Waterfront Terminology

8/2/2019 Waterfront Terminology

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WATERFRONT TERMINOLOGY

ABUTMENTThe foundation structure supporting the inshore end

of a pier, trestle or bridge, often acting as a partialretaining wall.

ACCRETIONDeposition of accumulating sediments.

ACQ

A timber preservative called Alkaline Copper Quat,which recently replaced CCA preservative treatment

for timber used in US residential markets. At this timeACQ is not recommended for timbers in marine

construction, such as pilings and bracing, which maybe exposed to marine borers.

ANODEThe positive end of an electrolytic cell. On waterfrontstructures, the anode is typically a sacrificial zinc,

magnesium or aluminum alloy bar fastened to

underwater steel to limit corrosion. An anode can alsohave an external power source to protect the steelwith an impressed electrical current.

ARTIFICIAL NOURISHMENTThe process of adding sediment to a beach (usually

sand), obtained from another location.

BATHYMETRIC SURVEYThe measurement of water depths, usually with

sufficient detail to map the underwater terrain

contours.

BATTER PILEAn angled pile used to develop lateral and vertical

resistance for a structure.

BEDROCK

Rock of great size and depth in its native location

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acting as a mass, typically the Earths crust. Slang

term "ledge".

BENCHMARKA fixed point (disk, nail or other marker) of known

elevation used for reference during a survey.

BENT

A line of piles framed together under a pier or trestle.

BERTH

The water area along the edge of a wharf or pier forvessel mooring.

BITT

A single- or double-post mooring fitting on a ship, pier

or wharf to which mooring lines are secured.

BOLLARDA vertical post mooring fitting typically mounted on a

dolphin, pier or wharf, used for securing vesselmooring lines.

BRACESHorizontal or angled members used on piles orcolumns to reduce the unsupported column length,

and increase resistance to horizontal forces through

load distribution. Referred to as cross braces, whenangled.

BRACKISH

Water that is part seawater and part fresh water.

BREAKWATER

A structure protecting an area, such as a harbor, fromwaves. Traditionally a stone rubble berm structure,however it may be a structural wall (solid or

permeable), often referred to as a wave screen.

BREASTING DOLPHIN

A structure with a fender system used to resist vesselberthing, and hold a moored vessel, often also fitted

with mooring bollards.

BULKHEAD

A vertical wall designed to retain earth, often tied




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back with rock or soil anchors.

CAISSON(1) The floating entrance gate to a basin dry dock. (2)A cast in place concrete pile/column, usually of large

diameter.

CAMEL

A floating structure placed between a vessel and adock structure, or between two vessels, designed to

distribute contact loads over a larger area.

CATHODIC PROTECTIONAn electrical method of controlling steel corrosion

within a conducting media (seawater or wet/moistsoil). An electrical current is applied to the steel using

a connected sacrificial anode, or an external electricalpower supply to an impressed current anode, within

the conducting media.

CCA

A timber preservative called Chromated CopperArsenate, which was recently discontinued forpreservative treatment of timber, used in US

residential markets. CCA continues to be thepreservative recommended for timbers, such as

pilings and bracing, which may be exposed to marine

borers and at this time it is typically available tocontractors for use in marine construction (thoughthere may be some additional state and local

restrictions).

CHECKINGA longitudinal separation between wood fibers opening

along the grain and across growth rings, caused bydrying and wood shrinkage. Common in timbers

pressure treated with water-based preservatives, buttypically not of structural concern in heavy waterfront

construction.

CHOCK

A piece of timber (or plastic lumber) between timberfender piles or rub strips, used to prevent lateralmovement of the pile/rub strip during vessel contact.




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CLEAT

A low capacity mooring fitting with two diverginghorizontal horns around which dock lines are wrapped.

CLIP (WIRE)

A wire clip is the U-bolt type of clamp typically used toform an eye at the end of a wire rope. Usually

multiple wire clips are needed at each eye to developthe capacity of the wire rope.

CLIP ANGLEA short length of steel angle bolted or welded betweentwo perpendicular members to form a connection.

COFFERDAMA temporary structure, typically formed from sheet

pile, steel plate or timber, used during construction toenclose an area of riverbed/seabed for dredging or

dewatering. Commonly used during construction ofbridge piers, where it is often left in place below low

water.

COPPER NAPHTHENATEA wood preservative available to the public and

contractors for the field treatment wood that is cut ordrilled after preservative pressure treatment.

CREOSOTEAn oil-based wood preservative, derived from coal tar,

once commonly used to pressure treat timberwaterfront structures.

CREVICE CORROSIONCorrosion of a metal within a crevice, caused by adifference in environment. Usually occurs on partially

embedded metal or at non-sealed steel lap joints.

CRIB

A box-like gravity structure formed from connectedhorizontal members (timber, precast concrete, or

stone blocks), which is filled with stone ballast. Cribsmay be used to support bridge and pier decks, or may

be used as retaining walls.

DEAD WEIGHT TONNAGEThe carrying capacity of a ship at the design




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waterline, less the empty ship weight. DWT includes

cargo, ship fuel, water, etc.

DEADMANA concrete block or sheet pile wall, buried in the

ground, which is attached a tie rod or cable foranchoring objects, such as bulkheads.

DECAYWood deterioration caused by fungi, usually in areas

exposed to oxygen and prolonged high moisture.

DELAMINATIONThe splitting apart of a material such as concrete into

layers, often caused by corrosion expansion ofembedded steel.

DIFFRACTIONWave energy is transmitted along the wave crest to

generate waves in a sheltered area, such as in theshadow of a breakwater.

DISPLACEMENT TONNAGEThe weight of water the ship displaces at the designwaterline (total ship weight).

DIURNAL INEQUALITY

The daily difference in tidal height extremes, primarilydue to changing declination of the Moon. For example;the difference in height between the morning and

evening high tides.

DIURNAL TIDE

A tide with one high and one low water in a day.

DOLPHINA stand-alone structure, usually consisting of a cluster

of piles, a concrete mass supported by a number of

piles, or a sheet pile cell, which is used to guideand/or moor vessels.

DRAFT

Maximum depth of a vessel's hull below the waterline.

DRY DOCK

A facility used to remove a ship from the water, either




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for repair, construction, inspection, or maintenance.

DRY ROTA loose term applied to wood decay, which requiredmoisture for fungi growth, but now may be dry.

EBB CURRENTA tidal current (flowing water) caused by a falling tide.

EXPANSION JOINTA joint in a structure intended to allow for expansion

and contraction movement, usually due to changes intemperature.

FAIRWAY

A navigable channel in a harbor or marina.

FASCIA

The vertical exterior face of a pier, wharf, or similarstructure, typically used to mount fender systems.

FEASIBILITY STUDYA planning study intended to evaluate a site for

potential development. This study typically includes asite survey and assessment, permitting evaluation,soil, wind, wave and current study, facility layout

alternatives, a market survey and cost/benefit

analysis.

FENDERA device placed between a dock structure and a

vessel, used to absorb berthing impact energy andprovide a wearing surface for the vessel while moored

to the structure.

FETCH LENGTHThe horizontal distance, over which the wind might

generate waves, usually evaluated for several

representative wind directions and water depths.

FLANGEThe portions of a structural member cross-section

furthest from the bending axis, which are typicallywidened to efficiently, resist bending stresses. The

term flange is most commonly to the sides of an H-pile or top and bottom of an I-beam or railroad/crane




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rail.

FLOOD CURRENTA tidal current (water flow) caused by a rising tide.

FLOTSAM AND JETSAMFloating waterborne debris.

FOULING

Growth of attached aquatic/marine life on submergedsurfaces of vessels and structures.

FREEBOARDHeight of a vessels deck above the waterline. Also theheight of a structure's deck above a design water

level.

GABION

A wire mesh box or mat filled with small local stone.Used to build gravity retaining walls and construct

revetments (armor slopes).

GALVANIC CORROSION

A form of corrosion occurring between dissimilarconnected metals in contact within an electrolyte,such as seawater.

GANGWAYA sloping ramp to provide access from a dock

structure to a vessel or floating dock from the shore.

GROIN

A shore protection structure built to trap littoralsediment drift (usually perpendicular to shoreline).

GROSS TONNAGEThe volume of all accessible (useable) spaces, in on aship, converted to an equivalent weight using one

ton per 100 cubic feet of storage volume. Usually fortaxation purposes.

GROUTA Portland cement mortar, having a consistency of a

liquid or paste, typically used for securing anchor boltsin concrete or shimming under structural supports.




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HIGHER HIGH WATER (HHW)

The higher of two high tides in any given tidal day.

HYDROGRAPHYThe study of the characteristics of seas, lakes, and

rivers, including the water properties andconfiguration of underwater terrain or sediments.

INSHORETerm used to distinguish an object from another by its

relative closer proximity to the shoreline.

INTERTIDAL ZONEThe zone between high and low water along the

shoreline or on a structure.

JETTYA longitudinal structure (such as a stone berm orsheet pile wall) at or near the entrance to a harbor or

river mouth, used to stabilize the entrance channellocation and control sedimentation.

KNOTA unit of speed defined as a nautical mile per hour.

LATITUDE

The location of a place on Earth measured north or

south from the equator. One degree of latitude isequal to 60 nautical miles.

LIGHT WEIGHT TONNAGE

The weight or displacement of a ship, excluding theweight of ship fuel, water, stores, people or cargo.

Often used as the basis for ship weight in dry docking.

LIMNORIAGenerally categorized as marine borers, Limnoria are

small crustaceans (1/8 inch) similar to shrimp, which

attack the outer surface of submerged timber. Timberpiles attacked by Limnoria are typically deteriorated toroughly an hourglass shape near low water level or

just above the mudline. A related species isSphaeroma.

LITTORAL DRIFTSediment moving in the littoral zone, under the




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influence of waves and currents.

LITTORAL TRANSPORTThe net movement of littoral drift, generally along thebeach.

LITTORAL ZONEA shoreline zone typically between mean high water

and -6' MLW.

LONGITUDE (MERIDIAN)

The location of a place on Earth, measured in degreeseast or west of Greenwich, England.

LOWER LOW WATER (LLW)

The lower of two low waters (for diurnal tides) in any

given tidal day.

LUNAR DAYThe rotation time of the Moon over the meridian of a

given place on Earth. The mean lunar day is 24.84hours long.

MARINE BORERA general term for marine organisms that bore intotimber or concrete.

MEAN HIGH WATER (MHW)The mean of all high water levels (two per day for

diurnal tides), observed over a 19 year tidal epoch(Metonic cycle).

MEAN HIGHER HIGH WATER (MHHW)The mean of the highest daily high water levels (one

per day), observed over a 19 year tidal epoch(Metonic cycle).

MEAN LOW WATER (MLW)

The mean of all low water levels (two per day fordiurnal tides), observed over a 19 year tidal epoch

(Metonic cycle).

MEAN LOWER LOW WATER (MLLW)

The mean of lowest low water levels (one per day),over a 19 year tidal epoch (Metonic cycle).




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MEAN SEA LEVEL (MSL)

The average height of the sea surface for all stages ofthe tide, measured hourly, over a 19 year tidal epoch(Metonic cycle).

METONIC CYCLE (Tidal Epoch)A time period of 235 lunar months, or 19 years 11

days, after which period the relative distancesbetween the earth, sun and moon (which influence the

tides) begin to repeat.

MID TIDE LEVEL (MTL)The elevation midway between mean high water and

mean low water. Also called half-tide level, it may notbe the same as mean sea level.

MILL SCALEA black surface oxide layer formed on iron and steel

when heated for rolling or forging. Mill scale offerssome protection against corrosion, however it may

somewhat inhibit the bond of concrete to embeddedsteel.

MOORING DOLPHIN

A structure on land or over the water that is used tosecure a vessels mooring lines. Often these dolphins

are set back from the breasting line for optimal line

angles, and they do not have typically have fendersystems.

MUDLINE

A general term often used to designate the seabed,riverbed, lake bed or harbor bottom. The interfacebetween a water body and the seabed/riverbed

bottom sediments. May, or may not, imply that thebottom is actually mud.

NAUTICAL MILE

A length unit equal to 6076 feet or 1852 meters (astatute mile is 5280 feet). One degree of latitude isequal to 60 nautical miles.

NEAP TIDEA tide of decreased range, occurring at quadrature ofthe moon with the sun. Typically 10% to 30% less




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than the mean tide range.

NET TONNAGEA volume measure of the ship space available forrevenue earning cargo or passengers.

OCCULTINGA light which is visible for longer periods than it is

invisible. (opposite to flashing)

OFFSHORE

A term used to designate the relative location ofsomething in the sea, away from land.

OGEE WASHER

A large cast iron washer used in heavy timber

construction to distribute loads and prevent timbercrushing at bolt ends.

OVERBURDEN

Soil that is above another strata of soil/rock or anobject.

PCBPolychlorinated Biphenyols, a toxic chemical oftenfound in sediments near industrial discharges.

Measured as several different alochors and destroyed

by incineration.

PERIGEAN TIDETides of increased range due to the Moon being at its

closest point to the Earth.

PERIGEE

The point in the orbital path of a heavenly body whereit comes closest to Earth.

PHOLADS

A wood or concrete boring mollusk, resembling aclam, up to a inch in diameter and 2.5 inches in

length. U.S. activity is confined to the Gulf of Mexicoregion. Species Martesia and Xylophaga.

PIERA deck supported on piles, extending into the water,

more or less perpendicular from the shoreline.




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PILE CAP

A beam used to connect the top of a line of pilestogether and support a structure above.

PILE HEAD

The top of a pile.

PILE

A pole, typically of timber, reinforced plastic, steel orconcrete, driven or otherwise set into the soil or rock

to resist applied vertical and/or horizontal loads.

PIPE PILEA hollow cylindrical pile with a circular cross-section.

Pipe piles are favored for waterfront construction dueto their efficient column capacity properties (same

radius of gyration in any direction) and smooth, lowsurface area relative to H-piles, used for superior

corrosion resistance.

PIT

A localized area of advanced metal surface loss, oftendue to paint coating damage, localized loss of marinegrowth/corrosion scale, metallurgical impurities or a

localized corrosion cell on the surface of the metal.

PLUNGING

Crest curls over an air pocket - "tube". Occurs onsteep beaches.

POSTINGA method for repairing the deteriorated top of a pile.

The damaged top section is cut away and replacedwith a post of timber, steel or concrete between theremaining pile and pile cap.

QUAY (Pronounced KEY)A solid man-made vessel landing, generally parallel to

the navigable waterway. Large gravity retaining wallsalong the shoreline that are used for vessel mooring

are often referred to as quay walls.

RANGER

A timber deck edge stringer, usually of larger sizethan the typical interior stringers.




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REBAR

Slang for "Reinforcing Bar," for reinforce concrete.

REFLECTED WAVEThe part of an incident wave that is returned seaward

after hitting a barrier (particularly a vertical barrier).

REFRACTION

The bending of waves caused by changes in waterdepth or currents.

REVETMENTA shoreline slope armored against wave action orcurrents, by a facing of stone, concrete, etc.

RIPARIAN RIGHTS

The rights of a person owning land containing orbordering a body of water.

RIPRAP

Slope erosion protection formed from stone orconcrete rubble, typically dumped and graded over

the surface of a prepared shoreline slope.

RUBBING FORCEThe vertical and longitudinal forces applied to a fender

system by a moving vessel. These forces are a

function of the contact normal force and thefender/ship coefficients of friction (static/dynamic,wet/dry).

SACRIFICIAL ANODEAn anode that provides its own electrical current for

cathodic protection of a steel structure by consumingor "sacrificing" itself. These anodes may be formedfrom various metals and alloys, but often mostly zinc

or aluminum.

SALINITYThe total salt content of water, usually expressed inparts per thousand (o/oo). Salinity can be measured

indirectly by water conductivity or optical refractionproperties.

SCABA small piece of timber fastened on the side of a pile




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as a connection to the pile cap or pile repair post.

SCALE (Corrosion)The iron-oxide by-product from the corrosion of steel,which is deposited on the surface of the steel member

above or below water level.

SCOUR

Removal of sediment by waves and/or currents, foundespecially at the bottom of piles and bridge piers.

SEAWALLA structure along the shoreline designed to preventland erosion or damage from to wave action.

SEICHE

A harmonic water level oscillation, which may occur ina largely enclosed waterbody, induced by tides, wind,or seismic forces. The tides are a form of seiche in

ocean basins.

SEMIDIURNAL TIDE

A tide with two high and two low waters in a tidal day,with little diurnal inequality.

SHAKE

A longitudinal separation between wood fibers opening

along the grain and between growth rings, usuallyoccurring during tree growth.

SHEET PILE

Interlocking structural piles driven into the ground toform a wall, cell or cofferdam. Sheet piles can be

timber, reinforced concrete, vinyl, fiber reinforcedplastic or steel (hot or cold rolled), with a wide arrayof interlock or tongue/groove configurations.

SHINGLE

Smooth, well-rounded stone pebbles or cobbles ofroughly the same size. The voids between shinglestones are not filled with finer material.

SHOAL (Noun)An elevated portion of seabed comprised of any

material, except rock or coral, which endangers vesselnavigation.




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SHOAL (Verb)

(1) To become shallow gradually. (2) To cause tobecome shallow. (3) To proceed from greater to lesserwater depth.

SHOTCRETEShotcrete (or gunite) is pneumatically applied stiff

concrete/mortar that is blown onto a surface(including vertical and overhead surfaces) without the

need for formwork.

SIDESCAN SONARAn instrument that uses acoustical energy, often

around 7.5 kHz, to create a "view" of the seabedsurface characteristics, particularly shadows from

elevated objects, such as shipwrecks.

SIGNIFICANT WAVE

A statistical term defined as the average height orwave period of the one-third largest waves in a given

sea (Hs). It is often the approximate height of wavesvisually estimated by an observer.

SINKHOLE

A hole or void that forms inshore of a soil retainingwall or bulkhead due to the loss of backfill through

holes or gaps.

SLACK WATER

The state of a tidal current when its speed is nearzero, as when reversing direction.

SPALLINGThe chipping or delamination of a surface, usuallyused to describe loss of concrete due to corrosion of

embedded steel.

SPILLING

Bubbles and turbulent water spill down the face of thewave - slow breaking. Occurs on very flat beaches.

SPITA point of low land or narrow shoal extending into a

body of water from shore.

SPLASH ZONE




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The portion of a marine structure subject to

intermittent wetting and high chloride exposure(seawater) due to wave action and spray. Typically azone of high steel corrosion levels.

SPRING TIDETides of increased range (lows and highs) occurring at

or near a new or full moon (SYZYGY).

STAINLESS STEEL

Alloy of steel, chromium and nickel offering highresistance to corrosion when exposed to air oroxygenated water (susceptible to crevice corrosion).

Grade 316 stainless steel is usually best suited tomarine use.

STRINGERStructural beams spanning between pile caps used to

support a pier or wharf deck.

SUBBOTTOM PROFILING SONAR

An instrument that uses acoustical energy at 3.5 kHzor lower, to create a vertical profile section into theseabed sediments.

SURGINGWave peaks but does not break. Wave slides up the

beach with little or no bubbles. Occurs on ledges.

SWELL

Decaying waves that have traveled out of the areawhere generated. Characteristics are long, regular

wave period and flat-sloped wave crest.

SYZYGYTwo points in the Moon's orbit when the Moon is in

conjunction or opposition to the Sun relative to theEarth (time of new or full Moon).

TEREDOA molluscan marine borer, which bores into,

submerged timber. Typically found only in water withsalinities above about 5 o/oo, this "shipworm"

typically leaves a tube of calcium deposits in thetimber, which may up to 4 feet long and an inch indiameter.




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TIDAL DAY (LUNAR DAY)

The time of rotation of the Earth with respect to theMoon, approximately 24.84 hours (24 hr and 50 min).Thus, high and low tides generally occur 50 minutes

later each day.

TIDAL PRISM

The volume of water within an area of study, locatedbetween low tide and high tide. This is generally the

tidal exchange in a harbor or bay, excluding any netriver inflow.

TIE ROD

A steel rod used to restrain a bulkhead or retainingwall by extending inshore to an anchor or buried

deadman.

TOMBOLO

A sand or gravel spit connecting an offshorebreakwater, shoal or rock with the shore. Usually

intertidal.

TRAINING WALLSWalls constructed to direct the flow of currents and

control scoured channel location in a harbor or river.

TREMIE METHOD

A technique for placing concrete underwater through apipe or hose, where the lower end of the pipe or hose

is kept embedded in the mound of fresh concrete tominimize the amount of concrete exposed to the

water and potential cement washout.

TRESTLEA pier-like structure used to provide access between

shore and an offshore structure.

TSUNAMI

A long-period wave caused by an underwaterdisturbance such as a volcanic eruption or

earthquake.

TYPHOON

A term for hurricanes in the Pacific or Indian Oceans.

ULTRASONIC THICKNESS MEASUREMENT




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Use of ultrasonic sound waves to measure the

thickness of a material from one side, calibrated forthe ultrasonic speed of the material being measured.

VARIATION

The angle between true north and magnetic north,caused by movement of earth's magnetic poles. Varies

by location and is continually changing.

WALE

A horizontal structural beam used to connect or bracemultiple piles, or distribute tie rod loads along sheetpile bulkheads.

WARPTo move a vessel by the use of ropes (warps).

WATER DEPENDENT USEUses that can only be carried out at the waters edge,

such as landing cargo, vessel docking, fishing,swimming, marinas.

WATER ENHANCED USELand uses that benefit from viewing or being close tothe water, such as restaurants, hotels, housing.

WAVE FORECASTING

The prediction of wave characteristics for a given site,usually based on previously observed or predictedwinds.

WAVE HEIGHTVertical trough to crest height. A wave breaks when

the water depth equals 1.28 His, with a breaking waveheight of 0.78 times the water depth.

WAVE HINDCASTING

The use of historical wind data to calculate the

characteristics of waves that probably occurred in thepast.

WAVE LENGTH

The horizontal distance between similar points onsuccessive waves, measured perpendicular to the

crest.




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Waterfront Terminology

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