UKH

Why so many different names for the same knot?

Doing a spot of top roping and 'girth hitch' was mentioned.

Never heard of that. Turns out it's a Lark's Foot! 

Which would be more commonly used? 

Lark's foot would be more common.

Similarly, you have the Munter hitch, Italian hitch or crossing hitch. All the same thing.

(Also known as the HMS if you're German!)

Turk's Head always sounds a bit iffy to me. Linguistically it would have to go in the same pigeonhole as Jap's Eye.

Oh, and just because I'm a pedantic git (and also, if I don't make the point, someone else will) a lark's foot isn't a knot, it's a hitch!

Not a knot but I think a tangle of rope can be referred to as "a rat's nest"

When I used to be in the fire service, it used to be called a "bunch of bastards".

Probably the same reason a bread roll is called by so many names in different areas, many knots have been in use since the invention of a rope. You'll have regional as well as national and continental variations on the name as well as slight variations on the knot.

Keep on finding new variations on a bowline

Beat me to it. In the Corps it was 'a bag of bastards'. Also per the OP, I had never heard of a girth hitch until I moved to the US. Still getting blank looks every time I tell somebody to stick a lark's foot around something.

Lark's foot is so much more evocative

Girth hitch is a fat man pulling up his sagging trousers 

Why call it a double fisherman's when you can call it a double double overhand.

There are probably different names for different knots because the origins of knot all have different local origins.  So in the case of nautical knots a port such as Hull and others would have evolved their own names for many of the knots.  This would have happend before books and standardised names came about perhaps.

Maybe, but it's actually a 1970s mistranslation of the even more descriptive French "Tete d'Alouette" (Lark's head - look at the pale supercilium and cheek margins on a skylark and you'll see why!)

It's also known as a Cow Hitch.

Girth hitch is the American term.

Then there's the old favourite of "death knot" which seems to get applied to every knot.

Why not? Many objects, maybe even most, have several names. More generally, all languages are full of synonyms. I'd save the surprised reaction for when there's only one word for something

Killick Hitch, and I'm sure it can be awkward and stubborn but reliable when needed ...

I've never heard another name for a super-fly double fishermans butterfly on the bight.

It's all I ever trust for tying in.

Comes undone really easy as well.

Yes though one may expect a certain standardisation within a specific arena of use, such as climbing, where ambiguity can be dangerous. 

Imagine a doctor asking for a scalpel only for the assistant to know it as something else.

Even in climbing, the standardisation tends to be regionalised.  American climbers have always used an entirely different vocabulary from British ones.  What causes confusion is the internet, so people now pick up information from sources which may be from anywhere in the world, and may not even have English as a first language.

Pretty much every time I tie one!

In the US it's "girth hitch."  Most US climbers wouldn't know what a larksfoot is.  The girth hitch is called a "cow hitch" in the context of tying an animal to an upright post.  Normally, a clove hitch would be the knot of choice, but the animal can walk round and round the post, unwinding a cove hitch until the end slips through, and there goes your cow.  The larksfoot/girth hitch doesn't have this property.  Even if the knot rotates around the post, it doesn't "unwind."

A square knot is sometimes called a reef knot, a figure-8 bend a Flemish Bend, a left-handed bowline a cowboy bowline or the Dutch Navy bowline, and of course the offset overhand the Euro Death Knot or EDK.

Sometimes it's a matter of which language the term comes from.  You folks descend by abseiling, but in the US it's rappelling.

In fishing parlance it's a bird's nest.

Ambiguity would only be dangerous if one name could refer to several knots (e.g. halyard knot in sailing).

Is that what they call the tangled up fishing line left in the bushes, with the occasional bird tangled in it for good meaure?

When I was first introduced to sailing I was told that the only knot that must be used to attach a rope (sheet) to a sail was the Japanese Mast Head Knot. I was given elaborate instructions on how to tie this and when done I realised it was a bowline. Cue amusement from my instructor at having carried on a tradition of winding up the new boy. 

Girth hitch more common down under

I would rephrase that as "a reef knot is sometimes called a square knot" ..............   

I don't know what you mean by "offset overhand". I'll stand corrected but I've always understood that the Euro Death Knot is the cross-loaded figure of eight used as an abseil tie. That's why we use the cross-loaded overhand which, as we all know, is counterintuitively more stable. We still back it up with a second overhand though.

AND another thing.

You know how you get hold of a bight of rope, tie a quick Fo8 in it, then clip the single loop formed onto a krab? Well that is NOT a "figure of eight on a bight". "In" a bight, "with" a bight, fine. But not "on" a bight. No.

No no no.

The Fo8 on a bight is what is commonly called the "bunny knot" because it creates two loops in the rope. It's the Fo8 equivalent of the bowline on a bight, which also creates two loops in exactly the same back-over-its-head-and-under-its-arse manner.

Oh. And ANOTHER thing.

As many of you will know, the bowline on a bight, as a re-thread, makes a very good tie-in knot. Unfortunately people have started calling it a "re-threaded double bowline", which it isn't. No.

No no no.

Not unless you make two turns in the standing rope instead of one when you begin. That's what defines a double bowline, not the two end loops. In this instance it would create a "re-threaded double bowline on a bight".

There, rant over. If you're not asleep already, good night.

Quite a rant 

No the EDK is an offset overhand ie an overhand tied with two strands. The failure version occurs when an Fig 8 is tied with the two strands.

and  we don't back it up with a 2nd overhand unless we are paranoid or don't leave enough tail. if you are concerned - thread one or both tails back through or tie a single fishermans with the two strands instead.

Have you read Mark Gommers "An analysis of offset abseil rope joining knots" ? 

Your understanding doesn't match any of the common terminology I'm aware of.  I have no idea what authority to appeal to, but will settle for Wikipedia as one of many sources.  https://en.wikipedia.org/wiki/Offset_overhand_bend .

Ok, fine, sure, but I never mentioned any of these things.  Free association?  Carry on!

http://www.paci.com.au/knots.php  well worth a read of "An analysis of offset abseil rope joining knots" it's #2 on the Wikipaedia source list

Love the rant !

As my earlier post, death knots and especially European ones are terms used for a number of different knots. Some safe some not.

Thanks for the comments. Whatever the terminology I think we're broadly in agreement - Fo8 bad, overhand good, at least as far as bends go. Thanks also for the reference to the PACI publication, I'll study it carefully. I was also delighted to see that Mark Gommers has just updated his "Analysis of Bowlines". Hours of fun there for an old pensioner who still gets out climbing and detests the Fo8.

The rest of my post wasn't free association but addressed the original theme, though I couldn't resist the rather scatological presentation. The business about the Fo8 on a bight actually goes right back to Bill March's "Improvised Techniques in Mountain Rescue". Published in the mid 1970's it was the first written source of information on the topic available in the UK. It was the technical bible when I was doing my instructor quals at the time. Things have moved on of course but I still think "Figure of Eight on a Bight" is more accurate than "bunny knot". I also recognise that this is a rather contrarian view and probably a waste of time.

I wasn't appealing to any authority at any point in my blether. There is no authority in climbing and long may it remain so.

Nice rant, but off target.

The EDK (as originally named by US climbers seeing it for the first time in the Alps) is simply an overhand knot tied into both strands of a double rope together. The name was retained in an ironic manner, as it is a perfectly safe knot for the purpose. 

Using a Fo8 for the same purpose is an ADK (Actual Death Knot), as a Fo8 will start rolling under loads where the single overhand is still perfectly safe.

CB

The business about the Fo8 on a bight actually goes right back to Bill March's "Improvised Techniques in Mountain Rescue". Published in the mid 1970's it was the first written source of information on the topic available in the UK. It was the technical bible when I was doing my instructor quals at the time. Things have moved on of course but I still think "Figure of Eight on a Bight" is more accurate than "bunny knot". I also recognise that this is a rather contrarian view and probably a waste of time.

Agree with you completely (as another aging climber). Cragrat

To answer the original posters question:

The reason why there are so many names for a particular knot species (within the outdoor recreation community) is down to the fact that abseilers/climbers/mountaineers/canyoners/cavers are users of knots. They are generally not experts in knot theory.
And this is not intended as a slur or insult - it is simply a statement of fact.
An analogy is computers.
Most people are competent users of computers (and this includes mobile/cell phones) but, they know little about the components and how they work 'under-the bonnet'.
The same goes for cars/vehicles, most people can drive a car but they generally know little about what goes on underneath-the-bonnet. If something goes wrong - you seek out a automotive mechanic who specializes in that type of vehicle.

With regard to knots - theoreticians refer to the Ashley Book of Knots (ABoK) as the primary reference source.
At illustration #1673 and #1694, you will find a structure that resembles a "Girth hitch".
The key difference between these illustrations is the presence of a tail (a rope end).
#1673 (Cow hitch / Lanyard hitch) is tied at the end of a rope.
#1694 (Strap hitch / Bale sling hitch) is tied-in-the-bight (TIB).

The distinction of 'TIB' is very important to knot theoreticians.

Most climbers will tie #1694 via the 'TIB' method - and there wont be a 'tail'.
Imagine a round sling, and you 'choke' that sling around an object - this is what most climbers refer to as a 'Girth hitch' (or larks foot).

The universal scientific name is therefore #1694.

...

At illustration #1047 - we find the Figure 8 eye knot (F8 eye knot).
There are two ways of tying the F8 eye knot:
1. Via the 'TIB' method; and
2. Via the 're-threaded/re-traced' method.

Regardless of which tying method is used - the end result is the same. Its #1047 F8 eye knot.

...

The Offset overhand bend is found at #1410.
The silly and unfortunate name given to #1410 by climbers is 'EDK'.
The term 'offset' refers to the knot core being displaced from the axis-of-tension.
Only an offset knot structure will easily translate around a 90 degree edge.

...

At illustration #1085 we see the Double Figure 8 loop knot (aka 'Bunny ears').
#1047 and #1085 are different knot species.
#1085 has 2 'eyes' - and each eye can be size adjusted.
When adjusting one eye, it has a corresponding opposite effect on the second eye.
For example, if you adjust one of the eyes to be smaller, the corresponding effect on the second eye is that it become larger.
Adjustments are made via the communicating rope segment.

...

Per Andy Long:
#1010 Simple Bowline is built from a single nipping loop.
#1013 Double Bowline is built from a double nipping loop.

A 'nipping loop' is loaded at both ends and has  a defined chirality (either S or Z).

Only a 'loop' can have chirality.
The fixed eye(s) in a 'Bowline' are not loops (they are more properly defined as an 'eye').
Another example is #1047 F8 eye knot.
The 'eye' of the F8 does not have chirality (because only a loop can have chirality).

In #1080 Bowline-on-a-bight, there are 2 fixed 'eyes'.
This knot is not inherently secure (you have to take further measures to lock down the structure).
Also, it only has the standard 2 rope diameters inside the nipping loop.
If you are going to tie-in with a 'Bowline' - it would be more logical to select one of the inherently secure Bowlines (eg EBSB Bowline, Scotts locked Bowline, Harry Butlers Yosemite Bowline, etc) which all have 3 rope diameters inside the nipping loop.

What does inherently insecure mean for practical purposes? A bowline-on-a-bight/retraced bowline as used for tying in would have a hard time coming undone, the entire re-thread would have to unthread itself and then the bowline shake lose. I mean, I'd always advocate a stopper knot as well what is the actual concern? A Yosemite bowline has its own issues and the other variants are not very widely known.

In Welsh we have "Cwlwm Diafol" - Devil's Knot. This is any knot that has been weighted until it's impossible to untie!