Thread: When decisions get turned on their bum what to do?

now i am going to take interest in these scalextric thingys so a knot is 1854 yards so therefore 1600 metres is a land miletherefore a 6 inch plank of any given timber over any given length with sg supplied according to moisture content...........then onto displacement,hull shape,harmonics, very confusing but with a plan easily obtainable,,,,,,,,,,

Originally Posted by bitofascallywag

now i am going to take interest in these scalextric thingys so a knot is 1854 yards so therefore 1600 metres is a land mile ...

to be a pedant, a land mile is 1609 metres and a knot is 2026.6667 yards and don't forget the leagues ...


ian

Originally Posted by ian

a knot is 2026.6667 yards

To be even more of a pedant, I think you mean a "Knotical mile", or maybe that a knot is 2026.6667 yards per hour.

Well, now I've got started, it's really something like the time it takes to traverse the distance between two knots on a rope, tied to a "log" you have chucked over the side, when you are going at a speed that would cover one second of arc if you were travelling along the equator. :eek: Yuk!

International agreement on the definition of a Nautical Mile was achieved in 1929, when the International Extraordinary Hydrographic Conference held in Monaco adopted a definition of one (1) international nautical mile as being equal to 1,852 metres. This value is very close to the average length of one minute of latitude.

Since the 1929 agreement, all nations have now adopted the international definition.

One minute of latitude represents one minute of arc along a line of longitude, which is a meridian based on a 40007 km longitudinal circumference. Note that the equatorial circumference is slightly greater at 40074 km.)

In the United States, the nautical mile was defined as 6080.2 ft (1853.249 m). It adopted the international definition in 1954.

Originally the Knot was derived from the fact that in some sailing ships, speed was measured by casting the chip log from the stern. The log was relatively immobile, and attached by line to a reel. Some sources suggest that knots placed at a distance of 47 feet 3 inches (14.4018 m) passed through a sailor's fingers, while another used a 28 second sandglass to time the operation. The knot count would be reported and used in the sailing master's dead reckoning and navigation. This method gives a value for the knot of 20.25 in/s, or 1.85166 km/h. The difference from the accepted value today is a bit less than 0.02%.

Having said all that, I have no idea why 47 feet 3 inches, I always thought it was every fathom.

Cheers,

P

Originally Posted by bitingmidge

Having said all that, I have no idea why 47 feet 3 inches, I always thought it was every fathom.

It was probably originally measured in cubits or something.
It would all have been much easier if "they" had adopted the metric system FIRST!

If you lot spent more time doing it with less yap things would happen build the bugger of your choice Dingo seek advice on your choice but at the end of the day your making the boat just get on with it.
I purchased our boat it was the third in line the bloke had built they were just getting bigger till he got to ours its well built as he is naval archetect and had a business building smaller craft till GRP put him out of business. If you buy a boat thats what you get a survey for to see if it is built properly and is safe for you and all who will sail or motor in it.

Originally Posted by Wild Dingo

Nope not Knees ol son stem.. sorta a bit larger than a canoe nice steady curve for a couple of feet...

Oh gawd, Canoethingy on steroids :eek:

Richard

Originally Posted by bitingmidge

Originally the Knot was derived from the fact that in some sailing ships, speed was measured by casting the chip log from the stern. The log was relatively immobile, and attached by line to a reel. Some sources suggest that knots placed at a distance of 47 feet 3 inches (14.4018 m) passed through a sailor's fingers, while another used a 28 second sandglass to time the operation. The knot count would be reported and used in the sailing master's dead reckoning and navigation. This method gives a value for the knot of 20.25 in/s, or 1.85166 km/h. The difference from the accepted value today is a bit less than 0.02%.

Cheers,

P

This is getteing WAY out of hand guys.

So I had better join in!

I have to go out so I may have been sloppy with the calculator. I don't think the 28 second hourglass goes with the 47.25 yard knot seperation.

47.25 X 3600/28 = 6075 feet not the 6080 required for a full knot. In a circumnavigation this would put you out by a minimum of 20.55 statute miles.

A bloody long walk to the shore!!!

That is why of course we all use GPS now.

One of the design features I hate about GPS units is that there is no place to tie a log line - if you could and the batteries had gone flat at least you can know how fast you are going.

Maybe there is a spot on the market for such an accessory to go with GPS units - a nice leather pouch with a log line and a 28 second hourglass.

I can see it now.

MIRACLE PRODUCT.

Turn your GPS into a speedo.

Works whether the batteries are charged or not
Useful safety feature

Finest quality components - only $19.95

Sell truckloads in the USA!

Actually the price is a little low - the pouch may have to be velveteen

MIK

Oh yes ANOTHER PRODUCT

How about a high capacity reel to pull in Midge's log line when he's blasting along at 28 knots heading interstate in an offshore cat.

47.25 X 28 = 1323ft of line to pull in.

And not a small amount of drag on the line either.

Compared to 8 knots

You have 3.5 times the rope out - multiply drag by 3.5

Viscous drag goes with the square of the velocity
3.5 squared - 12.25

So total drag is up by a factor of 42.875.

You might have to slow down to get the line in! Or sail a more sensible boat (Midge knows I am joshing with this last suggestion)

MIK

Actually that 12.25 is quite edifying - it is also the increase of drag for any boat comparing those two speeds. So directly related to the power required giving an idea of just how much grunt a multihull can develop with its massive stability or just how much more you have to pay for fuel for your runabout.

pedantic did someone say?
gee i said 1854 to begin with......anyway figure this one...whilst steaming from one trawl site to another with tuna jigs off the stern i hooked an albie.....yep lucky bugger aint i...so i pulled 300 yards or so in flat out picked him up and drained him,luckily he went back in ok,his head dipping now and again but he kept straigtening up so i thought he will be right so no bad luck for me....several hours later we passed by him again and the poor bugger went turtle not to return....so it was not i but the skip for steering in that direction,thats what i shall tell davey when i meet him at any rate....i found some interesting stories on the net last night about early,early craying down this way...look up the needy and the greedy by handy jaeger or jager.......good read but dont let the snarlies get you....

Mate!! Even for me that was totally un-understandable!!... what the blazes are you drinkin over there?? mmm Tassy? mmm apple isle? mmm twisted confused muddled story? mmmm scrumptiolishus fresh home brewed apple cider Im thinkin

albie...albatross of the wandering variety........trawl site.....trawlers fishing ground.........went turtle...drowned,upside down........google the bottom bit for a good laugh and you will understand snarlies.......hang on and i will try to attach the file..........

the cryptic question was as to how much drag on the line whilst retreiving the albatross,.......but did anyone enjoy the read in the attachment?....as it turns out a few freinds are related to capt billy the samoan......and what does ambigris look like as i am always looking now...it floats i guess?