6 hours ago, MtB said:

 

"Vee doors"????!!!!!
 

 

 

Yes, another Fenland term.  Quite common on sluices (eg Denver, Boston) which are also one way valves to keep the sea out.  This one (Boston Grand Sluice) has a weight and steel cables to pull the V doors shut.

37 minutes ago, Pluto said:

I would suspect that penstock is a river term to describe something used to hold back flowing water. Its use for canal locks is not widespread.

I am currently researching the history of the lock, and it does seem that not only did the exact meaning of many terms not only vary depending on location, but also over time. At least two other waterway historians, one of whom was also the engineer responsible for all waterway engineering in the Netherlands in the mid-19th century, mention the difficulty of interpreting terms in papers they have written. To some extent, it does seem to be dictated by the origin of the technology, so whether they developed from tide control, river flooding, or transportation.

Pen (lock chamber)  and Slackers (paddles) are common terms on the Fenland waterways.

3 minutes ago, David Mack said:

The Environment Agency.

Castle Mills Lock on the Great Ouse (August 2001)

 

And there was me thinking this was Ashline on the Middle Level (photo below), which I think has a similar notice referring to slackers.  Castle Mills can easily catch you  out, the penstocks/paddles are only a few feet apart and it is easy to open the wrong one (or to open both at once).

The enlarged photo shows a rope that goes up at an angle. So when the yellow thing hits the water (as the ramp is lowered) the rope goes slack. That might be useful information to the person operating the ramp??

I thought I would see if I could remember how I derived the formula, in case anyone writes to Canal Boat ...
 

 

2 minutes ago, Stroudwater1 said:

Can I question whether all side ponds were solely built for water conservation? 
 

Although obviously this is 99.9% the focus now it does speed transits up if all paddles are raised, not just the side ponds ones, then closed just as the level equalises. It doesn’t conserve as much but does conserve a decent amount. 
 

Im pretty sure this was how we operated Atherstone and perhaps explains why Atherstone fills so slowly now with no side ponds operational. (Appreciate gate paddles could explain it too)

 

This would have been the time when lock keepers were on Atherstone and we would have been admonished for using incorrectly. 
 

Although this is  not the instructions on Hanbury, they went up very recently during times of water conservation. 
 

Curiously I can’t find any old instructions on operating these in our old BW canal guides nor yet I can find in old Waterways world magazines. 

Can it really be that spending inefficient time between paddles by gates and paddles by side ponds all closed during transit was how it was intended. Efficient speedy transits were surely the aim? 

So going up, open side pond paddle half way up the lock, then open top paddles then return to side pond paddle and lower just as level equalises. 

Prerhaps the article explains its historical purpose more fully but is it and are we being led solely along the water conservation lines when there were two purposes.
 

Perhaps there was variable use, operating to maximise water saving in Summer and in Winter opening up to get through faster? 
 

It would be great to see any historical pictures especially if all paddles were up. 

An interesting thought - I don't know the answer.   

I assume that any overflow from the upper pound cascades down the side ponds, rather than directly into the lower pound.  That is certainly the case at Foxton which is of course a different situation,  (and I know the GU locks don't normally have bywashes!). 

6 minutes ago, Tacet said:

But is the formula correct when multiple side ponds serve the same lock?

Yes, that is what it was designed for.  It does assume the side ponds have the same area.

On 19/09/2013 at 20:24, Scholar Gypsy said:

For those who like algebra, if there are n side-ponds, and the total area of all the side-ponds is R times the area of the lock, which is appropriate if there is a finite amount of land to build the side-pond on, then the saving is

 

S = R / (1 + R + R/n)

 

For n=1 then this gives the same result as above from Dave (R / (2R+1) which approaches 50% for large R).

 

As n increases the saving increases, and it also approaches n / (n+1) as R increases. <CORRECTED!>

 

On the other hand if the area of each side pond is R times the area of the lock, then the saving is

 

nR / (1 + nR + R) which approaches 100% as n increases.

 

I also feel our calculations should take account of the probability of user error, or non-compliance, which will certainly increase as n increases and lead to water being wasted ....

I was rather pleased to see the second formula appearing in the latest edition of Canal World, in Martin Ludgate's article about the restoration of the side ponds on the Hanwell flight in London!

4 minutes ago, Tonka said:

Isn't there in September a tide free day when the Woolwich Barrier is closed.

Think it happens every year and a lot of canoe clubs do trips on that day

There are river closures on 12 September (and Limehouse is not available on that day either):  https://pla.co.uk/notices/M71-26

The next planned test barrier closure is in November:    https://pla.co.uk/notices/P5-26  It's only for a couple of hours so won't have a huge impact on the tides that day.

17 hours ago, blackrose said:

 

I always seem to end up doing things the hard way. But I've done the Thames through London both ways several times, and for me going into London with the ebb tide is a much more exciting experience as the famous sites appear around you. Going the other way always seemed like a bit of an anticlimax.

I rather agree. Going downstream also means that it starts easy (little traffic) and then gets progressively more challenging as you get to the centre of London. On the other hand if you start at Limehouse then you are straight in at the deep end, which can be a bit of a shock!

11 hours ago, Iceni_exporer said:

Thanks for the advice folks.

 

I have the VHF sorted but thanks for reminding me

 

Mike

Have a good trip.  You might find the attached helpful - prepared for the SPCC trip in June. I think it is up to date (but note the small print on the first page!).  It reminds me that you should check the Notices to Mariners on the PLA website, and also the events diary to check if there are any large events on the river.

bridges_upstream_v3.pdf

signals_lights.pdf

Here's a video of entering the lock at Limehouse.  (I was crewing for someone doing the trip for the first time, and offering a bit of advice which you can hear in the background!).

As you can see, we had to stop the turn as a Clipper came around the corner (VTS usually warn you about this!).  We had to hold station for a couple of minutes while the lock was prepared.  There was also an additional temporary fender on the way into the lock  -- did we hit it or not? 

Of course, getting to Limehouse by HWLB+2 is seriously hard to do on a narrowboat. I wouldn't want to try it

 

 

45 minutes ago, Tonka said:

Where is @Scholar Gypsywhen you need him

I'm here.

The problem is that at present Limehouse is only operating HWLB-2 to HWLB+2, given the water shortages on the Lower Lea (and the expensive boats in Limehouse marina don't like to sit on the bottom). [Actually this weekend I think it is completely shut]. So with a bit of luck/rain the restriction may be lifted and so one could depart at the ideal time of HWLB-3.5. Transits departing then can take anything between 2 1/4 and 3 hours, depending on the boat and the tide,

Slot B should run from HWLB-2.5 to HWLB-1.  I think HWLB on the date quoted must be 1309 BST (1209  GMT), this aligns with Brentford closing at 1609 which is 2 hours after local high tide, 3 hours after HWLB. 

 

So a transit at this time - 2 hours before HWLB - should be OK. The tide won't be as helpful as it usually is and you may well arrive at Brentford after high tide (1409).   I wouldn't thrash the engine but I wouldn't hang about either!

2 hours ago, ditchcrawler said:

That could well be the problem, Office hours

No, it's water shortages on the Lea.

Recent CRT notices:  https://canalrivertrust.org.uk/notices/019fcd28-87a4-767a-b668-4bee51b89a06    (HW-2 to HW+2)

https://canalrivertrust.org.uk/notices/01a01f77-1358-7b15-9b26-4294e59cf0a9  (closed until Wednesday)
 

And here is a log from a recent trip from Limehouse to Brentford. We departed 4 hours before HWLB. You can see the tide was running at 2 knots or so pretty much all the way (4 knots through the water is a good speed for a narrowboat, 4.6 mph). Without the tide it would take 50% longer ie 3:30 at least. 

 

Hope to say hello at some point - I am moored in the marina at Ely.

Hermitage (Earith) have quite a bit of hard standing and a variety of boats using it.

All the EA locks on the Nene and Ouse are like that, just wind them up and wind them down. Neat design,

23 hours ago, Fenlander said:

Hi all trip went exceptionally well no issues on the way round or heading into Denver the pilot who helped us round to King's Lynn is a You Tube fellow and made a lovely video of our journey, this can be seen here for those that are interested.

 

 

The boat is now prepped and we are ready to lock out again and continue north heading for the caladonian canal.

 

Big thanks to all for the help

Thanks for posting this - a fine trip! Lovely boat. Sorry I didn't see her on the Fens....

Try the Trent is the name of the Facebook group, and here is the website that holds most of the guidance notes

 

https://trythetrent.wordpress.com/

 

Grateful if anyone can recommend a supplier of small radiators, for a simple pumped system (that runs off the Bowman heat exchanger on the engine).  One of the radiators I installed 12 years ago has a pinhole leak.  The current one is 400x300 mm, but is mounted sideways in order to fit the available gap. I think very similar to this  https://www.screwfix.com/p/myson-300mm-x-400mm-680btu-white-type-11-convector-radiator/998rj. 

 

Standard 15mm plumbing. 

 

It's in the bathroom, to dry towels after the rare occasion of me taking a shower.

 

Many thanks.

On 10/05/2026 at 20:38, Momac said:

This is correct 

I also think the tide has to be a certain height so not all tides may be suitable 

I am no fan of facebook but this is a very good resource for the Trent 

Much of the content is also available here:  https://trythetrent.wordpress.com/

 

24 minutes ago, Fenlander said:

Thank you that's great any help is greatly appreciated 🙏 

 

I think this should take you to the correct playlist on youtube. I should also have said that Dan the Denver lockkeeper is very helpful. 

 

 

The only chart I am aware of is here:  https://scholargypsy.org.uk/wp-content/uploads/2021/11/kl_denver_foote_1992.pdf 

Lots of other stuff here: https://scholargypsy.org.uk/washing/ 

I would strongly advise you join the Spotted on the Wash group on Facebook. There's a  group of boaters who do this trip quite often and can advise on the sand banks and also the posts they have added to help mark them.  There is also a youtube channel with some videos. I will look for that later!

38 minutes ago, 1st ade said:

I would think the power boat, for not giving way?

There's no requirement in Colregs for powered boats to give way to rowing boats (just to sail). And all that is subject to the overriding responsibility of both skippers to avoid a collision, and to take account of any boats that have limited ability to maneuver.

I use this photo when briefing narrowboats about to go on the Tidal Thames, to stress the importance of keeping a good lookout, and shouting "Ahead sculler" or similar if they think a boat approaching from behind has not seen them.

5-7 June 2026.  If you are interested please drop me an email at  [email protected]  for further information and details of how to apply. 

 

Applications have already closed, but we always have a few dropouts for various reasons, and I can put you on the waiting list.

 

Best wishes