Mooring of ships - forces

Mooring of ships - forces
Kapt. K. De Baere Mooring of ship - TVS 1ste kan

Purpose of mooring configuration
To bring the ship alongside To keep the ship alongside To assist the ship when un-mooring Mooring of ship - TVS 1ste kan

Design criteria of mooring configurations
Based on the forces acting upon the ship Wind Current Waves Swell Other ships passing by (suction effect) Location of the berth – Protected or sea berth Types of ship – size, displacement, draught etc. Mooring of ship - TVS 1ste kan

Protected berths Design criteria – limiting values
Cross wind up till 15m/sec (6-7 Beaufort) Tidal current of 3 knots in longitudinal direction Cross current of 1 knot Cargo- and container ship are normally moored along well protected berths => Mooring winches are designed to pull the ship alongside with 1 headline and 1 stern line against a cross wind of 5 Beaufort Mooring of ship - TVS 1ste kan

Sea berths – designed for >wind
Design criteria – limiting values Cross winds up till 20m/sec or 8 Beaufort and gust of winds up till 10 Beaufort Tidal current of 3 knots in longitudinal direction Cross current of 1 knot Waves and swell Waves and swell with a short period have a limited influence Mooring of ship - TVS 1ste kan

Fetch The size of a wave depends on its fetch. The fetch is the distance a wave travels (see next slide). The greater the fetch, the larger the wave. If the wind is blowing for a longer period of time in the same direction => long fetch with a high wave height and a longer period => important dynamic effect on the ship Mooring of ship - TVS 1ste kan

Fetch – Definition Growth rate of wind generated waves
The distance that wind and seas (waves) can travel toward land without being blocked. In areas without obstructions the wind and seas can build to great strength, but in areas such as sheltered coves and harbours the wind and seas will be calmer. Mooring of ship - TVS 1ste kan

Mooring of VLCC’s Often moored outside the harbours along sea berths
Forces are so great that no winch is capable of bringing the ship alongside Tugs are always used when mooring and leaving berth The only criteria is the holding force of the winches The ship must be maintained in position related to the shore manifold (chiksans) Mooring of ship - TVS 1ste kan

Relation maximum pulling power – Displacement ()
Figures are used to design shore facilities (bollards, bits ……….. Etc.) 25% safety margin to be added 8000 ton – 100 kN ton – 300 kN ton – 600 kN ton – 600 kN ton – 1000 kN ton – 1500 kN 1 kN = 1 ton pulling power (not scientific) Mooring of ship - TVS 1ste kan

Mooring winch with undivided drum
Mooring of ship - TVS 1ste kan

Mooring winches – Divided drum-polyprop octopus

Chicksan Mooring of ship - TVS 1ste kan

Chicksan One of the biggest problems with the fixed loading/discharging systems is the restricted liberty of movement of the ship If one of the limits is breached => ESD-system activated Mooring of ship - TVS 1ste kan

Assessing the forces Forces due to wind and current are proportional to the square of their speeds. f.i. the force caused by a wind of 40 knots is 4 times the influence of a wind of 20 knots The wind speed increases with the height above the ground. A wind of 10 knots at 2 meters increases till 60 knots at 40 meters => importance of the freeboard (height of the structure). To obtain comparable figures all winds are recalculated to a standard height of 10 meters Mooring of ship - TVS 1ste kan

Maximum wind limits (400.000 dwt ship) in function of the breaking power of the winches

Wind limits The previous pictures learns us that;
The wind limit is determined by the holding power (breaking power) of the winches The wind limit is determined by the material of the mooring lines Mooring of ship - TVS 1ste kan

Assessing the forces Influence of a cross current is inverse proportional with the keel clearance. In case of a small keel clearance the current is obstructed by the ships hull and searches way out via the stem and the stern. A Suction effect is created trying the move the ship away from the berth. Mooring of ship - TVS 1ste kan

Theoretical example of the influence of the keel clearance
A ULCC with a draft of 15 meters is moored alongside a berth with 16.5 meters of water => relation water depth/draft = 1.1 Relative resistance factor in case of cross current = 5.6 In case of unlimited water depth a cross current of 1 knot produces a force of 60 tons Mooring of ship - TVS 1ste kan

In case of a limited water depth (example) this force is increased till 5.6 x 60 ton = 336 ton This equals 9 steel mooring ropes of 40mm diameter Mooring of ship - TVS 1ste kan

The relative proportion of the different elements has to be considered Ballasting decreases the keel clearance but also reduces the lateral wind surface. The wind effect is of greater importance than the the clearance effect (see next slide). Mooring of ship - TVS 1ste kan

Example of cross and longitudinal forces
& SDWT: Wind 60 knots (30m/s), current 5 knots longitudinal and 1 knot cross current SDWT: Wind 60 knots, current 3 knots longitudinal and 1 knot cross current Mooring of ship - TVS 1ste kan

Conclusions In ballast condition the most important forces are wind generated In loaded condition the most important forces are current generated The total force on the ship (alongships + athwartships) is greater in ballast condition than in loaded condition => influence of the wind is of greater importance Mooring of ship - TVS 1ste kan

Different materials 3 different configurations
All steel wire ropes (equipped or not equipped with tails) All ropes are synthetic Mixed systems (synthetic + steel wire rope) New materials Mooring of ship - TVS 1ste kan

Steel wire rope + tail (ralonge de la touline)
Purpose of the tail is to add elasticity to account for change in tidal heights Always use 8 strands nylon with an MBL 25% > steel wire rope To protect against chafing cover splice of the tail with leather or plastic The tail is connected to the steel wire rope by means of a Tonsberg shackle or a Mandal shackle In case of frequent use tails are changed every 18 months Mooring of ship - TVS 1ste kan

Steel wire rope + tail Steel wire rope have a high MBL and are not elastic. Steel wire rope are stored on winch drums with a manual brake Steel wire rope are relatively easy to handle up to 40mm  ???? Steel wire ropes last longer than synthetic ropes Price steel wire = synthetic Mooring of ship - TVS 1ste kan

Tonsberg shackles Mooring of ship - TVS 1ste kan

Mandal Shackle Mooring of ship - TVS 1ste kan

Full synthetic mooring configuration
Biggest problem is elasticity This elasticity can give an important « sway » (balancer) to the ship (breaking out) 3 mooring ropes – different materials – same length (50 m), MBL and load Steel wire – 0.3m elongation Polyprop – 5m elongation Nylon – 8 m elongation Mooring of ship - TVS 1ste kan

Breaking out Mooring of ship - TVS 1ste kan

Effect of the hawser elasticity on the restraint capacity
Materials with the smallest elasticity take the biggest load Short rope = big load Relation -  is not linear Mooring of ship - TVS 1ste kan

Synthetic fibres loose tensile strength (force de traction) if submitted to cyclic tensions attaining 30 to 50% of their MBL. Those cyclic tensions are not constant, due to resonance high tensions occure during short periods of time Mooring of ship - TVS 1ste kan

Because of; Cyclic tensions Internal friction Exposure to the marine environment Tensile strength of synthetic ropes will diminish after 1 year Tensile strength of steel wire rope will diminish after 5 years => more durable Mooring of ship - TVS 1ste kan

Another side effect is sagging (affaissement) The « sag » is function of;  m-n Weight of the mooring line Tension in the line Water depth (suction effect) Mooring of ship - TVS 1ste kan

Consequence of the sagging is that a synthetic rope can never be pulled as stiff as a wire rope. A wire rope will « react » faster on a breaking out of the ship. A synthetic rope will compensate the the sag before reacting Max. allowed distance between berth and ship is normally limited to 6% of the water depth Mooring of ship - TVS 1ste kan

Mixed mooring systems Mix of wire ropes and synthetic ropes
Certainly NOT the best configuration but the most common one. If possible use steel wire rope as springs and breasts and use synthetic ropes as head- and stern line Mooring of ship - TVS 1ste kan

New materials Composite materials
Expensive but excellent mooring system Kevlar –Aramid ropes are very strong, light and show little sagging. They react fast in case of breaking out of the ship. Mooring of ship - TVS 1ste kan

Efficient mooring The efficiency of a mooring rope depends on the following factors Material (steel wire or synthetic – elongation & MBL) Length Angles with longitudinal and transversal axis in the horizontal plane Angles with the horizontal in the vertical plane Mooring of ship - TVS 1ste kan

Function of the different ropes
Head- and stern lines & the springs are stabilising the ship alongside Breast line will prevent the ship to break free from the berth Breast lines must be as perpendicular as possible to the ships longitudinal axis Springs must be as parallel as possible to the berth Mooring of ship - TVS 1ste kan

Recommendations The function of springs and breast lines is clear. Springs are preventing longitudinal movement while breast are opposing transversal movements. The function of head and the stern lines depends on their angle with the longitudinal axis. Great angle => they serve mainly as breast line while small angle => stopping longitudinal movement Mooring of ship - TVS 1ste kan

Recommendations The ideal configuration will rarely be achieved.
To obtain a perfect mooring configuration their must be a perfect harmony between the ships equipment and disposition on board and the configuration ashore Berthing ships is always a matter of compromises Mooring of ship - TVS 1ste kan

Recommendations Following recommendations have been published by the OCIMF = Oil Company International Maritime Forum The recommendations are valid for a tanker moored alongside a T-berth Mooring of ship - TVS 1ste kan

Recommendations based on OCIMF – Effective mooring
The horizontal angles of head-, stern- and breast lines < 15° Mooring of ship - TVS 1ste kan

The vertical angle with the horizontal plane must be < 25° The effective force is proportional to the cosine of the angle If the angle is 25° the line is effective for 91% If the angle is 45° the efficiency is reduced to 71% => Springs & breasts must be long enough and not to steep Mooring of ship - TVS 1ste kan

Springs & Breasts Mooring of ship - TVS 1ste kan

Breast lines are most effective is  on the longitudinal axis. If  is 45° we have to increase the force in the breast line till 141 ton to obtain an effective transversal force of 100 ton Mooring of ship - TVS 1ste kan

Springs offer the greatest holding power in the longitudinal direction. Their length is  60 meters Mooring of ship - TVS 1ste kan

The impact of the head and the stern lines on the total holding power of the mooring configuration is less important than the influence of springs and breasts. This mainly because these lines are too long. Never the less they are important to compensate the dynamical forces. Length  110m = ½ coil Mooring of ship - TVS 1ste kan

Very short lines must be avoided. They always take the most important part of the load, especially when the ship is moving Short length = important vertical angle Mooring of ship - TVS 1ste kan

Short breast lines Long breast line: 52ton load is sufficient to obtain an effective holding power of 50 ton Short breast line: Load has to be increased till 88 ton to obtain same result Mooring of ship - TVS 1ste kan

All the mooring ropes in the same group (working in the same direction)must have a same tension. If not, the weakest line will break first. Total load will have to be received by the remaining lines => increased risk of breaking (chain reaction) Groups are f.i. aft spring + head lines, Stern lines + forward spring, breast lines Mooring of ship - TVS 1ste kan

Their must be an equilibrium between the 4 groups (head- and stern lines, springs and breasts. Example: Optimal mooring configuration is determined after studying the static and dynamical forces for a specific berth. Mooring of ship - TVS 1ste kan

Mooring example Maximum breaking out from the berth = 1 meter
Direction of the wind: 110° -> 290° Frequency 58% 25.2% 3 à 4 Beaufort 0.65% > 8 Beaufort Proposed configuration all nylon  80mm (MBL 110 ton): 4 breast lines (aft) + 1 stern line 3 headlines + 3 breast lines (fore) Mooring of ship - TVS 1ste kan

The fore ship will resist a wind pressure of 32 knots while the stern will resist a wind pressure of 33 knots => The berth will be operational till 7 Beaufort => not operational 5.8% per year The configuration of the berth is not ideal since the horizontal angles > 15°

The number of lines is function of the size of the ship and the prevailing weather conditions A – Panamax ( dwt) lines (2 headlines – 4 breasts – 4 springs – 2 stern lines: 2 –2 – 2 fore and aft) B – VLCC ( dwt) 16 lines (4 headlines – 4 breasts – 4 springs – 4 stern lines: 4 –2 – 2 fore and aft) Mooring of ship - TVS 1ste kan

A – Panamax & B - VLCC Mooring of ship - TVS 1ste kan

Mooring configurations bulk carriers
Cape Size: 4 –2 – 2 (fore and aft) Panamamax: 4 –1– 1 (fore and aft) Handy Size: 4 –1 (fore and aft) Mini Bulker: 3 –1 (fore and aft) Mini Bulker – moored so it can shift forward and backwards during loading/discharging Mooring of ship - TVS 1ste kan

Mooring configurations bulk carriers

Mooring lines must be passed ashore using the deck fittings (fairleads) because of friction and the curvature relation. Curvature relation =  curvature deck fitting/  mooring line In case of a mooring wire relation has to be > 20 to reduce loss in tensile strength Mooring of ship - TVS 1ste kan

Mooring configuration –concentrated on the fore ship

Mooring of ship - TVS 1ste kan

Deck fittings (accessoires de pont)

OCIMF equipment: Panama hawse- hole Pedestal Fairleads (Chaumard)

Info Suez & Panama Canal Mooring of ship - TVS 1ste kan

Suez Canal Total length is 190.25 km Water surface width is 280.345 m
Width between the buoys is m Canal depth is 22.5 m Maximum ship draught allowed is 62ft Speed allowed for loaded carriers is 13 km/h Speed allowed for unloaded carriers is 14 km/h. Average transit time is 14 hours Mooring of ship - TVS 1ste kan

Suez Canal

Panama Canal The Panama Canal is approximately 80 kilometers.
The Canal uses a system of locks The locks function as water lifts: they raise ships from sea level (the Pacific or the Atlantic) to the level of Gatun Lake (26 meters above sea level) Mooring of ship - TVS 1ste kan

Panama Canal Each set of locks bears the name of the townsite where it was built: Gatun (on the Atlantic side), and Pedro Miguel and Miraflores (on the Pacific side). The maximum dimensions of ships that can transit the Canal are: 32.3 meters in beam; draft 12 meters in Tropical Fresh Water; and meters long The narrowest portion of the Canal is Culebra Cut Mooring of ship - TVS 1ste kan

Panama Canal Mooring of ship - TVS 1ste kan

Gatun Lock Mooring of ship - TVS 1ste kan

Gaillard Cut

Pedro Miguel Locks Mooring of ship - TVS 1ste kan

Mira Flores Locks Mooring of ship - TVS 1ste kan

4-roller fear lead Towing Bracket

Smit Towing Bracket Mooring of ship - TVS 1ste kan

Chocks and buttons Mooring of ship - TVS 1ste kan

Bits and Bollards Mooring of ship - TVS 1ste kan

Panama chocks Mooring of ship - TVS 1ste kan

Roller Chocks Mooring of ship - TVS 1ste kan

Roller Fairleads Mooring of ship - TVS 1ste kan

Towing pads (point d’attache pour le câble de remorque)

Emergency Towing Systems
SOLAS Requirement Regulation Chapter II-1, A-1, 3-4 Since 1996, January 1, all tankers exceeding, 20,000 DWT are to have an emergency towing arrangement fitted at the aft and forward. This IMO resolution MSC35(63) which covers the installation of emergency towing arrangements on tankers was decreed after the unfortunate disaster of the MV Braer in 1993. Mooring of ship - TVS 1ste kan

Emergency Towing Systems - Aft beneath deck

Emergency Towing Systems Typical Arrangements Fwd

Demo Mooring of ship - TVS 1ste kan

Mooring alongside a classic berth (quay)

Different methods – see lab ship’s technique Practical techniques – see lab ship’s technique Mooring of ship - TVS 1ste kan

Mooring alongside a T-berth

Mooring with 2 anchors Mooring of ship - TVS 1ste kan

Ship to ship Mooring of ship - TVS 1ste kan

SPM – Single Point Mooring Buoy

SPM - buoy Mooring of ship - TVS 1ste kan

FPSO – single point mooring

FSO - operations Mooring of ship - TVS 1ste kan

STL – Submerged Turret Loading

STP – Submerged Turret Production

Safety in mooring operations
The purpose of moorings is: to assist the ship in heaving on to the berth and in leaving it, to prevent the ship from drifting away, and to hold it accurately in place in relation to any fixed cargo-handling systems. The latter is particularly important on tankers and Ro-Ro’s. Mooring of ship - TVS 1ste kan

Moorings have to maintain the ship’s position against forces of wind, current, swell, and suction from passing ships. They require adjusting as the ship’s freeboard changes during cargo and ballast operations, and due to changes in the level of the tide. In this respect, it is useful to display the times of high and low water adjacent to the gangway (ship’s office). Mooring of ship - TVS 1ste kan

It be remembered that the securing of a ship at a berth is not something which just happens— it requires knowledge of the ship’s equipment, application of good principles and careful planning—and this does not finish once the vessel is securely moored. Mooring of ship - TVS 1ste kan

Choice of moorings Two or more lines leading in the same direction should be of the same length and the same material. This is because the load on the line is proportional to its length and elasticity. It is best if all lines share the total load equally. If the vessel is provided with a mix of wire and fibre ropes, it is best to use the wires for breast lines and springs, and the fibre ropes for head or stern lines, and for the first line ashore during manoeuvring. Mooring of ship - TVS 1ste kan

Choose of moorings Wires are best for preventing the movement of the ship, so they are employed when this must be limited in relation to fixed cargo-handling equipment, for example on tankers. Wires usually have fibre rope tails to provide a minimal elasticity, and to assist with handling. Mooring of ship - TVS 1ste kan

Principles of mooring layout
Breast lines provide the bulk of athwart ships restraint. Springs provide the largest proportion of foreand-aft restraint. Very short lengths of line should be avoided, because they take a large proportion of the total load if the ship moves. Whenever a line is unable to act exactly in the same direction as the force it is trying to withstand, its holding power is reduced. For example, a line which leads 45° below the horizontal loses around a third of its effectiveness. Mooring of ship - TVS 1ste kan

Pattern of moorings On berthing, the Master will decide the number and layout of mooring lines for that particular berth. Often there will be a normal arrangement for the ship, but he may choose to vary this if: The berth is exposed to bad weather or swell. There is an unusually strong tide or current. Mooring of ship - TVS 1ste kan

Pattern of moorings The bollards ashore are not placed conveniently.
Mooring buoys or dolphins have to be used for some or all of the lines. The berth is much shorter than the ship. The ship has regularly to shift along the quay, for example, under a fixed loading spout. Local regulations dictate, or pilot advises some change. Mooring of ship - TVS 1ste kan

Supervising mooring operations
The officer supervising the mooring operations forward or aft must understand fully: The meaning of all mooring terms: head/stern lines, breasts, springs, bights, tails, messengers, surge, make fast. The length, size and type of all mooring lines, and their safe working load and breaking strain. The correct method of applying a rope or chain stopper. Mooring of ship - TVS 1ste kan

Supervising mooring operations
The operation of all mooring equipment, including the windlass and winches, and all their controls. The limitations of any self-tensioning devices. The brake holding power, and winch render loads. Routine and emergency communications from the mooring position to the bridge. Mooring of ship - TVS 1ste kan

Safe working environment
The decks in the working area around the mooring station should be clear of obstructions, free of oil and grease and preferably treated with non-slip paint. Steam pipes should be lagged to avoid accidental contact. Fairleads and rollers should be well lubricated and rotate freely. Winches should operate smoothly, including the brakes, with all controls and stops tested regularly. Mooring of ship - TVS 1ste kan

Safe working environment
Drum ends should be smooth, clean and free of rust, paint and oil. The entire area must be well illuminated at night. However, the 00W should obtain permission from the bridge before switching on any lights whilst the ship is manoeuvring, as these may interfere with visibility from the bridge. Mooring of ship - TVS 1ste kan

Safe fibre ropes Ropes should be covered when they are not being handled, and stowed away when not in use at sea, to prevent contamination by oils and chemicals, and degradation by sunlight. Ropes must be kept away from heat, oil, paint and chemicals. Ropes should be stowed on gratings for ventilation and drainage. Ropes must be examined regularly for wear, stranding, melting and powdering, and replaced if serious defects are found. Mooring of ship - TVS 1ste kan

Safe Wire Rope Wires should be lubricated regularly with an approved lubricant. Everyone who handles wires should wear leather -palmed gloves to protect their hands from snags. Wires must be examined regularly for wear, stranding, dry core, kinks, and excessively flattened areas. They must be replaced if the number of broken strands (snags) exceed 10% of the strands in any length equal to eight diameters, or if any other serious defects are found. Mooring of ship - TVS 1ste kan

Safe line handling – see lab
Flake out all mooring lines on the deck, clear, and ready to send. This will ensure that any fibre lines which have become buried on reels can be freed in advance, when there is less likelihood of accidents. Do not use a wire direct from a reel designed only for stowing. Have all necessary heaving lines, messengers, tails and stoppers available at the mooring station, and rat guards ready for use. Mooring of ship - TVS 1ste kan

Flaking out mooring lines
Lover les aussières à la française De trossen zijn klaar gelegd in franse bochten To avoid that someone puts his foot/feet in a loop Mooring of ship - TVS 1ste kan

Safe position between mooring ropes
Position yourself away from the whip Mooring of ship - TVS 1ste kan

Putting the mooring rope on the warping head of the winch
The anchor winch has maximum power when it runs in the sense of picking up the anchor (anti-clock wise) Mooring of ship - TVS 1ste kan

Have sufficient crew available. All crew should wear safety helmets and safety shoes, and have no loose clothing which could become entangled in the winches or trapped by the lines. Gloves should be tight fitting, to reduce the risk of becoming trapped by lines, and should have a leather palm to protect the hand against abrasion and prevent wounds caused by snags of wires; they should provide adequate insulation in cold weather. Mooring of ship - TVS 1ste kan

When one seaman is handling a line on a drum end, he should not stand too close to the drum to avoid being drawn in. There should be an additional seamen whose duty is to clear the loose line when heaving, and supply the loose line when slacking. The person operating the winch controls should have a clear view of the entire area including any seaman handling lines with that winch. Mooring of ship - TVS 1ste kan

Never leave winch controls unattended, particularly if running. They must NEVER be lashed ‘ON’. Do not allow anyone to stand on machinery to get a better view. Avoid excessive surging, which may cause synthetic lines to melt, and fuse or stick to the drum, then jump back with a serious risk of injury to personnel. Also, the rope will be permanently weakened. Try to slack the line by reversing the winch whenever possible. Mooring of ship - TVS 1ste kan

Do not use too many turns, three or four turns are recommended for fibre ropes. Do not bend wires sharply, particularly around a lead, because this damages the wire and weakens its strength. Do not cross wires on the drum end, as this causes them to flatten, and weaken their strength. Never allow anyone to stand in a bight of a line. Mooring of ship - TVS 1ste kan

Do not stop a line from running by grabbing or standing on it; this can result in severe injuries and loss of limbs. If a line begins to run uncontrolled, ensure that all personnel stand dear. It is better to lose a line than lose a seaman. It is recommended that the tail end is securely fixed onboard to prevent complete loss of the line in such circumstances. Mooring of ship - TVS 1ste kan

Chinese stopper Mooring of ship - TVS 1ste kan

Traditional stopper A traditional stopper using a single line may be used only on a mooring line made of natural materials, as shown below, but such mooring lines are no longer common on board ship Mooring of ship - TVS 1ste kan

Stand well clear of all lines under tension. This means everybody, not just those handling that line. Synthetic fibre ropes may break without warning, and the resultant whiplash may cause severe injuries or even death. Synthetic fibre mooring ropes should be stoppered using two tails of fibre rope, halfhitched under the mooring rope, with the two free ends criss-crossed over and under, as shown in the diagram below: (This is sometimes known as a Chinese stopper.) Mooring of ship - TVS 1ste kan

Mooring wires should be stoppered using a chain stopper with a well-spaced cow hitch (Lark’s head)(Deux demi clefs renversées)(it is recommended that the two hitches are at least 25 cm. apart) and with the remainder of the chain and its rope tail turned up several times against the lay, as shown in the diagram below. The cow hitch is used because it is easily pulled loose when no longer required, a clove hitch (mastworp -Deux demi clefs à capeler (noeud de cabestan)) is likely to jam. Mooring of ship - TVS 1ste kan

Chain stopper Mooring of ship - TVS 1ste kan

Carpenter’s stopper As an alternative to the chain stopper, some ships are provided with a specially designed patent device, known as a Carpenter’s stopper Mooring of ship - TVS 1ste kan

Carpenter’s stopper Mooring of ship - TVS 1ste kan

Do not use a stopper on the only rope which is tight. The stopper cannot hold the same weight as a mooring line. Always have a second line tight before making fast the first. When making a synthetic fibre rope fast to bitts, DO NOT use a figure of eight alone, but FIRST use two round turns (NO MORE) around the -leading post of the bitts (for large size bitts) or around both posts (for bitts with smaller circumferences). Mooring of ship - TVS 1ste kan

Mooring lines on a bitt Mooring of ship - TVS 1ste kan

Safe mooring All operations must be carried out ONLY under the direct orders of the supervising officer. The supervising officer must ensure that communications with the bridge are -CONTINUOUSLY maintained. If using radios all calls should start with the ship’s name (to avoid confusion), and then the caller should immediately identify himself and who he is calling to avoid confusion on one’s own ship A spare fully-charged battery should be carried whenever portable radios are used. A back up system must be readily available at all times.

Safe mooring Check with the bridge before sending the first lines, and before making any lines fast. Keep the bridge informed of distances off the quay, any obstructions and other moored ships, lighters or other floating objects. Advise the bridge if there is any possibility that a slack line may become entangled in the propeller - or thrusters. Warn the bridge if any lines become excessively taut. Mooring of ship - TVS 1ste kan

Safe mooring Make fast and cast off tugs only on orders from the bridge. When heaving lines are being thrown, ensure that all personnel ashore and on board are alerted, and stand well clear. The supervising officer must make sure he can always see both the winch operators and the particular line when giving orders for adjusting the tension in a line. Mooring of ship - TVS 1ste kan

Safe mooring Secure the lines as per the Master’s orders. i.e. which lines to leave on the drums, which lines to make fast on bitts, Which lines to leave in auto/self-tension, if any, and what level to set the controls. Ensure rat guards are properly fitted to all lines. The supervising officer must remain at the mooring station, with his full crew, until he is dismissed by the Master. Mooring of ship - TVS 1ste kan

Plague Control ? Deratisation Rat guards

Mooring of ship - TVS 1ste kan

Self Tensioning Winches
Self tensioning winches can be set to a certain holding force. If this value is exceeded, then the winch automatically adjusts the length of wire to the new force (too much holding force: slacking; too little holding force: heaving). This system is frequently used by ships that load and discharge quickly (container ships and Ro-Ro-vessels) or if there is a large tidal range in the port. Mooring of ship - TVS 1ste kan

Control lever for the winch Cooling fan Control for the self-tension setting Mooring of ship - TVS 1ste kan

The heaving power of a winch is always lower than its render force. This means that if a winch is left in self-tension, and the external forces increase, the line will pay out, and it may not be possible to heave it in again until such external forces reduce. Also, the render force of the winch is much less than the holding power of the brake Self-tensioning winches at opposite ends of the ship can work against each other, so that the ship can sometimes ‘walk’ along the berth, when an external force is applied at one end. Mooring of ship - TVS 1ste kan

Hence it is recommended that mooring lines are NOT left in self-tension once the ship is secure alongside. With short breast lines in fair weather, these controls may be useful during rapid load/discharge operations. However, those winches which are directly counteracting any external forces must be left on the brake. Self-tensioning winches are useful during berthing operations with reduced manning, as once the line is ashore and the controls set, they will reel in any slack, maintain the tension in the line, and prevent the line being damaged through excessive strain. Mooring of ship - TVS 1ste kan

Keeping moorings taut The OOW must ensure that the mooring lines are kept sufficiently taut at all times to keep the ship firmly alongside. At rapid loading or discharging berths, the Chief Officer may assign additional crew to assist the OOW, as the operation of adjusting the lines may have to be done frequently. The 00W must never attempt to adjust a mooring line by himself, unless it is permanently wound on its own drum. If the lines are not in equal tension, they may part in succession if the ship is subject to exceptional high forces, such as very strong winds, large swells or water surges from other ships passing too close and/or too fast. Mooring of ship - TVS 1ste kan

Keeping moorings taut Brake linings can lose their grip when oil and rust are present, and are susceptible to loss of holding power during periods of rain or high humidity. The OOW should remember to adjust any fire wires as the ship’s freeboard changes, to ensure that their ends remain clear of the water. It is essential for the OOW to check the moorings when other ships are arriving at or leaving from the berth immediately ahead or astern of their ship. It is good practice for the OOW to be in attendance forward or aft whenever the adjacent ship is arriving or sailing to watch out for contact damage, or other incidents, in addition to monitoring the moorings. Mooring of ship - TVS 1ste kan

Fire wire Strong steel wire 1 end is put on a bollard
Other end is hanging overboard +/- 1 meter above the water The outer end is held in position by means of a weak line. Middle part is flaked out on deck In case of fire a tugboat can grab the outer eye and pull the tanker free of the berth Fire wire

Excerpt from terminal rules and regulations - Saoudi Arabia
TOWING-OFF WIRES OF ADEQUATE STRENGTH AND CONDITION MUST BE MADE FAST TO BOLLARDS ON THE TANKER. FORWARD AND AFT, AND THEIR EYES RUN OUT AND MAINTAINED AT OR ABOUT THE WATERLINE. THE WIRES MUST BE OVER THE OFFSHORE SIDE. IN ORDER THAT SUFFICIENT WIRE CAN BE PUT OUT TO ENABLE THE TUGS TO TOW EFFECTIVELY, ENOUGH SLACK MUST BE RETAINED BETWEEN THE BOLLARD AND CHECK AND PREVENTED FROM RUNNING OUT BY A ROPEYARN OR OTHER EASILY BROKEN MEANS Mooring of ship - TVS 1ste kan

Chafing (Frotter – Raboter)
The OOW must check the moorings at least hourly during his watch, not only to ensure they remain taut but also to look out for chafing, where the rope rubs against an obstruction, and may part. This may occur when the ship is surging back and forth along the quay due to a large swell, or when there is excessive movement of a mooring buoy. Synthetic fibre ropes possess very low resistance to chafing when under load; the friction generates heat which causes them to melt and fuse, and the rope is then permanently weakened, and may part quite quickly. Mooring of ship - TVS 1ste kan

Chafing (Frotter – Raboter)
Ropes may chafe by rubbing against each other, or against the ropes of another ship. The officers on stand-by fore and aft during mooring operations must be alert for this when sending ropes to different bollards ashore through different leads on board. If they notice any chafing, they should have that line removed and sent from a different lead. Short leads with substantial dips are prone to chafing on the ship’s structure. Mooring of ship - TVS 1ste kan

Chafing Sometimes a change in freeboard, or some external factors such as a change in the sea state, may cause lines to start chafing. If he notices any chafing, OOW must clear the obstruction, change the lead of the mooring rope, or wrap the rope in canvas or some other material to bear the rubbing and wearing away action. The outside of the canvas may be greased to reduce the friction, but this grease must not be allowed to remain in contact with fibre ropes as it will cause them to deteriorate. The OOW must always advise the Chief Officer of his observations and actions. Mooring of ship - TVS 1ste kan

The recommended action is:
Emergencies Occasionally unexpected changes of load may cause the brakes of the mooring line drums to slip, and the vessel is at risk of moving off the berth. DO NOT RELEASE THE BRAKES AND ATTEMPT TO HEAVE THE SHIP BACK ALONGSIDE USING ONLY THE POWER OF THE WINCH. The recommended action is: If the winches are in self-tension apply the brakes IN ADDITION. If the brakes are in use, tighten them, put the winch in gear and heave on as many lines as possible. Mooring of ship - TVS 1ste kan

Emergencies Inform the senior officers, and seek extra crew assistance
Summon tug assistance if necessary. Consider reducing the freeboard by ballasting. The OOW should remember that brake holding power is always greater than winch heaving power, but that the two together increase the load. For example: Winch render force = 35 tonnes. Brake holding power = 65 tonnes. Total holding power = 100 tonnes. Mooring of ship - TVS 1ste kan

Emergencies He should be careful this does not exceed the breaking strain of the rope, or the safe working load of the leads and rollers. However, in an emergency it will usually be preferable to endeavour to hold the ship in position and risk breaking the lines. Mooring of ship - TVS 1ste kan

Mooring equipment ashore

Equipment ashore Bollards and bitts Winches - capstans
Quick release hooks Laser docking systems Mooring line monitoring systems Fenders Mooring of ship - TVS 1ste kan

Bitts and bollards Mooring of ship - TVS 1ste kan

Capstans Mooring of ship - TVS 1ste kan

Quick Release Hooks The basic starting point to any integrated mooring system Can be released manually or (electric, hydraulic or telemetry) and can incorporate load pins for optional multipoint computer-based remotely mooring line tension monitoring systems Mooring of ship - TVS 1ste kan

Quick Release Hooks Mooring of ship - TVS 1ste kan

Quick release hooks Explosion proof double hook unit
Quad. hook with load monitoring and remoter release system Mooring of ship - TVS 1ste kan

Mooring Line Monitoring System
The vessel Mooring Line Monitoring system (MLM), provides real time monitoring of all mooring lines and warns of excessive or out-of-range loads. Changing weather conditions or current loading can cause unequal load sharing within the mooring system. This can lead to potential failure of mooring lines and damage to jetty Mooring of ship - TVS 1ste kan

Mooring Line Monitoring System
Load on the hooks is measured by load pins Data is transferred to the jetty control room Data is completed with environmental data and data concerning the movement of the ship alongside Mooring of ship - TVS 1ste kan

Environmental data Data is collected by a buoy and presented on graphic display Mooring of ship - TVS 1ste kan

Laser docking systems The primary benefit of a Docking Aid System or DAS is the provision of real time data of the vessel’s position and progress relative to the jetty by measuring distance from the jetty and speed of approach in the critical 0 to 200 meters zone. With this data the vessel’s master and pilot can better direct tug and shipboard personnel in the safe manoeuvring of the vessel towards the jetty and minimize any potential for damage to the berth Mooring of ship - TVS 1ste kan

Laser docking systems Typically, two sensors are located on the jetty measuring distance to bow and stern sections of the ship. This together with average speed are captured at the jetty control unit and displayed to the ship and mooring crew on wireless monitor, computer screen or jetty mounted display board, as required. Earlier systems used radar sensors, however today laser sensors are the most reliable technology employed for vessel docking. Mooring of ship - TVS 1ste kan

Laser docking systems Mooring of ship - TVS 1ste kan

Docking systems – GPS based f.i. e-fix system
Ship trials (speed and manoeuvring) Oil and gas tanker approaches and docking operations SPM/FSO Docking and Drift Warning Oil rig positioning Navigation of ships into locks & docks Ferry operations Mooring of ship - TVS 1ste kan

It should be noted that the E-Sea Fix system can be integrated into existing Laser Docking Systems. All data from an existing Laser Docking System (such as environmental data, load arm monitoring, mooring load monitoring and drift warning information) can be relayed and displayed on the pilot monitor. A receiver is capable of receiving signals from both the US constellation as well as the Soviet based GLONASS constellation. This dual constellation ensures that the number of satellites visible to the receivers is maximised. Mooring of ship - TVS 1ste kan

Accuracy Speed accuracy better than any ship’s log, ± 1 cm per second i.e. ± 0.02 knots Heading accuracy better than any gyro system, approximately ± 0.01 degree Rate of turn better than any rate gyro system, approximately ± 0.02 degree/second and up Position accuracy to a few centimetres Mooring of ship - TVS 1ste kan

Signal is used as input for an ECDIS based on C-map or S-57 maps. Portable version exists Mooring of ship - TVS 1ste kan

Berth management systems
A « Berth Manager» monitors the vessel approach, mooring load and environmental situation in a single integrated system, with a range of optional displays, readouts and functions, and provides the port operator with comprehensive reporting on the behaviour of vessels while in the confines of the port. The system assists the docking procedure and monitors mooring performance. Mooring of ship - TVS 1ste kan

Berth management systems

Fenders Used to: Fenders can be fixed or mobile Divide the load
Protect the berth Protect the ship Fenders can be fixed or mobile Mooring of ship - TVS 1ste kan

Yokohama Fenders Mooring of ship - TVS 1ste kan

Fixed fenders Mooring of ship - TVS 1ste kan

Mooring equipment on board

Mooring equipment on board
Heaving line (ligne d’attrape) Messenger (grelin) Tails Mooring of ship - TVS 1ste kan

Heaving line (ligne d’attrape)

heaving line (Ligne d’attrape)

Messenger - grelin Mooring of ship - TVS 1ste kan

Tail (allongement de la touline)

Passing ropes ashore Before arriving at the dock all crewmembers should put on their Personal Protective Equipment and move out onto the deck. All lines should be prepared for docking making sure that they will feed out freely. There should always be someone on the dock to receive the line. Do not attempt to throw the line to the bitt. If the boat is to be moored some distance from the dock a messenger line (grelin) with a monkey’s fist can be thrown and then hauled in to transfer the mooring line safely to the dock. Mooring of ship - TVS 1ste kan

Passing ropes ashore If you are sharing the bitt or bollard with another vessel feed the eye of the mooring line through the eye of the line already on the bitt and then place the eye over the bitt. This will allow you or the other vessel to quickly remove a line without disturbing the remaining line. Mooring of ship - TVS 1ste kan

Passing ropes ashore Mooring of ship - TVS 1ste kan

Putting 2 ropes on the same bitt
Wrong Correct The « other » ship can leave without disturbing our mooring configuration Mooring of ship - TVS 1ste kan

Passing ropes ashore While handling lines you must be very conscious of the placement of your hands and feet in proximity to the line. Never put your hand in the bight of the line at the bitt, and watch that you do not step into the bight of the line on the deck with your foot. If the boat surges you can be caught in an instant, resulting in serious injury or death. Mooring of ship - TVS 1ste kan

Passing ropes ashore Never place yourself in a position where the line can pinch you up against the bulwarks or equipment on deck. You will never be able to move quick enough to get out of the way or have the strength to keep the line off you! Mooring of ship - TVS 1ste kan

Mooring of ships - forces

Similar presentations

Presentation on theme: "Mooring of ships - forces"— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

Mooring of ships - forces

Similar presentations

Presentation on theme: "Mooring of ships - forces"— Presentation transcript:

Similar presentations

About project

Feedback