Extended Operational and Trade Vocabulary

Port Engineering, Dredging, Breakwaters, and Quays glossary

Vocabulary of port and coastal engineering: concrete armour units such as Accropode and A-Jack for rubble-mound breakwaters, ADCIRC hydrodynamic surge and tide modeling, cutter suction dredgers and anchor poles, and the breakwater, quay-wall and reclamation design terminology underlying harbour construction and protection works.

287 defined terms.

Showing 250 on this page (page 1 of 2).

A

A-Jack: Concrete armour unit with twelve legs used for shoreline and breakwater protection, manufactured under license by Armortec.
AAPA: American Association of Port Authorities, trade body representing seaports in the Americas.
Accropode: Single-layer concrete armour unit developed by Sogreah (now Artelia) of France in 1980 for rubble mound breakwater armouring.
Accropode II: Improved single-layer concrete armour unit developed by Artelia in 1999 as a successor to the original Accropode.
Active berth length: Length of quay actually available for berthing operations after deducting structural and operational setbacks.
ADCIRC: Two- and three-dimensional finite element hydrodynamic circulation model widely used in the United States for storm surge, tide, and coastal modeling.
Air gap: Vertical distance from the fuel surface to the top of the tank, used in ullage measurement.
Allowable axial load: Maximum vertical load that a pile or sheet pile section may carry within the design code's factor of safety.
Ambiorix: DEME self-propelled CSD of 19,200 kW total installed power, named after the Eburones chieftain.
Anchor pole: Auxiliary spud-like pole at the stern of a cutter suction dredger used to step the vessel forward between working positions.
Anchored sheet pile wall: Sheet pile quay restrained near the top by horizontal tie rods or strands connected to an anchor wall or pile group.
Approach channel: Navigable channel between sea and port basin.
Approach speed: Forward velocity of a CTV against the boat landing fenders, normally between two and four knots depending on swell and bow puffer design.
Arcelor sheet pile: Steel sheet pile sections, including the AZ, AU, and PU profile families produced by ArcelorMittal at its Belval mill in Luxembourg.
Armour layer: Outer protective layer of a rubble mound breakwater composed of rock or precast concrete units.
Armour rock: Large quarried stone placed as the outer protective layer of a rubble mound breakwater to resist wave attack.
As-built survey: Hydrographic survey carried out after dredging or construction to verify the work against the design.
ASPA: Antarctic Specially Protected Area, a Madrid Protocol designation requiring a permit for entry into ecologically or scientifically sensitive zones.
Athena: Jan De Nul CSD of 17,729 kW total installed, named after the Greek goddess of wisdom.

B

Backfill: Granular or rock material placed in a trench above a buried subsea cable to restore the seabed profile.
Backhoe Dredger: Hydraulic-excavator-mounted dredger.
Baggerwerken Decloedt: Belgian dredging firm, one of the two predecessors that merged in 1991 to form DEME Group.
Bartolomeu Dias: Jan De Nul TSHD of 17,500 m3 capacity, named after the Portuguese navigator.
Bathymetric survey: Seabed depth mapping campaign required for siting tidal arrays, wave farms, CO2 injection wells, and subsea hydrogen pipelines.
Beach nourishment: Coastal protection technique.
Bend Radius: Minimum curvature a wire rope or sling may follow without losing capacity.
Berm breakwater: Rubble mound breakwater with a wide seaward berm that allows the armour to reshape under wave action into a stable profile.
Berthing dolphin: Isolated marine structure designed to absorb the lateral berthing energy of vessels alongside a jetty.
BHD: Backhoe dredger acronym, in international tender documents.
Block-work quay: Gravity quay wall built from stacked precast concrete blocks bedded on a prepared rubble foundation.
Bollard: Mooring fitting on quay or dolphin.
Bollard pull: Tug pulling force in tonnes.
Booster station: Inline pumping unit installed on a dredger discharge pipeline to extend pumping distance when transporting slurry from cutter or hopper to placement site.
Boskalis: Dutch dredging and salvage major, parent of SMIT Salvage since 2010.
Bottom door: Hopper hull opening, hydraulically actuated, used for dumping sediment at sea.
Boulder protection: Heavy rock placed locally on the bed to deflect anchors or prevent scour around marine structures.
Bow thruster bay: Pocket recessed into a quay or jetty deck arrangement that accommodates bow thruster wash and may include scour protection.
Brabo: Trailing suction hopper dredger operated by Jan De Nul Group.
Brabo II: Successor trailing suction hopper dredger in the Jan De Nul fleet bearing the Brabo name lineage.
Breakwater: Coastal structure providing wave shelter.
Breasting dolphin: Isolated structure absorbing berthing impact.
Breasting line: Mooring line led roughly perpendicular to the berth, resisting off-berth motion of the vessel.
Bucket ladder dredger: Chain of buckets on inclined ladder, the oldest mechanical dredger type, still operating in tin mining off Indonesia.

C

Caisson breakwater: Vertical breakwater formed of monolithic or cellular reinforced concrete caissons set on a rubble foundation.
Caisson quay: Gravity quay wall constructed from floated-in reinforced concrete caissons ballasted and founded on a prepared bed.
Capital dredging: initial dredging to deepen or widen a channel or berth.
Cashman Dredging: United States dredging contractor based in Quincy near Boston, Massachusetts, active on coastal navigation and remediation projects.
Cathodic Protection: Sacrificial or impressed current system protecting subsea steel from corrosion.
CCCC: China Communications Construction Company, parent of the country's major dredging units including CHEC and the Shanghai, Tianjin, and Guangzhou dredging companies.
CEDA: Central Dredging Association, the European branch of WODA, headquartered in Delft.
Cellular caisson: Reinforced concrete caisson with internal cells that are flooded or filled with sand to provide stability against sliding and overturning.
Cellular cofferdam: Circular or diaphragm sheet pile structure filled with granular material, used as quay walls or temporary works in deep water.
Channel centerline: Reference line along which the design depth and width of a navigation channel are measured.
Channel cross-section: Geometric shape of a dredged navigation channel, typically trapezoidal in dredged sand and approximating triangular in narrow rock cuts.
Channel marker: IALA buoy or beacon.
Charles Darwin: Jan De Nul TSHD of 30,500 m3 hopper, one of the largest trailers in the world.
CHEC: China Harbour Engineering Company, the international engineering and dredging arm of CCCC.
Closure dam: Temporary or permanent earth or rock dam used to close off a tidal opening as part of reclamation or coastal works.
Combiwall: Composite sheet pile quay wall combining heavy king piles with intermediate light sheet piles to span between them.
Compaction grouting: Injection of low-mobility grout into loose granular soils to densify them prior to quay or breakwater construction.
Composite breakwater: Breakwater with a rubble mound base supporting a vertical concrete superstructure, common in deep water.
Concrete armour unit: Precast concrete element placed singly or in two layers as the armour of a rubble mound breakwater.
Container quay: Continuous quay wall designed for ship-to-shore container cranes and heavy stacking surcharges from the marshalling yard.
Conveyor: continuous belt for moving dry bulk between vessel, shore, and storage.
Core-loc: Single-layer concrete armour unit developed by the United States Army Corps of Engineers in 1996 as a successor to Dolos.
Cottrell Contracting: Virginia-based United States marine contractor active in dredging on the East Coast and Chesapeake region.
Crest level: Top elevation of a breakwater or revetment, determined by overtopping limits and design water level.
Cristobal Colon: Jan De Nul TSHD of 46,000 m3 hopper, tied with Leiv Eiriksson as the world's largest trailing suction hopper dredger.
Cross-shore transport: Movement of beach and nearshore sediments perpendicular to the shoreline driven by waves and water level changes.
Crown wall: Concrete superstructure cast on top of a rubble mound breakwater to limit wave overtopping and provide a service road.
CSD: Cutter Suction Dredger, removes hard material through a rotating cutter head.
Cutter head: Rotating toothed cutting tool at the lower end of a CSD ladder that excavates compact soils and rock.
Cutter ladder: arm carrying the cutter head on a CSD.

D

D'Artagnan: DEME CSD of 28,200 kW total installed power, named after the musketeer.
Daewoo E&C Marine: Marine and dredging arm of Daewoo Engineering and Construction of South Korea.
Deadman anchor: Buried plate or concrete block anchor that resists the tie-rod force of an anchored sheet pile quay.
Deep water quay: Quay wall designed for vessels with drafts greater than about 14 meters, typical of modern container, bulk, and tanker terminals.
Delft3D: Open-source modeling suite for hydrodynamics, morphology, and water quality.
DEME: Belgian marine contractor with subsidiaries including DEME Offshore active in foundation and turbine installation.
Design vessel: Reference vessel selected as the basis for sizing channels, basins, fenders, mooring fittings, and quay structures.
Design wave: Statistically derived extreme wave height used in structural design of offshore wind foundations.
Detached breakwater: Offshore breakwater for coastal protection.
DHI: Danish Hydraulic Institute, developer of the MIKE 21 and MIKE 3 modeling suites.
Diaphragm wall: Cast-in-place reinforced concrete wall built using bentonite-slurry trench techniques, sometimes used for quay walls in soft soils.
Discharge pipeline: Floating, sinker, or shore pipeline that carries pumped slurry from a CSD or hopper dredger to the placement area.
Disposal area: Designated water or land site for placement of dredged material, licensed under the London Convention for marine disposal.
Dolos: Concrete armour unit shaped like an H with twisted flukes, invented by Eric Merrifield in East London, South Africa in 1963.
Dolphin: Isolated marine structure.
Donjon Cape May: Donjon Marine yard in Cape May, New Jersey, that supports East Coast dredging and marine construction operations.
Donjon Marine: US east coast salvage contractor with OPA 90 OSRO standing.
Drag arm: Suction pipe assembly of a TSHD, including gimbal, intermediate sections, and drag head.
Drag head: Drag head of a trailing suction hopper dredger.
Drag head visor: Movable shield on a drag head that adjusts to soil conditions and helps direct material into the suction inlet.
Dragline: Crawler crane with drag bucket, historically used for marsh dredging.
Dredge cycle: Complete sequence of loading, sailing, discharging, and returning that characterizes TSHD productivity.
Dredge pump: Centrifugal pump, mounted inboard or outboard on a dredger, that conveys soil-water slurry through the suction and discharge piping.
Dredging International: Former name for DEME's dredging division.
Dredging tolerance: Permitted vertical deviation, including paid overdepth, between the design dredge level and the as-dredged bed.
Dustpan dredger: USACE Mississippi River dredger with wide horizontal suction mouth, exemplified by Hurley and Jadwin.

E

EADA: Eastern Dredging Association, the Asia-Pacific branch of WODA.
Earth pressure: Soil resistance against cutter, key driver of cutter motor sizing on CSDs.
Ebb shoal: Sand body deposited by tidal currents on the seaward side of a tidal inlet, often requiring maintenance dredging.
Echo sounder: Acoustic depth sensor.
EGD: Egyptian General Dredging, the state-owned dredging company affiliated with the Suez Canal Authority.
Embedment depth: Depth to which a sheet pile or king pile is driven below the dredge level to develop passive resistance.
Energy absorption: Capacity of a fender system to absorb the kinetic energy of a berthing vessel without exceeding allowable reaction forces.
Engineered armour unit: Precast concrete unit such as Tetrapod, Dolos, Accropode, Core-loc, or Xbloc used in place of natural rock on the armour layer of breakwaters.
Equilibrium beach profile: Idealized cross-shore beach profile that develops under prolonged average wave conditions.

F

Fairway: Navigable channel.
Fall-Pipe Vessel: Rock-dumping vessel installing protection over subsea infrastructure.
Fender pile: Pile installed in front of a quay or dolphin face that supports a fender system to absorb berthing energy.
Fender System: Timber, rubber or steel structures protecting bridge piers or lock walls from vessel impact.
Filter layer: Graded granular or geotextile layer placed between fine subgrade and coarse armour to prevent loss of fines.
Fixed bed model: Physical hydraulic model with non-erodible bed used to study hydrodynamics around port and coastal structures.
Flexible dolphin: Single tubular pile or pile cluster designed to deflect elastically under berthing impact.
Floating breakwater: Pontoon based wave attenuator.
Floating dock: U-shaped or L-shaped floating dry dock.
Free length: Length of a tie rod or anchor strand between the wall and the anchor block, treated as elastic in the design.
FUNWAVE: Open-source fully nonlinear Boussinesq wave model developed at the University of Delaware.

G

Geobag: Large geotextile bag filled with sand or grout, used for scour protection, breakwater cores, and temporary works.
Geosynthetic clay liner: Factory-manufactured composite of bentonite between geotextiles used to seal disposal cells and reclamation containment.
Geotextile filter: Permeable synthetic fabric placed beneath armour or scour protection to prevent loss of underlying fines while allowing drainage.
Gimbal: Pivot supporting jack-up leg-to-hull connection or crane base.
Gland water: Clean water supplied to dredge pump shaft seals to prevent abrasive slurry from damaging the gland.
Goliath: DEME giant backhoe dredger with 40 t bucket and 40 m reach.
Goliath II: Backhoe dredger operated within the DEME fleet, successor to the original Goliath.
Grab Dredger: Crane-grab-based dredger.
Grab hopper dredger: Self-propelled hopper dredger fitted with a grab crane that loads dredged material into the onboard hopper.
Granular column: Vertical column of compacted gravel installed in soft soils to improve bearing capacity and reduce settlement beneath quays.
Gravity quay: Quay wall whose stability against earth and water pressures relies on its own dead weight, typically built from caissons or blocks.
Gravity-base structure: Marine structure that resists loads by its own weight on the seabed, including caissons and concrete blocks.
Great Lakes Dredge & Dock: Largest United States dredging contractor, founded 1890 in Chicago and now headquartered in Houston, Texas.
Guangzhou Dredging Company: Dredging subsidiary within the CCCC group based in Guangzhou, China.
Guide Wall: A wall extending upstream or downstream of a lock entrance to align approaching tows.

H

Harbor basin: Sheltered water area within a port where vessels manoeuvre and berth.
Heavy-lift quay: Quay wall designed for very high deck and crane loads, typical of project cargo and offshore fabrication terminals.
Helios: Jan De Nul CSD of 23,200 kW installed, the largest CSD afloat alongside Spartacus.
Hellas: Trailing suction hopper dredger in the Jan De Nul fleet.
Hellespont: Trailing suction hopper dredger in the Jan De Nul fleet.
Hopper: funnel-shaped container receiving bulk from grabs and feeding conveyors or trucks.
Hopper bin: Compartment within the hopper of a hopper dredger that contains the dredged spoil.
Hopper coaming: Top edge of hopper, set above the loading line to retain overflow.
Hopper draft: Vessel draft of a hopper dredger, which varies as the hopper fills and discharges.
Hopper overflow: Controlled spill of excess slurry from the hopper of a TSHD during loading once the desired sand fraction is retained.
Hopper well: Open compartment in the deck of a TSHD that provides access to the hopper for loading and inspection.
Hyundai E&C Marine: Marine engineering and dredging division of Hyundai Engineering and Construction of South Korea.

I

IADC: International Association of Drilling Contractors; daily drilling report standard.
IAPH: International Association of Ports and Harbors.
Iconic armour unit: Specially designed precast unit, such as Dolos, used as a recognizable signature element on major breakwaters.
In-fill reclamation: Reclamation in which dredged sand is placed within a perimeter bund to create new land.
Inlet stabilization: Construction of jetties or training walls at a tidal inlet to fix its position and improve navigation.
Israel Dredging Co: Dredging company active in Israeli and Mediterranean ports.

J

J F J De Nul: Self-propelled cutter suction dredger operated by Jan De Nul Group.
Jacket: Outer protective casing on a tank container.
Jan De Nul Group: Belgian marine contractor operating WTIV Voltaire, floating heavy-lift vessel Les Alizes, and cable lay vessels Isaac Newton, Connector, and Willem de Vlamingh.
Jet ring nozzles: Ring of high-pressure water jets around a drag head or cutter that fluidize cohesive soil to aid intake.
Jet Trencher: Tracked or skidded subsea vehicle that fluidizes seabed sediments to embed cables and small pipelines.
Jet water: High-pressure water injected through nozzles on a drag head or cutter to mobilize sediment for pumping.
Jetty: Marine structure projecting from shore for berthing.
Joint Sealant: NSF-listed sealant used at junctions of food contact surfaces to provide cleanable continuity.

K

Kedge Anchor: Smaller secondary anchor carried for warping the ship off a grounding or to hold the stern in tide.
King pile: Heavy tubular or H-section pile that forms the primary load-carrying element of a combiwall quay between intermediate sheet piles.

L

Ladder: pilot ladder, accommodation ladder, or fixed quay ladder for personnel.
Landside apron: Paved area immediately behind a quay wall used for crane rails, container handling, or cargo storage.
Leeward apron: Rubble apron placed on the harbor side of a vertical or composite breakwater to protect the foundation from overtopping flows.
Leiv Eiriksson: Jan De Nul TSHD of 46,000 m3 hopper, sister to Cristobal Colon.
Levee: Earth or rock embankment built to contain water or dredged spoil within reclamation areas.
Lock Chamber: Enclosed basin of a lock between gates.
Long-period wave: Wave with period in the range of about 30 seconds to several minutes that can excite harbor resonance.
Lower discharge tube: Vertical pipe through the hull of a hopper dredger used for bottom or pump-ashore discharge of cargo.

M

Magnor: Backhoe dredger in the Boskalis fleet.
Maintenance dredging: periodic dredging maintaining design depths.
Manson Construction: Seattle-based US dredging contractor, second largest in US after GLDD.
MIKE 21: Two-dimensional hydrodynamic, wave, and sediment transport modeling suite developed by DHI.
MIKE 3: Three-dimensional hydrodynamic and ecological modeling suite developed by DHI.
Mole: Massive coastal structure projecting into the sea.
Mooring analysis: Static and dynamic mooring analysis per OCIMF and PIANC.
Mooring dolphin: Isolated structure for mooring lines.
Multibeam echo sounder: Hull or pole mounted sonar that ensonifies a swath of seabed in a single ping to produce high-resolution bathymetry.

N

Nautical bottom: depth at which density makes navigation impossible.
Navigation channel: Dredged or natural waterway providing safe passage for vessels between open water and a port or terminal.
Nominal armour size: Equivalent cube side length used to characterize armour rock or concrete units in stability formulas.

O

Open caisson: Caisson open at top and bottom, sunk through soft soils by excavation from within, used for deep foundations.
Open piled jetty: Marine berthing structure consisting of a piled trestle and deck rather than a continuous wall, used in deep water and soft soils.
Outfall: Discharge structure releasing wastewater to the sea.
Overdepth allowance: Additional dredged depth beyond the design level, paid to the contractor as a contractual tolerance.
Overflow plume: Sediment plume generated by hopper overflow during TSHD loading, an environmental concern in sensitive areas.
Overwidth allowance: Additional dredged width beyond the design channel width, paid to the contractor as a contractual tolerance.

P

Passing Distance: BMP5 recommendation to maintain at least 8 nautical miles from Somali coast in transit; greater off Yemen.
Pearl River: South China river system, with the Xi Jiang the principal navigable branch.
Penta-Ocean Construction: Tokyo-based marine contractor with TSHD and reclamation expertise across Asia and the Middle East.
Permeability layer: Coarse rock or geotextile layer that maintains drainage between armour and core of a breakwater.
PIANC: World Association for Waterborne Transport Infrastructure.
PIANC WG30: PIANC Working Group 30 report on approach channels, providing harmonized international design guidance.
Pile cap: Reinforced concrete element that ties together the heads of a pile group and transfers superstructure loads to the piles.
Piled embankment: Earth embankment supported on piles to limit settlement over soft soils behind quay walls.
Plain suction dredger: Stationary suction dredger without a cutter head, used in loose granular soils where the suction alone is enough to mobilize the bed.
Pneumatic Fender: Air-filled rubber fender, typically Yokohama-style, deployed between assisted vessel and quay.
Postnik Yakovlev: Backhoe dredger in the Van Oord fleet, named after the Russian master builder of Saint Basil's Cathedral.
Primary armour: Outer protective rock or concrete unit layer of a rubble mound breakwater, sized to resist the design wave.

Q

Quay wall: Vertical retaining structure forming berth face, designed under BS 6349.
Quayside crane rail: Steel rail embedded in the quay deck on which ship-to-shore container cranes travel.

R

Rainbowing: Discharge of slurry as a high-velocity jet from TSHD bow, used to build reclamation profile and as marketing icon.
Reclamation: Creating new land from the sea.
Reefer plug bank: Group of refrigerated container power outlets installed on the landside apron of a container quay.
Return Period: Average interval between events of a specified magnitude.
Revetment: A bank protection structure of articulated concrete mats or stone.
Ring anchor: Anchor or tie system that distributes anchor loads around a circular sheet pile cell or similar structure.
ROMS: Regional Ocean Modeling System, a free-surface, terrain-following ocean circulation model widely used for coastal studies.
Roundhead: Outer end of a breakwater, typically armoured with larger units due to higher local wave forces.
Royal Boskalis Westminster: Parent company of Boskalis Salvage and Boskalis Heavy Lift.
Rubble mound breakwater: Breakwater using armour stone and underlayers.
Run-up: Maximum vertical elevation reached by an individual wave above still water level on a sloping structure.

S

Salient: Cuspate accumulation of sand that builds in the lee of a detached breakwater without connecting to it.
Samson: Backhoe dredger in the Van Oord fleet.
Samsung E&C dredging: Dredging and marine reclamation activities of Samsung Engineering and Construction of South Korea.
Sand source: Borrow area from which sand is dredged for reclamation or beach nourishment.
Scour Protection: Rock or mattress placed at the base of offshore foundations to prevent seabed erosion that would expose cables.
Scow: Flat-bottomed barge used to transport dredged material from the dredger to a placement or disposal site, often with split or bottom doors.
Secondary armour: Filter layer of medium-sized rock placed beneath the primary armour of a rubble mound breakwater.
Sediment plume: Plume from dredging activities.
Segmented breakwater: Series of detached breakwater units separated by gaps, used to balance shoreline protection with longshore sediment transport.
Settlement: payment in discharge of the claim.
Shanghai Dredging Company: Major dredging company based in Shanghai within the CCCC group, active in Yangtze estuary and coastal projects.
Sheet pile interlock: Mechanical joint along the edge of a sheet pile section that engages adjacent sections to form a continuous wall.
Sheet pile quay: Quay wall formed by interlocking driven steel sheet piles, often anchored back to a deadman or rock anchor.
Ship-bank interaction: Hydrodynamic forces and yawing moments experienced by a vessel transiting close to a channel bank.
Side slope ratio: Ratio of horizontal to vertical run of a dredged channel or trench side slope, typically expressed as 1V:nH.
Significant wave height: Average of the highest one third of waves in a given period, the standard parameter governing CTV transfer limits.
Single Point Mooring: Generic term covering CALM, SALM, and turret moorings allowing weathervaning of moored tankers and FPSOs.
Skirt pile: Pile driven through a sleeve on a jacket or template to fix it to the seabed.
Sloping top caisson: Vertical breakwater caisson with an inclined upper face designed to deflect wave run-up and reduce overtopping.
Sounding: Measured depth.
Spartacus: DEME CSD of 44,180 kW total installed power, the world's most powerful CSD, delivered 2021 and LNG dual-fuel.
Split hopper: Hopper dredger or barge whose hull splits longitudinally to release the cargo by gravity.
Spud: A vertical steel beam dropped through a barge well into the riverbed to hold position.
Spud carrier: Movable trolley that carries the working spud of a CSD and allows the dredger to step forward without losing position.
Spud pole: Spud used as the working anchor and pivot point of a cutter suction dredger.
Squat: Loss of underkeel clearance due to speed in shallow water.
Submerged breakwater: Breakwater whose crest lies below the still water level, used to dissipate wave energy without obstructing views or navigation.
Submersible pump dredger: Suction dredger using a submerged pump mounted at the lower end of the suction or ladder to improve suction performance.
Suction inlet: Mouth of dredge pump suction pipe.
Suction pipe: Dragarm assembly on TSHD or fixed pipe on CSD.
Suez Canal Authority: Egyptian authority operating compulsory pilotage through the Suez Canal.
Swan: Boskalis semi-submersible heavy-transport vessel of the legacy Dockwise fleet.
SWASH: Simulating Waves till Shore, a non-hydrostatic wave-flow model developed at Delft University of Technology for nearshore and harbor applications.
Swing winches: Pair of winches that pull a CSD laterally around its working spud to cut an arc across the dredge face.

T

Telemac-2D: Two-dimensional shallow-water finite element hydrodynamic model in the open TELEMAC-MASCARET suite, originally developed by EDF.
Tetrapod: Four-legged concrete armour unit developed by Pierre Danel and Paul Anglès d'Auriac at Sogreah in France in 1950.
Tetrapod handling: Specialized lifting and placing of Tetrapod armour units using purpose-built clamps and templates.