Rope diameter in hanging – thick vs. thin ropes

[AreWeWinning]

TL;DR Rope diameter may not matter much. Thicker ropes may just be as effective as thinner ones.

I usually follow threads about hanging, and the consensus appears to be that the rope shouldn't be too thick, because it may not block blood flow effectively. The logic is that surface area is inversely proportional to pressure, so for a given force, a thinner rope creates more pressure and blocks blood flow more effectively.

I have also been convinced that a thicker rope is less effective and can be problematic. However, I'm beginning to doubt whether this is really true. In this post, I'll explain what I mean. I'm also interested if anyone has any thoughts or personal experiences regarding this.

Research on tourniquets

What got me thinking is the scientific research on tourniquets (source). Research says that wider tourniquets are more effective at stopping blood flow and require less pressure. Note that contact pressure is not the same as the force used to tighten the tourniquet. Still, the relationship between width and required pressure cannot be ignored and is quite relevant.

Rules of physics:

• For a given pressure, force is proportional to surface area. So if the required pressure were constant, wider tourniquets would require proportionally greater pulling force.
• For a given surface area, force is proportional to pressure. So for the same tourniquet width, less pressure means less pulling force.

Let's consider both effects together. Wider tourniquets need lower pressure. Although the greater width of the tourniquet increases the pulling force required, that effect may be partly (or entirely) offset by the lower pressure needed to stop blood flow. In other words, wider tourniquets may need slightly less, slightly more, or a similar amount of pulling force to be effective.

I don't know how to calculate the pulling force from the pressure when it comes to tourniquets or ropes. However, I have a feeling that the idea of thicker ropes being less effective in hanging may be false. When it comes to ropes, it may not matter too much whether a rope's width is 12, 16, 20, or 25 mm (1/2, 5/8, 3/4, or 1 inch). A slightly thicker rope may be just as effective, or the difference may be insignificant.

Anecdotal evidence

First, there's anecdotal evidence to support this idea. For example, when I test losing consciousness, it doesn't matter whether I use a thin rope, a thick rope, or a belt. Seemingly, the amount of force I need to apply is roughly the same.

I'm not saying that using something overly thick (e.g. a bedsheet) would also work well. However when the thickness of the ligature is within reasonable limits (e.g. it's an actual rope), there is no practical difference in effectiveness in my experience.

Rope ≠ tourniquet

Research on tourniquets usually discusses standard-size tourniquets, typically 3.8 cm (1.5 inches) wide or wider. These tourniquets behave slightly differently from ropes, because ropes are usually 25 mm (1 inch) or less in diameter.

What's interesting is that the phenomenon I described above – that wider tourniquets require less pressure – is much more pronounced with narrower tourniquets. This is especially relevant when it comes to ropes, because ropes are quite narrow to begin with. If a tourniquet (or rope) is quite narrow, the pressure required to stop blood flow drops sharply as its width is increased. This effect is clearly visible in the graph below. (Source: Occlusion of Arterial Flow in the Extremities at Subsystolic Pressures Through the Use of Wide Tourniquet Cuffs, 1993, Graham et al.)



I think this graph is very relevant when it comes to ropes around the neck. Any rope below about 25 mm (or 1 inch) would fall within the far left portion of the graph. This means that a thicker rope will require significantly less pressure to stop blood flow. I believe this is the reason why slightly thicker ropes work equally well as thinner ones.

Mechanism of action

It's also interesting to consider the reason why wider tourniquets require less pressure. I have looked at some research papers, and as far as I can tell, the exact physical or physiological mechanism is not known.

What is known is that surface pressure at the skin doesn't translate well to deeper tissues. This is why narrower tourniquets are less effective. The pressure has to be quite high to pinch and completely shut the arteries.

With wider tourniquets, surface pressure translates more effectively into deeper tissues. They may not shut the arteries completely, but even just compressing them over a longer section may create enough friction resistance to stop blood flow. As one research paper puts it:

It is possible that the different patterns of tissue pressure beneath narrow and wide tourniquets are associated with different mechanisms of flow reduction through compressed vessels. If a wide cuff produces a deformation in an artery that parallels its pressure profile, then blood flow would approach zero even without total collapse of the vessel because of the accumulation of frictional resistance to flow along the compressed length. On the other hand, flow elimination with a narrow cuff might require a pressure sufficient to collapse the vessel completely. Current models of flow in collapsible tubes have not explicitly considered this case. (internal citations omitted) (Source: Wide tourniquets eliminate blood flow at low inflation pressures, 1987, Moore et al.)​

So, what do you think? Are thicker ropes less effective, more effective, or is there no significant difference? What's your analysis or personal experience?

 

[JesiBel]

It's an interesting debate; I hope more users will participate.

I'm leaving a short draft exploring on the topic. I'm not a physics expert, so please correct me if I make any mistakes. I tried to explain it with my own limited words.

---

I think the action mechanisms of a tourniquet and a ligature (on the neck) are very different (although both require external pressure to compress the blood vessels).

• Tourniquet:

Mechanical tension (manual, own physical strength), circumferential pressure to a limb. The force is controlled to compress deep arteries (that are under thick muscles) against a bone.

Pressure distribution: distribute pressure over a larger surface area ('wide' bands), to reach deep vessels while minimizing localized damage to the skin, nerves, and superficial tissues.

• Ligature (hanging):

The force is created by gravity pulling down on the body mass. Directional tension, toward a specific point of suspension (anchor point). Increased pressure on the front and sides of the neck (using a self-tightening knot)

Pressure distribution: concentrate force onto a small surface area (ropes, cables, cargo straps, more or less "narrow" materials). The concentration leads to high localized pressure (V shaped mark on the neck).

The blood vessels on the neck (carotid arteries and jugular veins) are more superficial where the muscle layer is thinner and vulnerable to external pressure.

Smaller Area = Greater Pressure

If you increase the weight/force but keep the area the same, pressure increases.

(A person of little weight and a very thick rope would not be a good idea)

If you keep the weight/force the same but reduce the area, pressure increases.

1) For example: Hanging 20 kg weight tied on a leg.
(The force stays exactly the same in both cases, 20 kg, downward pull)

Thin rope: Small contact area - High pressure - Divides the force into a small space, causing the rope to dig into the flesh. More localized pressure.

Thick rope: Large contact area - Low pressure - Spreads the exact same force over a wider surface.

2) Changing the force (weight) and changing the area (rope thickness):

Example 1: Thick Rope + 10 kg weight tied on a leg, downward pull

10 kg creates a smaller pulling force
The thick rope spreads this small force over a wide surface (area).
A small force spread over a large area results in small pressure.

Lowest pressure: the smallest force combined with the largest area.

Example 2: Thin Rope + 20 kg weight tied on a leg, downward pull

20 kg doubles the pulling force
The thin rope compresses this heavier force into a small area. High pressure.

Highest pressure: the largest force combined with the smallest area.

---

From a practical view point: tying knots with a very thick rope is more awkward; they are more rigid and resist tight bends.

They would make some setups impossible since they wouldn't fit in certain places (for example, the rope over the door, passing the rope through a narrow gap).

In terms of effectiveness, I suppose it's how that force is distributed and the pressure it exerts.

Early studies suggested that little weight was needed to occlude the blood vessels in the neck; even now, several forensic texts still cite this table:



This appears to be incorrect, as these numbers were obtained in experiments with corpses, applying force perpendicularly to the blood vessels (corpse lying on a surface) and not obliquely as would happen in a real hanging case.

So it could be a combination of the person's weight and the material used to exert pressure.

 

[AreWeWinning]

@JesiBel Thanks for your comment! I was beginning to wonder whether anyone would respond at all, and whether this question is too complex.

Regarding your comment, I think you may have missed some of the points I was making. Below, I'll try to highlight what they are.

Tourniquets vs. ropes

I think the action mechanisms of a tourniquet and a ligature (on the neck) are very different (although both require external pressure to compress the blood vessels).

• Tourniquet:

Mechanical tension (manual, own physical strength), circumferential pressure to a limb. The force is controlled to compress deep arteries (that are under thick muscles) against a bone.

Pressure distribution: distribute pressure over a larger surface area ('wide' bands), to reach deep vessels while minimizing localized damage to the skin, nerves, and superficial tissues.

• Ligature (hanging):

The force is created by gravity pulling down on the body mass. Directional tension, toward a specific point of suspension (anchor point). Increased pressure on the front and sides of the neck (using a self-tightening knot)

Pressure distribution: concentrate force onto a small surface area (ropes, cables, cargo straps, more or less "narrow" materials). The concentration leads to high localized pressure (V shaped mark on the neck).

I don't think tourniquets and ligatures (e.g. ropes) are very different. I think they're directly comparable. The only real difference is thickness, but this is why we're discussing them in the first place.

The question is not whether the force is circumferential or directional but how surface pressure translates to deeper tissues. The tissue doesn't "know" which direction the force is coming from. Regardless of the direction, the pressure caused by a thin ligature doesn't translate well to deeper tissues, where the arteries are located.

It is true that thinner ligatures create more concentrated pressure, but that fact does not undermine the argument: concentrated pressure is not required and may be less effective at stopping blood flow. If a ligature is very narrow (e.g. a rope) to begin with, increasing its width has a substantial effect: as width increases, the required pressure decreases steeply. This is clearly visible from the graph I posted.

On the graph I posted, ropes around the neck fall at the very left edge of the graph. An average neck circumference of 350 mm and an average rope width of 16 mm gives a Width/Circumference ratio of about 0.05. Look at where this is on the horizontal axis. In those ranges, even a minimal increase in ligature width results in a significant drop in required pressure.

Location of the arteries

The blood vessels on the neck (carotid arteries and jugular veins) are more superficial where the muscle layer is thinner and vulnerable to external pressure.

This isn't quite accurate. The carotid arteries run deep within the neck. The distance from the skin is similar to what it is at other parts of the body, e.g. the arms or the legs.

The veins are the vessels that are closer to the surface. This is also similar to how it is at other parts of the body.

Pressure vs. force

If you keep the weight/force the same but reduce the area, pressure increases.

1) For example: Hanging 20 kg weight tied on a leg.
(The force stays exactly the same in both cases, 20 kg, downward pull)

Thin rope: Small contact area - High pressure - Divides the force into a small space, causing the rope to dig into the flesh. More localized pressure.

Thick rope: Large contact area - Low pressure - Spreads the exact same force over a wider surface.

2) Changing the force (weight) and changing the area (rope thickness):

Example 1: Thick Rope + 10 kg weight tied on a leg, downward pull

10 kg creates a smaller pulling force
The thick rope spreads this small force over a wide surface (area).
A small force spread over a large area results in small pressure.

Lowest pressure: the smallest force combined with the largest area.

Example 2: Thin Rope + 20 kg weight tied on a leg, downward pull

20 kg doubles the pulling force
The thin rope compresses this heavier force into a small area. High pressure.

Highest pressure: the largest force combined with the smallest area.

I understand the relationship between pressure, force, and surface area. I very briefly commented on this in my post, in section "Research on tourniquets", under "Rules of physics". I understand that for a given force, thinner ligatures create more pressure and may be more likely to completely close the arteries.

However, research shows that complete closure of the arteries is not necessary. Quite the contrary: partially compressing arteries over a larger segment may effectively stop blood flow. This is why a narrow ligature and high amount of pressure aren't required, and this is why wider ligatures may be effective even if they produce less pressure.

Considering physics and the required force, the relationship roughly looks like this:

• Same pressure requirement and thinner ligature ➡ less force required
• Same pressure requirement and thicker ligature ➡ more force required
• Less required pressure and thicker ligature ➡ a similar amount of force required

You may still wonder why it isn't necessary to completely compress the arteries to stop blood flow. First, we don't really need to know the exact reason, because experiments have already confirmed that it isn't necessary, and that wider ligatures are effective at lower pressures. Still, it's interesting to think about the why. The exact mechanism is unclear but likely related to blood viscosity and frictional resistance. Here is a study that discusses this:

The manner in which arterial flow is impeded by a wide tourniquet inflated to subsystolic pressure is not known. The analysis of blood flow within a collapsible tube is complex, owing to the non-Newtonian characteristics of blood, its variable viscosity under conditions of changing shear rates, and the autoregulation of biologic systems. The authors concur with Moore et al., however, that accumulation of frictional resistance along a segment of a blood vessel that is partially collapsed under a low-pressure pneumatic tourniquet may completely eliminate flow without actual occlusion of the vessel lumen. (internal citations omitted) (Source: Occlusion of Arterial Flow in the Extremities at Subsystolic Pressures, 1993, Graham et al.)

Thick ropes are awkward to work with

From a practical view point: tying knots with a very thick rope is more awkward; they are more rigid and resist tight bends.

This is a valid point, and I agree. An overly thick rope can be awkward to work with and is unnecessary. It is an important point to consider when choosing a rope.

Currently, I think any rope is fine as long as it is (a) strong enough and (b) easy to work with. Thicker ropes can be too stiff, which is not ideal. However, a slightly thicker rope (e.g. up to about 18–20 mm or 3/4 inch) should be fine if it's soft and easy to handle. Note that I'm talking about ropes. I still wouldn't recommend using something overly thick, like a bedsheet. I would also be cautious about using too much padding.

Early studies on forces required

Early studies suggested that little weight was needed to occlude the blood vessels in the neck; even now, several forensic texts still cite this table:

This appears to be incorrect, as these numbers were obtained in experiments with corpses, applying force perpendicularly to the blood vessels (corpse lying on a surface) and not obliquely as would happen in a real hanging case.

Yes, I agree that those values may not be accurate. I'm not really sure how to interpret them. Personally, I feel like I have to apply more than 5 kg of force to lose consciousness. However, this is not very relevant to the points I'm making regarding rope thickness vs. effectiveness.

So, have you experimented with losing consciousness? Is there a big difference in the amount of force you need to apply when you use a thinner or thicker rope, or when you use a belt or a strap?

 

[Gustav Hartmann]

The pressure p on a cylinder, for example a neck or extremity is equal to the circumferencial force F divided by the radius of the cylinder r and the width d of the rope around the cylinder.

p = F/(d×r)

You can test this: Put your wrist in a noose and hang on your wrist and than put a noose around your thighs and hang on it. The pressure on the wrist is much higher. The radius of an elastic cylinder, like your neck will become smaller under pressure, so this effect is self-reinforcing. Regarding hanging: F is proportional to the bodyweight and a heavier person has normally a thicker neck, so this effect is compensated.

You can do the above test with different rope-diameters and you will find out that thinner ropes hurt much more. Imagine the effect of thin steel-wire used as a garrotte.

When I used my karate-belt for hanging, I observed that the belt is rolling around his longitudinal-axis, so that the full width cannot be applied.

I agree that a thick rope will exert enough pressure on the neck because the pressure to block the arteries is suprisingly low.

I don't understand how they found the formula that is presented in the graph. Obviously they think that the pressure on the neck must be higher than the blood pressure, what is true in principle. But with respect to hanging the pressure must be higher than the deformation resistance of the neck tissue. The intersection of rope and blood vessel is so small, that the blood pressure is irrelevant. When the rope digs into the neck the vessels are closed, no matter how high the blood pressure is.

I doubt, that the surface pressure on the skin doesn't translate well to the deeper tissue, because 75% of the tissue is water.

 

[AreWeWinning]

The pressure p on a cylinder, for example a neck or extremity is equal to the circumferencial force F divided by the radius of the cylinder r and the width d of the rope around the cylinder.

p = F/(d×r)

You can test this: Put your wrist in a noose and hang on your wrist and than put a noose around your thighs and hang on it. The pressure on the wrist is much higher. The radius of an elastic cylinder, like your neck will become smaller under pressure, so this effect is self-reinforcing. Regarding hanging: F is proportional to the bodyweight and a heavier person has normally a thicker neck, so this effect is compensated.

This is an interesting point, which I hadn't thought of. However, it doesn't really change my analysis. It makes sense that pressure is inversely proportional to limb (or neck) circumference, since reducing circumference reduces the surface area. We already know that reducing surface area increases pressure.

In any case, after reading your comment, I noticed another interesting fact which I hadn't considered: the graph I posted doesn't show whether the lower required pressure is a result of increased width or reduced circumference. Maybe this is also what you had in mind when you wrote your comment. While the graph may not be proof in itself, the study, and many other studies that did their own tests, explicitly make the claim that wider tourniquets require less pressure to work. The researchers who wrote these studies are generally smarter than us (at least speaking for myself), so I'm quite confident that they've compared various tourniquet widths on similar limb sizes before they came to their conclusion.

When I used my karate-belt for hanging, I observed that the belt is rolling around his longitudinal-axis, so that the full width cannot be applied.

I agree that a thick rope will exert enough pressure on the neck because the pressure to block the arteries is suprisingly low.

Regarding rope thickness, if I remember correctly from one of your earlier posts, are you planning to use a rope that's about 20 mm in diameter?

I don't understand how they found the formula that is presented in the graph. Obviously they think that the pressure on the neck must be higher than the blood pressure, what is true in principle. But with respect to hanging the pressure must be higher than the deformation resistance of the neck tissue. The intersection of rope and blood vessel is so small, that the blood pressure is irrelevant. When the rope digs into the neck the vessels are closed, no matter how high the blood pressure is.

I doubt, that the surface pressure on the skin doesn't translate well to the deeper tissue, because 75% of the tissue is water.

I'm not sure what your main point is here, but here are some thoughts that come to mind.

Regarding the graph, they didn't use a formula. They simply did the tests and plotted the results.

In my opinion, the fact that tissue is 75% water may be precisely why surface pressure isn't transmitted directly to an artery that is 1–3 cm below the surface. When the ligature digs into the tissue and pushes some tissue sideways, away from the ligature, this also requires force, which in turn reduces the force transmitted downward. Think of it this way: if you put a tube on a table and put a block of jelly over it, it takes more pressure to fully compress the tube by pressing on the jelly than it would if you pressed directly on the tube.

According to studies, it's not necessary to completely shut the artery to stop blood flow.

Regardless of the specifics, it seems we agree that a thick rope can still block the arteries. This is my main point. Rope thickness is not as important as some people may think, as long as it's within reasonable limits and the rope is easy to handle. Obviously, the rope also has to be strong enough.

 

[iminhell]

Would 10mm work for sure if person is 110 lbs?

 

[iminhell]

Would 10mm work for sure if person is 110 lbs?

Bumping this because urgent. Thank you.
If you think 12mm is better for 110lb person with thin neck, please tell me.

Is it preferred for comfort reasons? Or for strength, i.e. able to hold weight.

I thought 10mm is easier to make knots and also more effective.

Please reply, thank you

 

[AreWeWinning]

Bumping this because urgent. Thank you.
If you think 12mm is better for 110lb person with thin neck, please tell me.

Is it preferred for comfort reasons? Or for strength, i.e. able to hold weight.

I thought 10mm is easier to make knots and also more effective.

Please reply, thank you

I understand that this is urgent, but I would prefer a more general discussion about rope thickness in this thread. If someone has personal experiences with thicker ropes, those comments would also be welcome! Regarding your specific question, I see you've already created another thread, so I'll reply there.

 

[JesiBel]

@JesiBel Thanks for your comment! I was beginning to wonder whether anyone would respond at all, and whether this question is too complex.

Regarding your comment, I think you may have missed some of the points I was making. Below, I'll try to highlight what they are.

Tourniquets vs. ropes

I don't think tourniquets and ligatures (e.g. ropes) are very different. I think they're directly comparable. The only real difference is thickness, but this is why we're discussing them in the first place.

The question is not whether the force is circumferential or directional but how surface pressure translates to deeper tissues. The tissue doesn't "know" which direction the force is coming from. Regardless of the direction, the pressure caused by a thin ligature doesn't translate well to deeper tissues, where the arteries are located.

It is true that thinner ligatures create more concentrated pressure, but that fact does not undermine the argument: concentrated pressure is not required and may be less effective at stopping blood flow. If a ligature is very narrow (e.g. a rope) to begin with, increasing its width has a substantial effect: as width increases, the required pressure decreases steeply. This is clearly visible from the graph I posted.

On the graph I posted, ropes around the neck fall at the very left edge of the graph. An average neck circumference of 350 mm and an average rope width of 16 mm gives a Width/Circumference ratio of about 0.05. Look at where this is on the horizontal axis. In those ranges, even a minimal increase in ligature width results in a significant drop in required pressure.

Location of the arteries

This isn't quite accurate. The carotid arteries run deep within the neck. The distance from the skin is similar to what it is at other parts of the body, e.g. the arms or the legs.

The veins are the vessels that are closer to the surface. This is also similar to how it is at other parts of the body.

Pressure vs. force

I understand the relationship between pressure, force, and surface area. I very briefly commented on this in my post, in section "Research on tourniquets", under "Rules of physics". I understand that for a given force, thinner ligatures create more pressure and may be more likely to completely close the arteries.

However, research shows that complete closure of the arteries is not necessary. Quite the contrary: partially compressing arteries over a larger segment may effectively stop blood flow. This is why a narrow ligature and high amount of pressure aren't required, and this is why wider ligatures may be effective even if they produce less pressure.

Considering physics and the required force, the relationship roughly looks like this:

• Same pressure requirement and thinner ligature ➡ less force required
• Same pressure requirement and thicker ligature ➡ more force required
• Less required pressure and thicker ligature ➡ a similar amount of force required

You may still wonder why it isn't necessary to completely compress the arteries to stop blood flow. First, we don't really need to know the exact reason, because experiments have already confirmed that it isn't necessary, and that wider ligatures are effective at lower pressures. Still, it's interesting to think about the why. The exact mechanism is unclear but likely related to blood viscosity and frictional resistance. Here is a study that discusses this:

​

Thick ropes are awkward to work with

This is a valid point, and I agree. An overly thick rope can be awkward to work with and is unnecessary. It is an important point to consider when choosing a rope.

Currently, I think any rope is fine as long as it is (a) strong enough and (b) easy to work with. Thicker ropes can be too stiff, which is not ideal. However, a slightly thicker rope (e.g. up to about 18–20 mm or 3/4 inch) should be fine if it's soft and easy to handle. Note that I'm talking about ropes. I still wouldn't recommend using something overly thick, like a bedsheet. I would also be cautious about using too much padding.

Early studies on forces required

Yes, I agree that those values may not be accurate. I'm not really sure how to interpret them. Personally, I feel like I have to apply more than 5 kg of force to lose consciousness. However, this is not very relevant to the points I'm making regarding rope thickness vs. effectiveness.

So, have you experimented with losing consciousness? Is there a big difference in the amount of force you need to apply when you use a thinner or thicker rope, or when you use a belt or a strap?

Hello! Sorry for late reply.


A tourniquet could be considered similar to the ligature strangulation method.

• Force angle: horizontal, compress the neck uniformly. The material used is wrapped around the neck (limbs if it were a tourniquet), exerting pressure equally around the entire circumference.

You rely on your own strength here to tie the material as tightly as possible.

Hanging (Full/Partial)

• Force angle: directed upward and obliquely toward the anchor point.

The ligature (Arbor Knot), closes itself around the neck, but does not exert full circumferential pressure. The pressure will be less at the back of the neck, where the knot rests and the rope ascends toward the anchor point. The greatest concentration of this pressure will be at the front and sides of the neck, in that order.

Here you rely on gravity and your weight (gravity pulls the body mass downward).

Example, all the cases of Partial Hanging in the forum. Those of little weight and using belts/bed sheets or other "wide" materials. And their frequent "exploding head syndrome".

By this I mean that one cannot speak in isolation about the material used without taking into account all the variables.

I don't know if what I'm trying to say is clearer now.

Speaking of deep tissue, it's weird to compare the limbs and the neck. The muscle mass is very different. You'll undoubtedly need to reach more pressure in a thigh* to block the arteries than in the neck.

*and around the entire circumference, since they are almost located in the center of the leg

So, up to this point, thinking of Hanging as if we had a tourniquet around our neck doesn't seem very accurate to me.

Spoiler: Blood vessels, sensitive content

When you say "as width increases, the required pressure decreases steeply". Yes, the diagram is about tourniquets. As I said before, the mechanism in Hanging is different; you must also take into account the person's weight and the other variables I mentioned.

I know pressure is distributed across various anatomical structures before reaching the arteries.
When the force is applied to the skin (surface); it propagates through deeper layers. Adipose and connective tissue (more elastic), muscles (more dense), cartilage (airway), blood vessels ("fluid-filled tubular tissue"). When the external pressure exceeds the internal fluid pressure, the vessel collapses and stops the blood flow.

Considering the standard size of a tourniquet, would a thick 38 mm (1.5 inches) rope/material be a good option? Including people of low weight (40-50 kg). The contact area is very large. It remains to be tested.

---

I was looking for a formula that could be better adapted for Hanging, and I found this:

Article:

P-value is directly proportional to the loop tension and inversely proportional to the radius of the curvature and neck-ligature contact area.

Thus, in horizontal neck encirclement the strangulation groove forms a circumference, and P-value is invariable along the loop, as in typical cases of homicidal strangulation (my note: also ligature strangulation).

In oblique position of the loop it makes an ellipse with changeable curve curvature, as in most hangings.

Pressure on the neck calculated for any point along the ligature. Vladislav D. Khokhlov

Full pdf

Feel free to correct my "analysis attempt".

Pressure (P) on the neck is directly proportional to loop tension (T), and inversely proportional to the radius of curvature (R) and the neck-ligature contact width/area (W).

• • Loop Tension (T): If tension increases, pressure increases.

Tension is the pulling force acting along the length of the rope (gravity + body's mass downward)

More body weight increases tension (T), which directly increase the pressure (P) on neck tissues.

In Partial Hanging Suspension, the tension (T) exerted on the ligature depends on the body posture and the degree of contact with the ground. Small changes in position can change the pressure pattern.

•• Ligature Width (W): If the ligature width increases, the pressure (P) decreases.

A wider ligature (like a thick scarf, belt) spreads the tension across a larger surface area of skin. Distribute the pressure widely, leaving minimal or no visible external marks.

A narrow ligature (like a cable, 'normal' rope) concentrates that same force into a smaller area. More localized pressure, leaving deep furrow marks.

•• Radius of curvature (R): Pressure (P) increases as the radius of curvature (R) decreases. A tighter bend of the ligature around the neck concentrates the force over a smaller curved surface, increasing local pressure.

Oblique loop (Hanging): The pressure of the ligature on the neck structures is greatest on the side opposite the ligature knot (that is behind the neck). The loop is slanted, and the pressure changes at different points.

Horizontal loop (Ligature strangulation): it forms a circle; the pressure value stays the same at every point along the loop.

---

Regarding the questions... Right now, I have a 8 and 12 mm rope. I have a slender neck (27 cm circumference) and low body weight.

I doubled up the 8 mm rope to make a 16 mm one, and it worked fine, it was quick (vision began to darken, and the legs began to feel weak), perhaps the difference wasn't all that significant. I just bent my knees to let my weight drop (I was standing with the Arbor Knot already around the neck, I threw the rope over the edge of the door, and was holding the other end of the rope with one hand).

With the 12 mm one, I don't have enough length to double it up.

I tried with a belt (about 4 cm wide), it felt somewhat uncomfortable; it was too flat and wide. I pulled hard on the end to apply pressure, as if it were a ligature strangulation.

 

[Gustav Hartmann]

Hello! Sorry for late reply.


A tourniquet could be considered similar to the ligature strangulation method.

• Force angle: horizontal, compress the neck uniformly. The material used is wrapped around the neck (limbs if it were a tourniquet), exerting pressure equally around the entire circumference.

You rely on your own strength here to tie the material as tightly as possible.

Hanging (Full/Partial)

• Force angle: directed upward and obliquely toward the anchor point.

The ligature (Arbor Knot), closes itself around the neck, but does not exert full circumferential pressure. The pressure will be less at the back of the neck, where the knot rests and the rope ascends toward the anchor point. The greatest concentration of this pressure will be at the front and sides of the neck, in that order.

Here you rely on gravity and your weight (gravity pulls the body mass downward).

Example, all the cases of Partial Hanging in the forum. Those of little weight and using belts/bed sheets or other "wide" materials. And their frequent "exploding head syndrome".

By this I mean that one cannot speak in isolation about the material used without taking into account all the variables.

I don't know if what I'm trying to say is clearer now.

Speaking of deep tissue, it's weird to compare the limbs and the neck. The muscle mass is very different. You'll undoubtedly need to reach more pressure in a thigh* to block the arteries than in the neck.

*and around the entire circumference, since they are almost located in the center of the leg

So, up to this point, thinking of Hanging as if we had a tourniquet around our neck doesn't seem very accurate to me.

Spoiler: Blood vessels, sensitive content

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When you say "as width increases, the required pressure decreases steeply". Yes, the diagram is about tourniquets. As I said before, the mechanism in Hanging is different; you must also take into account the person's weight and the other variables I mentioned.

I know pressure is distributed across various anatomical structures before reaching the arteries.
When the force is applied to the skin (surface); it propagates through deeper layers. Adipose and connective tissue (more elastic), muscles (more dense), cartilage (airway), blood vessels ("fluid-filled tubular tissue"). When the external pressure exceeds the internal fluid pressure, the vessel collapses and stops the blood flow.

Considering the standard size of a tourniquet, would a thick 38 mm (1.5 inches) rope/material be a good option? Including people of low weight (40-50 kg). The contact area is very large. It remains to be tested.

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I was looking for a formula that could be better adapted for Hanging, and I found this:

Article:

P-value is directly proportional to the loop tension and inversely proportional to the radius of the curvature and neck-ligature contact area.

Thus, in horizontal neck encirclement the strangulation groove forms a circumference, and P-value is invariable along the loop, as in typical cases of homicidal strangulation (my note: also ligature strangulation).

In oblique position of the loop it makes an ellipse with changeable curve curvature, as in most hangings.

Pressure on the neck calculated for any point along the ligature. Vladislav D. Khokhlov

Full pdf

Feel free to correct my "analysis attempt".

Pressure (P) on the neck is directly proportional to loop tension (T), and inversely proportional to the radius of curvature (R) and the neck-ligature contact width/area (W).

• • Loop Tension (T): If tension increases, pressure increases.

Tension is the pulling force acting along the length of the rope (gravity + body's mass downward)

More body weight increases tension (T), which directly increase the pressure (P) on neck tissues.

In Partial Hanging Suspension, the tension (T) exerted on the ligature depends on the body posture and the degree of contact with the ground. Small changes in position can change the pressure pattern.

•• Ligature Width (W): If the ligature width increases, the pressure (P) decreases.

A wider ligature (like a thick scarf, belt) spreads the tension across a larger surface area of skin. Distribute the pressure widely, leaving minimal or no visible external marks.

A narrow ligature (like a cable, 'normal' rope) concentrates that same force into a smaller area. More localized pressure, leaving deep furrow marks.

•• Radius of curvature (R): Pressure (P) increases as the radius of curvature (R) decreases. A tighter bend of the ligature around the neck concentrates the force over a smaller curved surface, increasing local pressure.

Oblique loop (Hanging): The pressure of the ligature on the neck structures is greatest on the side opposite the ligature knot (that is behind the neck). The loop is slanted, and the pressure changes at different points.

Horizontal loop (Ligature strangulation): it forms a circle; the pressure value stays the same at every point along the loop.

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Regarding the questions... Right now, I have a 8 and 12 mm rope. I have a slender neck (27 cm circumference) and low body weight.

I doubled up the 8 mm rope to make a 16 mm one, and it worked fine, it was quick (vision began to darken, and the legs began to feel weak), perhaps the difference wasn't all that significant. I just bent my knees to let my weight drop (I was standing with the Arbor Knot already around the neck, I threw the rope over the edge of the door, and was holding the other end of the rope with one hand).

With the 12 mm one, I don't have enough length to double it up.

I tried with a belt (about 4 cm wide), it felt somewhat uncomfortable; it was too flat and wide. I pulled hard on the end to apply pressure, as if it were a ligature strangulation.

Your analysis is completely correct. I wrote the exact formula above. It matches yours if you set
T = F/A
where A is the cross-sectional area of the rope.

The formula
p = F/(d*r)
is frequently used in engineering mechanics; any mechanical engineer can derive it in their sleep.

In my opinion, the fact that tissue is 75% water may be precisely why surface pressure isn't transmitted directly to an artery that is 1–3 cm below the surface. When the ligature digs into the tissue and pushes some tissue sideways, away from the ligature, this also requires force, which in turn reduces the force transmitted downward. Think of it this way: if you put a tube on a table and put a block of jelly over it, it takes more pressure to fully compress the tube by pressing on the jelly than it would if you pressed directly on the tube.

With a single force, for example, when you press your finger against the neck, the pressure does not spread downwards. In elasticity theory, the case of a single force acting on an elastic half-space has often been studied. It is relevant in soil mechanics.

When hanging, we have a completely different situation, which can be well represented by an elastic cylinder under external pressure. In this case, the external pressure acts across the entire cross-section of the cylinder as if it were a fluid. You can verify this using elasticity theory, specifically the formulas for rotationally symmetric stress.

If the rope digs into the neck and pushes the tissue sideways, the pressure does work, but the pressure itself is not reduced.

 

[AreWeWinning]

@JesiBel, @Gustav Hartmann, thanks for the reply!

I brought up the studies on tourniquets to support my argument, not to use them as a direct proof or to make a like-for-like comparison. @JesiBel, you think I'm saying that "Wider tourniquets are more effective, so wider ligatures are always more effective in hanging, and the wider they are, the better." That's not what I'm saying at all.

Considering the standard size of a tourniquet, would a thick 38 mm (1.5 inches) rope/material be a good option?

No, I do not think that. I'm talking about ropes.

The misunderstanding

Tourniquet studies show that full collapse of the arteries is not necessarily required to stop blood flow. They also show that the relationship between ligature thickness and effectiveness is more complex and nuanced than it may appear at first sight.

You're explaining to me that (a) thinner ligatures are more likely to completely collapse the arteries; (b) the circumferential force of tourniquets isn't the same as the directional force in hanging; and (c) how the relationship between pressure, loop tension, radius, and ligature width works. However, I understand these, and I fully agree with everything you say! I just don't see how any of these are relevant to my takeaways from the tourniquet studies that I highlighted above.

My main argument

My main argument is this: rope thickness doesn't matter much as long as the rope is somewhere between 10 and 20 mm (about 3/8 and 3/4 inch). It's not worth obsessing over rope width. A few millimetres' difference in diameter makes no practical difference.

I would even risk saying that a 25 mm (1 inch) cotton rope would also work well in almost all cases. Still, for practical reasons, I wouldn't recommend it, and this type of rope wouldn't be my first choice. But it would work.

What prompted this thread is that I often see people obsessing over rope thickness too much. They think they might make a critical mistake if they choose a slightly thicker or thinner rope. I think this is nonsense, and I wanted to share a few interesting things that support that view. The research on tourniquets is one of these interesting things, but not the only one.

Tourniquet research

Even without the tourniquet studies, there are reasons to think that rope thickness doesn't matter too much (more on these reasons later). Though, I felt that the research on tourniquets might also give us some interesting insights.

I didn't say that the use of tourniquets is directly comparable to hanging. Obviously, they're not the same. While I used the phrase "directly comparable" in my previous comment, I was comparing tourniquet materials to ropes and was pointing out some interesting ideas about how width affects effectiveness, in general. This wasn't a like-for-like comparison of the methods as a whole. I didn't suggest we should disregard other factors or consider rope thickness in isolation either.

At this point, I feel that focusing on the "tourniquets vs. hanging" issue and going down this rabbit hole won't move this discussion forward, because we're talking past each other.

I thought it would be helpful to mention the tourniquet studies because they raise some relevant points. But it ended up getting the discussion off track. Everyone seems to assume that I'm making a like-for-like comparison, or else they try to analyse the underlying physics in detail, while missing my main point in the process. This may be my fault, as I may not be expressing myself clearly enough, despite my best efforts.

@JesiBel, @Gustav Hartmann if you don't think tourniquet studies have anything useful to teach us about how a rope's thickness may affect its effectiveness in hanging, that's fair. We may have to agree to disagree on this one. Perhaps it's best to move on.

Forget tourniquets

Forget tourniquets for a moment. All I'm saying is this: it's hard to imagine a situation where a 16 mm (5/8 inch) or 18–20 mm (about 3/4 inch) rope wouldn't be effective, but a 12 mm (1/2 inch) rope would be. Worrying about whether a rope is slightly thicker or thinner can lead to over-analysis.

I'm not saying that a 10 mm (3/8 inch) or a 12 mm (1/2 inch) rope is a bad recommendation. It's an excellent choice! Such ropes are widely available and easy to handle. However, if someone has a slightly thicker rope, because that's what they prefer, or because that's what they found at their local hardware store, I believe that's perfectly fine too.

Even if we forget about tourniquets, there are other supporting evidence that rope thickness may not matter as much as we may think (some of which are anecdotal, but still):

• Your own experiments, @JesiBel, when you doubled up the rope
• My own experiments
• The fact that it's unclear how they calculated the 5 kg pressure that's required to block the carotid arteries and what type of ligature was used there
• The fact that in hanging, even in partial suspension, the forces on the neck are far greater than necessary
• Videos of hangings in which a wide ligature was used (examples below)

Videos where a wide ligature was used:

1. HOW THE CHOKING GAME KILLS DEMONSTRATED (YouTube) – very wide ligature; the person is very small and has low body weight
2. (NSFW) Chasing Orgasmic Bliss. Almost There 2 - LiveGore.com – relatively thick cotton rope, person has low body weight
3. (NSFW) Hanging suicide compilation - LiveGore.com – consider the first woman in the video; she uses a relatively thick ligature; she has low body weight

In video 1., the ligature is extremely wide. It covers the person's entire neck. Yet, she loses consciousness very easily. Considering this, is it reasonable to think that there's a great difference between a 12 mm (1/2 inch) and a 16 mm (5/8 inch) rope, for example?

Video 2. and 3. show controlled, erotic hangings. In both examples, they use relatively thick ligatures. My assumption is that these BDSM room setups are used by multiple people, and it seems like thicker ligatures work quite well for them. So, do we need to be really precise about rope width?

All in all, I still maintain that rope thickness is not a critical factor, and as long as a rope is strong enough, it's safe to use.

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Physics

When hanging, we have a completely different situation, which can be well represented by an elastic cylinder under external pressure. In this case, the external pressure acts across the entire cross-section of the cylinder as if it were a fluid. You can verify this using elasticity theory, specifically the formulas for rotationally symmetric stress.

I don't think that hanging is a different situation. If I wrap a tube in meat and tie a rope around the outside, the pressure on the tube will be distributed differently than if I tie the rope directly around the tube. In a soft material, pressure applied at the surface doesn't travel straight inward toward the centre. Instead, it spreads through the material in multiple directions, whether the object is cylindrical, cube-shaped, or something on a flat surface. I doubt that any formulas would tell you otherwise.

I wanted to point this out to clarify what I meant by the jelly example. However, as I already mentioned, I also feel like these deep theoretical inquiries are not moving this discussion forward at this point, because they're beside the point I was originally trying to make.

 

[JesiBel]

I don't mean to be a pain, but I want to emphasize that when we talk about Hanging, we must consider both Full and Partial. And this is where things get complicated...

[If we start attaching evidence, with videos or photos, of successful attempts, we'll see that people have used countless thicknesses and materials. From thin ropes/cords or cables to thick scarves or fabrics and other overly "improvised" materials. And they all managed to end their lives.

• Videos of successful full suspension hanging attempts
• Videos of successful partial suspension hanging attempts

So the discussion would end here; materials matter little in the face of the desire to die and despair.]

Spoiler: I'm being repetitive, ignore me

I will leave aside the tourniquets and the formulas since we will not make any progress, and the discussion is going around in circles about what has already been said.

It makes no sense (for me) to try to fit together things* that are not similar from a mechanical or physics perspective.

*A medical device (wide, flat band) designed to act in a specific way on certain parts of the body.

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Returning to the main topic...

(I will only comment on ropes, and no other material)

•• Effectiveness

1) In Full Suspension Hanging, a range of 10 mm to 20 mm as you mention could probably work. Because you use your full weight.

Each user should "test" for themselves, and see what they find more comfortable or better.

I will use myself as an example, anyway I'm not a standard for anything. Underweight person (40 kg), small build, and thin neck (I can literally see and feel my pulse in my neck). The range between 8 mm and 16 mm according to the previous testing worked. Using the 8 mm one did hurt a little.


2) In Partial Suspension Hanging (the most popular here), a range of 10 mm to 20 mm as you mention... I'm no longer very sure about this amplitude. Because you only use a portion of your weight.

I am attaching this study, which we are already very familiar with: Calculation of tension exerted on a ligature in incomplete hanging (Vladislav D. Khokhlov), Full pdf (many body positions can be observed)

A very thick rope and a position where only a small fraction of one's own weight is used would not be a good combination. And if the person has the "disadvantage" of being underweight, then it would be a problem.
We often read their vents about their characteristic "head exploding syndrome".

In the test I did with a maximum thickness of 16 mm, I was standing with my knees barely bent, so I was using almost my full weight.

Many of the users here attempt Partial with very low anchor points like the doorknob, which, when in an almost seated position, they waste a considerable amount of their weight.

In this case, it would be better to move to thinner thicknesses within the range (in my opinion).


•• Practical aspects

With the above mentioned, at this point, each user should choose a "more appropriate" range for what they choose to do.

They will need to establish if their attempt will be Full or Partial, and what setup they plan to use.

For example: if they plan to use a door as an anchor point (fairly frequent setup), a thinner rope without an internal core will allow the door to close completely. (I know not all houses and doors are the same. I'll just mention that with my 12 mm hollow braid rope I can close the door completely giving it a small push so that the rope is flattened between the frame and the top)

Without comparing or saying "it's better or not". The user should keep in mind that:

The thicker the rope... stiffer handling, bulky knots, resists tight bending. Thick ropes require more body weight/mechanical tension to fully compress the core (if it has any) and collapse the internal gaps.

In short, I prefer to be more cautious regarding all these aspects.

Because, you know, then they might say...
"Oh, X user said a range of 10 to 20 mm would work: my knots are loose, I can't get the rope through such and such a place, I tried partial lying in bed -choosing the worst position of all- and it didn't work," and that kind of thing.

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Thanks for being so patient.

 

[Gustav Hartmann]

We should not forget torniques, around the neck they are a method to kill oneself. If you cannot leave the bed they are the last way out. You only need a shoelace and a pencil.
If they are used for execution they are called garrotte.
The question, how deep the pressure goes inside the neck is also important for those who are overweight and have a fat neck, for both cases hanging and garrotting.

 

[Wreckage]

My thought on the subject is that rope stretches, which is why it is pre stretched for several hours before use. I'd like to think this would apply to short drop or no drop applications for suicide as it would for judicial hanging. So, if somebody wants to hang themselves, they'll want to spend a day to have the rope under tension - preferably as close to body weight as possible - before use.

That said, I think a steel wire or relatively narrow (10 mm or so) cable would be ideal. No stretching required and no worry about the wire or cable not providing sufficient ligature or constriction to the blood supply in the neck. Could cover the noose portion that contacts the neck with tape or rubber/silicone tubing if comfort is a concern. After that it's a matter where to secure the other end of the wire or cable. I don't think any distance drop will make much difference.


I often think this would be a good choice to go. But I think of other methods - some more creative than others - about how I want to go. I've still got a fair amount of time to consider my options.

 

[AreWeWinning]

Back to the question of rope thickness, I wanted to dig a little deeper (pun intended), so I looked at a few more studies. I found one that made specific observations about rope thickness. It's a German study by Brinkmann et al. from 1981, titled Halskompression und arterielle Obstruktion (Compression of the Neck and Arterial Obstruction). I've translated it into English via our 'beloved' AI tools. I've attached the full translation, as well as the original document. If someone's interested, the attached document has detailed notes on how the translation was made.

In the study, they measured the tensile forces required to stop blood flow using ligatures of various diameters (0.5 mm, 7 mm, and 15 mm). Basically, they used corpses, removed the specimens' brains, opened their chest, and attached tubes to the arteries and pumped water through them.

Rope thickness vs. required force

According to this study, thinner ligatures are more effective and require less force, indeed. There isn't always a great difference, but rope thickness matters, nonetheless. It looks like a difference in rope width has a more pronounced effect at higher arterial pressures.

Figure 1 shows the exact measurements the researchers made:

Spoiler: Figure 1

Strangdicke --> Ligature diameter
Zugkraft [kg] --> Tensile force [kg]
Blutdruck [mmHg] --> Blood pressure [mmHg]

Figure 1 — Horizontal ligature strangulation (at all neck levels). Plot of the occlusion forces (= tensile forces required to stop perfusion through the carotid arteries). • Individual values and ○ arithmetic means, arranged according to ligature diameter and intra-arterial pressure.​

Here are the approximate forces according to the figure:

	200 mmHg of arterial pressure	300 mmHg of arterial pressure
7 mm ligature	average about 6 kg (min: 4 kg, max: 10 kg)	average about 8 kg (min: 5 kg, max: 10 kg)
15 mm ligature	about 7 kg for all tested specimens	about 10 kg for all tested specimens

Figure 3 also shows measurements of the required force. In this figure, the researchers pulled the rope a bit upward, which is more similar to hanging. The difference in required force between a 7 mm and a 15 mm rope is greater here. However, they did this test only on 2 specimens, and the graph only shows the averages.

Spoiler: Figure 3

A. carotis --> Carotid artery
A. vertebralis --> Vertebral artery
Arrow-like markers --> Artery not yet occluded at the indicated applied force

Figure 3 — Atypical ligature strangulation with an oblique ligature course rising symmetrically toward the nape. Plot of the occlusion forces for both vessel types. Means from N = 2 specimens. Two ligature diameters (• 7 mm and ○ 15 mm). Three blood-pressure ranges. The arrow-like symbols indicate that the arteries had not yet been occluded at the stated forces.​

There are also some interesting comments about rope thickness in the Discussion section of the study.

It notes that even a ligature of considerable diameter may block the carotid arteries effectively without using excessive force. It points out that the situation may be similar with regard to partial hanging. I think the only reason they specifically mention partial hanging is that forces on the neck are reduced during partial suspension. If the observation is true for partial suspension, it must also be true for full suspension.

"It must be established that, even with a ligature of considerable diameter and during a strangulation-agonal hypertensive crisis, it is possible to occlude the carotid arteries without excessive force. Analogous conclusions may also be permissible with regard to incomplete hanging situations." (Brinkmann et al., 1981, translated using AI tools, as described in the attached file)​

The study also notes that further increases in rope thickness will eventually make the rope ineffective, although it doesn't make any specific claims regarding exactly how thick is too thick. While the study focuses on strangulation homicides here (see the quote below), I think the main point applies to hanging as well: rope thickness can't be increased indefinitely.

"The cautious conclusion is permissible, however, that, with a further increase in the thickness of the ligature and taking the perpetrator's strength into account, a point will be reached at which immediate occlusion of the carotid arteries is no longer achieved and, therefore, more prolonged resistance as well as more pronounced signs of congestion are to be expected." (Brinkmann et al., 1981, translated using AI tools, as described in the attached file)​

The authors note that things like neck circumference or rigor mortis (post-mortem rigidity) had no apparent effect on the tensile force required to block blood flow.

So that's the essence of it. I'll refrain from drawing any further conclusions here, but to me, the data in this study appears fairly clear.