Again, for the Walker log experts

[oldvarnish]

I am getting interested in my old Walker log again and am planning a navigational experiment.

So I have been reading an (authoritative) book which contains the following:

"If the reading is too high this may well be corrected by lengthening the log-line, or if under-reading the remedy may lie in shortening the line."

I cannot quite see how that would be the case. Surely, one revolution of the spinner translates, via the line, to one revolution of the log? Can there be any loss or gain along the way?

(Let us assume flat water, and not complicate it with wave action, although I suspect that would average out over time).

 

[Topcat47]

Me neither. I have an old taffrail log in my loft which is obviously designed for something bigger than a Nic26, so I't's never been out of the box. I'll open it up and see if there's a handbook in there.

 

[NDG]

We've got one which we sometimes use on longer passages, partly in case the GPS packs up as the boat's own thru-hull log has never worked, and partly becuase it's quite interesting. The biggest problem is weed catching on the spinner which happens quite a lot.

We used it from Falmouth across Biscay to Coruna once. When we got there I compared the reading on the log with the stated from/to distance on the gps, and from memory it was only about 5% different, which I thought was pretty good.

I doubt the line length makes much difference, provided it is above a minimum so that it clears the turbulance from the boat's wake.

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[Seajet]

I would guess that the instructions refer to keeping the spinner away from prop-wash when motoring, I noticed this effect on my Wasp trail log - which has served me very well, I also have a big ship Walker log in a case, but it's regarded as an antique ornament now.

Why no-one is making a modern trail log remains a mystery, we're not all slaves to GPS and electrickery...

 

[VicS]

Instructions for Walker Knotmaster log, if of interest/use to anyone

 

[oldvarnish]

Thanks for that VicS. It would seem that the length of line only needs adjusting if you are sailing at high speeds - to stop the spinner coming out of the water. Nothing to do with over/under reading.

 

[clyst]

Im probably talking a load of old bo**ocks but would one revolution of the spinner equal one at the head ? Wouldnt the spinner due to friction etc tend to "wind" the string up a bit before it got to the head?

 

[oldvarnish]

Im probably talking a load of old bo**ocks but would one revolution of the spinner equal one at the head ? Wouldnt the spinner due to friction etc tend to "wind" the string up a bit before it got to the head?

No, you're quite right. When you first fling the spinner over the back you can see the 'twists' working their way along the string. But it doesn't take very long for them to get there, and you wouldn't have travelled far in the time, so I don't think that adds an inaccuracy worth worrying about.

 

[clyst]

No, you're quite right. When you first fling the spinner over the back you can see the 'twists' working their way along the string. But it doesn't take very long for them to get there, and you wouldn't have travelled far in the time, so I don't think that adds an inaccuracy worth worrying about.

so what you are saying is that when under way the spinner and head are turning in unison so the is no "twist" in the string ?

I have a walker in a wooden box but have never used it so have no idea of the length of "string". Maybe I should drag it out and try it .

 

[oldvarnish]

so what you are saying is that when under way the spinner and head are turning in unison so the is no "twist" in the string ?

I have a walker in a wooden box but have never used it so have no idea of the length of "string". Maybe I should drag it out and try it .

It's one of those things that becomes clear when you see it, so give it a try.

To answer your question: you end up with a permanent twist in the line - which is why you have to remove it and stow it in a special way or you get a cat's cradle.

 

[clyst]

It's one of those things that becomes clear when you see it, so give it a try.

To answer your question: you end up with a permanent twist in the line - which is why you have to remove it and stow it in a special way or you get a cat's cradle.

Ok you have convinced me to give it a try . As liveaboard we are sailing at xmas so will give it a try then .

 

[Seajet]

clyst,

also watch out for dinghies etc cutting close astern, this only seems to happen when trailing a log !

As oldvarnish mentions it takes a little while to tension the line, and Walkers used to supply spare spinners as sharks etc took a fancy to them.

My Wasp trail log is mounted on the pushpit, and it gently reverberates through the hull, quite a comforting feeling and sound when off watch, and one gets to know by this how the boat is progressing / what the wind is doing.

The bod on watch has to keep an occasional eye on the spinner, to ensure it hasn't picked up weed etc to disrupt the reading; if it has, a quick upwards tug usually clears it but if having to pull it in do it really quickly, or as oldvarnish says you get the mother of all cats' cradles !

 

[johnalison]

To answer your question: you end up with a permanent twist in the line - which is why you have to remove it and stow it in a special way or you get a cat's cradle.

Rather important, that. I once asked SWMBO to hand the log line on our Walker log without instructing her first, as a joke. I think I had to discard the line.

 

[Uricanejack]

The log line twists untile the tension in it turns the mechanisim in the indicator. it takes a little time to twist up.
Check the line once a day and move the weight slightly and you wont have a problem with sharks.

 

[snooks]

but if having to pull it in do it really quickly, or as oldvarnish says you get the mother of all cats' cradles !

The secret to avoid a world of twists is to unhook the log end and as you pull the spinner in, you let the log end out over the back into the water to untangle itself. When you reach the spinner then coil the line back up. No twists

Don't let go of the line though

 

[VicS]

The secret to avoid a world of twists is to unhook the log end and as you pull the spinner in, you let the log end out over the back into the water to untangle itself. When you reach the spinner then coil the line back up. No twists

Don't let go of the line though

pass the line round a stanchion or over the taff rail.

 

[binch]

log-line

If the line is too short, the log impellor is tilted up.
The length of log-linerequired for accuracy depends on the height of the log counter above sea-level. It makes quite a difference in ships but I suspect it is fancy waistcoats in a small yacht.
Aboard Fare Well, I used a length of 40 fathoms and had very good results.

 

[Seajet]

If the line is too short, the log impellor is tilted up.
The length of log-linerequired for accuracy depends on the height of the log counter above sea-level. It makes quite a difference in ships but I suspect it is fancy waistcoats in a small yacht.
Aboard Fare Well, I used a length of 40 fathoms and had very good results.

binch,

40 fathoms of line ? Wow !

My ship size Walker log doesn't have that much, though the wooden case has lubrication oil and instructions stuck inside the lid.

Snooks,

my Wasp log is nigh on impossible to disconnect at the reading end so it really is a case of 'pull it in quick !'

It has a fair size flywheel as a dampener to moderate out spurious high and low readings.

As mentioned I can't understand why there isn't a manufacturer of decent trail logs since Wasp and Stowe...

 

[Thijs]

I am getting interested in my old Walker log again and am planning a navigational experiment.

So I have been reading an (authoritative) book which contains the following:

"If the reading is too high this may well be corrected by lengthening the log-line, or if under-reading the remedy may lie in shortening the line."

I cannot quite see how that would be the case. Surely, one revolution of the spinner translates, via the line, to one revolution of the log? Can there be any loss or gain along the way?

(Let us assume flat water, and not complicate it with wave action, although I suspect that would average out over time).

However slight, there is friction between the log-line and the water as the spinner--and with it, the log-line--rotate. The longer the log-line, the greater the friction. Therefore, I would expect that a longer line results in fewer knots being recorded on the Walker log. However, this is theoretical, and I am curious how your navigational experiment will turn out.

 

[RichardPerou]

Me neither. I have an old taffrail log in my loft which is obviously designed for something bigger than a Nic26, so I't's never been out of the box. I'll open it up and see if there's a handbook in there.

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