Engineering Dictionary

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An alphabetical listing of General terms and items.

Cable   Dico Tools
a structural element formed from steel wire bound in strands; the suspending element in a bridge; the supporting element in some dome roofs

Cable-Stayed Bridge   Dico Tools
A bridge in which the roadway deck is suspended from cables anchored to one or more towers

Caislean   Dico Tools
A Irish castle dating from the 12th century which was based on the Norman `motte and bailey' castle.

Caisson   Dico Tools
A watertight, dry chamber in which people can work underwater

Caisson Disease   Dico Tools
An affliction developed by people moving in and out of caissons quickly; also called the bends and decompression sickness

Calender-van Dusen Equation   Dico Tools
An equation that defines the resistance-temperature value of any pure metal that takes the form of RT = RO(1 + AT + BT2) for values between the ice point (0 C) and the freezing point of antimony (630.7 C) and the form RT = RO[1 + AT + BT2 + C(T-100)T2] between the oxygen point (-183.0 C) and the ice point (0 C).

Calibration   Dico Tools
The process of adjusting an instrument or compiling a deviation chart so that its reading can be correlated to the actual value being measured.

Calorie   Dico Tools
The quantity of thermal energy required to raise one gram of water 1 C at 15 C.

Cannon Basket   Dico Tools
See gabion.

Cantilever   Dico Tools
A projecting structure supported only at one end, like a shelf bracket or a diving board

Capital   Dico Tools
The line bisecting the salient angle of a fortification. (L. caput, head).

Caponier   Dico Tools
(1) A covered passage that traverses a dry ditch from the curtain to the ravelin or from the covert way to an arrow or detached redoubt, covered on either side by a parapet and equipped with gun ports, through which cannon and muskets were used to sweep the ditch of enemy forces. (2) A single parapet at the entrance of the ditch in front of a ravelin, equipped with a small cannon, which were used to dispute the passage of the ditch.

Caravaserai   Dico Tools
A fortified hostel along a trade route.

Cardo Maximus   Dico Tools
The line which bisects the decumanus maximus or the centre line of a Roman fortification.

Carrago   Dico Tools
A field fortification formed by surrounding an army with armoured wagons. See gulaigorod,wagenburg.

Casatorri (Family Towers)   Dico Tools
Italian slender towers, usually connected to the house by a drawbridge, with no ground floor entrance, which could be used as a refuge in times in strife.

Cascan   Dico Tools
The entrance to a gallery which provided a vent for an enemy mine.

Casemate, Casement, Cazemate, Cazematte   Dico Tools
(1) A chamber within a tower used to house artillery away from the elements such as catapults, Greek from the 4th century BC. (2) A gallery which was built at the base of a fortifications wall from which defenders could fire into the faces of surface miners and battering ram parties. (3) A well having a number of underground branches which can be extended to intercept enemy mines. (4) A magazine for storage of explosives. (5) A place for quartering troops. (F. casemate, fr. It. casamatta, prob. from casa house + matto, f. matta, mad, weak, feeble, dim. from the same source as E. -mate in checkmate).

Cashel   Dico Tools
A Irish defensive enclosure consisting of a dry stone ring wall.

Cassaro   Dico Tools
An Italian word meaning castle.

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Cast Iron   Dico Tools
a brittle alloy with high carbon content; iron that has been melted, then poured into a form and cooled; can be made into any shape desired

Castella   Dico Tools
A flanking tower or redoubt attached to the vallum of a castra stativa, which was used to provide flanking fire at the gates, corners and at regular intervals along the ramparts, constructed of wood and earth or stone.

Castellae   Dico Tools
A small Byzantine frontier castle.

Castellated   Dico Tools
(1) A building constructed in the form of a castle. (2) A building provided with defences, such as battlements thus making it fortified. (3) An area provided with a castle.

Castellated Manor House   Dico Tools
A fortified manor house. See fortified manor.

Castellation   Dico Tools
A fortification, usually a castle.

Castelle   Dico Tools
The Norman word for castle.

Castello   Dico Tools
(1) An Italian castle, which was mainly used as a fortified residence. (2) A term which generally refers to an Italian fortified village.

Castellum   Dico Tools
A small Roman detached fort or fortlet which served as a watch tower or signal station.

Castle   Dico Tools
A fortified building or set of fortified buildings used to provide both active and passive defence, as well as a residence for the castles lord and household. See fortification, keep, tower. (L. castrum, fortress).

Castra   Dico Tools
An Italian fortified settlement dating from the 10th to the 13th century. Usually sited on a hill top or spur, defences consisted of a surrounding curtain wall and a separate tower.

Castra Stativa   Dico Tools
When a Roman encampment was reinforced by strengthening the ramparts with a wooden stockade or stone wall, it became more than just a temporary defence works, it became what is known as a `castra stativa'. The castra stativa served as a base from which actions could be launched into the surrounding area, and if necessary a place to fall back to if things did not go well. More elaborate castra stativa were provided with castellas or watch towers, which were used to flank the gates and at the corners and at regular intervals along the vallum. There were two types of castra stativa

Castron   Dico Tools
A small fortified outpost of the Byzantine empire.

Cation   Dico Tools
A positively charged ion (Na+, H+).

Cavalier   Dico Tools
A gun platform which is raised higher that the rest of the works, used to command the surrounding works, usually situated on a bastion or curtain but were also sited in the gorges of bastions. Cavaliers were also built by besiegers to gain a commanding position. See gun platform. (L. caballus, horse).

Cavalier Battery   Dico Tools
A cannon battery in which the gun platform was raised above the level of the bastion. See cavalier.

Cavitation   Dico Tools
The boiling of a liquid caused by a decrease in pressure rather than an increase in temperature.

Cawd   Dico Tools
A field fortification made of kneeling baggage animal (camels?). See kuklos. (Arabic)

Celsius (centrigrade)   Dico Tools
A temperature scale defined by 0 C at the ice point and 100 C at boiling point of water at sea level.

Cement   Dico Tools
A binding material, or glue, that helps concrete harden

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Center Of Gravity (Mass Center)   Dico Tools
The center of gravity of a body is that point in the body through which passes the resultant of weights of its component particles for all orientations of the body with respect to a uniform gravitational field.

Centre Of The Bastion   Dico Tools
(1) The intersection made by two demigorges. (2) The point at which two adjacent curtains of a bastion intersect each other.

Centripetal Force   Dico Tools
A force exerted on an object moving in a circular path which is exerted inward toward the center of rotation.

Ceramic   Dico Tools
Polycrystalline ferroelectric materials which are used as the sensing units in piezoelectric accelerometers. There are many different grades, all of which can be made in various configurations to satisfy different design requirements.

Ceramic Insulation   Dico Tools
High-temperature compositions of metal oxides used to insulate a pair of thermocouple wires The most common are Alumina (Al2O3), Beryllia (BeO), and Magnesia (MgO). Their application depends upon temperature and type of thermocouple. High-purity alumina is required for platinum alloy thermocouples. Ceramic insulators are available as single and multihole tubes or as beads.

Cespites   Dico Tools
The turves which were used to cover the outer face of the rampart of a Roman fortification, their purpose was to hold the ramparts in place. See gazion.

CFM   Dico Tools
The volumetric flow rate of a liquid or gas in cubic feet per minute.

Character   Dico Tools
A letter, digit or other symbol that is used as the representation of data. A connected sequence of characters is called a character string.

Charge Sensitivity   Dico Tools
For accelerometers that are rated in terms of charge sensitivity, the output voltage (V)is proportional to the charge (Q) divided by the shunt capacitance (C). This type of accelerometer is characterized by a high output impedance. The sensitivity is given in terms of charge; picocoulombs per unit of acceleration (g).

Chashi   Dico Tools
A fortification dating from the late 6th to the 13th century, which consisted of a position surrounded by earthen ramparts and ditches. The ancestors of the Ainu, the Ezo built the chashi to protect their region and the population centres from the depredations carried out by the armies of the Yamato court. These fortifications are found on the Japanese islands of Hokkaido and the north east of Honshu.

Chateau   Dico Tools
(1) Originally, a French castle, also known as a chateau-fort. (2) A French country residence. (O.Fr. chastel; L. castrum, fortress).

Chateau-fort   Dico Tools
A fortified French chateau.

Chatris   Dico Tools
An India 14th century kiosk built over the main gate where the rule could see and be seen. (Indian)

Chatter   Dico Tools
The rapid cycling on and off of a relay in a control process due to insufficient bandwidth in the controller.

Chemin De Ronde   Dico Tools
A sentry path or a passage around the revetment of a rampart which was provided with a small parapet. The position was used by musketeers keeping an eye on the glacis so as to prevent the placement of scaling ladders by the enemy. Later, it was generally discarded because of its susceptibility to artillery fire.

Chemise   Dico Tools
The curtain wall, or the additional counterguard wall surrounding a keep or attached to it. (L. camisia, shirt).

Chemise Foot Bridge   Dico Tools
A foot bridge connecting the curtain wall to the entrance of a Norman keep of the 11th and 12th centuries. See flying bridge (2).

Cholli Castle   Dico Tools
A medieval Korean defensive wall built by the Koryo dynasty from the Yalu river to the east coast.

CHROMEGA   Dico Tools
A chromium-nickel alloy which makes up the positive leg of type K and type E thermocouples (registered trademarks of OMEGA ENGINEERING, INC.).

Church (fortified)   Dico Tools
(1) A fortified church provided with defences such as battlements and arrow slits. (2) A church which was used as part of, or as a fortification.

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Cippi   Dico Tools
An obstacle consisting of sharpened branches set in a trench used to defend a Roman fort.

Circumvallate, Circumvallation (lines Of)   Dico Tools
(1) A siege works constructed by a besieging army to protect their camp from sorties by the besieged garrison, consisting of encircling earthen ramparts and entrenchments. From the line of circumvallation attacks against the besieged position could be launched and further advancement of the earthworks could be constructed. In conjunction with the line of contravallation, these fortifications enable the besieging army to stop the flow of information, supplies and reinforcements reaching the besieged. (2) The process of carrying out the construction of lines of circumvallation. See circumvallatio, contravallation, counter vallation. (L. circum, round; vallum, rampart).

Circumvallatio   Dico Tools
The ditch and rampart which was constructed by a besieging Roman army, which encircled a besieged city fortress, situated between the city and the Roman positions. See circumvallate.

Citadel   Dico Tools
A fortress in or near a city which was used to control the city and its inhabitants; providing a strong defensive position, and once the outer defences had fallen it could be used as a final refuge. (L. civis, citizen).

Civil Engineer   Dico Tools
An engineer who plans, designs, and supervises the construction of facilities essential to modern life

Clavicula   Dico Tools
The external or internal right angled extension of the rampart at the gateway of a Roman fort, which made the assailants turn to their left thus exposing their unshielded right side to the fire of the defenders on the ramparts and the castella.

Clear   Dico Tools
To restore a device to a prescribed initial state, usually the zero state.

Cliff Castle, Cliff Fort   Dico Tools
A fort which was situated on a spit of high ground and was protected on three sides by sheer cliffs, leaving only one line of approach which was defended by a rampart and ditch across the narrowest neck of the peninsula. If suitable headlands were not available, straight lines of cliff edges could be used by raising L or V shaped ramparts. Also known as a promontory fort, the majority occur on Britains western seaboard. Some can also be found on heights above rivers further inland. They were easily constructed and could be defended by only a small force, however, they had one major flaw, if an enemy did manage to break in it would have been impossible to escape.

Clipping   Dico Tools
The term applied to the phenomenon which occurs when an output signal is limited in some way by the full range of an amplifier, ADC or other device. When this occurs, the signal is flattened at the peak values, the signal approaches the shape of a square wave, and high frequency components are introduced. Clipping may be hard, as is the case when the signal is strictly limited at some level; or it may be soft, in which case the clipping signal continues to follow the input at some reduced gain.

Clock   Dico Tools
The device that generates periodic signals for synchronization.

Closeness Of Control   Dico Tools
Total temperature variation from a desired set point of system. Expressed as "closeness of control" is 2 C or a system bandwidth with 4 C, also referred to as amplitude of deviation.

Clover Leaf Keep   Dico Tools
See quatrefoil keep.

CMR (Common-Mode Rejection)   Dico Tools
The ability of a panel meter to eliminate the effect of AC or DC noise between signal and ground. Normally expressed in dB at dc to 60 Hz. One type of CMR is specified between SIG LO and PWR GND. In differential meters, a second type of CMR is specified between SIG LO and ANA GND (METER GND).

CMV (Common-Mode Voltage)   Dico Tools
The AC or DC voltage which is tolerable between signal and ground. One type of CMV is specified between SIG LO and PWR GND. In differential meters, a second type of CMV is specified between SIG HI or LO and ANA GND (METER GND).

Coffer   Dico Tools
A sunken panel in a ceiling

Coffer Dam   Dico Tools
A fortified dam retaining the water of a moat.

Cofferdam   Dico Tools
A temporary dam built to divert a river around a construction site so the dam can be built on dry ground

Coherence Function.   Dico Tools
A frequency domain function computed to show the degree of a linear, noise-free relationship between a system's input and output. The value of the coherence function ranges between zero and one, where a value of zero indicates there is no causal relationship between the input and the output. A value of one indicates the existence of linear noise-free frequency response between the input and the output.

Color Code   Dico Tools
The ANSI established color code for thermocouple wires in the negative lead is always red. Color Code for base metal thermocouples is yellow for Type K, black for Type J, purple for Type E and blue for Type T.

Column   Dico Tools
a vertical, structural element, strong in compression

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Command   Dico Tools
When any work is constructed higher than another the work overlooking the other is said to command it.

Common Mode   Dico Tools
The output form or type of control action used by a temperature controller to control temperature, i.e. on/off, time proportioning, PID.

Common Mode Rejection Ratio   Dico Tools
The ability of an instrument to reject interference from a common voltage at its input terminals with relation to ground. Usually expressed in db (decibels).

Communication   Dico Tools
Transmission and reception of data among data processing equipment and related peripherals.

Compensated Connector   Dico Tools
A connector made of thermocouple alloys used to connect thermocouple probes and wires.

Compensating Alloys   Dico Tools
Alloys used to connect thermocouples to instrumentation. These alloys are selected to have similar thermal electric properties as the thermocouple alloys (however, only over a very limited temperature range).

Compensating Loop   Dico Tools
Lead wire resistance compensation for RTD elements where an extra length of wire is run from the instrument to the RTD and back to the instrument, with no connection to the RTD.

Compensation   Dico Tools
An addition of specific materials or devices to counteract a known error.

Compiler   Dico Tools
A program that translates a high-level language, such as Basic, into machine language.

Complex Function   Dico Tools
Any mathematically defined relationship given by the following expression:

Complex Wave   Dico Tools
The resultant form of a number of sinusoidal waves that are summed together forming a periodic wave. Such waves may be analyzed in the frequency domain to readily determine their component parts.

Compressed-Air Chamber   Dico Tools
The space at the bottom of a caisson into which air is introduced under pressure to exclude water so that excavation can take place

Compression   Dico Tools
a pressing force that squeezes a material together

Concentric Castle   Dico Tools
The castle introduced into Europe in the late 12th century which consisted of two or more complete rings of bastioned curtain wall within one another, each increasing in height towards the keep in the centre. A variation on this design was were the gatehouse doubled as the keep. The aim of the design was to present the enemy with sides of equal strength at the time allowing a faster response to attack by the garrison. And with each ring of defence increasing in height towards the centre the defenders on the higher walls and towers could fire at the enemy over the lower defences, so that the amount of missile fire was increased compared to contemporary designs. If the outer defences fell to the enemy, they would be confronted by yet another line of defence; and each set of walls had to be taken completely before the attackers could move on to the next, thus increasing the losses to the besieging force as the siege continued. Also known as a multiple castle.

Concrete   Dico Tools
A mixture of water, sand, small stones, and a gray powder called cement

Conductance   Dico Tools
The measure of the ability of a solution to carry an electrical current. (See Equivalent Conductance)

Conduction   Dico Tools
The conveying of electrical energy or heat through or by means of a conductor.

Confidence Level   Dico Tools
The range (with a specified value of uncertainty, usually expressed in percent) within which the true value of a measured quantity exists.

Conformity Error   Dico Tools
For thermocouples and RTDs, the difference between the actual reading and the temperature shown in published tables for a specific voltage input.

Connection Head   Dico Tools
An enclosure attached to the end of a thermocouple which can be cast iron, aluminum or plastic within which the electrical connections are made.

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Console   Dico Tools
See corbel.

Constantan   Dico Tools
A copper-nickel alloy used as the negative lead in Type E, Type J, and Type T thermocouples.

Construction Manager   Dico Tools
A person who coordinates the entire construction process -- from initial planning and foundation work through the structure's completion

Continuous Span Beam Bridge   Dico Tools
Simple bridge made by linking one beam bridge to another; some of the longest bridges in the world are continuous span beam bridges

Continuous Spectrum   Dico Tools
A frequency spectrum that is characterized by non-periodic data The spectrum is continuous in the frequency domain and is characterized by an infinite number of frequency components.

Continuous Wall Walk   Dico Tools
An uninterrupted wall walk around a curtain or tower wall, allowing the fast movement of equipment and troops to any quarter under attack. See bastille.

Contour Fort   Dico Tools
A hill fort which was constructed by reinforcing the natural defences of the position by digging a bank and ditch along the contour line surrounding a hill. See hill fort.

Contravallatio   Dico Tools
A series of field work consisting of earthen ramparts and ditches excavated parallel to the circumvallatio but facing outwards, which were used to protect the Roman encampments against the attack of a relieving army; and in conjunction with the circumvallatio, prevented supplies and reinforcements reaching the besieged city. See circumvallate, circumvallatio, contravallation.

Contravallation (Lines Of)   Dico Tools
A chain of redoubts and breastworks constructed by a besieging army which encircled a fortification, situated parallel to the circumvallation but facing the opposite direction. This set of works was used to protect the besiegers camp and positions from assault by a relieving army. See circumvallate, counter vallation.

Control Character   Dico Tools
A character whose occurrence in a particular context starts, modifies or stops an operation that effects the recording, processing, transmission or interpretation of data.

Control Mode   Dico Tools
The output form or type of control action used by a temperature controller to control temperature, i.e., on/off, time proportioning, PID.

Control Point   Dico Tools
The temperature at which a system is to be maintained.

Convection   Dico Tools
1. The circulatory motion that occurs in a fluid at a non-uniform temperature owing to the variation of its density and the action of gravity. 2. The transfer of heat by this automatic circulation of fluid.

Cop   Dico Tools
A term used to refer to a merlon.

Corbel   Dico Tools
A projecting structure made of stone of wood located near the top of a wall, which were used to support such structures as; breteches, hourdings and machicolations. See bracket. (L. corvus, crow).

Corbelled Bartizan   Dico Tools
A bartizan built out on corbels, which was used to provide flanking fire thus reducing dead ground. See bartizan.

Cordon, Cordone   Dico Tools
(1) A row of stones along the line of a rampart. (2) A continuous rounded coping at the top of a masonry revetment. (3) A chain of military posts.

Core   Dico Tools
Central region of a skyscraper; usually houses elevator and stairwell

Coriolis Force   Dico Tools
A result of centripetal force on a mass moving with a velocity radially outward in a rotating plane.

Corner Buttress Turret   Dico Tools
A corner turret projecting only a small distance beyond the walls of a Norman rectangular keep; the turret had little if any military value as far as flanking ability was concerned. See square keep.

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Corner Flanker   Dico Tools
A flanking tower projecting from the corner of a keep, which was used to flank the wall between the towers, and to protect the vulnerable corners from sapping by miners and battering rams.

Correction (Balancing) Plane   Dico Tools
A plane perpendicular to the shaft axis of a rotor in which correction for unbalance is made.

Coulomb   Dico Tools
A measurement of the quantity of electrical charge, usually expressed as pico coulomb (10-12 coulombs).

Coulomb Sensitivity   Dico Tools
Charge/unit acceleration, expressed in Pc/g (charge sensitivity).

Counter Approach   Dico Tools
A temporary work usually consisting of entrenchments built by the besieged forward of permanent fortifications, to check the approach of an enemy army.

Counter Arch   Dico Tools
An arch connecting two counterforts.

Counter Mine   Dico Tools
A mine dug to intercept the mine of a besieging force, so that a counter attack could be launched, the objective of which was to collapse the mine of the besiegers.

Counter Salient   Dico Tools
A salient in the opposite direction.

Counter Trench   Dico Tools
A trench which was excavated by the besieged in opposition to those of the besiegers. The parapet was turned against the enemy's approaches, and was flanked by artillery providing enfilade fire so that if the enemy took the trench it would be rendered useless.

Counter Vallation, Contrevallation (Lines Of)   Dico Tools
The lines of earthworks thrown up by besiegers to protect their camp and positions from attack from a relieving army, used in conjunction with the lines of circumvallation during a siege of a fortification. See circumvallation, contravallation.

Counter Weight   Dico Tools
A weight added to a body so as to reduce a calculated unbalance at a desired place.

Counter Work   Dico Tools
Any type of work which was used to oppose those of an enemy; an opposing work.

Counterfort   Dico Tools
An inner buttress used to strengthen the masonry of a ramparts revetment.

Counterguard   Dico Tools
An outwork, triangular in shape, open at the rear, situated before the face of a bastion, ravelin or redan, used to protect these works from enemy cannon fire.

Countermure   Dico Tools
(1) A strengthening wall built in front of another wall. (2) A wall which was built behind that of another as a reserve defence. (Fr. contremur).

Counterscarp   Dico Tools
The outer side of a ditch of a fortification, in some permanent fortifications it was faced with stone to make entering and retreating from the ditch more hazardous.

Counterscarp Gallery   Dico Tools
A gallery which located in the counterscarp of the salients, used to flank the ditch of a fortification.

Counts   Dico Tools
The number of time intervals counted by the dual-slope A/D converter and displayed as the reading of the panel meter, before addition of the decimal point.

Coupure   Dico Tools
(1) An entrenchment made by the besieged behind a breach in the defences. (2) A passage through the glacis to allow the defenders to sally forth to attack an approaching enemy force. (Fr. couper, to cut).

Coursiries   Dico Tools
Mobile wooden parapets attached to the inside walls, which were used in France around the 11th century.

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Court   Dico Tools
A space enclosed by walls or buildings. See bail, bailey, barbkin.

Courtyard Castle   Dico Tools
A castle where the domestic buildings were integrated into the curtain walls and arranged around a central courtyard. See keepless castle, quadrangular castle, quadrilateral castle.

Covered Way   Dico Tools
A pathway or road running along the top of the counterscarp, provided with a protective enbankment which formed the crest of the glacis. The enbankment gave the soldiers standing in the covered way some protection from enemy fire, being high enough to obstruct the besiegers view. Also known as the covert way.

Covert Way   Dico Tools
A pathway in front of the ditch protected by a parapet which formed the crest of the glacis. The covert way was used by soldiers who's job it was to break up the general line of assault. See covered way.

CPS   Dico Tools
Cycles per second; the rate or number of periodic events in one second, expressed in Hertz (Hz).

CPU   Dico Tools
Central processing unit. The part of the computer that contains the circuits that control and perform the execution of computer instructions.

Crannog   Dico Tools
An Irish fort or lake dwelling dating from the Bronze Age and used up to the 16th century which was located on islet, often an artificial one which was built up in a lake or marsh. (Ir. crann, tree).

Cremaille   Dico Tools
(1) A zig-zag line of a fortification. (2) A sawtooth pattern on the inside line of a parapet. (Fr. pot hook).

Crenallate   Dico Tools
To fortify or embattle.

Crenaux   Dico Tools
A small loophole in the wall of a fortification, constructed with a widening aperture on the inside to allow the defenders a larger field of fire, but also allowing for the protection of the defenders. See loop.

Crenel Shutter   Dico Tools
A wooden shutter which covered a crenel and was used to defend a crenel, hinged at the top it enabled the defender to open the shutter to fire at the enemy, while gaining protection from the shutter in the closed position. See crenel.

Crenel, Crenelle   Dico Tools
The part of a parapet which is indented alternating with the solid uprights called merlons, which allowed the defenders to fire at the enemy while gaining protection from the merlons against the returned fire. See battlement, embrasure, reveal. (L. crena, a notch).

Crenellated   Dico Tools
Fortified or provided with crenels. See battlemented, embattled.

Crenellation   Dico Tools
A parapet consisting of merlons and crenels. The Licence to Crenellate was a royal licence giving permission to holder to build a fortification or to fortify a present building. See crenel, merlon, parapet.

Crest   Dico Tools
The apex of the glacis, either formed by the parapet of the covered way, or where the glacis meets the top of the counterscarp. Also known as a ridge.

Critical Damping   Dico Tools
Critical damping is the smallest amount of damping at which a given system is able to respond to a step function without overshoot.

Critical Speed   Dico Tools
The rotational speed of the rotor or rotating element at which resonance occurs in the system. The shaft speed at which at least one of the "critical" or natural frequencies of a shaft is excited.

Cross And Orb Gun Loop   Dico Tools
A gun loop provided with a cruciform sighting slit above the circular aperture for the cannon. The design came from adapting the cruciform arrow slit shape for the sighting slit, it provided effective sighting and a vent for the gases produced by cannon fire. See gun loop, gun port.

Cross Slitted Gun Port   Dico Tools
See cross and orb gun loop, gun port.

Cross Wall   Dico Tools
(1) A strong wall which divided a keep in half, the wall provided additional strength to the structure. (2) The wards between the walls of a type of concentric fortification were sectioned off by cross wall which ran between the outer and inner walls. If the enemy broke through the outer defences they were more easily disposed of (in a virtual killing ground).

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Crosslet Slit   Dico Tools
(1) An opening in the wall of a castle in the form of a cross for firing crossbows at an enemy without. (2) A cruciform aperture in the wall of a castle which was designed for the use of both bows and crossbows. Also known as a croslet arrow loop. See balistraria, loop.

Crotchet   Dico Tools
A pathway around a traverse in the covered way.

Crown   Dico Tools
To construct a work on the apex of the glacis or the top of a breach.

Crownwork   Dico Tools
An outwork consisting of two long flanks and a front with a bastion and two demibastions, thus forming the shape of a crown.

Cruciform Arrow Slit   Dico Tools
An arrow slit provided with a horizontal slit, which was used to increase the available field of fire, dating form the end of the 12th century. See arrow loop, arrow slit.

Crusader Castle   Dico Tools
A castle erected or modified by the 'Crusaders' to occupy and control their territorial gains in the Holy Land.

Cryogenics   Dico Tools
Measurement of temperature at extremely low values, i.e., below -200 C.

CSA   Dico Tools
Canadian Standards Administration.

Cunette   Dico Tools
A trench or drainage ditch sunk into the floor of a main ditch. (It. lacuna, ditch).

Cure Point   Dico Tools
The temperature at which a normally magnetic material goes through a magnetic transformation and becomes non-magnetic.

Current   Dico Tools
The rate of flow of electricity. The unit of the ampere (A) defined as 1 ampere = 1 coulomb per second.

Current Proportioning   Dico Tools
An output form of a temperature controller which provides a current proportional to the amount of control required. Normally is a 4 to 20 milliamp current proportioning band.

Curtain   Dico Tools
See curtain wall.

Curtain Angle   Dico Tools
The angle made by a flank (a work such as a bastion) with a curtain.

Curtain Tower   Dico Tools
A tower which was a part of a curtain wall, from which defenders could provide flanking fire to the curtain wall since they usually projected further into the field. See bastion, mural tower, wall tower.

Curtain Wall   Dico Tools
(1) A fortified wall which enclosed a bailey or ward. (2) The fortified wall which ran between two towers. (3) The rampart which ran between two bastions. See chemise, rampart.

Curtes Regia   Dico Tools
A fortified residence of a Carolingian king.

Curtes, Curtis   Dico Tools
A Frankish fortification of the 8th century constructed on a rectangular ground plan, using ditches and earthen ramparts topped by palisades.

Curticula   Dico Tools
A forward element of a Frankish fortification.

Curve Fitting   Dico Tools
Curve fitting is the process of computing the coefficients of a function to approximate the values of a given data set within that function. The approximation is called a "fit". A mathematical function, such as a least squares regression, is used to judge the accuracy of the fit.

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Curved Merlon   Dico Tools
The design of merlons underwent a change due to the fact that they were one of the most vulnerable parts of a fortification to artillery fire. The merlons were thickened and curved backwards, and the actual number of crenels was reduced. Also known as shot deflecting battlements. See merlon.

Curvilinear Wall   Dico Tools
A wall consisting of round bastion which were built so close together that only a small portion of each protruded.

Cut And Cover   Dico Tools
A method of tunnel construction that involves digging a trench, building a tunnel, and then covering it with fill

Cuvette   Dico Tools
See cunette.

Cycle Time   Dico Tools
The time usually expressed in seconds for a controller to complete one on/off cycle.

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