowest part of the canal. It is 70 feet long (22 metres or so) and about 7 feet (2.2 metres) wide. Any water leaking in through the top gates will cause a slight current at the lower exit. Any water leaking through the bottom gates will cause little or no current at the top.

That’s my theory, anyway.

Double gates are more expensive to make. Thus, whilst two pairs of double gates might be marginally more perfect in operation, having double bottom gates makes more difference than double top gates.

In my experience, the unicycle goes in, the rider just looks silly.:o

First assume an oval horse…

Enjoyable RR, BTW.

Cheers Danny It is actually called the horse tunnel: see

Hi Cathy, and thankyou. With the exception of a short stretch that was maybe 5 feet wide the towpath was at least 8 feet wide, and often much more. The ridden track was usually less, but there was grass either side. So I felt pretty safe, as as Mike has said, I think the unicycle is far more likely to bounce into the water. (especially a coker!) But keep away from the locks and the water is rarely more than about three feet deep anyway. When I have ridden along other sections of the Macclesfield canal, the towpath in places was very narrow, but I wasn’t really worried that I might fall in. The unicycle falling in did concern me. But I had a 5 metre length of cord coiled up in my pocket, and tied around both my waist and to the seat. When I fell off the cord was pulled from the pocket, and had the uni gone into the water I would have just hauled it out and dried it off. I would be in more danger riding a pavement the same width, cars don’t make such a soft landing. If you can ride a pavement, a canal towpath the same width should not be much harder, apart from that infernal gravel covering in places!.

The ride, looking at the maps, was somewhere around 2 to 2 and a half miles, but I take it easy in short stages, so it was more like 10 rides of a quarter mile.

Leaking locks: I am tending to see Muniac’s view more than Mike’s. The top lock gate is actually far less tall than the lower gates, the lower part of it being solid immovable stonework. And it only has two joints around which water can leak. Assuming all sluices are closed. The lower gates have three joints and are probably 2 or three times taller. So with a full lock I would expect them to leak more than the top gates would with an empty lock, carpentry etc being equal. Left to its own devices a lock would, I guess over a period assume a level at which both sets of gates leak equally. Have to consider ground leaking and leaking through stone joints to be realistic too I guess. But what I don’t understand Mike is your suggestion that similar leakage rates through the gates would result in a higher current flow due to the lower gate. Unless of course I have misunderstood you. If an upper gate leakage of say 10 litres per second causes a current past the lower gates of x metres per minute, then surely 10 litres leakage through the lower gate would cause a current of x to flow past the upper gate. The canal depth just above the upper gate being similar to the depth just below the lower gate.

However, how about this for an idea? Water flow in the lock chamber, when either filling or emptying includes a downstream flow component. This would tend to push a boat toward the lower gates. If the lower gates meet in a V in the middle, then the boat cannot pose much of an obstruction to the gate being opened, once the filling or emptying is done, because the point of the V stops the boat from going too far. The top gate opens away from the boat in any case, so no problem. That’s my theory.

Not sure if it is THE reason. Double gates are more expensive to make, and also need a bridge to allow you to operate them both. There has to be a cost/advantage justification.

that sounds great, and what a beautiful place to be riding in. I am super-jealous.

In the normal course of events, a boatman leaving the lock will not deliberately close the exit gate. He should lower all the paddles (sluices) but leave the gate open.

So the starting points are either:

  1. Top gate open, lock full, bottom gate closed, or
  2. Bottom gate open, lock empty, top gate closed.

If the top gate is open, and the lock full, and the bottom gate is closed, then water will leak through the bottom gate at various points - but mainly near to the bottom of the gates, where the pressure is greater. There will be no single point of leakage.

The leaks will be about 70-75 feet downstream of the top gates. The rate of leakage will be fairly slight. This will not be enough to cause a significant current at the top of the lock. Although it is not quite accurate, imagine the bottom gates attempting to “suck” the top gate closed. Not likely.

The water is leaving the lock chamber from some distance below the surface. There is a similarity here to what happens at the shallow end of your bath when the plug is not quite in place. The water level goes down without any significant lateral movement.

(Can I just clarify for the other readers that I have not studied Naomi in the bath, and this is a purely hypothetical example.)

However, if the top gate is closed, lock empty, bottom gate open, then all the leakage through the top gate is focussed into the lock chamber. The water tends to cascade down into the chamber because although the leaks are some way down the body of the top gate, they are typically above the level of the water in the lock chamber.

The flow is directed along the lock chamber which is a constant width and depth, then over a small sill (at the foot of the bottom gates). This flow of water is in a consistent direction, and there is a slight Venturi effect which tends to draw the bottom gate out of its resting place. Once the bottom gate is slightly into the current, the current then “blows” the gate shut.

Still not with you on this MIke, Let me try and clarify my thinking for you.

To make the problem as idealised as possible will you allow the following assumptions:

  1. the canal is of constant width…not too unrealistic, as the exit and entry into the lock tend to remain at 7 foot wide for a short distance along the canal proper.

  2. the canal depth above and below the lock is the same, and constant.

  3. no leakage through stonework and adjacent ground. All leakage through the gates . Sluices efficient and closed.

  4. gates are perfectly watertight when closed , except for a vertical line of one inch holes drilled every 6 inches. These holes simulate the leakage.

The gates, top or bottom, when open, reduce the canal width by the same amount, say 10%, a bit idealistic and implies the single top gate is twice the thickness…but for the sake of the argument acceptable.

For simplicity the top gate is 5 feet in height, the bottom gate is 20 feet high, canal depth is 5 feet, lock drop is therefore 15 feet.

Situation A. Top gate open lower gates closed.

You have 15 feet of gate leaking water through 30 holes. The holes at the bottom are fair squirting out the water due to greater pressure, those are the top are dribbling.
So we have quite a lot of leakage. Much of it due to high pressure leakage due to 15 feet of water. Total leakage is related to average pressure times number of holes 7.5 times 30 equals 225 in some appropriate units. You could summate for the individual holes but its easier this way.

Situation B Lower gate open, top gate closed. We have 5 feet of gate depth leaking, 10 holes, most of them dribbling rather than squirting. Which stacks up to suggest a much lower leakage rate. Total leakage now 2.5 x 10 = 25 units

It would seem we have 9 times the leakage through the lower gates compared to the upper gate. And we have also ignored the real life fact that the lower gates have 3 vertical leaking joints rather than 2. This factor of 9 seems to be at odds with your suggestion that the rate of leakage through the lower gates is slight. A square law related to water depth difference across the gate would seem to be operating.

The leakage translates into current flow, and considering the canal sections above and below the lock, it becomes clear that A now generates 9 times the currect flow in the canal that B does. Leakage through the lower gates causes much greater flow than leakage through the top gate. It is this flow that passes the closed gates. So that generates an increased venturi effect passing the top gate, when compared to the lower gates. So the top gate is also pushed open into the stream, and by an increased venturi effect.

The gates when open, top or bottom, are both in 5 feet of water, and flow rate past them is therefore related directly to leakage.

As an aside, in order that you will have no need to undertake any direct research, let me assure you that a water molecule in my bath, on average, travels half the length of the bath en route to the plughole. A spider standing on one of these molecules may well consider this lateral movement to be significant enough for him to experience the Coriolis effect directly. :wink:

Let me know if you see flaws in my argument please. And apologies to any who couldn’t care less about lock gates.

Nao Have fun.

Well, there are some of the flaws in your argument: the artificial premisses!:wink:

Generally, the canal is wider immediately before and after the lock because there has to be room for boats to pass: one entering, one leaving.

The depth isn’t constant. The lock chamber is likely to have a constant depth. The main part of the canal is less constant in depth and profile. More significantly, there is a sill below the water line which acts as a small dam. It is there for the bottom gate to seal against.

All leakage won’t be through the gates because often the sluices are routed through the walls of the lock chamber. If the sluices were in the top gates, then in some circumstances the water could cascade onto a boat int he lock, flood it and sink it. This has been known in locks with this design.

But the basic difference is this:

Leakage through the top gates (or side sluices) goes into the lock chamber, and is “organised” or “focussed” so that all the water flows in the same general direction.

Leakage through the bottom gates is abstraction from the lock chamber though a number of separate holes at different depths, and does not draw the current through the chamber in such an homogenous fashion.

When the bottom gates are closed, and the chamber is full and the top gate is open, there is no consistent current past the open top gate, or if there is, it is so slight as not to draw the gate closed.

When the top gate is closed, the chamber is empty and the bottom gates are open, any extra water in the lock chamber pours out, over the sill, in a consistent (but slight) stream, causing a venturi effect - albeit a small one.

Of course, I could be wrong, but you have not yet persuaded me of this by your arguments.

Sorry to ressurect this thread but i plan on unicycling this route. Romiley to marple as the canal is about 1/4 of a mile from my house. It is about 3 1/2 miles to marple so 7 mile round trip. If i survive this i will go futher into derbyshire to the end of the peak forest canal (20 mile round trip). :astonished: Expect pics sometime.