Scholar Gypsy

I'd go by truck. My next tideway trip (I hope) will be on the Steam paddle steamer Waverley, from Ipswich to Tower Bridge. Correct. Most of what I know about navigation downstream of Sheerness is neatly set out in this article. https://www.kentonline.co.uk/kent/news/man-sails-round-isle-of-sheppey--a85754/

This isn't quite right. When a boat goes into a lock then y of water is pushed out of the lock into the pound; and vice versa when you leave the lock. Once the boat is in the lock the amount of water that moves when the lock is filled or emptied is x. To see this, you need to think about the volume z of water that is in the lock and below the lower pound level. When the lock is empty, the amount of water in the chamber is z-y; and when the lock is full the amount of water in the chamber is z+x-y. The difference between the two is x, independent of y (and z). This is one of those situations where the question needs to be very precisely posed .... The maths of side ponds is quite interesting.....

A lock will use more water to move boats uphill compared to downhill. Imagine a canal where each lock has to be left empty after use, and boats are very infrequent (ie operate independently of each other), Then, assuming the capacity of the lock is indeed 180 tonnes, when a 20 tonne boat goes uphill a total of 200 tonnes (180+20) would move from the upper pound to the lower pound. When it goes downhill 160 tonnes (180-20) would move from the upper pound to the lower pound. This makes sense in terms of conservation of energy, thinking about the potential energy of the water and the p.e. of the boat. (Note, this result requires you to think about water movement when the boat moves into and out of the lock, not just the boat going up and down in the lock). You are of course right that a lock is not very efficient (20/180 = 11% in this example). Inclined planes, boat lifts etc use much less energy. If you then add back pumps, or a reservoir, then to replenish the water level in the upper pound a total of 180 tonnes would need to be pumped. This is independent of the displacement of the boat, and whether it is going up or downhill.

My favourite unit of volume is the acre-foot, which is used in the United States for water management, for example recent media coverage of the shortages on the Colorado River system. ! acre-foot is about 270,000 Imperial gallons.

Your assumption is correct, If there are no bookings for a particular window (HW-2 to HW+2, between 0700 and 1900) then it is quite possible the lock will not be manned. The bookings should be made on the CRT licencing website. The phone does work "on the day", I have used it to talk to the lockkeeper and update them on our ETA.

It's a nice walk along the river between Thetford and Brandon. https://scholargypsy.org.uk/2020/10/05/little-ouse-river-brandon-and-thetford/

True, but there are people who do it...

Don't forget the Eastern waterways (though you can get to the North by crossing the Wash)

Not answering the question, but you may find this helpful for other aspects of planning your trip! https://goba.org.uk/a-guide-for-visitors-to-the-east/

I use this firm, who also supply parts for the regular maintenance https://www.lifejackets.co.uk/child-lifejackets/childrens-gas-lifejackets/c20 One advantage of inflatable ones is that, if fitted properly, it is easy to forget you are wearing them. The ones with big foam ears etc are bulky and a bit awkward. If anyone is not convinced about crotch straps, please watch this video from the RNLI

Next you'll be telling me the earth is not flat ....

Many boats have nav lights installed in baffle fittings - you can see the starboard one here, just under the windscreen - to prevent light straying over the centre line. As others have noted, there will be a small cone - maybe a few degrees around dead ahead - where you can see red and green lights. If you can see neither then you will be only a few feet away and your lookout has already failed...

In which case there is no water shortage there. The other issue is the wide variation in lock volumes, in particular Irthlingborough must be 3x the volume of Upper Ringstead and 2x Lower Ringstead. EA will be trying to reduce the water used at Irthlingborough.

No, I don't think that is the reason. To see why, imagine a stream of boats all day, downstream boats arriving on the hour and boats heading upstream arriving at 30 mins past. Let's also assume the gates make a perfect seal - they are better than many on the canals. With the normal mode of operation, with the boat heading upstream leaving the lock empty and the guillotine up, two lockfuls of water will be moved each hour from the upper reach to below the lock. With the new mode of operation, only one lockful will be used, halving consumption. In practice, of course, the saving will be less than 50%, but it should still be significant (and will more closely match the consumption of the locks with V doors at both ends). PS I don't think Loddon's point is relevant here as flows are so low.

I agree the notice is rather unclear. There is an argument for boats going upstream shutting the V doors but leaving the lock full, as I would suspect the V doors leak less than the guillotine. (That is certainly the case on those narrow canals with single top gates and twin bottom gates: the latter rarely seal well, which is why the guidance on most canals is to leave all gates and paddles shut).

You can subscribe to alerts here, https://teamup.com/ks42748cc81f4df974 Click on the "person" icon top right, create an account, and then set up alerts for this calendar. You will then get an email when anything changes. The same facility is available on the Ely Ouse Calendar https://teamup.com/ks7f3fcbc3e94ed8f0 The notice is not hugely clear. Basically when leaving the lock (in either direction) just make sure all the slackers are down and leave the gates you have just used open. That's the same as for the locks with V doors at both ends,

I had a very small leak in my coolant system, but only when the engine was running. When it was cold, and pumped up to 15 psi with the pressure tester, the pressure held absolutely constant for four hours. But as I say when the engine was warm I got a small leak from one of the joints, now fixed. What colour is your coolant?

Sorry, I can't remember. I was allowed into the control room at Grand Sluice, Boston, a bit more recently. I think my favourite big button was in the control room for an underground power station in Norway, where you could turn the waterfall (at Vøringsfossen) on and off remotely... I wasn't allowed to press that one either.

During the last strike the bridge was closed (for boats), as the box was not manned. This must mean it's possible to switch this box out of use, and either the signals run on automatic mode or the signal blocks are longer than usual. I was allowed into the signal box many years ago, and was allowed to press the button to operate the bridge.

Here is a commendably honest article about this trip. The RNLI were quite busy that day ..... http://judgefamily.synology.me/scholargypsy/articles/Ilfracombe.pdf

That is exactly the one I use - actually I now have two, one connected to my fixed set and one (via a couple of connectors) to the handheld. They are excellent (I have picked up VTS near Sonning on the Thames, though they couldn't hear me). Note that you need to solder the plug on yourself, which is a bit fiddly but the instructions are clear. The magnetic mount is handy as my radios are used on a large number of boats .... You can see them both here ...

It's the other way around. Being plastic it doesn't need to be earthed. A metal back box needs to be earthed so that if, for example, the live cable became detached and touched the metal then the fuse/circuit breaker would trip immediately. (This is belt and braces, really, as the backbox is connected to the unit via the bolts, and the latter are earthed as well, as you can see in that photo).

It looks to me as though the two earth terminals are connected (by the metal strip), so your electrician can use either or both as convenient. For example you might use one to connect the cables and the other to bond to the metal back box (which you won't need).

Do you mean a second earth connection in the backbox? Are you installing a galvanic isolator, a transformer, or neither?

Thank you, I had forgotten that.