Daily Log

d.r.wing
25th August 2008, 15:43
Just sitting here mind a blank then a word came to me out of the blue,
but was it 'churikieff, cherekieff,or some other variant',they used to throw them over the stern to measure distanced travelled per day, When did they go out of use? I suspect a lot of you used them.

Orbitaman
25th August 2008, 16:08
The name of the log you are looking for is 'Chernikeeff' and although they don't manufacture the old fashioned trailing type logs, they still produce electromagnetic speed logs.
I don't remember seeing one of the old trailing logs since the early 1980's.

d.r.wing
25th August 2008, 17:05
Thanks Orbitaman, as Eric Morecombe would say the right letters but not necessarily in the right order and I left the n out in each attempt. I finished at sea in 1962 and don't remember any electro magnetic types I suppose they must have been around but the old technology was still in general use, I believe the trailing log goes back to the days of sail.

JimC
25th August 2008, 20:07
Thanks Orbitaman, as Eric Morecombe would say the right letters but not necessarily in the right order and I left the n out in each attempt. I finished at sea in 1962 and don't remember any electro magnetic types I suppose they must have been around but the old technology was still in general use, I believe the trailing log goes back to the days of sail.

It certainly does.

In the old days, a log line was just that - a line attached to a log (originally) and later to a wooden triangular shaped float.
The line was graduated by knots tied in it at pre-determined intervals.
The float (log) was streamed astern and the number of knots passing a fixed point on the stern rail in a given time was noted.
A nautical mile is 6080 feet. It follows that if four knots tied 25ft 4" apart passed the fixed point in 1 minute then the speed would be 1 knot. Not, I hasten to add 4 knots. (do I hear something about 'getting knotted'?)
In half that time it would be 2 knots etc. There were
variation s of the theme I understand and obviously there would be a better system then the one I have suggested but it gives us the idea where all the old terminology came from.

Pat Kennedy
25th August 2008, 21:10
The Chernikeeff patent log was invented by a Captain Vasily Chernikeeff of the Imperial Russian Navy in 1917.
It was a torpedo shaped object about a foot long with fins, attached to a long braided line, which in turn was attached to a geared mechanism bolted to the gunwhale on the poop.When trailed behind the ship, it would rotate and give a reading of the speed through the water. It was in common use in most of the ships I sailed in 1950s to 70s.
pat
Pat

randcmackenzie
25th August 2008, 23:02
I think the system you have just described is the Walker's log. I never saw a Chernikeef, but if I remember rightly it was a small propeller fixed to the hull.
Any advance on that, anybody?

K urgess
25th August 2008, 23:26
Chernikeef's patent is here
http://www.wikipatents.com/gb/514153.html
The ones trailed over the stern were Walker's patent log and had an impeller at the end of a logline attached to a meter mounted at the stern or on a midships boom. Usually with repeaters in the wheelhouse.
The Chernikeef was more a rotating propeller in a housing mounted in the water flow. It is also used for measuring flow in pipes etc.

holland25
26th August 2008, 00:11
The RFA Olmeda had a Chernikeef log fitted. It was there in 1969, the main electronics box was installed in the NBCD steering position. From memory it was based on valve technology.

d.r.wing
26th August 2008, 12:57
This is very interesting the two types of flow log one trailing the other fixed, but I do remember that we obviously mistakenly referred to the Walkers log as a Chernikeef log perhaps we wanted to pretend we were more advanced technically than we were.

Pat Kennedy
26th August 2008, 19:58
My mistake, and thanks for putting me straight.
It was the Walker patent log that was in use in my time at sea, but for some reason was referred to as the Chernikeeff by many.
Regards,
Pat

K urgess
26th August 2008, 20:07
I saw plenty of Walker's logs.
We were taught the four varieties at college for the electronics ticket.
Apart from the Walker's there was the Chernikeef, SAL (pitot) and doppler.
Nowadays I believe they've developed one that measures the magnetism in the passing water and gets the rate of flow and distance travelled from that.
Apparently still needed to confirm satellite data.

Kris