Cambridge
School of Navigation John Starkie, PhD, RNR
E Echo
I am altering my course to starboard
Earring, Ease, East, Ebb tide, Echo sounder, Eddy, Eight, Electricity, Electrolysis, Elevation, Embargo, Embankment, Embark, Embayed, Emergency, Emergency wreck marker, ENC, End for end, Engine, Engine room, Ensign, EPIRB, Epoxy, Equator, Equinox, Estimated position, Estimated time of arrival, Estuary, ETA, Euphroe, EVDS, Evening, Extinguisher, Extremis, Eye bolt, Eye splice
Ear ring
Lengths of rope used to fasten the corners of a sail to a yard (or a gaff or boom).
The earring is spliced to the cringle in the sail. To stretch the sail along the yard (or boom) the earring is passed twice through a hole near the end of the spar and through the cringle and pulled tight; it is then passed around the spar and through the cringle several times before being made off with two half-hitches on the standing part.
Ease
To slacken a line little by little. To make a taut line a little slack. To ease the jib sheets is to release the tension on them and so let the sail out.
Ebb tide
When the height of tide is decreasing and the foreshore is progressively being exposed.
Vessels sailing, anchored or moored in shallow water may touch the bottom and become grounded. They might not float again until the next flood tide. If a vessel grounds within a few minutes of the top of a spring tide it may be two weeks (or several months) before it floats on another spring tide.
Echo sounder
See Sounder
East
If an observer faces toward the true North, everywhere on his right hand side is East and everywhere on her left hand side is West.
If an observer faces toward the true South, everywhere on her left hand side is East and everywhere on his right hand side is West.
'The West' is everywhere to the West of the Greenwich (Prime) meridian; 'the East' is everywhere to the East of the Prime meridian.
Colloquially, 'the West' might mean North America and Europe: 'the East' might mean the Orient. At one time there might have been an implication of cultural and technological advancement or delay which can no longer be considered appropriate (or even true).
Eddy
A nominalised adjective describing a current of water.
A current of water flowing in, perhaps, an unexpected direction and, often, a circular manner. With a tidal stream flowing around the end of a groyne or wharf the turbulence creates (or is) an eddy current.
Similarly, tidal streams around a headland create eddy currents, often circular, within the downstream bay.
Eight
n The ninth integer in the sequence of decimal numbers.
n A long, thin boat with eight oars and a cockswain. Traditionally used in races and tests of strength and speed by universities such as Cambridge, Oxford and York, and by schools and clubs with access to rivers or lakes.
Electricity
The movement of electrons through wires to be converted into heat, or light or movement.
Sources of electricity include batteries, alternators driven by engines, generators powered by engines, the wind or movement through the water, solar panels, power stations (into buildings and some boats through electrical sockets and plugs) and lightning.
Boats usually have one or more banks of electrical batteries to provide 12 volts or 24 volts for use around the boat. The electricity is used for lighting, for refrigeration and for starting the diesel engines. Small boats sometimes use electric outboard motors powered by batteries.
The batteries are recharged with electricity from alternators on the diesel engines, solar panels or wind turbines. When in a marina the boat may often be plugged in to the shore-side mains electricity to recharge the batteries and to power the on-board appliances.
Electricity can be dangerous, even at low voltages: "It's the amps wot kills yer, not the volts." Electrical wiring should be undertaken by a qualified expert.
Lightning is very dangerous and cannot be used on a boat. Many boats have conductors to carry the lightning away from the boat.
Electrolysis
When two dissimilar metals, such as steel and copper, are linked together by an electric circuit and immersed in an electrolyte (such as sea water) an electric current flows from one to the other. The flow of electricity tends to degrade and damage the metal lower in the electrochemical series than the other.
Sea water is a sufficiently good conductor of electricity to cause electrolysis of items such as keel bolts, outboard motor legs, steel hulls. To prevent damage to important metal parts most boats are fitted with sacrificial zinc anodes; zinc is lower in the electrochemical series than most metals and is preferentially degraded. Zinc anodes should be examined often and replaced as necessary.
Elevation
Height, usually above mean sea level.
Embark
To go on board a ship or boat for a voyage or cruise.
When the ship or boat leaves its moorings and gets under way for a voyage or cruise.
Embayed
When a sailing vessel is blown into a bay and trapped there by an onshore wind.
This rarely happens to modern sailing vessels which can sail close to the wind.
Emergency
A situation which may cause injury, damage or loss of life unless it receives attention in this moment.
Emergencies include fire on board, flooding of the hull and someone falling off the boat*. Medical emergencies include heart attacks, diabetes-related illness, broken bones. At times the crew cannot deal with the emergency themselves and must ask for help from outside the boat. They can set off flares or send a Mayday by radio or activate an Emergency Position-Indicating Radio Beacon (EPIRB).
*(I'm indebted to Dave Bowden for the three Fs of Safety)
Fire
Fire on board is one of the most serious emergencies imaginable.
A fire needs three things
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Something to burn, like fuel or plastic or bedding.
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Oxygen
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Heat, to start the ignition.
The causes of fire include dropped cigarette, overloaded electrical wiring, escaping gas, spilt fuel.
Cigarettes. Most skippers forbid smoking anywhere on board. Some skippers allow smoking in one location, usually aft of the wheel or tiller. Serious addicts may be tempted to light up in the seclusion of their bunk, when they are off watch. They fall asleep and the lighted cigarette ignites their bedding and starts a fire.
Electrical. Most boats are powered by two (or more) sets of 12 volt batteries. One will be dedicated to starting the engine, and is electrically isolated from the others. A bank of two or more batteries powers the lights, instruments and other domestic needs. A separate battery may be located close to the anchor windlass and dedicated to that use.
Even low voltage wiring can become overloaded and catch fire. Such a fire might start behind panelling or headlining and be difficult to locate and extinguish. The wiring to the anchor windlass battery is long and should be very substantial. The windlass uses a very high current and its wires and switches can become hot.
The batteries on a boat (usually 12 volts) are charged by current from an alternator or mains-powered charger. As they are charging they release hydrogen as a gas; this, mixed with atmospheric oxygen, is very explosive. Overcharging a battery can cause a fire.
12 volt batteries can deliver very high currents for short periods of time, as when starting an engine. The battery itself, and the wires carrying the current can become hot. If the battery terminals are connected together directly (short-circuited) the wires can melt or ignite and the battery can explode. I once dropped a spanner across the terminals of a battery . . . . . .
The anchor windlass draws a very high current for longer than a starter motor. The associated wiring can become very hot and the battery can be damaged.
Gas. On most boats cooking is powered by bottled gas, which is heavier than air and, when it escapes, sinks to the bottom of any compartment. A stray spark or flame will ignite the gas and cause an explosion.
Gas bottles should be stored securely on deck, or in a separate compartment which drains overboard. The tap on the bottle should be closed when the gas is not in use. There should be additional shut-off taps in the pipeline. The cooker taps should be 'flame-failure': if the burner is extinguished (say, by a draft of air) then the gas supply should be cut off automatically.
Fuel. Diesel fuel has a high flash point and is difficult to ignite. It does not explode, but can burn fiercely when hot.
Petrol has a relatively low flash point and will ignite easily and burn fiercely.
Extinguishers. There are 4 basic types of fire extinguisher.
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Water-based extinguishers spray water or a water-based foam under pressure; the water cools the fire and steam deprives it of oxygen. Fuel fires will float above water, so these extinguishers simply spread the flames. Water is a moderately good conductor of electricity, so electrical fires could be made worse.
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Foam is mostly water and a foaming agent.
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Carbon dioxide-based extinguishers release carbon dioxide gas which deprives the fire of oxygen. It also deprives people of oxygen and can kill them.
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Dry powder extinguishers spray a dry powder over the fire which deprives it of oxygen.
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Flood
A flooded boat will usually sink.
Most boats have many holes through which water can enter, the most obvious one being the companionway hatch.
Windows are vulnerable to heavy seas, which can break them, unless they are fitted with storm boards.
Virtually all yachts have seacocks through which water is drawn into the boat or pumped out. Each heads has an intake and an outlet. The engine has an intake for raw cooling water and, sometimes, an outlet for warm water. If there is no outlet then water is pumped out through the exhaust pipe which itself could allow ingress of water. Each of the sinks has a drain through the hull. Each one of these seacocks is connected to a flexible hose, and each one has the potential to fail and allow water into the boat.
Each seacock should have a soft wooden bung attached to it; this bung can be driven into the hole created by a broken hose or seacock. The action of the handle should be checked often and the valves should be cleaned and lapped when necessary.
The boat should have at least one good bilge pump. An electrical pump might fail if sea water short-circuits the supply; an engine-driven pump might fail if sea water gets into, and damages, the engine. Manual bilge pumps work well; even better when the user is frightened.
"The best pump is a frightened person with a bucket"
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Falling off
If you fall off the boat into warm, calm Mediterranean water you'll probably still be alive when the crew brings the boat back for you.
If you fall off the boat into cold, stormy English Channel water the crew may never find your body.
Diving and swimming from the boat is relaxing, invigorating and healthy exercise. Falling off is a surprise; it catches you unaware. 'Cold water shock' causes your skin temperature to fall sharply; your skin capillaries close and your blood pressure increases so that your heart suddenly must work much harder. You gasp, perhaps inhaling water, and you breath up to ten times faster than normal. This lack of control leads to panic, and, often, a heart attack. The effect of 'cold water shock' is short-lived; and so are you.
A lifejacket can keep you afloat, with your head out of water, long enough to survive the shock and, perhaps, be rescued.
There are two solutions
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Don't fall off the boat; use a harness and clip on every time you leave the cockpit.
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If you must fall off, wear a lifejacket that has recently been checked and serviced.
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Medical emergency
It is part of the skipper's responsibilities to know the medical condition of all crew members, and to know what to do if any of them becomes unwell.
The skipper should be trained and competent in First Aid and emergency procedures.
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Calling for help
The moment it becomes clear that the crew cannot control the emergency; call for help. In UK coastal waters the Maritime and Coastguard Agency (MCA) is waiting for your call.
Flares. These are somewhat dangerous pyrotechnic devices.
Hand-held flares, when activated, produce violent red flames and sparks which can be seen for several miles. The also produce thick, toxic smoke.
Parachute rocket flares send a rocket several hundred feet into the air where it bursts into red or orange flames.
Smoke flares usually float on the sea surface and release clouds of thick orange smoke.
It is illegal to use flares except in an emergency and it is illegal to dispose of them except through the proper facilities (no-one seems to know what these are, or have access to them!).
There is now a range of Electronic Visual Distress Signals (EVDS), or "laser flares" which are not pyrotechnic.
MOBOS. Man OverBoard Operating System. The system operates automatically when the lifejacket to which it is attached is inflated. It uses Ultra High Frequency (UHF) radio to pass a GPS position to the craft from which the MOB has fallen, and to guide the helmsman to the MOB.
MOB Systems. There are four kinds.
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Proximity alarms
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DSC systems
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AIS systems
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121.5MHz systems
PLB. Personal Locator Beacon. A device which can be clipped to a lifejacket. When activated by a person in the water (MOB) it sends alert and location signals which can be picked up by the MCA.
EPIRB. Emergency Position-Indicating Radio Beacon. A device with the same function and purpose as a PLB, but attached to the boat.
Mayday. DSC and VHF voice procedure for declaring an emergency and asking for help.
DSC radio. Digital Selective Calling radio, with a Maritime Mobile Service Identity (a unique number which can selectively be called from another DSC radio).
Liferaft. An inflatable raft, often equipped with water, oars, a drogue, to provide emergency flotation and survival accommodation for people whose boat has sunk.
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Emergency Wreck marker
To indicate the presence of a new and dangerous wreck.
The buoy itself has vertical blue and yellow bands and the topmark is a vertical yellow cross. The light flashes alternately blue and yellow.
Emergency wreck markers may be arranged in a ring around the wreck and their lights are arranged to flash synchronously.
According to Trinity House,
"Trinity House has a statutory duty under the Merchant Shipping Act 1995 to mark and, if appropriate, remove wrecks which are a danger to navigation"
ENC
Electronic Navigation Chart
End-for-end
A line which has been used for a single purpose (such as a ha'lyard) for some time might begin to show wear or chafe at places where it passes through a block, or is made up on a cleat.
Rearranging the line so that the bitter end becomes the free end, and vice versa, usually moves the points of chafe and gives the line a new lease of life.
Engine
A mechanical device for converting fuel into useful work.
Modern (early C21) auxiliary yachts are fitted with a diesel powered internal combustion engine for auxiliary propulsion. The engine is mounted permanently in the boat and is attached through a gearbox to a propeller at the stern. Inboard petrol auxiliary engines were common in the early to mid C20, but petrol has a lower flashpoint than diesel and so these relatively dangerous engines are now rare.
Smaller sailing yachts and dinghies may use a petrol or electric (rarely diesel) outboard engine which can be attached to, and detached from, the transom.
Motor yachts and power boats are fitted with one or more diesel engines. Increasing numbers of lower speed power boats are fitted with electric engines.
At the end of the Age of Sail ships were fitted with external combustion steam engines, using coal or wood as fuels. Such engines are now rare, but many ships burn oil to provide high pressure steam to drive electricity generators, which in turn, power electric propulsion engines.
The concept of ‘steaming’ (meaning to move a boat by means of a steam engine) lives on: the masthead light is often called a ‘steaming light’.
The power of internal and external combustion engines is measured in horsepower; the power of electric engines is measured in Kilowatts.
The words 'engine' and 'motor' don't quite mean the same thing.
The Latin ingenium, from in (in) and gignere (beget) meant 'talent' or 'device': think of 'ingenious' or 'ingenuity' or 'cunning'. In Middle English it came to denote 'the product of ingenuity', a 'plot' or 'snare'; sometimes a 'tool' or 'weapon'. The large mechanical catapults (American: 'slingshot') or 'trebuchet' were known as 'engines of war'. Later, anything large and mechanical, with levers (a machine), was an 'engine', such as a 'steam engine' or an 'internal combustion engine', whether stationary or a locomotive. In modern English an 'engine' converts fuel into movement or work. In modern Scots the word survives as 'ingine' to mean 'ingenuity' or 'cunning'.
The Latin movere means to move; motor meant 'a mover'. In late Middle English it implied 'a person who imparts motion' (figuratively), 'an instigator'. God was the motor of the heavens; Elizabeth was the motor of religious reform. In modern English a motor imparts movement.
In modern English (and American) the two words (engine & motor) are virtually synonymous.
Engine room
The space inside the vessel which contains the engine.
Ensign
The flag which indicates a vessel's nationality, or state of registration. It is flown as far aft as possible: yachts often have a staff socket on the taffrail or the transom; gaff-rigged vessels often fly their ensign at the peak of the gaff. At sea the ensign is flown all the time; in harbour it is flown from 0800 to sunset.
n The Union Flag of the United Kingdom is not an ensign and may be flown as a jack only by vessels of the Royal Navy.
Ships of the (British) Royal Navy fly the White Ensign, a white flag with a red vertical cross with the (British) Union Flag in the upper hoist canton.
Ships of the British Merchant Navy (any British vessel!) fly the Red Ensign, a red flag with the (British) Union Flag in the upper hoist canton.
The Blue Ensign may be flown only by members of certain yacht clubs and reserves.
Between 1652 and 1864 there were three squadrons of the Royal Navy, with red, white and blue ensigns. Each squadron had its admirals, vice-admirals and rear admirals; Lord Nelson was Vice Admiral of the White; the Admiral of the Red was also Admiral of the Fleet.
There is no yellow ensign. 'Yellow'. indicates a retired Admiral; "on the beach".
n An ensign was once a junior officer responsible for carrying the ensign. It is now a rank in the US Navy comparable with a midshipman.
EPIRB
Emergency Position Indicating Radio Beacon.
An emergency position-indicating radio beacon (EPIRB) is a type of emergency locator beacon, a portable battery powered radio transmitter used in emergencies to locate vessels and persons in distress. In the event of an emergency, such as the ship sinking, the transmitter is activated and transmits a continuous radio signal (at 406MHz) which is detected by satellites operated by an international consortium of rescue services, COSPAS-SARSAT which is used by SAR teams to locate the EPIRB. The feature distinguishing modern EPIRBs, often called GPIRBs, from other types of emergency beacon is that they contain GPS receivers and broadcast their position, usually accurate within to 100 metres.
Other types of emergency locator beacons include
ELT (emergency locator transmitter), which are carried on aircraft and are activated in the event of a crash.
EPIRB (emergency position-indicating radio beacon) are carried on ships and signal maritime distress.
SEPIRB (submarine emergency position-indicating radio beacon) are EPIRBs designed only for use on submarines.
SSAS (ship security alert system) are used to indicate possible piracy or terrorism attacks on sea-going vessels.
PLB (personal locator beacon) are carried by individuals and intended to indicate a person in distress, perhaps having fallen overboard.
Epoxy
A synthetic resin which, when activated with a hardener, becomes hard. Its low viscosity allows it to penetrate the surface and the end-grain of materials such as wood and so it is widely used as a glue. It has the advantage of filling large gaps.
Some people become allergic to epoxy resin; this is especially dangerous if it affects the lungs. Many users wear protective gloves, clothes and respirators.
Hardened epoxy resin can be sanded, especially when pre-mixed with wood dust or glass microballoons. The dust is non-reactive, but is cleared from lungs and bronchi with some difficulty.
Glued plywood clinker (lapstrake in the USA) boats are glued with epoxy resin, as are 'stitch-and-glue' plywood boats.
Equator
Meridians of longitude are imaginary lines around the earth passing through both poles.
Parallels of latitude are imaginary lines around the earth at right angles to the meridians. The shortest parallels of latitude, with no length at all, are at the poles. The longest parallel of latitude, around the ‘middle’ of the earth, is the equator.
The equator separates the Northern hemisphere from the Southern hemisphere. The other parallels are measured in angular distance North and South of the equator. The poles are 90° North and 90° South of the equator. Since each minute of arc on a meridian is one sea mile, the poles are (90 x 60) = 5400 sea miles from the equator.
The equator is the point on any meridian which the sun appears to cross halfway between midwinter and midsummer; half way between its Northernmost limit at the Tropic of Cancer and its Southernmost limit at the Tropic of Capricorn; at the Spring equinox and the Autumn equinox..
Equinox
The moment, each Spring and each Autumn, when the sun appears to cross the Equator.
On the day of each equinox the day-length is equal to the night-length.
Estimated Position (EP)
The predicted position of the boat using the heading, the boat speed (through the water) and the tidal stream. The value of Estimating a Position is in plotting the ground track, and seeing whether the ground track is safe or not.
2 Convert the Compass heading to Magnetic
3 Apply* leeway to the Magnetic heading
4 Convert the corrected Magnetic heading to True heading
5 Plot the heading (a Water Track, one arrow) from the fix: mark off one hour of boat speed to the DR
6 Calculate the set and drift of the tide as follows:
6.1 Find the time of high water at the reference port
6.2 Calculate the hour of high water
6.3 Find the tidal hour of the voyage
6.4 Look up the set and drift of the tide (the tide vector) from the table of diamonds or the tidal stream atlas
7 Plot the tide vector (three arrows) from the DR
8 Mark the EP (with a dot inside a triangle) at the end of the tide vector, and label it with the predicted time and log reading.
9 Plot the Ground Track from the fix to the EP: mark it with two arrows
The RYA's Estimated Position is the Dead Reckoning positions of Falconer and Smyth.
* With the wind on the starboard bow the leeway should be subtracted; with the wind on the port bow it should be added.
Estimated time of arrival
ETA; the time at which a moving object is expected to reach its destination.
For a water-borne vessel,
ETA = (Distance to go/SOG) + time now
nM / (nM/hrs) = hrs
Estuary
That part of a river, near its mouth, which is subject to tides. At all states of the tide there is sea water in the river bed: the river bed is at or below chart datum.
The water in an estuary is a variable mixture of fresh and sea water.
The upstream beginning of an estuary is where the fresh water of the river meets the highest salt tide; the downstream ending of an estuary is rarely fresh.
Estuaries may take the form of rias (drowned river valleys), fjords (formed by glaciation), lagoons (where sedimentation forms bars at the estuary mouth) and tectonic cracks.
Estuaries often form natural harbours, and ports and marinas may be sited within them.
ETA
Estimated time of arrival.
Euphroe
A block with a number of sheaves, or dumb sheaves, for distributing equally the tension on a number of lines.
The euphroe shown in the photograph distributes the tension of the two-sheave block on the left to the 'sheetlets', or lines, (on the right) to the battens of a junk-rigged sail.
These 'sheetlets' are derivatives of vangs.
EVDS
An abbreviation for Electronic Visual Distress Signal.
Pyrotechnic flares (PF) are dangerous and almost impossible to discard safely. EVDS are sold as possible (but not legally accepted) alternatives to pyrotechnic flares.
PF have a 'shelf life' of 2 or 3 years: EVDS have a 'shelf life' of many years, possibly decades.
PF have a 'burn time' of a few minutes: EVDS can be displayed for up to 24 hours before their batteries expire, or longer if their batteries can be replaced.
PF are very dangerous and can cause severe, even fatal, burns: EVDS are electronic devices which cause LEDs or lasers to flicker and flash, and are very safe.
PF are mandatory for some pleasure vessels and all commercial vessels: EVDS are not yet (2020) accepted as alternatives for PF.
PF are immediately recognised and recognisable as emergency beacons: EVDS might not be recognised by a casual observer.
Extinguisher
A fire extinguisher is a device for putting out, stopping, extinguishing, a fire.
There are, broadly, three kinds of fire extinguisher.
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A water-based extinguisher is filled with water which might be expelled from the device as a spray or jet of water, or as a water-based foam; the evaporation of the water cools the fire below its flash point. Since fuel oils float on water, a water-based extinguisher should not be used on fuel-based fires. Since water is a moderately good conductor of electricity, they should not be used on electrical fires.
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Carbon dioxide based extinguishers are filled with compressed carbon dioxide which is expelled from the device as a gas which deprives the fire of oxygen. (It also deprives of oxygen the human occupants of the space, possibly fatally) As the gas expands out of the device it cools rapidly; water vapour in the air often freezes onto the container; the user's hands might freeze onto the device.
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Dry-powder extinguishers release a powder which deprives the fire of oxygen.
Fire blankets are used to cover fires at the galley; the fire then deprives itself of oxygen.
Candle snuffers are metal cones which are lowered onto a candle flame which then uses up the small amount of oxygen available under the snuffer and is extinguished.
On a boat, fire extinguishers should be mounted close to the exits of each compartment so that they can be collected as the occupants leave.
Fire blankets should be mounted close to the galley, but not so that the user must reach over the flames.
The extinguishers in the engine room or compartment should be automatically activated by excess heat in the engine room. Alternatively, an extinguisher should be discharged through the small hole in the engine cover.
Fire extinguishers should be checked regularly (perhaps annually) and refilled or replaced as necessary.
Extremis
The point at which a stand-on vessel must finally give way to a give-way vessel which has failed to give way.
Eye Bolt
One end of the bolt is threaded, the other end is turned into an eye, or loop. The bolt is passed through a timber, a washer and nut are attached to hold it in place and a line may be bent to the eye.
Typically, an eye bolt is passed through the stem of a dinghy and a painter is bent to the eye.