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‘Alnwick’ on the move!


NB Alnwick

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5 hours ago, BEngo said:

Can you not start up on petrol Graham?

 

I would if I could - but we haven't used the petrol start in our 16 years ownership and a K3 is a big beast to turn over by hand. I much prefer the electric start that our engine was built with. it has a very powerful 24v starter motor and normally spins the engine over nicely on full compression. The failure to start was entirely my fault through not maintaining the batteries.

New maintenance-free batteries are being delivered on Wednesday!

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4 hours ago, tree monkey said:

I heard the chufity chufity as they passed about 7 I think

 

That was us! We had spent the morning mopping out the back cabin bilge (after the automatic bilge pump had failed to drain the stern gland compartment) and drying out all the stuff that we usually store in the bilges.

 

Then, when were ready to leave for the last six or seven miles to Glascote, the start batteries died completely and didn't even have enough electrickery to engage the starter solenoid. After a failed attempt to re-charge them with the generator, I transferred two batteries from the domestic set of four and we got underway at about six pm. We arrived at Glascote in time to watch the final episode of "Line of Duty" - our remaining domestic batteries proved quite sufficient for that . . .

 

Apologies to anyone we disturbed by cruising at such a late hour - however, for us, the experience was very pleasant. The Coventry Canal beyond Nuneaton is as good as it gets in terms of canal cruising.

 

"chufity chufity" is an apt description of the sound that our boat makes - one can sing "Teddy Bears Picnic" to the rhythm at the speed normally selected for passing moored boats whereas open canal cruising speed is a bit more "Nellie the Elephant". Those who have crewed with us will know these songs well!

 

Edited by NB Alnwick
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1 minute ago, NB Alnwick said:

 

Apologies to anyone we disturbed by cruising at such a late hour - however, for us, the experience was very pleasant. The Coventry Canal beyond Nuneaton is as good as it gets in terms of canal cruising.

Absolutely nothing to apologise for, the engine sound is delightful and you have every right to cruise anytime you want

 

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52 minutes ago, NB Alnwick said:

 

That was us! We had spent the morning mopping out the back cabin bilge (after the automatic bilge pump had failed to drain the stern gland compartment) and drying out all the stuff that we usually store in the bilges.

 

Then, when were ready to leave for the last six or seven miles to Glascote, the start batteries died completely and didn't even have enough electrickery to engage the starter solenoid. After a failed attempt to re-charge them with the generator, I transferred two batteries from the domestic set of four and we got underway at about six pm. We arrived at Glascote in time to watch the final episode of "Line of Duty" - our remaining domestic batteries proved quite sufficient for that . . .

 

Apologies to anyone we disturbed by cruising at such a late hour - however, for us, the experience was very pleasant. The Coventry Canal beyond Nuneaton is as good as it gets in terms of canal cruising.

 

"chufity chufity" is an apt description of the sound that our boat makes - one can sing "Teddy Bears Picnic" to the rhythm at the speed normally selected for passing moored boats whereas open canal cruising speed is a bit more "Nellie the Elephant". Those who have crewed with us will know these songs well!

 

 

Nothing to apogise for, at least you slow down for moored boats.

 

The biggest risk to cruising at night on the Coventry is to your chimney on the low bridges!

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33 minutes ago, ditchcrawler said:

So now the basin is officially closed then?   ?

 

Hopefully not - I am awaiting confirmation that 'Alnwick' is in the dry-dock . . .

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On 02/05/2021 at 13:20, NB Alnwick said:

 

One of the peculiarities of the Kelvin gearbox is that the propeller shaft, as well as rotating, is also required to move ahead and astern slightly for the respective cone shaped clutches to engage/disengage. When running at cruising RPM the thrust on the propeller (in either direction) is sufficient to keep the clutches engaged. Unfortunately there is a tendency for the clutches to disengage at the slowest canal speeds - an issue that we have addressed by hanging a 7lb weight on the gearwheel to keep it engaged at slow speeds. The amount of movement on the prop. shaft is only about an inch but it does add a little more wear and tear to the stern gland packing.

Having said all that, our stern gland is good and was not dripping at all with the boat stationary. The float switch is also working OK now but was probably stuck before I cleaned all the old grease and muck out of the wet bilge. We live and learn and the secret of happy boating is regular maintenance!

Tom designed and built a device which puts a Kelvin positively into gear. It is a fairly hefty bit of kit but it does avoid the movement of the shaft and allows a thrust block and splined cardan shaft which is in my opinion a btter engineering solution than the standard one albeit with a small degree of added complexity.It does make for simple installation and avoids some wear on the shaft bearing.This was for an F4 but the same principle applies. We were going to use it on Judith Ann but this now has an AS2 fitted. Regards, HughC.

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41 minutes ago, hughc said:

Tom designed and built a device which puts a Kelvin positively into gear. It is a fairly hefty bit of kit but it does avoid the movement of the shaft and allows a thrust block and splined cardan shaft which is in my opinion a btter engineering solution than the standard one albeit with a small degree of added complexity.It does make for simple installation and avoids some wear on the shaft bearing.This was for an F4 but the same principle applies. We were going to use it on Judith Ann but this now has an AS2 fitted. Regards, HughC.

I am curious.  Do you have any pictures please?

 

N

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53 minutes ago, hughc said:

Tom designed and built a device which puts a Kelvin positively into gear. It is a fairly hefty bit of kit but it does avoid the movement of the shaft and allows a thrust block and splined cardan shaft which is in my opinion a btter engineering solution than the standard one albeit with a small degree of added complexity.It does make for simple installation and avoids some wear on the shaft bearing.This was for an F4 but the same principle applies. We were going to use it on Judith Ann but this now has an AS2 fitted. Regards, HughC.

 

I would love to see the drawings of this arrangement but we are quite happy with the standard Kelvin transmission as fitted to the K series. The only problem is that at slower speeds it does have a tendency to work itself out of gear - effectively settling in a neutral state where there is no power transmitted to the prop. As previously stated, we overcame this problem by hanging a 7lb weight on the gear wheel when it is in gear. The only disadvantage of the Kelvin control is that it takes half a dozen or so complete turns of the wheel to get from the ahead to astern so it isn't a rapid process for executing an emergency stop.

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Another solution to the disengagement issue is to drill and tap the side of the support column, adding a bolt which pinches the gear rod. I used to hang weights on our J3, this was a neater and more effective alternative.

4CDB4487-E58F-46EA-9968-B548BB2867AE.jpeg

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16 minutes ago, dave moore said:

Another solution to the disengagement issue is to drill and tap the side of the support column, adding a bolt which pinches the gear rod. I used to hang weights on our J3, this was a neater and more effective alternative.

 

A very neat and, now that I have seen it, a very obvious solution.

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2 hours ago, BEngo said:

I am curious.  Do you have any pictures please?

 

N

It is buried at the back of my workshop. Tom has broken his wrist so it may take me a while to extricate it. Once I have I'll post a photograph.

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3 hours ago, NB Alnwick said:

 

I would love to see the drawings of this arrangement but we are quite happy with the standard Kelvin transmission as fitted to the K series. The only problem is that at slower speeds it does have a tendency to work itself out of gear - effectively settling in a neutral state where there is no power transmitted to the prop. As previously stated, we overcame this problem by hanging a 7lb weight on the gear wheel when it is in gear. The only disadvantage of the Kelvin control is that it takes half a dozen or so complete turns of the wheel to get from the ahead to astern so it isn't a rapid process for executing an emergency stop.

Have a look at your cones.  They may need relining. The gearbox to block gasket may also be thicker than original.

 

With new linings (ex factory) there  should be about 1 turn from ahead to astern.  With new,  modern, slightly thicker than the imperial originals, linings there is no more than a quarter turn either way from neutral to in gear. 

 

My J arrangement is chain reduced by about 2:1 from the gear wheel to the thrust box.  It goes in and out nicely with about  one turn either way from neutral and will stay in gear at tick over for at least the length of the Golden Nook moorings on  the Shroppie ( a distance normally measured in astronomical units?.)

N

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I am sure that Alnwick's cones are long overdue for re-facing or re-lining - I haven't opened up the gearbox in sixteen years of ownership and I doubt the previous owner did.

Apart from setting valve clearances, injection timing and regular oil changes the engine and gearbox has needed no attention and the only breakdowns have been ancillary items such as the starter motor and injection pump. Being of the mindset that "if it isn't broken don't fix it" - I am happy to keep it as is but no doubt it will need heavy repairs one day!

Our gear control wheel has a quite small chain sprocket so the reduction ratio with the larger 'K' box is probably closer to 4:1 - I will check this by counting the chain teeth on the respective sprockets when I return to the boat.

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  • 2 weeks later...

On re-checking the gear control wheel more thoroughly - I can see that I significantly exaggerated the number of turns necessary to move the shaft from ahead to astern. It is roughly two and a half full turns of our control wheel and the gearing is nearer to 3 to 1. This means that there is about one whole turn of the gearbox sprocket to go from one direction to the other. Having said that, in an emergency it seems like a lot more than just 2½ full turns of the wheel!

 

The good news is that 'Alnwick' is now back on its home mooring at Cropredy - the return journey which I completed single handed was much less eventful and quite pleasant despite the odd shower.

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