O/T: knots

On Tue, 15 Dec 2015 13:20:02 -0800 (PST),
wrote:

I've never had much use for the bowline, but it comes free with the
sheet bend.

?

A bowline is a rope tied to its own standing part with a sheet bend.

Likewise, the prussik comes almost free with the cow hitch -- a
prussik is turned two or more times around the rope, a cow hitch only
once.

And the taut-line hitch comes free with the prussik -- you pass twine
around a chair leg or whatever anchor is convenient, tie it to itself
with a prussik, and you can lengthen or shorten the tether on your
sewing bird to keep a comfortable tension on your fabric.
http://wlweather.net/pagesew/SEWBIRD.HTM (in the picture, the bird is
anchored with two half hitches and tension is adjusted by moving the
chair.)

As taught to me, the taut-line hitch was intended to fasten a rope to
a tent peg. That situation doesn't come up very often.

--
Joy Beeson
joy beeson at comcast dot net
http://wlweather.net/PAGEJOY/

On Tue, 15 Dec 2015 13:20:02 -0800 (PST),
wrote:

When/whatfor does one use a sheet bend, vs. a square knot?

You use a square knot (or a surgeon's knot) when you want to pull the
line tight while tying it, as when tying your shoes, tying a package,
or (so I have been told) when reefing a sail.

You use a sheet bend (or some other bend) when you want to tie two
lines end-to-end. The square knot isn't suitable if the two lines
don't match, it may jam and be impossible to untie, and it's apt to
capsize into two half hitches when wooled around.

But when I want to tie two threads together, I generally just hold
them together and tie a half hitch in the ends. It holds, and I never
meant to untie it anyway. It does make the thread more likely to
break when pulled, so I'd never use this technique on rope.

And I'll confess to using a square knot on cord elastic. When pulled
firmly, the elastic deforms permanently, so *any* knot will hold. (But
if I have to open a seam to re-tie elastic that's come undone, I use a
sheet bend.)

--
Joy Beeson
joy beeson at comcast dot net
http://wlweather.net/PAGEJOY/

On Wed, 16 Dec 2015 01:49:38 +0000, Phil W Lee
wrote:

John B. considered Tue, 15 Dec 2015 06:58:10
+0700 the perfect time to write:

On Mon, 14 Dec 2015 21:16:37 +0000, Phil W Lee
wrote:

John B. considered Sat, 12 Dec 2015 08:25:57
+0700 the perfect time to write:

On Fri, 11 Dec 2015 15:53:09 -0800 (PST),
wrote:

Hi, this isn't about bicycles,...

I was reviewing knots from my old boy scout and sailing
daze, and could remember just four. Getting old sux -

There are plenty of well illustrated books. I figure
I can learn 10 - 12. So, I'm looking for suggestions, a list.

Why am I posting this question here? There must be a
few bike mechanics on this board, and mechanics
know lots of technical tricks - including maybe, rope -

Anyway, I'm looking for a 'most useful' list - so tell
not only which ones to focus on, but why, what's the app?

What knots one uses is very dependent on what one does :-) but on the
other hand one uses perhaps one or two in daily life so the rest are
immaterial.

Partly true - you use what you know (even if it's less than ideal for
the intended purpose), and most people only know one or two. But
different knots have different uses, and "knots" covers a wide range
of different types - bends, stoppers, hitches, lashings, whippings,
splices, etc.

A modern sailor, for example uses one or two (disregarding one's dress
shoes) the square knot and a bowline.

That depends on how much of his own maintenance he does.
What you describe may well be true of what we used to call "yachties"
when I lived in Burnham-on-Crouch (weekenders, who came down to sail
their boats, but used a yard to look after them, and tended to be the
worst for needing dragging off mudbanks and other types of rescue),
but is far from true for those who take a pride in maintaining their
own boat in good condition, live on it on a low budget, or use it for
long distance cruising or ocean racing.

No, I was describing people that largely live on boats (yachts) and
journey to far off places. The bulk of the folks in the marina I used
to keep my boat (when I had one) in had come from Europe, The U.S.,
Australia, Half the world away.

But what sort of exotic reefs and bends do you think people use in
these days of aluminum spars and synthetic ropes?

My wife and I lived on a 40 ft. fiberglass boat for 15 years and the
only knot I remember using regularly was when I tied the dinghy
painter to the rail.

I'd use one of several hitches for that (depending on how great the
need for security balances with that for convenience) - I'd think
doing it with a square (reef) knot or bowline would be far more
awkward.


Well, if you are on the boat and the dinghy drifts away you get to
swim to shore, so security does have some importance.


And how would you join two lines together safely, hang a coil of rope,
secure a line under tension, etc?

if you want to hang up a rope you just hang a loop over the upper horn
of the cleat, if you want to secure a line under tension you use a
conventional cleat or maybe a "jam cleat" and why would you want to
join two lines together?

I don't think anyone in their right mind would describe me as a seaman
(at best I'd be a hand), but I know and have used at least a dozen
different knots, and have seen used (by seamen, climbers, and rescue
workers, among others) more than I can remember, almost always in
situations where nothing simpler fits the use.

--
cheers,

John B.

On December 15, Joy Beeson wrote:
When/whatfor does one use a sheet bend, vs. a square knot?

You use a square knot (or a surgeon's knot) when you want to pull the
line tight while tying it, tying a package,

ha, when was the last time anyone saw a string tied
package sent through post office?

Still, it might be useful - which knot is dedicated for packages?

You use a sheet bend (or some other bend) when you want to tie two
lines end-to-end. The square knot isn't suitable if the two lines
don't match, it may jam and be impossible to untie, and it's apt to
capsize into two half hitches when wooled around.

Is there a trick to easily tie a sheet bend? I find it
awkward. I recall learning, long ago, that you really
know a know when you can tie it blindfolded.

--
Rich

On Wed, 16 Dec 2015 13:29:04 -0800 (PST),
wrote:

ha, when was the last time anyone saw a string tied
package sent through post office?

I don't think I've *ever* mailed a string-tied package. Used to see a
lot of ribbon-tied packages at celebrations.

I used to use a surgeon's knot to tie newspapers into bundles for
recycling. (They pick paper up at the house now, and I just throw it
loose into a small bin.)

For small packages, I use rubber bands. We get six a week on our
newspaper, so there's always a band around when I want one.

--
Joy Beeson
joy beeson at comcast dot net
http://wlweather.net/PAGEJOY/

- John B. / Tue, 15 Dec 2015 11:49:53 +0100

Of course with plastic ropes and fixtures,
you don't need a knot any more for many things.

But for rescuing »man overboard« or joinig ropes
for more length, classical knots are still used.

What ropes would that be? The main halyard? About 80% wire rope? The
main sheet? Wire again, or the jib sheet... wire once again.

Well, it used to be considered as a good precaution to
have a roll of rope lying somewhere in the boat.
Even in cars, towing-ropes can be found.


May be except for GPS sailors, they don't know
what a knot or even a rope is.

Sort of snarky remark isn't it? After all big ships navigate with GPS,
airplanes navigate with GPS. It has been quite a number of years now
since anything commercial used the stars.

Nobody with a little bit of experience (bike or car drivers
included) relies on GPS only.

The snarky remark was meant about people who have
no orientation at all without GPS (can't even find
their own bathroom)



jk



--
no sig

On 12/19/2015 8:25 PM, Jakob Krieger wrote:
- John B. / Tue, 15 Dec 2015 11:49:53 +0100

Of course with plastic ropes and fixtures,
you don't need a knot any more for many things.

But for rescuing »man overboard« or joinig ropes
for more length, classical knots are still used.

What ropes would that be? The main halyard? About 80% wire rope? The
main sheet? Wire again, or the jib sheet... wire once again.

Well, it used to be considered as a good precaution to
have a roll of rope lying somewhere in the boat.
Even in cars, towing-ropes can be found.


May be except for GPS sailors, they don't know
what a knot or even a rope is.

Sort of snarky remark isn't it? After all big ships navigate with GPS,
airplanes navigate with GPS. It has been quite a number of years now
since anything commercial used the stars.

Nobody with a little bit of experience (bike or car drivers
included) relies on GPS only.

The snarky remark was meant about people who have
no orientation at all without GPS (can't even find
their own bathroom)

I'm just back from an almost-an-hour drive to attend a friend's party.

On my way there, the country highway to his house was unexpectedly
closed. I think it may have been due to a bad car crash, since it was
open on my way home, and there was no sign of construction work. Oh,
and there were no detour signs, which would have been normal for
construction work.

So I made my way by dead reckoning over very minor country lanes. I was
interested to note that I was navigating - or at least, confirming my
direction - by looking at the stars. First time in a long time!

--
- Frank Krygowski

On Sun, 20 Dec 2015 02:25:09 +0100, "Jakob Krieger"
wrote:

- John B. / Tue, 15 Dec 2015 11:49:53 +0100

Of course with plastic ropes and fixtures,
you don't need a knot any more for many things.

But for rescuing »man overboard« or joinig ropes
for more length, classical knots are still used.

What ropes would that be? The main halyard? About 80% wire rope? The
main sheet? Wire again, or the jib sheet... wire once again.

Well, it used to be considered as a good precaution to
have a roll of rope lying somewhere in the boat.
Even in cars, towing-ropes can be found.


May be except for GPS sailors, they don't know
what a knot or even a rope is.

Sort of snarky remark isn't it? After all big ships navigate with GPS,
airplanes navigate with GPS. It has been quite a number of years now
since anything commercial used the stars.

Nobody with a little bit of experience (bike or car drivers
included) relies on GPS only.


I see. Do you really think that the 1st officer on, say the Emma
Maersk" is out on the bridge wing every day taking his noon sight? Or
that a B-52 comes equipped with a sextant? Or that any modern
commercial or military vehicle comes with a copy of the six H.O.
tables?

The U.S. navel Academy stopped teaching celestial navigation nearly 20
years ago stating that while celestial was accurate to a 3 mile radius
that GPS was accurate to a 60 ft. radius.


The snarky remark was meant about people who have
no orientation at all without GPS (can't even find
their own bathroom)



jk
--
cheers,

John B.

On Sun, 20 Dec 2015 17:50:33 +0700, John B. wrote:

I see. Do you really think that the 1st officer on, say the Emma Maersk"
is out on the bridge wing every day taking his noon sight?

Been a few cases where that would have been handy. Faulty GPS and all
that.

On Sun, 20 Dec 2015 20:04:43 +0000, Phil W Lee
wrote:

John B. considered Sun, 20 Dec 2015 17:50:33
+0700 the perfect time to write:

On Sun, 20 Dec 2015 02:25:09 +0100, "Jakob Krieger"
wrote:

- John B. / Tue, 15 Dec 2015 11:49:53 +0100

Of course with plastic ropes and fixtures,
you don't need a knot any more for many things.

But for rescuing »man overboard« or joinig ropes
for more length, classical knots are still used.

What ropes would that be? The main halyard? About 80% wire rope? The
main sheet? Wire again, or the jib sheet... wire once again.

Well, it used to be considered as a good precaution to
have a roll of rope lying somewhere in the boat.
Even in cars, towing-ropes can be found.


May be except for GPS sailors, they don't know
what a knot or even a rope is.

Sort of snarky remark isn't it? After all big ships navigate with GPS,
airplanes navigate with GPS. It has been quite a number of years now
since anything commercial used the stars.

Nobody with a little bit of experience (bike or car drivers
included) relies on GPS only.


I see. Do you really think that the 1st officer on, say the Emma
Maersk" is out on the bridge wing every day taking his noon sight? Or
that a B-52 comes equipped with a sextant? Or that any modern
commercial or military vehicle comes with a copy of the six H.O.
tables?

The U.S. navel Academy stopped teaching celestial navigation nearly 20
years ago stating that while celestial was accurate to a 3 mile radius
that GPS was accurate to a 60 ft. radius.

Almost everything of any size used inertial navigation in between
traditional and GPS, and certainly until VERY recently, it was not
legal to use GPS as the primary means of navigation in an aircraft of
UK registry.
That's what radio beacons are for, in all their various types - VOR,
DME, NDB, and ILS (and yes, I know how to use them all, although not
for all the various functions required for a full UK instrument rating
- the NDB approach is notoriously difficult). I'm fairly sure that in
coastal waters, ships use a similar system of beacons, mostly housed
in what used to be primarily lighthouses (and sometimes still perform
that function as well).

So, do you navigate across the Atlantic, or even worse, across the
Pacific with radio beacons?

Bubble sextants were certainly part of the standard equipment on the
Vulcan, so why not the B-52?

The last (I believe) U.S. made aircraft that had the ability to use
celestial navigation were early models of the Boeing 747, which were
phased out in the 1960's. The SR071 had a automated celestial and
inertial navigation. The last SR-71 left service in 1989. The last
Vulcan was delivered in 1965.

You are talking about old technology.


Note that INS units had to be "borrowed" from some old airliners in
museums to strap down in the crew compartment of the Vulcans used in
the "Black Buck" operations of the (pre-GPS) Falklands war. In their
original (nuclear) role, they were expected to navigate by DR and
celestial, as it was assumed that most beacons would be off air or out
of range, and the DR part is kind of difficult over a featureless
ocean like the South Atlantic, as it relies on position checks (which
were carefully surveyed for the routes the Vulcan force was assigned
to on their nuclear role). All INS units are large, as they have big
gyros in them, so aren't suitable for small craft, and have to be set
up with accurate starting positions - in aircraft this is done by
positioning the craft on a carefully plotted navigation marker painted
on the hardstanding and hand entering the exact latitude and
longitude. The aircraft has to be kept completely still for several
minutes while the internal gyros spin up to speed and self-tests are
performed. They also accumulate errors over time, as they have to
make a "best guess" approach to precession.
I had no idea that US naval navigators were so badly trained - aren't
naval forces supposed to be able to operate in time of war, when EMP
could have killed the GPS constellation, along with most other outside
reference signals?
Or maybe they rely on being able to scavenge some old kit out of
obsolete vessels in that situation?

Of course, on smaller craft, the bigger problem is likely to be
reliance on power - particularly on sailing vessels.
One of the major certification requirements for aero engines is that
they be electrically self-contained, usually achieved by using magneto
ignition.

I hate to be the one to disillusion you but I don't believe that any
operational U.S.A.F. engine today uses magneto ignition :-)

I did, how ever, work on what may have been the last of the
reciprocating powered bombers that the USAF had - the B-50 which did
have magnetos.... however to start the engines the system used
"voltage boosters" that served to feed a higher voltage to the
ignition system than the magnetos could produce at starting RPM. The
"voltage boosters" were operated by the air craft's electrical system,
that for starting was powered by an external power supply.

That goes pear-shaped pretty quickly if you then can't find
a runway to land on as soon as the power goes off! This is also why
at least a basic set of primary instruments are vacuum powered, so you
can at least keep the aircraft flying the right way up and in the
right direction if all the smoke comes out of the electrical system.


The snarky remark was meant about people who have
no orientation at all without GPS (can't even find
their own bathroom)

Yes, a good sailor should be able to maintain and repair the boat, as
well as drive it. Anything can break if sufficiently abused over a
long enough period, and extended abuse is not a bad working
diefinition of a trans-oceanic voyage in a small boat!
Of course, if you creep around the coastal areas, you can generally
find a port to put into if (when) something goes wrong or the weather
turns nasty.

That sounds like a very logical argument... Until one discovers that
few if any commercial shipping carry sufficient personal and/or
equipment to "to maintain and repair the boat". The Emma Maersk, for
example carries a crew of 13, 4 Deck Officers, 2 Engine Officers, 3
ABs, 2 OS, 2 Oilers. Who do you think repairs the navigation gear? Or
the bow/stern thrusters?
--
cheers,

John B.