STANDARD DEFINITIONS‘ End : The end of a system, block or repeater, into which the positive (or negative, A’ depending upon local convention) current is usually fed. ‘ Terminal : Usually refers to the Terminal supplying positive (or negative, depending A’ upon local convention) current into the cable system. Acrylic coating : The protective buffer coating used on optical fibres to protect the glass from mechanical damage. Aft : Direction towards the stern of a ship. Alter Course (A/C) : Point along a cable route where the course bearing changes. Amplifier : Used to boost transmission signals, and inserted at intervals along a cable system in a watertight housing called a ‘ repeater’ See Repeater . Area Slack : See Slack Armor / Armour wires : Normally galvanised steel wires (of circular cross-section) laid around the core of the cable, to provide both tensile strength and protection from external damage. Armor / Armoured cable : Cable covered with protective armour wires. Used mainly to minimise the risk of damage to the cable by fishing gear, anchors etc. See Cable Types Articulated Piping : A system of articulated split pipes which are fitted over the cable to give additional protection to that afforded by armoured cables (usually at shore end landings). Articulated pipes are usually applied by divers after the cable has been laid, however some types of piping can be applied as the cable is deployed from the vessel. As Laid List: See Route Position List, Straight Line Diagram (SLD). Assembly of Submarine Plant : The activity of jointing cable sections and repeaters into a continuous system length suitable for testing, loading and laying. Attenuation : The loss of optical or electrical signal strength suffered by a transmission signal passing along a fibre (or cable). Average Ship Slack : See Slack ‘ End : The end of a system, block or repeater, into which the positive (or negative, B’ depending upon local convention) current is usually fed. ‘ Terminal : Usually refers to the Terminal supplying positive (or negative, depending B’ upon local convention) current into the cable system. SCIG Information Guide 1 Section : 3 Issue : 1 See Ordnance Clearance Beach Joint : The joint between the land cable and the submarine cable. For instance it may be invasive and continuous. such as resistivity or seismic refraction can be used. or to the U-shaped loop of cable exiting the cable tank in which a repeater is positioned. using techniques such as cone penetrometer tests (CPTs). Bellmouths can also appear at the front of ploughs. from the cable tank. in a controlled manner. Jet Burial and Trench burial. which may be used to constitute a BAS. usually embedded in the ground to act as a permanent anchor for the shore end cable. Block : See Mini System. or similar to cable joints where fibres can be spliced and looped back to allow optical tests. Bow: The forward end of a ship. Burial Assessment Survey (BAS) : A survey of the seabed to determine the likely success of any type of burial operation and to assist in the appropriate selection of cable armouring. The height and design of the bellmouth assists the cable to uncoil freely. which will be laid at sea. Beach Manhole : Concrete vault at the top of the beach landing point used to accommodate the beach joint. Block End Seal : A cable end fitting designed to seal a cable end. or any combination of the above. Bight : Any U-shaped loop of cable or rope. – See Electronic Burial Assessment (EBAS) and Plough Assessment Survey (PAS). or by core recovery. usually located in the beach manhole. SCIG Information Guide 2 Section : 3 Issue : 1 . There are different combinations of tools. Such structures are sometimes located above cable tanks. Other geophysical methods. Burial can be achieved by a number of means including Plough Burial. such as a mini-plough or grapnel shaped tool. Block end seals may be simple fittings to prevent water ingress. to guide the cable smoothly into the burial tool. Branching Unit (BU) : A BU is the sub-sea unit used at the point where the cable system splits into two legs or branches. Burial : Burial of the cable into the seabed for additional protection against external hazards. The structure is often used to provide a location for the beach anchor. and for the storage of extra cable.Beach Anchor : Secure point. Often refers to the single U-shaped loop of cable paid out from the cable ship as a final splice. or where the metallic conductor in the cable can be in either open circuit or short circuit with the sea. Beach Clearance : Activity of removing debris from beach to provide a clear corridor for cable and manhole installation. Bellmouth : A cable guiding structure which can be shaped in outline like a bell and acts to control the safe bending radius of a cable when it makes a turn. Alternatively sampling can be carried out at discrete sites. and on some tracked vehicles. Cable Awareness Chart : A chart published and distributed (usually free of charge) showing the positions of all submarine cables in the area. repeaters and BU’ suitable for the systems in that area. Cable Route Engineering : The process of planning the build of an undersea cable system. The cable types are selected and the levels of cable slack are defined to allow complete in-fill of the undulating seabed. Cable Pan : A portable cable storage tank. optical and mechanical details of the cable. Following the receipt of the ‘ cable route survey’ report the final engineered cable route is optimised and selected. s Cable Head : Refers to the cable end positioned in the Cable Terminating Cubicle (CTC). Cable Catenary : Term used to describe the shape of a cable in the water column from the ship to the seabed. Cable Ship : A vessel usually custom built to install (lay) and repair cables. In the case of system cable data the geographical details of the as-laid system are usually given in a standard form known as a Route Position List (RPL). Following SCIG Information Guide 3 Section : 3 Issue : 1 . Cable Crossing ( Pipeline) : See Pipeline Crossing Cable Data Sheet : Information giving the electrical.Burial Depth : The distance between the top of a buried cable and the seafloor. Cable crossing points are usually post lay buried by jetting to ensure that the cable remains in a safe. Cable Route Survey : This is the marine survey operation to obtain all the necessary information to design and engineer a cost effective and reliable cable system. As-Laid Diagram or splice list. Cable Crossing (Surface Laid) : The point at which a new cable crosses an existing surface laid cable. See Trench Depth Burial Protection Index : A concept relating depth of burial to the level of protection achieved taking into account the strength of the material into which the cable is buried. Cable Depots : Depots strategically placed around the world which store spare cable. Negotiations with the existing cable owner are required to agree to a mutually acceptable crossing procedure / methodology for buried cables. The end result of the route engineering process is a cable Straight Line Diagram (SLD) which is used to manufacture the cable system. Generally the cable type selected is similar to that already laid underneath. Cable Terminating Equipment (CTE) or Power Feed Equipment (PFE). stable position. The objective of the concept is to provide the optimum economic level of burial protection. This information is usually targeted towards fishermen to avoid cable damage and loss of fishing equipment. There is typically an agreed exclusion zone on each side of the existing cable where no towed bodies such as ploughs or grapnels can be used. Cable Crossing (Buried Cable) : The point at which a cable crosses an existing buried cable. Cable Types : The following internationally recognised cable types are offered by a variety of system suppliers Rock Armour Cable. with conventional left hand lay armour cable.armoured cable design offered as a spare cable for use in deep water where cable abrasion has caused system failures. Chain stopper : Tapered or untapered chain of high strength steel applied in half-hitches to cable. Can be based on the SA or SAL/LWA cable structure leading to the terms DAH (heavy) or DAL (light) respectively. In some cases when the inner cone has been reached.Deep Water Protected Cable. Usually used in association with an ROV.Double Armour Cable.Lightweight Cable. Sometimes referred to as Fish-Bite Protection. Generally used in areas where good burial is expected. based on LW cable with a single layer of armour wires. Conventional coiling starts at the outer edge of the tank and works inwards. a special semi . temperatures and prevailing weather conditions. Cable Tonnage : See Lift Capacity Cable Tracker : A device used to locate and track along submarine cables (surface laid or buried). the cable is taken out to the outer edge of the tank and the process is repeated. Cable Terminating Cubicle (CTC) / Cable Terminating Equipment (CTE) : Secure box or cabinet where the cable end is secured and electrical power applied to the conductive cable elements.receipt of the ‘ cable route survey’report the installation cable route is optimised based on data obtained on the seabed bathymetery (depth contours etc. Dependant on the number and size of armour wires this type of cable is sometimes referred to as SAH (heavy) or SAM (medium). Cable Tanks : Large tanks in a ship or depot in which cable is stored. Coiling : Coiling cable in a tank is usually done in a clockwise direction. SCIG Information Guide 4 Section : 3 Issue : 1 RA - . SA . based on LW cable with a single layer of small diameter armour wires for protection. DA . Commercial Acceptance : See Ready for Provisional Service (RFPS). Mainly used on armoured cable during recovery or when the cable under the chain stopper will not be reused. The survey will determine if cable burial is required or indeed is possible.Single Armour Cable. currents. sub-bottom profiling together with other useful information such as side scan sonar. Generally used as a surface laid cable where burial is not possible. based on LW cable with a metallic screen and outer polymeric sheath. DWP . LWA / SAL .Light Wire Armour / Single Armour Light Cable.).Lightweight Protected / Lightweight Screened / Special Application Cable. used in benign deep water areas. a specialised double armour cable with a very short lay outer armour to provide enhanced crush resistance and improved bending stiffness. LWP / LWS / SPA . LW . based on LW cable with two layers of armour protection. Cone Penetrometer Test (CPT) : A test carried out on the seabed where a cone is forced into the seabed material. COTDR : Coherent Optical Time Domain Reflectometer. In this way a conventional loss versus distance display is obtained for each outgoing fibre span on the fibre pair being measured. The functionality is similar to a conventional OTDR instrument. weather patterns. fault location and integrity testing of cables. The equipment is used for routine testing. See Survey Swathe. CPTs are usually carried out at discrete locations along the cable route in areas where burial may be considered. It prevents the cable from being stowed at less than the minimum bending radius and also holds the cable in position. fishing. Cutting Drive / Cutting Run : The grappling operation that results in cutting the cable on the bottom of the ocean. Core sample : A cylindrically shaped soil sample taken from the seabed using a core or vibro-core sampling machine. Daily Report : An operational report summarising work completed in the last 24 hours and indicating what work is planed for the next 24 hours. bathymetry. The survey corridor may vary in width dependant on the water depth. A fibre pair is tested by launching a test signal into the out going fibre and receiving the scattered light on the in-coming fibre. the actual implementation optimised for long systems. other cables (both in use and out of use) etc. temperatures. and are used to validate the electronic survey data. shipping. Corridor : Refers to the width of the sea bed corridor investigated during the survey operation. SCIG Information Guide 5 Section : 3 Issue : 1 . The desk top study draws on published information of interest to the cable engineers planning the route and selecting suitable cable types. Data obtained from the force required to penetrate the seabed allows the shear strength or relative density of the material to be determined. The desk top study will therefore provide information on climate.Cone : Structure in the centre of the cable tank. An instrument that is used to perform out of service backscattered light measurements on optically amplified line systems. Cut and Hold Grapnel : A grapnel capable of cutting the cable and then gripping the cable on one side of the cut. DC Test Set : Equipment used for resistance and capacitance testing of cables and subsea plant. Coherent optical detection is performed to greatly improve the sensitivity of the instrument. Desk Top Study : This is the first stage of any cable route survey operation. along the proposed route. Light scattered in the transmission fibre is coupled to the incoming fibre in the loop-back couplers in each amplifier pair in a repeater. Crinoline : A movable framework in a cable tank which can be moved up and down to restrict the tendency of cables to whip if the distance from the top of the stow to the bellmouth is too great and payout speed is high. Drum Cable Engine : A capstan device for controlling the cable pay out / recovery. temperatures. shipping. along the proposed route. The desk top study draws on published information of interest to the cable engineers planning the route and selecting suitable cable types. (accuracy is typically better than ±5 m). Diver Swim Survey : Usually carried out as part of the inshore survey operation. See Cable Types.e. Desk Top Study : This is the first stage of any cable route survey operation. Down Time : Equipment or vessel downtime (i. The drum engine is used in conjunction with a back tensioning unit known as a Draw Off & Hold Back (DOHB) Gear. The DOHB gear may be a tracked caterpillar engine or a tire engine capable of traversing across the working width of the drum engine. The desk top study will therefore provide information on climate. See Linear Cable Engine (LCE). time not operating correctly) is recorded on the operational daily report Draw Off & Hold Back (DOHB) Gear : Term applied to the back tensioning equipment used in conjunction with a cable drum engine. See Cable Types Depressor : Device fitted to plough or other burial tool which pushes the cable down into the trench. Directional Drilling : A specialised technique to drill under features without disturbing the landscape. The double layer of armour wires makes this a heavy cable with enhanced bottom stability and abrasion protection. bathymetry. Differential Global Positioning System (DGPS) : A satellite based positioning system which makes differential corrections to GPS signals to ensure the most accurate navigational position.Deep Water Protected Cable (DWP) : A special design of semi-armoured cable offered as a spare cable for deep water repairs in local areas where non-armoured cable abrasion as proven to be a persistent problem due to a rough seabed and high bottom currents. A diver will swim the cable route to locate and identify any seabed features or obstacles likely to cause problems when the shore end cable is landed. fishing. Double Armour Cable (DA) : Type of cable armouring often used at shore ends consisting of two layers of armour wires. This technique is used in environmentally sensitive areas where local wildlife or plant life is protected and may be endangered by normal cable installation (excavation) techniques. weather patterns. Direct Shore End Landing : Where the main lay vessel can safely approach a landing point to within a distance where cable can be floated directly ashore. Cable Drum Engines can be top loading or bottom loading and are fitted with fleeting knives or rings to control the position of cable on the drum. Duct : A pipe or set of pipes (manufactured from steel. concrete or polymeric material) through which cable can be drawn (pulled). other cables (both in use and out of use) etc. Directionally drilled ducts are often pre-installed SCIG Information Guide 6 Section : 3 Issue : 1 . De-Trenching Grapnel : Grapnel used to de-bury (and often recover) buried cable. PAS. Flatfish Grapnel : A grapnel used to cut undersea cables. Elastomer remover / stripper : Equipment used during cable jointing operations to remove elastomer compound surrounding the fibres. See BAS. Fleeting knives : Machinery operated to keep cable turns in the correct position on a cable drum engine. Equaliser : Passive device used to achieve nominally flat gain versus wavelength over a specific transmission band throughout an ocean block within a cable system. Electrodes (conventional) : Two devices trailed by a repair ship used to detect a tone that has been applied to a submarine cable from a terminal. Emergency Power Shutdown : Associated with power-feed equipment. Suitable DP systems allow vessels to automatically maintain station (position) or to move along a selected route at a given speed. generally coupled with CPT and video/sonar surveillance equipment. Fiber / Fibre Optics : Transmission medium. Electronic Burial Assessment Survey (EBAS) : A burial assessment survey (BAS) which does not depend on a continuous seabed invasive tool like a plough or grapnel (See Plough Assessment Survey). Fleeting rings : Perform same function as fleeting knives. such as resistivity or shear wave sensors. Operated in the event of danger to personnel or cable plant. Equalising Strop / Bridle : Length of wire rope used to ‘ equalise’ weight between 2 stoppers. ‘ C-BASS’is an example of an EBAS tool. side scan sonar imagery (a measure of bottom reflectivity. over glass fibres. Electronic Route Survey : That part of the marine survey in which all data is acquired electronically. employed in modern telecommunications cable systems utilising pulsed lasers to transmit and receive signals over glass fibers.at environmentally sensitive shore end locations where local wildlife or rare plant life could be endangered by normal cable installation techniques. which is then detected at the terminal. SCIG Information Guide 7 Section : 3 Issue : 1 . used to identity surface seabed materials) and sub bottom profiling (used to obtain information on the composition of the top 2 to 3 metres of seabed material). Equalisation can be typically achieved with a Passive Equalisation Unit (PEU) or Gain Equalisation Unit (GEU). Electrodes (reversed) : Two devices trailed by a repair ship used to inject a tone into a submarine cable. Dynamic Positioning (DP) : Term applied to an integrated computer system used to control the propulsion of a vessel. refers to 3D bathymetry. Instead EBAS uses sensors towed along the ground surface. This concept maximises the main lay cable ship’ time in cable laying and avoids potentially long transits s for the cable ship. evenly distributed between 6 planes to ensure that a minimum of 4 satellites are visible to a receiver anywhere on the earths surface. The space segment of the system consists of 24 satellites. (accuracy is variable and dependant on signal quality. Where a surface buoy is undesirable. Hydrodynamic Constant is a function of the cable diameter. Also refers to the final joint in a repair operation. Fusion splicer : Equipment used to join two fibres together by a process of arc fusion. Used on hard or rough bottoms. Grap Rope : Usually a wire core rope used for towing a grapnel. worldwide position fixing.Freighter Transfer : A means of shipping cable from the cable factory to the cable installation vessel by means of a freighter fitted out with cable tanks. Holding Drive / Holding Run : A grappling drive / run to recover cable as opposed to a cutting drive / run. but typically ± 100 m). The housing offers pressure resistance by means of a tubular casing. which is deliberately degraded for non military use. Global Positioning System (GPS) : GPS is a military satellite navigation system. In Line Transition : A change in cable types manufactured on the armouring line in the cable factory. GPS provides a 3-Dimensional high accuracy navigational position. drag coefficient and submerged cable weight. GPS will therefore provide continuous. Ground chain : Length of heavy chain between grapnel rope and grapnels to keep front end of grapnel low as grapnels are dragged over the seabed. Housing : Term sometimes used for cable joints and repeaters. Grapnel : A hook like device used on the end of a length of rope to raise the cable to the surface. SCIG Information Guide 8 Section : 3 Issue : 1 . Hydrodynamic Constant : A convenient measure of the sinking rate of a cable. it can be used as a grappling tail into which the ship can grapple to recover the system cable without damaging it. Gifford : A type of grapnel comprising four wide seated hooks at right angles to each other. Great Circle : The shortest distance between two points on a spheroid (note that to follow a great circle exactly requires continual changes of course). Final Splice : Final joint in a cable installation. Ground rope : Rope attached to cable which lies on the seabed to which buoy moorings are attached. See Rhumb Line Distances. making the system complete and able to commence commissioning tests. provides an electrical path for powered systems and provides the mechanical strength to protect the cable fibres and other components within the housing. owned and operated by the United States Department of Defense. Lift capacity (Cable Tonnage) : The weight of cable (normally in tonnes) that a ship is able to carry. Instantaneous Ship Slack : See Slack International Maritime Organisation (IMO) : Responsible for the publication of codes of safe working practices and other maritime rules and regulations.Injector Shoe : A jet burial tool fixed to the side of a shore end installation barge. Water jets remove seabed material to form a trench into which the cable is lowered. Plough Burial. The cable construction is usually one where the inner steel wires (strength members) are surrounded by an insulant of polyethylene. See Trench Burial. Jet Burial : Cable burial in suitable seabed materials (sands and soft silts/clays only) by an ROV or sledge equipped with a jetting tool . The time required to manufacture an optical joint is variable and dependant on cable type and the number of fibres. Jointless Lay ( Seamless Lay) : A marine operation (lay) which is planned to completion without making a shipboard joint. LWA / SAL is generally more flexible than SA. enabling deep burial (up to 10m) in soft materials in water depths up to 40m. and then a final (exterior) polyethylene sheath coating for additional bending stiffness and abrasion protection. having a lower bending stiffness SCIG Information Guide 9 Section : 3 Issue : 1 . Lightweight Protected / Lightweight Screened / Special Application Cable : Based on lightweight cable with the addition of a longitudinally continuous (circumferentially overlapped) metallic screen around the core LW cable. Lay : Term used to describe the operation of paying out cable to the seabed. Jointer : The person who performs the above operation Jointing : The process of joining two ends of cable together. Layback : Horizontal distance from the stern (or cable deployment point) to the position of a towed vehicle or point at which the cable touches the seabed. Lightweight Sheathed Cable : Based on lightweight cable with the addition of an extra polyethylene sheath coating for additional bending stiffness and abrasion protection. Lightweight (LW) cable : Generally the cable type used in benign areas of the seabed in deep water. Joint : The product and the assembly process used to join two cables (perhaps of two different types) to form a continuous segment. The addition of a metallic screen has been shown to offer improved protection over abrasion and fish-bite damage. Light Wire Armour (LWA) / Single Armour Light (SAL) : Type of cable armouring consisting of a single layer of small diameter armour wires applied over a lightweight structure. beam trawls). Widely used for measuring cable tension on cable engines and ploughs. wavelength up to 60cm (usually 5-12 times height Megaripples . NOTS : Abbreviation for ‘ Nominal Operating Tensile Strength’ which is a defined cable handling parameter. Being lighter the LWA / SAL cable characteristics mean that the cable can be deployed in greater water depths. post lay burial operation’or ‘ rock dumping operation’which tend to use smaller vessels. the more ‘ wheel pairs’ are required to grip the cable and control deployment without slippage. as distinct from a ‘ separate shore end operation’ ‘ . It is important to note that different values of minimum bending radius can apply dependant on the tension in the cable and the time duration of the bend. this equipment is used to pay out / pick up cable. Minimum Bending Radius : Cables should be handled and stored to the manufacturer’ s specifications. When the sandwave is mobile. The greater the outboard tension. Main Lay : Refers to the operation where a significant proportion of the cable in a system is laid from a cable ship.5cm to 1m height. See Universal Transverse Mercator. Mercator : Map projection with straight lines of latitude and longitude at right angles – a constant bearing is a straight line in Mercator projection. Load cell : Instrumentation device incorporating strain gauges configured to measure load. See Drum Cable Engine.>1m height. One important parameter which has to be observed is the cable minimum bending radius which ensures that the cable elements are not over strained or damaged. Load / Load Out : Term used to describe the operation of physically taking cable onboard the vessel (usually from a cable factory). an assembly of one or more repeaters and cable joined on the repair ship prior to a repair operation. Maul : Term used to describe the damage sustained by a cable when it has been hit by towed fishing gear (bottom trawling. wavelengths >15 times height (sometimes in excess of 100 times height). Mini System : This is short for “Mini-Repair-System”. Such an assembly can enable a speedy repair if there is reason to believe prior to the operation that such an assembly will be needed to replace a faulted portion of the system. Linear Cable Engine (LCE) : Generally situated at the aft end of a cable ship. Megaripples : These are sedimentary (transverse) bedforms which form at 90 degrees to the dominant current regime and are usually associated with lower current velocities and high sediment supply. The equipment consists of two opposing tracks or a series of pairs of wheels and tyres (usually arranged in the vertical plane) which grip the cable. otter boards. Mushroom : A mushroom shaped anchor which comes in various sizes and is used for anchoring buoy moorings.and torsional stiffness. wavelengths generally >15 times height Sandwaves . cable ends etc. It is the maximum tension which can be applied to the cable in SCIG Information Guide 10 Section : 3 Issue : 1 . a condition exists where the seabed shifts and may potentially expose previously buried cable. Transverse bedforms can be classified as : Ripples up to 5cm height. NPTS : Abbreviation for ‘ Nominal Permanent Tensile Strength’ which is a defined cable handling parameter. Pipeline Crossing : The point at which a cable crosses an existing pipeline. A plough is a passive device that is pulled through the seabed by a ship (usually the cable laying vessel) simultaneously with the vessel laying the cable. qualified to survey. OTDR : Optical Time Domain Reflectometer. Ordnance Clearance : Usually undertaken by a specialist team of engineers. integrity and suitability of the fibre. NTTS : Abbreviation for ‘ Nominal Transient Tensile Strength’ which is a defined cable handling parameter.9 % fibre survival probability. See ROV. Pipe Tracker : A device used to locate and track along pipelines and cables (surface laid or buried). An instrument which is used to accurately measure the following parameters : fibre length. These parameters allow the transmission engineer to access the quality.suspension from the ship for 48 hours with a greater than 95 % fibre survival probability for its entire design lifespan. Some cables which fall into this category continue to function in other capacities. for instance in seismic research. It is normal for cables to cross pipelines at 90 degrees and to continue at 90 degrees to the pipeline for a distance either side of the pipeline. Negotiations with the pipeline owner are required to agree a mutually acceptable crossing procedure / methodology. Out of Use (OOU) Cable (Out of Service Cable) : Term used to describe a cable which is still in situ on the seabed. The plough is equipped with a share which cuts a narrow trench in the seabed and then guides the cable into the bottom of the trench. It is the maximum tension which can be applied to a cable for one hour with greater than 95 % fibre survival probability for its entire design lifespan. Usually used in association with an ROV. but is no longer in commercial transmission service. There is usually an agreed exclusion zone on each side of the pipeline where no towed bodies such as ploughs or grapnels can be used. detect and dispose of munitions and other abandoned armaments. splice loss etc. Ploughs can be fitted with auxiliary shares to bury larger diameter bodies in the cable such as joints and repeaters. It is the maximum tension which can be left permanently in a cable (for its entire designed life span) with greater than 99. Instrumentation fitted to the plough confirms in real time the burial depth of the cable. This is done without the optical signal being regenerated by conversion to an electrical signal and then converted back into an optical signal (as is the case with optical regenerators). SCIG Information Guide 11 Section : 3 Issue : 1 . attenuation per kilometre. Pipeline crossing points are often rock dumped to ensure that the cable remains in a stable position and is not disturbed by fishing activities. Subsea Optical Amplifiers are packaged in housings in a similar manner to repeaters and continue to be referred to as repeaters. Optical Amplifier : An optical amplifier uses Erbium doped fibre and a laser pump to amplify an optical signal. Plough / Plow : A tool for burying cable into suitable seabed materials. for instance at ‘ plough skips’ (where the plough has been recovered for repair or maintenance). pitch. manufacturing variations. This operation is normally performed by towing a surveyor plough or detrenching grapnel along the proposed cable route and recording data such as tow tensions.coupled with the soft sediment . Power Budgets : A tabular listing of optical parameters that in total determine the transmission performance of the repeatered undersea system. Pock Marks : Most pock marks are formed by the decay of organic matter within the sediment matrix which causes gas to seep upwards and to be released at the seabed as bubbles. It next list the impairments that can occur over the life of the system (e. mainly dependent on the level of gas release and bottom currents.. Post Lay Burial (PLB) : This operation involves the burial of cable into the seabed after the cable has been deployed.are a direct threat to plough operations. Post Lay Inspection & Burial (PLIB) : This operation is usually carried out in areas of plough burial after the cable installation by an ROV. which is centred around the area of greatest gas release. This operation is often specified by pipeline owners as part of the cable crossing agreement and is specified to prevent cable movement over and along the pipeline after installation. Pock mark width and depth can vary greatly. degrading supervisory effects) to determine the expected beginning of life performance. See BAS. and then it accounts for all the possible impairments (e. The tow force is usually measured at the plough tow point..g. The sediment grains in this area are forced apart by the gas and can be winnowed away by even very low bottom currents. SCIG Information Guide 12 Section : 3 Issue : 1 . roll and depth of burial.Plough Assessment Survey (PAS) : A marine survey operation carried to determine the suitability of the seabed to bury cables. Post Lay Inspection (PLI) : This operation involves the inspection of the installed cable after it has been deployed and possibly buried. The operation can be carried out by divers in shallow water (generally less than 30 m) or by an ROV equipped with jetting or trenching tools. See Jet Burial. up to a maximum percentage of the buried cable length) confirms the burial depth. but can be calculated from the tow tension measured on the ship at the tow winch. If necessary additional burial (usually by jetting) can be implemented in localised areas. added loss due to repairs) to determine worst-case end-of-life performance. EBAS Plough Burial : Burial of the cable into the seabed for enhanced cable protection using a plough (usually towed from the installation vessel as the cable is deployed from the vessel). Plough Tow Tension : Tow force required to pull the plough along the seabed during ploughing operations. The cable is guided into the bottom of a narrow trench cut into the seabed by the plough depressor . after cable deployment. Trench Burial. Post Lay Rock Dump : Term used to describe the accurate dumping of graded rock over a defined area of the seabed. At the top is the ideal performance considering only the intrinsic noise of the optical amplifiers.g. Some of the larger pock marks can be tens of metres deep and have very steep side-slopes. ageing of repeaters and cable. The slopes . The inspection operation (usually over selected areas of the buried cable route. non-linearity of the fibre. The typical conical shape of pock marks is caused by this winnowing. Pre Lay Rock Dump : Term used to describe the accurate dumping of graded rock over a defined area of the seabed. in the event the cable is powered. designed to be wrapped around cables and fitted with an eyelet to allow transfer of tension from the cable to another rope without damaging the cable insulation. Pulse Echo Fault Locator (PEFL) : Sometimes known as a reflectometer. Ready For Provisional Service (RFPS) : Date on which the cable system has completed all commissioning tests / purchaser acceptance tests and has been accepted by the purchaser of SCIG Information Guide 13 Section : 3 Issue : 1 . The result is a pre laid shore end. joints) in cables. Power Safety Officer (PSO) : The person on the cable ship who has responsibility to the Captain (or Offshore SuperIntendent) for the safety of all personnel on the cable ship with respect to the voltage and current used during laying and repair operations. Can be used in conjunction with both armoured and nonarmoured cables. but can be verbal) exchanged between the cable ship and the terminal stations to define who has power safety control and in what condition the cable head is to be maintained. It has been designed to locate mismatch conditions (open circuits. This operation is often specified by pipeline owners as part of the cable crossing agreement.Power Feed Equipment (PFE) : A constant current / high voltage power supply used to supply DC power to a submarine cable system. Pre Laid Shore End (Separate Shore End) : Where the main lay vessel cannot safely approach the landing point (due to draft. prior to the cable deployment. It allows the vessel to work on a faulty leg of a system without loss of traffic on the main leg. which the main lay vessel can recover and carry out an initial splice before laying away. Ready for Provisional Acceptance (RFPA) : Date on which the System Supplier offers the cable system to the purchaser for acceptance (all main lay marine installation operations. or prevailing weather conditions) a separate shore end landing operation is carried out using a smaller vessel with a shallow draft allowing for a closer approach to the beach landing. The nature of the mismatch can be ascertained by comparing the reflected pulse with the original transmitted pulse. Power Safety Message (PSM) : A message (usually written and faxed. fishing equipment etc) which could foul the burial machine and cause cable damage is removed. Preformed Stoppers : A preformed wire helix. Pre Lay Grapnel Run (PLGR) : This operation is carried out shortly before burial operations and involves towing a grapnel along the planned burial route to ensure that any discarded material (such as abandoned ropes. This activity is separate from ‘ Route Clearance’ . short circuits. supplier commissioning and acceptance tests having been completed). Also known as an In Service Repair (ISR) or Hot Repair. Protection Grounding Unit (PGU) / Power System Branch Repair Unit (PSBR) : Provides the earth path or ground. during a repair on a system that is fitted with Branching Units. Rotometer (Roto) : An instrument used on ships for measuring the movement of cable. The cable system is ready for commercial use.the system. dropped objects and towed equipment such as fishing gear. ROV’ are usually fitted with cameras. See Great Circle Ripples : See Megaripples. Remotely Operated Vehicle (ROV) : A submersible unmanned vehicle used to inspect. Route Clearance : A Pre Lay Grapnel Run. Re Laid : A term used for the relaying or re-routing of a cable system. Identified cables are recovered or cut back to provide a clear corridor for the installation for the new cable system. They can also be used to carry out surveys and inspection of the cable on the seabed. subject to some additional works being carried out. which is required due to the losses inherent in the transmission media. Repeatered Cable System : A powered cable system fitted with repeaters (or optical amplifiers). Repair : Operation whereby the integrity of a cable system is restored. Repeaters also typically contain DC power regulation and supervisory functions. Route Engineering Study : An enhanced Desk Top Study which involves visiting the landing sites and gathering additional local information. cable tracking equipment and for s burial operations can be fitted with a jetting or trenching tool package. Request for Quotation (RFQ) : Request sent to specialist sub-contractors to supply a quotation for work specified in an attached scope of work. debury. paid out or picked up. The outer layer of armour wires will have a very short lay length to provide enhanced crush resistance and hence provide improved protection against external damage caused by impacts from rocks. SCIG Information Guide 14 Section : 3 Issue : 1 . See Cable Types. See Plough. The rotometer is usually a wheel which runs on the cable to measure the length and speed at which cable is loaded. Remote Amplifier Box (RAB) : Term used to describe an erbium amplifier housing positioned in an unrepeatered cable system. Rhumb Line Distance : The constant bearing distance between two points on a spheroid. bury or re-bury cables. where specific out of service cables are targeted for removal from the cable route. The cable system is ready for commercial use. Repeater : An element of submersible plant (housing / amplifier) used for boosting the signal. (Also known as Commercial Acceptance) Ready For Service (RFS) : Date on which the cable system has completed all commissioning tests / purchaser acceptance tests and has been accepted by the purchaser of the system. Rock Armour (RA) Cable : A special type of double armoured cable. Skid : The parts of the plough which run along the seabed are called skids. SAL is generally more flexible than SA. repeaters. Depending on the diameter of the armour wires used for protection some suppliers use the terms Single Armour Medium (SAM) and Single Armour Heavy (SAH). positions of alter courses. and cable slack values are recorded. The use of side scan sonar is helpful in cable repair operations in identifying surface laid cables and in localising fault locations. See Cable Types. Route Survey : See Cable Route Survey Sand Waves : When mobile. but there are several different precise definitions given below. Single Armour Light (SAL) / Light Wire Armour (LWA) Cable : Type of cable armouring consisting of a single layer of smaller diameter armour wires applied over a lightweight cable structure. Being lighter the SAL cable characteristics mean that the cable can be deployed in greater water depths. Seabed Slack : See Slack Siemens Stopper : A platted wire rope stopper applied to armoured cables. Functions in a similar manner as pre formed stoppers. a condition exists where the seabed shifts and may potentially expose previously buried cable. while allowing the plough to ride over rugged terrain. See Megaripples Scientific Cable : Cables used for research purposes and not for commercial telecommunications. Slack values are usually expressed as a percentage: SCIG Information Guide 15 Section : 3 Issue : 1 . joint housings. Some scientific cables are used as part of the World Wide Ocean Circulation Experiment (WWOCE) to measure ocean currents and their effect on climate change. sectional and cumulative cable length. Used primarily during survey operations prior to ploughing operations. Separate Shore End : See Pre Laid Shore End Share : Part of the plough which engages in the seabed to bury the cable.Route Position List (RPL) : A standard format for providing information on the planned and then as laid positions of the cable system. Details on the cable type. this may include out of service cables which have been donated or sold to an academic institution. all of which are important in cable-work. Single Armour (SA) Cable : Type of cable armouring consisting of a single layer of armour wires applied over a lightweight cable structure. predictions and modelling. The function of a skid is to support the weight of the plough. having a lower bending stiffness and torsional stiffness. See Cable Types. Slack : The term ‘ Slack’ defines a ratio of excess cable length to distance. See Depressor Ships Slack : See Slack Side Scan Sonar : An acoustic technique to map the reflectivity of seabed material identifying potential obstructions on the seabed . Instantaneous Ship Slack = (‘ Cable Payout Speed’– ‘ Ship Speed’ / ‘ ) Ship Speed’ Seabed Slack = (‘ Incremental Length of Cable on Seabed’ – ‘ Increment of Length measured along the seabed’ / ‘ ) Increment of Length measured along the seabed’ Spear Point grapnel : A type of grapnel used in softer seabeds to achieve greater penetration for cable recovery. Average Ship Slack = (‘ Cable length overboarded from ship between two points’ – ‘ route distance at sea level between the points’ / ‘ ) route distance at sea level between the points’ Average Ship Slack is typically quoted on an ‘ laid RPL’ that forms part of the as normal lay report. and is used for defining the cable lengths to be manufactured. The SLD provides information on the cable types and lengths required to make the system. Spheroid : The assumed shape of the earth. Stern : The aft part of a ship. Stow : A term to describe the stowage of cable in a cable tank. Sub Bottom Profiling (SBP) : This is an acoustic method of determining the vertical lithological distribution of the upper seabed.) in the system. Strumming : A term used to describe the standing wave vibration set up in unsupported cable during deployment or when in suspension between localised high spots on the seabed. and then a final (exterior) polyethylene sheath coating for additional bending stiffness and abrasion protection. water depths and slack allocations.‘ route distance at sea level between waypoints’ / ‘ ) route distance at sea level between waypoints’ Area slack is the figure generally quoted on the route position list of a planned lay. Special Application (SPA) / Lightweight Protected / Lightweight Screened Cable : Is based on lightweight cable with the addition of a longitudinally continuous (circumferentially overlapped) metallic screen around the core LW cable. together with a manufacturing tolerance and identifying critical areas of cable which are required to be accurately positioned (for pipeline crossings etc. Straight Line Diagram (SLD) : The SLD is the result of the cable engineering process carried out after the cable route survey. The addition of a metallic screen has been shown to offer improved protection over abrasion and fish-bite damage. Stowage Factor : A term indicating the volume occupied by a known length of cable. See Cable Types. Stinger : A rigid share supported from a shore end barge which is fitted with water jetting nozzles and capable of deep burial of cables (up to 5 m burial) in suitable seabed materials. SBP equipment releases quite low power. WGS84 datum (World Geodetic System 1984) is normally used. together with plough up and down positions. Repeater positions (and separations) are usually indicated in the SLD. Strumming is induced by the drag forces generated when water currents flow across the cable in suspension. high SCIG Information Guide 16 Section : 3 Issue : 1 .Area Slack = (‘ Planned Cable length on seabed between waypoints’ . but also from layers within the seabed. laid and handled safely. Transponder : An acoustic beacon which relays positional information (bearing and distance) to a hydrophone receiver (usually hull mounted) on the surface vessel. UTS : Abbreviation for the Ultimate Tensile Strength which a cable can support before mechanical failure. Trailed Electrode : See Electrodes Transition : The length of cable (or body) between two different cable types. an unsupported length of cable held in a catenary by the residual cable tension at each side of the suspension. Surface Lay : Operation where cable is paid out from the vessel and laid directly onto the seabed without being buried.e. a cable vibration induced by the flow of water across the cable suspension. The acoustic energy reflects back not only from the seabed surface. i.frequency. This technique is typically used where plough burial cannot achieve adequate protection. Plough Burial. System Load and Lay Instructions (SLLI) / Handling Guidelines : A document prepared by the system manufacturer for the marine installer detailing how the cable system (including joints and repeaters) will be loaded. Transponders can be used to locate subsea equipment such as ploughs. ROV’ etc. Trench Burial : Cable burial in the seabed achieved by a mechanical cutter such as a chain cutter or a rock wheel cutter. Under running : Under running is the process of passing a cable over an under running sheave to allow the vessel to move towards a fault location or cable end. Cable in suspension can suffer damage at the contact points where abrasion can occur (chafe) and may be subject to strumming. SCIG Information Guide 17 Section : 3 Issue : 1 . because of differing physical properties associated with different geological units. Suspension : A term used to describe cable in free span. Swathe : Refers to a survey swathe or width of the survey corridor. This process becomes necessary to reduce the amount of cable removed during a repair when grappling has occurred some distance from the fault.. short pulses of acoustic energy into the water column and measures energy reflected back from the seabed and sub-seabed. See Jet Burial. A project plan is included. Instructions on the equipment and services to be provided and the required safety standards to be maintained during the operation are defined. Trench Depth : The distance between the bottom of the cut trench and the seafloor (See Burial Depth) Turn Over : Process of moving cable from one tank to another to facilitate jointing. inspection/restowing or assembly of a larger system. to mark a s target area on the seabed or to ensure accurate placement of equipment on the sea bottom. Whiskers : A guide manufactured from shaped steel plate forming a three dimensional structure used to guide cables into and out of the vessel over a roller sheave so that the cable minimum bend radius is controlled. Unrepeatered Cable System : An un-powered cable system. Latitude and longitude may be converted into grid terms and vice versa using the appropriate formulae. V Sheave : Type of grooved bow or stern roller sheave used as a cable guide. Universal Quick Joint : A type of cable jointing for non-repeatered systems. X Rays : A process used to detect defects such as voids. inclusions and non-concentricity occurring in moulded joints during cable repair operations. without repeaters. A method of transmitting optical signals at several wavelengths over the same fibre at the same time. WDM : Wavelength Division Multiplexing. Yale Grips : A custom made webbing stopper for use on rope and armoured cable. course changes. that uses an agreed set of equipment and tooling for assembly and uses an international standard for qualification testing. Waypoints : Discrete locations along a cable route where special events occur. SCIG Information Guide 18 Section : 3 Issue : 1 . i.Universal Joint / Universal Coupling (UJ / UC) : A type of cable jointing and repeater coupling that uses an agreed set of equipment and tooling for assembly. Wrap / Coil : Term used to describe the coiling and storage of fibres inside a joint housing. each consisting of 6 degrees of longitude. Whiting Chalk : A chalk applied to armoured cables to prevent cables sticking together when seepage of the armour compounds may occur in hot storage conditions. and has been approved using an international standard for qualification testing. Wire pennant : Length of wire used to hand off cables and ropes when transferring them to and from cable drums.e. Universal Transverse Mercator (UTM) : Grid system in which the world is divided into 60 zones. The cable is capable of carrying a small current and voltage to monitor Insulation Resistance for a fault condition.