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  • A/V Display
    Every locate receiver has an audio/visual display – commonly referred to as a “read-out”.
  • Abandoned Line or Facility
    Any underground or submerged line or facility no longer in use. They are usually left in the ground, but are no longer used or maintained in a usable condition. If it is an abandoned pipeline they are emptied of oil or gas and filled with nitrogen, water, or some other non-flammable filler.
  • AC/DC
    Transmitters are powered by batteries (DC current), but send out an AC current.  An AC current is easier to detect because it contains “phase”. See Alternating Current or Direct Current
  • Access Pedestal (AP)
    A phone pedestal that is sometimes referred to as a “splice box” or “1248” due to it’s size 12 inches deep x 48 inches high.
  • Access Point
    A bare metal spot on a pipe or cable whereby one end of the conductive transmitting antenna is attached.
  • Active Corrosion
    Indicates that pipeline corrosion is occurring now and is deteriorating the pipe.
  • Advanced Traffic Management System (ATMS)
    A traffic monitoring and driver alert system that consists of video cameras, and VMS Boards (Variable Message Sign).
  • Aerial River Crossing
    An aerial river crossing is a location where a pipeline is suspended to cross a waterway, either by cables over the waterway or attached to the girders of a bridge designed to normally carry vehicle traffic.
  • Aerial Transformers (Aerial Cans)
    A transformer that is attached to a pole and alters the primary line to a secondary at that point, which allows power to run directly from the pole line to a building.
  • Alleyway
    A private or public passage or way which (i) is less than the usual width of a street or road; (ii) may be open to but is not designed primarily for vehicular traffic; (iii) intersects or opens onto a road or street; and is primarily used for the ingress or egress or convenience of two […]
  • Alternating Current
    AC is the common form of electricity that we get in the United States when we plug an appliance into the wall.  It is an electrical current for which the current direction, or positive to negative flow (known as polarity), changes back and forth over a specified period of time. The frequency with which the […]
  • Alternative Dispute Resolution
    ADR is any process or procedure other than litigation that is agreed to by the disputing parties as the means for resolving a dispute, and is binding or non-binding pursuant to the agreement by the disputing parties. ADR includes, but is not limited to, advisory boards, arbitration, mini-trials, mediation, partnering, and standing neutrals.
  • Alumina
    A very thin oxidation layer on aluminum – which prevents the flow of current.  Any locator will need to scrape any oxidation off to provide a solid connection.
  • Amperage
    This is also known as “Current” and is something that is detected and displayed on receiver.  The signal with the highest amperage (current) is the one that has stayed on the target line.
  • Anode
    The point where the current leaves the conductor.  It is the exact point where our signal reaches the earth, and travels back to the ground rod at the transmitter.
  • APWA Color Codes
    American Public Works Association put together a standard color code for marking utility lines nationwide.
  • Aqueduct
    Any constructed water channel
  • Armored Cable
    A corrugated aluminum/steel sheath that protect telephone and fiber optic cables against other EM interference.
  • As-Built Drawing (Record Drawings)
    A detailed depiction of facilities as installed in the field.
  • ASCE 38-02
    Is a national engineering standard entitled “Standard Guideline for the Collection and Depiction of Existing Subsurface utility Data.”
  • Attracting Field
    A magnetic field whose energy moves toward another field; this field is not circular.
  • Attribute
    Characteristic that helps describe the data.
  • Backfill
    To fill the void created by excavating.
  • Bandwidth
    A spectrum of frequencies. Since exact frequencies do not occur – an electro-magnetic spectrum is helpful for locating. If you set  a locate machine to 8 kHz, it is not just sending a signal at precisely 8 kHz.  That is just the center of the signal.
  • Bell Hole
    A hole dug into the ground over or alongside a pipeline to allow the line to be surveyed, inspected, maintained, repaired, or replacing pipe sections. It is so called because of its upside-down bell shape, wide at the top and narrowing to a smaller diameter around the pipeline to be examined. The walls of the […]
  • Bleed-Off
    Technically referred to as “unwanted signal coupling” – is the current on any other conductor in the ground except the target line. The ground rod will always be an antennae for bleed-off, so, the farther it is from your connection point, the less bleed off you will have to deal.
  • Bonding Straps
    Short wires in a pedestal that the phone technician connects onto the cable sheaths.
  • Boulevard
    The area between the edge of pavement (or curb if present) and the sidewalk (or property line if no sidewalk exists).  A boulevard includes a terrace.
  • Buckle
    A partial collapse of the pipe wall due to excessive bending associated with soil instability, landslides, washouts, frost heaves, earthquakes, etc. Buckles can also occur in pipeline construction during a field bending operation using a side boom. Buckles cause localized stress concentrations and must not be installed in new construction or, if found, must be […]
  • Bulkhead
    A wall built or installed along a coastline or waterway to protect an adjacent pipeline from washout or soil erosion.
  • Candlesticks
    A line marker that is either a box or tube shape that serve as both a line marker but also have an opening on the top that reveals a tracer wire.
  • Capacitance
    Is the amount of current that any conductor can carry.
  • Catch Basin
    Open manhole structure that allows rain water in then drains into the main storm system.
  • Cathode
    The point where the current first reaches the conductor.  Any direct connection point we make automatically operates just like a cathode.
  • Cathodic Protection
    Is a method of protecting metallic pipelines from corrosion.  a method of corrosion prevention in which the pipeline is allowed or made to act as the cathode in an electrochemical corrosion cell. A sacrificial anode having a lower electrolytic potential than the pipe is provided to complete the cell. The same electrolytic action that causes […]
  • Cathodic Protection Monitoring or Survey
    Is an activity performed by pipeline operators to assess the adequacy of cathodic protection on the pipeline.
  • CATV Passive
    Designed to detect the transmission of cable TV signal on coaxial cables.
  • Cellular (Cell Site)
    Cellular communication at the cell sites (typically on tops of buildings) is sent and received through the panel antennas.
  • Cheat Wire
    see also extension wire
  • Clean Out
    A large manhole (often with multiple lids) that is used for trapping garbage in a storm system.  Once it is filled up it is sucked out with a vacuum truck.
  • Closed End
    The end of a line leg where the transmitter is located
  • Coaxial Cable
    A cable used for multiplex communication – that was developed to prevent impedance problems that could occur in a twisted pair of regular phone cables.  The modern use for coaxial cable is Cable TV.
  • Compliance
    Adherence to the statute and its regulations.
  • Conductive (Conductive Locating)
    This is often referred to as the “direct connection” method or “metal to metal” connection.  Basically, you are transferring the transmitters energy onto a pipe or cable.  When making a connection, one lead wire is connected to the utility line (the conductor), the other wire to the ground rod.  Often considered the preferred method since […]
  • Conductive Transmitting Antenna
    A wire with two ends which connects the transmitter to: 1) the pipe or cable and, 2) the earth
  • Conductor
    Is the metallic portion of the utility line
  • Confined Space Entry
    Refers to manholes. These can be a very dangerous place to be due to trapped gases and tight spaces – so you need training and also the right equipment which typically include: manhole guard, blower, gas detector, hardhat, etc. Detailed information on confined space entry is available from OSHA.
  • Confirmation Digs
    Are excavations performed at selected pipeline locations to expose the pipe to allow confirmation of the existence and characteristics of potential anomalies in the pipe wall that were identified by inline inspection techniques.
  • Consequence Analysis
    Is the evaluation or analyses of a postulated action or condition or series of events to determine the logical result. A consequence analysis may be performed to determine the expected effects of events leading to a pipeline accident, independent of the likelihood of such events occurring.
  • Contractor
    Anyone who works under contract for another company or municipality.
  • Corrosion Fatigue
    A reduction of the durability of a pipe due to corrosion.
  • Coupler Induction
    This device can be clamped around a utility line, and induce the signal onto the line.  When using induction, this should be the first choice since it ensures that the induction signal is closest to the target line.
  • CPS Passive (Cathodic Protection System)
    Useful tool for detecting cathodically protected gas and water pipes.
  • Critical Bond
    A critical bond is a wire connecting one pipeline to another, nearby pipeline to help prevent corrosion.
  • Cross Connect (Cross Box)
    A phone system enclosure that is the cross-over point in phone cables from transmission (feeder)  to distribution.  They are typically identified by two swing doors on the front of the cabinet.
  • Cul De Sac
    A road or street that is not a through road or street, that is open at one end for egress and exit.  At the end of a cul de sac is a special provision or area for vehicles to turn around (generally a circular area which may or may not have a center curb area). […]
  • Culvert
    Any pipe, duct or structure to facilitate drainage or transfer of surface water, storm water or other forms of runoff water. A culvert may be a freestanding structure or part of another structure such as a roadway, bridge, alley, private road, driveway, or parking lot.
  • Curb Lane(s)
    Traffic or parking lane of a road or street immediately adjacent to the curb.
  • Curb to Curb
    The paved area of a road or street between the outermost two curb lines.  If multiple curbs are present, such as on a boulevard, the curb to curb area is not the traffic lane in either direction, but the entire area encompassing both road surfaces, the center boulevard and the curbs.
  • Curb to Property Line:
    The area between the curb and the closest property line, including any adjacent boulevard, terrace or sidewalk.
  • Curbline
    The point where the curb meets the edge of the road or street pavement.
  • Currency flow reading
    A measurement on the transmitter of the amount of energy leaving the transmitter.
  • Damage
    Any impact or exposure that results in the need to repair an underground facility due to a weakening or the partial or complete destruction of the facility, including, but not limited to, the protective coating, lateral support, cathodic protection, or housing for the line, device, or facility.
  • Damage Prevention Initiatives
    In addition to enforcing Damage Prevention Regulations in the Code of Federal Regulations, the Office of Pipeline Safety has undertaken a variety of other initiatives to promote pipeline damage prevention. These initiatives, some of which involve collaboration with various stakeholder industry groups, promote public awareness of pipelines and other underground facilities; education of the public […]
  • Damage Prevention Regulations
    Damage prevention regulations for pipelines are found in the Code of Federal Regulations. They require pipeline operators to implement programs to prevent damage to buried pipelines from excavation activities. The regulations specify requirements for operators to interact with the public near pipelines and with companies/persons likely to perform excavation near pipelines. Pipeline operators may comply […]
  • Damage Reporting
    The immediate reporting to a one call center and the facility owner/operator of any damage caused or discovered in the course of excavation or demolition work; to immediately alert the occupants of premises as to any emergency that such person may create or discover at or near such premises; to contact emergency responders, if necessary, […]
  • Demolition Work
    The partial or complete destruction by any means of a structure served by, or adjacent, to an underground line or facility.
  • Depth Measurement
    A setting on your receiver that will allow you to get a rough approximation of horizontal position. Due to a variety of factors such as soil condition and depth readings coming from the location of the trace wire (which may not be at the same depth) – this method of determining depth can be very […]
  • Designating
    The engineering term for finding underground utilities electronically
  • Designer
    Any architect, engineer, or other person who prepares or issues a drawing or blueprint for a construction or other project that requires excavation or demolition work.
  • Dig Safely
    Dig Safely is the nationally recognized campaign to enhance safety, environmental protection, and service reliability by reducing underground facility damage. This damage prevention education and awareness program is used by pipeline companies, one-call centers, and others throughout the country. Dig Safely was developed through the joint efforts of the Office of Pipeline Safety and various […]
  • Digital Imagery
    A computer-compatible version of land-related information including, for example, topography, physical features, road/street networks, and buried facility networks obtained from a variety of sources including, for example, aerial photographs, satellite photographs, road maps, survey plans, and buried facility records.
  • Digital Photography
    Is an excellent and affordable method of documenting the proposed excavation scene with date and time stamp.
  • Dip Pole
    A utility line that goes from aerial to buried.
  • Direct Connection Method
    Is the preferred means of transmitting a detectable signal by connecting one transmitter clip to the targeted line and the other clip to a grounding stake.  Passive signals are naturally occurring signals that are present on many underground conductors.
  • Direct Current
    Direct current refers to an electrical current that flows in only one direction. As an example, direct current is the form of electricity we get from flashlight batteries.
  • DIRT
    Is a secure, web-based application used for collecting and reporting underground damage information.
  • Disbonded Coating
    Disbonded coating refers to any loss of bond or adhesion between the protective coating applied to the outside of a steel pipe and the pipe itself. Disbondment can result from adhesive failure, chemical attack, mechanical damage, hydrogen concentrations or other causes.
  • Discovery of a Condition
    Under the Pipeline Integrity Management requirements found in the Code of Federal Regulations, ‘discovery’ refers to the point in time at which an operator has adequate information about a defect, anomaly, or other pipeline feature to determine the need for repair. Depending on the circumstances, adequate information may be available when a preliminary inline inspection […]
  • Distribution Line
    A distribution line is a line used to supply natural gas to the consumer. A distribution line is located in a network of piping located downstream of a natural gas transmission line. As defined in natural gas pipeline safety regulations, a distribution line is a pipeline other than a gathering or transmission line.
  • Distribution Mains
    Lines that distribute the utility to various parts of the neighborhood.  This is the most common utility line in the ground.
  • Downstream
    The direction of stream flow of an utility operation.  Everything from the starting point (central utility office) outward is considered downstream.
  • Dryer/Compressor
    System that forces air through a small air hose at different points along the length of paper telephone cables – the forced air helps prevent water damage in the cable (corrosion of the conductor).
  • DSL
    A standard phone cable that transmits true digital communications (ie high speed internet and digital high resolution TV programs.
    DSL cabinets that also referred to as concentrators or multiplexers.
  • Duct Run
    A group of cables that are grouped together in a common trench.
  • Easement
    A utility easement is a land use grant obtained through negotiations between the private landowner and the pipeline company that provides an easement for a specific purpose such as building and maintaining underground pipelines.
  • Electromagnetic Field (EMF)
    The circular field that radiates around the current. It also radiates around the conductor in a wide pattern.  This is what the receiver actually detects and not the current itself.  In other words, the signal detected by the EM locator is the EMF radiating around the AC current that is applied by the transmitter.
  • Electronic Marker System (EMS)
    Method of marking and later locating, a specific point of any buried utility plant through the use of round metal coil with a capacitor attached to the loop.  They are technically speaking, a transponder so they send and receive a signal.
  • Electronic Null
    A receiver response whereby two symmetrically and horizontally positioned peak antennas record identical signal strengths.
  • Electronic Positive Response
    Communication by telephone, fax, e-mail or Internet from a facility owner/operator to an excavator providing the status of an owner/operator’s statutorily required response to a notice of intent to excavate.
  • EM Locator (or EMF Locator)
    A device that is among the most commonly used tools in designating buried utilities. Typically used in 3 different operations: conductive locating, inductive locating, passive locating.
  • Emergency
    A sudden or unforeseen occurrence involving a clear and imminent danger to life, health, or property; the interruption of essential utility services; or the blockage of transportation facilities that requires immediate action.
  • Emergency Flow Restricting Device
    EFRD is a device used to restrict or limit the amount of oil or gas that can release out of a leak or break in a pipeline. Check valves and remote control valves are types of EFRDs.
  • Emergency Notice
    A communication to the one call center to alert the involved underground facility owners/operators of the need to excavate as a result of a sudden or unforeseen occurrence or national emergency involving a clear and imminent danger to life, health, environment, or property (including the interruption of essential utility services or the blockage of transportation […]
  • Emergency Response
    A facility owner/operator’s response to an emergency notice.
  • Emergency Response Personnel
    Are persons engaged in the immediate response to accidents and emergencies. Emergency response personnel can include firefighters, police/sheriffs, medical personnel, civil defense and emergency management personnel, and, sometimes, military, manufacturing and transportation personnel. Emergency response personnel are sometimes referred to as ’emergency responders’ and ‘first responders.’
  • Encapsulated Pedestals (Encaps)
    Round, flush-mounted phone pedestals made of plastic.
  • Encroachment
    Refers to the unauthorized use of a right-of-way in violation of the terms by which the right-of-way was established (e.g., easement).
  • Energize
    To transfer the transmitter’s energy to a pipe or cable.
  • Event Tree
    Is a logic diagram that is used to identify and analyze individual events and event sequences that can or did lead to a singular, usually larger, event of interest, such as an accident. It is called a tree because on the diagram each individual event is shown on a branch connected to a trunk that […]
  • Excavation
    Any operation using non-mechanical or mechanical equipment or explosives to move earth, rock, or other material below existing grade. This includes, but is not limited to, augering, blasting, boring, digging, ditching, dredging, drilling, driving-in, grading, plowing-in, pulling-in, ripping, scraping, trenching, and tunneling.
  • Excavators
    Are those that disturb the earth with powered or non-powered equipment.
  • Explosives
    Any chemical compound or mechanical mixture that is commonly used or intended for the purpose of producing an explosion or the rapid combustion of highly heated gasses.
  • Extension wire
    A tool that is used to force a ground.  It is a wire with clamps at both ends and with one end clamp to the bare metal of the pipe and other other end clamp to another ground rod.
  • Facility
    An underground or submerged conductor, pipe, or structure used to provide electric or communications service (including, but not limited to, traffic control loops and similar underground or submerged devices); or an underground or submerged pipe used in carrying, providing, or gathering gas, oil or oil product, sewage, storm drainage, water, or other liquid service (including, […]
  • Facility Owner-Operator
    Any person, utility, municipality, authority, political subdivision, or other person or entity who owns, operates, or controls the operation of an underground line/facility.
  • Far end
    The end of a line leg opposite of the transmitter location.
  • Fault
    The point where the insulation has been damaged and the current is going to ground.  Typically seen creating loss of power in power cables and disturbance in telephone cables.
  • Fault Finder
    An device that is connected on some receivers that can be used to find the exact location of the fault.
  • Fault Tree
    Is a logic diagram that is used to identify and analyze potential causes or failures that can or did lead to an event. It is called a tree because each possible fault or cause is shown as a branch on a trunk that leads to the accident.
  • Feature
    Any visible utility connection such as: phone pedestal, gas meter, power pole, manhole, water meter, etc.  Even line markers are often described as a utility feature.
  • Fiber Optics
    Cable communications whose wire has internal reflections so that light waves can travel over great distances. The cable is made of glass and plastic which is coated to shield from the light escaping.
  • Fiber Wrench
    Specialized tool to gain access to fiber optic pedestals
  • Figure 8 Conduit
    A specialized cable that is used only for aerial fiber lines.  It helps to provide rigidity which protects the fiber from excessive motion in the air.
  • Flags
    Commonly used to mark lines that are on the grass or dirt.
  • Fracture Toughness
    Is the ability of a material (e.g., steel pipe) to resist stress and prevent cracks in the material from spreading.
  • Frequency
    The transmitter’s energy as measured in hertz or kilohertz
  • Front Lot Line
    The property line adjacent to the road or street right of way.  In the case of a corner lot do not use the term “front lot line” to describe the excavation area since it may be confusing.
  • Frontage Road
    A local road or street auxiliary to, and located on the side of, a highway or other limited access road.  A frontage road is usually for service to abutting property and adjacent areas, and for control of access to the highway.  The frontage road does not include the highway or the area between the highway […]
  • Gain Control
    Increases or decreases the “volume” of the signal being received. It does not alter the frequency or power of the signal from the transmitter.  It allows you to hear and see the signal at the best “volume”.
  • Gas Casing
    Thick steel pipe that the gas line is inserted through to protect the gas line from damage such as heavy above ground traffic or railways.
  • Gathering Lines
    Lines that “gather” the utility from a distant source.  Typically gas, water, and power.
  • Geographic Information System
    GIS is an organized collection of computer hardware, software, and geographic data used to capture, store, update, maintain, analyze, and display all forms of geographically referenced information.
  • Geospatial Data
    Data that identifies the geographic location and characteristics of natural or constructed features and boundaries on the earth.
  • Global Positioning System
    GPS is a system consisting of 25 satellites used to provide precise position, velocity, and time information to users anywhere on earth. Location information can be received using a GPS receiver. The GPS receiver helps determine locations on the earth’s surface by collecting signals from three or more satellites through a process called triangulation. Simple […]
  • Good current
    With the receiver held stationary, a peak response that does not fluctuate.
  • Grade
    The surface of the earth (i.e., ground level) upon which a structure is built or prepared.
  • Ground
    A return path for the current, or any portion of the return path.
  • Ground Marker
    Newer markers that are sometimes meant to be placed directly above the utility line.  They are small discs or plaques which come with a strong adhesive backing, and can be “glued” to the street or curb.
  • Ground Penetrating Radar
    GPR is an portable, user-friendly and affordable locate tool. It works by sending a pulse of electromagnetic energy into the ground and then displaying the reflected signal as a graph of the time it takes the signal to travel to a target and return over the distance the antenna has moved. It is the only […]
  • Grounding device
    A piece of metal driven into earth so that the conductive transmitting antenna may be attached.
  • Grounding Systems
    A system of one or more ground conductors or ground rods providing a low-resistance path-to-earth ground potential through a mechanical connection to structures, conductors, and equipment.
  • Handholes
    Are simpler version of a manhole – typically only 3’ deep. These do not require any confined space entry equipment or procedures.
  • Hazard Analysis
    A hazards analysis is an analysis performed to identify hazardous conditions that could result in an accident. A hazards analysis is performed in a systematic fashion using procedures such as Hazard and Operability Analysis and Fault Tree Analysis.
  • High Consequence Area
    A HCA is a location that is specially defined in pipeline safety regulations as an area where pipeline releases could have greater consequences to health and safety or the environment. For oil pipelines, HCAs include high population areas, other population areas, commercially navigable waterways and areas unusually sensitive to environmental damage. Regulations require a pipeline […]
  • High frequency
    Any transmitting frequency 10 kilohertz and above (up to 480 kilohertz)
  • High Profile Utilities
    Are those that can present a serious danger to life or property, or are extremely expensive to repair. These would include: Fiber Optics, Transmission Gas (high pressure), Transmission Electric (high voltage), Telephone Duct run, Paper/Lead phone cables, Toll phone cables, T-Screen phone cables, Surplus gas pipes.
  • High-high frequency
    Any transmitting frequency from 200 kilohertz or greater
  • High-low frequency
    Any transmitting frequency greater than 1 kilohertz up to 10 kilohertz
  • Highly Volatile Liquid
    A HVL, as defined in pipeline safety regulations, is a hazardous liquid that will form a vapor cloud when released to the atmosphere and has a vapor pressure exceeding 276kPa (40 psia) at 37.8oC (100oF).
  • Highway
    A public street or road  for purpose of vehicular travel.  A highway includes the entire width or area within the highway right of way boundary lines.
  • Holiday
    A holiday is a discontinuity or break in the anti-corrosion coating on pipe or tubing that leaves the bare metal exposed to corrosive processes. Excavators that hit a pipeline might observe damage only to the coating on the pipe and, therefore assuming they’ve done no real damage, cover the line back up. However, this coating […]
  • Horizontal Directional Drilling (HDD)
    Process of drilling that allows utility pipes and cables to be place under streets without having to dig up the road.
  • Immediate Repair Condition
    An immediate repair condition is a defect or anomaly in the condition of the pipe for which pipeline safety regulations require immediate action to repair the anomaly.
  • Incident Command System
    In widespread or major emergencies that could affect large populations or have significant environmental impacts an Incident Command System (ICS) is usually established to coordinate the combined actions of various emergency response personnel. Such emergencies could include natural disasters, such as tornados, train wrecks involving hazardous materials or major oil or natural gas pipeline releases. […]
  • Induction (Inductive Locating)
    Transferring the transmitter’s energy onto a pipe or cable without any actual connection onto the metal material of the utility. You can use either coupler induction or standard induction. In either case, the signal will radiate around the transmitter or around the coupler and the signal will go to any nearby conductor.  Just unplug the […]
  • Inductive Transmitting Antenna
    A coil located in the transmitter whose purpose is to energize the pipe or cable without using a metal-to-metal connection.
  • Industry Cost of an Incident
    The industry cost of an incident is defined as all costs to the operator and its contractors.
  • Infrastructure
    Underlying elements of any system. This would include the entire utility network for a city or town.
  • Inground Induction Loops (Traffic Loops)
    A  loop wire in the street that has a small current flow that detects metal objects in motion because it will detect disturbances in the current.
  • Initiating Event
    An initiating event is the first event in a sequence of events that leads to, for example, a pipeline accident.
  • Inner-Duct (Sub-Duct)
    Conduit that keeps multiple fiber cables evenly spaced within a regular conduit.  The color of the conduit help identify whose fiber it is.
  • Inside Plant (ISP)
    Any cables or pipes that are inside. These will have fire-resistant qualities due to safety hazards that are found inside.
  • Inspection
    Visually checking the job site from various vantage points. This is important because it is a common cause of damages that are listed as locator’s fault.
  • Integration of Data
    As used in pipeline integrity management regulations, integration of data (or data integration) is the process of bringing together all available risk and integrity-related data and information. Data integration is necessary and useful in evaluating the combined impact of diverse factors on pipeline risk.
  • Interchange
    A system of interconnecting roadways in conjunction with one or more grade separations providing for the movement of traffic between two or more roadways on different levels.
  • Intersection
    The general area where two or more roads, streets, highways (or combination of the above) join or cross.  The intersection includes not only the road or street surface, but also all other roadside facilities for traffic movements in that area.  This would include curbs, turning lanes, and any pedestrian lanes, including sidewalks. When a highway […]
  • Joint Trench
    When 2 or more utility lines are buried together within the same trench.
  • Junction Enclosure
    Also referred to as a “ground sleeve” or “J-box” is a cabinet used to splice different power cables together. All the power cables connecting into a junction enclosure are primaries.
  • Land Base
    Mapped data that depicts features of the surface of the earth and is tied to real-world geographic coordinates, such as latitude and longitude.
  • Large/Complex Project
    A single project, or a series of repetitive, small, short-term projects that are related in scope, that impact facilities over a long period of time or a large area.
  • Lateral
    A lateral is a segment of a pipeline that branches off of the main or transmission line to transport the product to a termination point, such as a tank farm or a metering station (see also Service line).
  • Latitude (Lat)
    Distance measured north or south of the equator.
  • Leads
    2 wires, one red and one black that are attached to the E-M locate transmitter. One is attached to the conductive material of the target line, and other is attached to the ground rod.
  • Line Leg
    A single direction section of a pipe or cable that has metallic continuity.
  • Line Marker
    Is any above the ground feature whose only purpose is to indicate the presence of a buried utility line.
  • Load Coil
    A group of metal rings that balances current on phone cables to allow for a voice signal to be heard clearly.
  • Local Distribution Company
    A local distribution company is a pipeline operator responsible for distributing natural gas locally to its customers. An LDC purchases gas from gas pipeline transmission companies for resale to the consumer. LDC’s operate and maintain the underground network piping, regulators, and meters that connect to each residential and commercial customer.
  • Local Emergency Planning Committees (LEPCs)
    LEPCs are committees appointed by the State Emergency Response Commissions (SERCs) and are composed of representatives of the following groups and organizations: elected officials, public safety and health personnel, local environment and transportation agencies, community groups and media, and representatives of affected facilities. LEPC’s are responsible for development and maintenance of emergency plans for response […]
  • Locate
    To indicate the existence of a line or facility by establishing a mark through the use of stakes, paint, whiskers, or some other customary manner that approximately determines the approximate horizontal location of underground line or facility. Such markings identify the location of the underground facility so that excavators can avoid damage to the facility […]
  • Locate Request
    A communication between an excavator and one call center personnel in which a request for locating underground facilities is processed.
  • Locate Technician
    A person that is trained and responsible for indentifying and visually verifying buried utilities.
  • Longitude
    Distance measured east or west from a reference meridian (Greenwich).
  • Looped Fiber
    A fiber network is often run in a large circular pattern around around a city which helps prevent lost connections (when fiber is cut) because the communications are automatically switched onto an other route.
  • Lot Line
    A line marking the legal limits of the property of a person. The term property line and lot line shall have the same meaning.
  • Lot Line to Lot Line
    The area between the two side lot lines on private property or the entire public right of way along the curb line for that property address or lot.
  • Low Frequency
    Any transmitting frequency below 10 kilohertz
  • Low-High Frequency
    Any transmitting frequency less than 200 kilohertz but greater than 10 kilohertz
  • Low-Low Frequency
    Any transmitting frequency one kilohertz or below
  • Low-To-High
    A utility locating best practice that says that you always make your connection at the downstream feature so that you can locate the power line going upstream (towards the sub-station).
  • Magnatometers
    Are used to detect ferrous metals (iron and steel) that are up to 8 ft down into the ground.  They are used to find buried manhole lids, water valves, and other iron or steel features.
  • Magnetic Field
    The product of alternating current flowing on a pipe or cable.
  • Main
    A main is a natural gas distribution line that serves as a common source of supply for more than one service line.
  • Mainline Valves
    A mainline valve is a valve positioned at a location along the pipeline system that can be closed down to isolate a line section in an emergency. Mainline valves are especially important to minimize hazards and damage or pollution from an accidental release of oil or natural gas. Mainline valves may also be referred to […]
  • Mandatory Membership
    Some states do not currently require mandatory membership in the state’s 811 program. When it is not required the facility owners are given the option to either participate in state’s 811 or have an in-house program that meets some of the same operational requirements. Whether they are members or are not of the state’s 811 […]
  • Manhole (MH)
    Larger vaults typically at least 6’ or 7’ in depth. To enter you need to use the procedures and equipment that is appropriate for any confined space entry.
  • Manifold
    The connection from the air hose to the cable in a pressurized telephone cable system.
  • Manual on Uniform Traffic Control Devices (MUTCD)
    The national standard for traffic control put together by the Federal Highway Administration through the American Traffic Safety Services Association.  Be sure to follow your companies procedures when it comes to traffic control.
  • Mark and Standby (or Mark and Monitor)
    Following company procedures to notify supervisor about high profile lines.
  • Marking Standards
    The methods by which a facility owner/operator indicates its line or facility in accordance with the APWA guidelines. (See Appendix B, “Uniform Color Code and Marking Guidelines.”)
  • Median
    The portion of a divided highway separating the traveled ways for traffic in opposite directions.
  • Member Database
    Structured collection of data defined for a particular use, user, system, or program; it may be sequential, network, hierarchical, relational, or semantic.
  • Membership
    Persons who participate voluntarily in a one call center because they have an interest in the protection of lines or facilities or because they have a statutory responsibility to protect lines or facilities.
  • Metal to Metal
    Another term for the use of a conductive transmitting antenna
  • Metallic Continuity
    A line leg that has no insulators or unarmored splices.
  • Metering and Regulating Stations
    M&R stations are installations containing equipment to measure the amount of gas entering or leaving a pipeline system and, sometimes, to regulate gas pressure.
  • Meters
    Typically used in natural gas, water, and electric power. In these instances, the meter serves as the end point of ownership for the utility operator.
  • Microwave (Cornucopia)
    Large metal tower systems (previously used for microwave broadcasts) that are abandoned, but may have been converted to house phone cable or fiber cable that are feeding the structure.
  • Moles
    Smaller horizontal boring machines that pound their way through the soil.
  • Multi-attribute Utility Decision Model
    A multi-attribute utility decision model is a model that helps compare the relative value (or expected benefit) of various proposed actions by examining the impact of those actions on a set of attributes (such as safety, environmental impact, etc.), and assigning relative weights to each of the attributes. Such models are frequently used to prioritize […]
  • Multiplexing
    Ability to send seperate transmission in both directions on a single circuit or wire.
  • Municipal
    A business that is run by a government entity.
  • National Response Center
    Is an entity within the U.S. Coast Guard that serves as the central point for reporting for all accidental discharges of hazardous materials into the environment of the United States and its territories. The NRC serves as the communications and operations center for the National Response Team and coordinates with other federal agencies having oversight […]
  • Near Miss
    An event where damage did not occur, but a clear potential for damage was identified.
  • Non-active Corrosion
    Is corrosion that has been discovered and treated (coated, chemically inhibited, or otherwise controlled) to stop the metal particle loss. Non-active corrosion areas are often monitored over time to verify the corrosion process is in fact halted.
  • Non-metal to Non-metal
    Another term for the use of an inductive transmitting antenna
  • Non-target Line
    Any pipe or cable not intended to be detected
  • Notice
    The timely communication by the excavator/designer to the one call center that alerts the involved underground facility owners/operators of the intent to excavate.
  • Notice of Proposed Rulemaking
    A NPRM is a formal notice by a federal agency of its intent to adopt specific proposed requirements into regulations. The NPRM is published in the Federal Register (unless all persons subject to the proposed requirements are personally served with copies), invites comments from the public on the proposed requirements, and specifies when, how, and […]
  • Notices of Probable Violations
    NOPVs are commonly used as an enforcement tool. After routine inspections, incident investigations, or other oversight activity by authorized Federal or Interstate Agent pipeline inspectors, the PHMSA Regional Director will determine if probable violations have occurred, and, if appropriate, issue an NOPV to the operator. The NOPV alleges specific regulatory violations and, where applicable, proposes […]
  • Notification Period
    The time beginning when notice is given and ending when the work may begin.
  • Occupational Safety and Health Administration
    OSHA is the federal agency responsible for implementing the Occupational Safety and Health Act of 1970, regulating safety in U.S. workplaces.
  • Office of Pipeline Safety
    OPS is the agency within the U. S. Department of Transportation, Pipeline and Hazardous Materials Safety Administration (PHMSA), that is responsible for regulating the safety of design, construction, testing, operation, maintenance, and emergency response of U.S. oil and natural gas pipeline facilities.
  • Offset
    An indication of the location of a buried utility line, but written on the ground in a separate location from the utility.  Typically done on One Call locates where you need the marks to last a while through the elements.  An example: “GAS 2’ BOW” which would indicate that the gas line is 2 feet […]
  • One Call Center
    An entity that administers a system through which a person can notify owners/operators of lines or facilities of proposed excavations.
  • Operating Stress
    The stress imposed on a pipe or structural member under operating conditions. This term normally refers to stress resulting from the internal forces due to the pressure of the gas or liquid in the pipeline; however, other forces such as thermal growth, expansion, or contraction may impose stress as well.
  • Operator
    An individual who performs work with a particular machine, or in governmental terminology, an operator of utilities, is any company or municipality that operates a utility system.
  • Operator Qualification
    A requirement of the Office of Pipeline Safety (a branch of the US Dept. of Transportation) that requires anyone who physically deals with gas or petroleum lines to be properly trained to do the work. This class can be administered by a gas company if the employer does not have a program of their own.
  • Opposite Curb
    Indicates excavations on both sides of the pavement with probable bore of pavement.  The excavator is recommended to also indicate the compass point directions (north to south, or east to west) when using this term to avoid any confusion. Opposite curb, long side and road bore have the same meaning.
  • Orthophoto
    An aerial photograph of a site that has been differentially rectified to correct the distortion caused by the terrain and attitude (tip, tilt, and yaw) of the camera. A multicolored, distortion-free, photographic image.
  • Outside Force Damage
    Is damage to an underground facility, such as a pipeline, resulting from some external force acting on the facility. Outside force damage to a pipeline or its protective coating is most often associated with damage from excavation activities around the buried pipe as a result of excavation equipment hitting the pipe, or from agricultural practices […]
  • Outside Plant (OSP)
    Any cables or pipes that are outside. These will have weather-resistant qualities due to exposure to outside elements.
  • Ovality
    Is a condition in which the internal diameter of the pipe is not consistent around the entire circumference of the pipe. This can be thought of as the internal diameter of the pipe being, to varying degrees, egg-shaped. Ovality can be measured by inline inspection tools known as caliper pigs or geometry pigs.
  • Pair Gain
    Any technology that can take a single pair telephone service and increase it’s capability.
  • Parallel Conductor
    A conductor that has an optimum chance of being induced.
  • Passive (Passive Locating)
    Using only the receiver and not the transmitter to detect different signals from another source (ie electrical power, broadcast waves, etc.) The five most common are passive modes: Power Passive (50/60 Hz), Radio Passive, Telephone Passive, CPS Passive, CATV Passive.
  • Path of Least Resistance
    The route the transmitter’s energy follows in order to return to the transmitter.
  • Peak
    A receiver response taken at the apex whereby the coil orientation is vertical.
  • Pedestal
    Phone service enclosures that hold the service wire connections to the cable.
  • Pedestal Wrench (Can Wrench)
    Tool that opens phone enclosures such as phone pedestals, cross-boxes, T-screen cabinets, etc.
  • Pest Duct
    PVC conduit that has a metal sheath on the inside to protect fiber cable from rodent damage.
  • Phase
    The pulsation of AC current. Whether on one conductor or two, the flow of current is shifting back and forth, but with all current moving in synchronization.  Anytime there are multiple currents at the same frequency, but not in complete phase with each other, there may not be a detectable signal.
  • Pig
    Is a generic term signifying any independent, self-contained device, tool, or vehicle that is inserted into and moves through the interior of a pipeline for inspecting, dimensioning, or cleaning. These tools are commonly referred to as ‘pigs’ because of the occasional squealing noises that can be heard as they travel through the pipe.
  • Pipeline
    Used broadly, pipeline includes all parts of those physical facilities through which gas, hazardous liquid, or carbon dioxide moves in transportation. Pipeline includes but is not limited to: line pipe, valves and other appurtenances attached to the pipe, pumping/compressor units and associated fabricated units, metering, regulating, and delivery stations, and holders and fabricated assemblies located […]
  • Pipeline and Hazardous Materials Safety Administration (PHMSA)
    The PHMSA is one of ten agencies within the U.S. Department of Transportation (DOT). PHMSA works to protect the American public and the environment by ensuring the safe and secure movement of hazardous materials to industry and consumers by all transportation modes, including the nation’s pipelines. PHMSA was created under the Norman Y. Mineta Research […]
  • Pipeline Component
    A pipeline component is some feature or part of a pipeline, such as pipe, valves, fittings, flanges, closures, tees or cathodic protection.
  • Pipeline Corridor
    A pipeline corridor is a linear area where two or more pipelines (either part of the same or different pipeline systems) are closely grouped in a single right-of-way.
  • Pipeline Crossing
    A pipeline crossing is a point where two or more pipelines cross without a physical connection existing between the pipelines.
  • Pipeline Facility
    From a regulatory perspective, a pipeline facility is: 1) New and existing pipelines, rights-of-way, and any equipment, facility, or building used in the transportation of gas or in the treatment of gas during the course of transportation (Reference 49CFR 192.3); and 2) New and existing pipe, rights-of-way and any equipment, facility, or building used in […]
  • Pipeline Intersection
    A pipeline intersection is a point where a physical connection between two pipelines occurs.
  • Pitting
    Is metal loss causing the formation of small depressions in a metallic surface. Pitting may be the result of sand blasting, mechanical gouging, acid etching or corrosion.
  • Planning
    An activity at the beginning of a project where information is gathered and decisions are made regarding the route or location of a proposed excavation based on constraints, including the locations of existing facilities, anticipated conflicts and the relative costs of relocating existing facilities, or more expensive construction for the proposed facility.
  • Plant
    Entire utility structure whose total operations are extended over the entire area of their utility lines.
  • Plat
    A map or representation on paper of a piece of land subdivided into lots, with streets, alleys, etc., usually drawn to a scale.
  • Positive Response
    Communication with the excavator prior to excavation to ensure that all contacted (typically via the one call centers) owner/operators have located their underground facilities and have appropriately marked any potential conflicts with the areas of planned excavation.
  • Positive Site Identification
    See also Premarking
  • Potable Water
    Commonly referred to as culinary water. This is simply drinking water.
  • Potholing
    Use of vacuum excavation to expose and determine the exact location of utilities
  • Power Control
    Transmitter settings to control variable power. The higher the power setting, the faster you use up battery power, however, it can improve a signal without significantly increasing the bleed-off.
  • Power Grid
    A portion of the power company’s plant (fed from coal processing, hydro-electric dam, etc).
  • Power Passive
    Generally set at a very wide bandwidth of 30 Hz to 100 Hz to detect any residual power signals (from aerial power lines and buried power lines) that are changing to other frequencies as they attach onto conductors in the area. Has two main uses, verifying the existence of a conductor where our signal was […]
  • Power Sub-Station
    Where the transmission lines enter and then the power lines become distribution power.
  • Premarking – Aka Whitelining
    The marking of the proposed excavation site/work area consistent with APWA guidelines.  Also see Positive Site Indentification
  • Primary Cables
    Are not positive or negative, they are a single current carrying cable typically coming from a power sub-station. They are usually aerial, but can also be buried.
  • Prints
    In years past, these were basic and were created for maintenance and regular operations, never just for locating purposes. They serve as a guideline, but not to be fully relied upon for the correct or most recent utility location.  Newer software mapping programs allow for these prints to be updated and overlayed by the locate […]
  • Private Property
    Typically any area that is not owned by city, county, state, or federal goverments. Even if it they invite the public on their property (for business for instance) they still have the same property rights that a homeowner would have.  So it is a privilege to be on their property not a right.
  • Private Road or Driveway
    A entrance, path or means of egress to or from the land of a private property owner and a street, road or highway.  A private road or driveway is designed for vehicular travel.  The private property owner has the right to restrict or deny access to a private road or driveway. An excavator should not […]
  • Probability Analysis
    Is an evaluation of the probability of occurrence of specific events, such as an analysis of the probability of certain pipeline failures.
  • Protective Coating
    A protective coating is a substance or material applied to the exterior of the pipe or a pipeline component to prevent contact with the outside environment. Protective coating is generally applied to prevent corrosion. Many types of protective coatings are used on pipelines, including coal tar, tape wraps, and fusion bonded epoxy compounds.
  • Public Cost of Incident
    Defined as public and private (non operator) costs for the incident.
  • Pullbox
    A very small hand-hole that is commonly used in traffic systems – where every signal pole will be fed by a pullbox.
  • Raceway
    Common term for a number of cables in conduits placed side by side.
  • Radio Passive
    Generally set to a bandwidth of 16 kHz to 19.5 kHz to detect any dying broadband signals (from radio stations, ham radio operators, cell phone systems, police and fire departments, 2-way radios, etc.) As transmitting radio waves move through the air and deteriorate, they penetrate the ground and attach to conductive materials – like utility […]
  • Railroad Operating Corridor
    The property that is essential to a railroad company to enable it to discharge its function and duties as a common carrier by rail. It includes the road bed, right of way, tracks, bridges, stations, and such like property.
  • Rear Lot Lines
    Property lot line at the rear of the lot (area opposite street or front lot line) that connects the two side lot lines.  If an alley is present, the rear lot line shall be the side of the lot or property adjoining or nearest to the alley.  The term rear lot line should not be […]
  • Receiver
    A handheld antenna or series of antennas used to determine the strength and location of a magnetic field.
  • Receiving Antenna
    A symmetric metallic winding induced upon by a magnetic field.
  • Record Drawings (aka As-Builts)
    A detailed depiction of facilities as installed in the field.
  • Regulator Station
    Where the transmission gas line will feed into a regular gas main.They typically consist of a fenced area with restricted access to transmission and distribution lines coming out of the ground and a small shed.
  • Regulators
    Regulate the difference in pressure in gas systems between two different pipes (they do not control the flow of gas).
  • Relocate Ticket
    Is a communication tool that extends the valid work period of an existing locate.
  • Remote Terminal Unit (RTU)
    The device at the remote controlled utility that sends and receives data – serving as the communications link with the office.
  • Repeater
    Also referred to as a triode vacuum tube – this allows for voice signals to be sent across the country.
  • Repelling Field
    A magnetic field whose energy moves away from another field; this field is not circular
  • Restricted Access
    Any commercial or residential property that restrict a tech from access and connecting to a utility on their property.  This could be due to fences, dogs, or other obstacles.  Check with your employer to define which facilities are classified as restricted access (or even “no access”)
  • Retention Pond
    Similar to a small lake meant to hold temporary run off water.  Which is the end point of some storm systems.
  • Right of Way
    Land area which you have access to on any day, and at anytime of day, but can be restricted on a temporary basis in events like a city parade.
  • Riser
    A portion of a gas pipe that comes up out of the ground, and then connects with the meter on the side of the building.
  • Root Cause Analysis
    Is a problem solving process that focuses on the task of finding the root cause and determining the best prevention solutions to a problem.
  • Round Field
    A magnetic field that is not an attracting or repelling field.
  • Routine Maintenance of Transportation Facilities
    The adding of granular material to unpaved roads, road shoulders, airport runways, airport taxiways, and railroad roadbeds; removal and application of patches to the surface of paved roads, runways, and taxiways; cleaning and sealing road, airport, and canal lock facility cracks or joints; replacing railroad ties and related appliances excluding road crossings; adjusting ballast on […]
  • Safety Wrap
    Is a reusable pipe wrap designed to protect lines from damage due to accidental impact while digging around them.
  • Secondary Pedestal
    A power enclosure downstream from a transformer that feeds into different end uses (homes for example).
  • Secondary Water
    Also referred to as reclaimed water, this water is usually from storm drain systems and canals, but unlike potable water, it is not treated – just pressurized.
  • Service
    Line that connects the distribution line to the building (see also lateral).
  • Service Cards
    Are a record of a single utility service.
  • Service Regulator
    Disc shaped attachment on the side of a riser on a gas service.
  • Sheath
    The metallic covering around the conductors and the outer insulation itself
  • Short Side
    The excavation to take place on same side of the road, street or highway as the address listed.
  • Side Lot Lines
    The two property lines which normally extend away from the public right of way at approximately 90-degree angles.
  • Sideways Induction
    Placing the transmitter on its side. This can help isolate a certain pipe for instance and keep the induction off another one that is close to it.
  • Signal
    The part of a magnetic field that intersects a receiving antenna.
  • Signal Splits
    A location along the pipe or cable where the transmitter’s energy can begin to travel on two or more new line legs.
  • Signal Strength
    Percentage of possible signal the receiver can detect.
  • Single Person Induction
    Process of back and forth movement on the transmitter (working in induction) performed by one person.
  • Single Phase Secondary
    Power line that is fed into your house meter.
  • Siting
    Is the process of determining the location where a facility or structure, such as a pipeline, will be constructed.
  • Sleeving
    A sleeve is a method used to repair a pipeline. Technically speaking – a sleeve is a full-encirclement of a pipeline with a reinforcing material at the location of a damage or defect to restore the strength of the pipe. Sleeves may be fabricated from steel or composite material. Sleeves may be for reinforcement only […]
  • Slip-Lined
    A process of inserting an expandable material into the sewer line, then forcing pressure into the pipe, which seals the material in the inside of the pipe, and gives it many more years of use.
  • SNI Insert
    Small adaptor that fits a SNI shaped insert into a pedestal wrench.
  • SNI Wrench
    A wrench with a long thin rod which fits the locking mechanism on the telephone protectors (single network interface).
  • Sonde Locating
    A small locating transmitter for use in storm or sanitary pipes.
  • Sound Resonance
    Used for locating plastic water pipes using sound waves. Depending on the method (manufacturer)  it involves attaching the machine to a fire hydrant.
  • Spark Gap Insulator
    A small attachment inside of a pedestal that prevents any lighting strike form having a detrimental affect on the phone lines.
  • Spill Response Plan
    Is a plan required of hazardous liquid pipeline operators for responding, to the maximum extent practicable, to a worst case discharge (spill) of oil, or the substantial threat of such a discharge.
  • Split Duct
    Conduit that put around exposed fiber cable for protection in manholes/handholes in between  the inner-duct.
  • Stake Chasers (Whiskers)
    A colorful small plastic brush-like object with a metal hoop.  A long nail is placed into the hoop to nail it down into the ground. Often used in gravel and asphalt roads because they can be run over and still retain color and position.
  • Standard Induction
    Also referred to as “drop box procedure”. The transmitter is placed on the ground over an area where the target line is known to be.  Depending on the transmitter, either pull the lead wire connection or push a switch to put machine into standard induction.  The two most often methods are: tandem induction and single […]
  • Star Wrench
    A tubular wrench used on fiber manholes
  • Step Down Transformer
    Steps down the voltage to the secondary power cable (any cable that feeds a building, street light, or any other end use).
  • Storm Sewer
    Is the system of collecting run off water from streets, parking lots, etc. into catch basins or manholes then ultimately into a river, irrigation system, ditch, or water treatment plant.
  • Strand
    Fiber optic line, of which there are many in a single fiber cable.
  • Stress Corrosion Cracking
    Is cracking that occurs in the steel pipe material that is caused by a combination of stress, corrosive environment, and temperature. Technically speaking – SCC is environmentally-assisted cracking that can result when the combined action of stress, an electrochemical cracking environment, and temperature causes cracks to initiate and grow in susceptible line-pipe steel.
  • Subsurface Utility Engineering
    SUE is a highly efficient, non-destructive engineering process that incorporates science and engineering to map the horizontal and vertical location of underground utilities.
  • Supervisory Control and Data Acquisition (SCADA)
    Remote control setup to control portions of a utility system by an operator.
  • Survey
    Refers to measurements, inspections, or observations performed to discover and identify events or conditions that indicate a departure from normal operation of the pipeline. One example is a leak survey.
  • Survey Grade GPS
    The most accurate GPS available.  It has sub-centimeter accuracy (about a third of an inch) both horizontal and vertical.  Method uses: Coarse Acquistion GPS codes, survey monument markers, and other control points.
  • Sweeping
    Distinguishing our signal from all other signals on the outset by walking in a 180 degree semi-circle around the transmitter with the receiver facing down. This will also need to be done far away from the transmitter (10’-15” away) and facing away from it as well. This is a critical step in getting one definite […]
  • Switch Gear
    Power enclosure that is used by the power company to shut off all power that is downstream.
  • T1 System/T-Screen
    T1 system allows for multiplexing of telephone cables. Due to fiber optics replacing many of these systems – many of the T1 cabinets have been recycled to be fiber huts for fiber optics or other communication cable.
  • Tagging
    Marking curbs with paint on both sides of the street with a solid dash mark.
  • Tandem Induction
    Process of two techs that perform a standard induction locate together.  Each tech holds one piece of equipment (receiver or transmitter) and then walk in unison to scan an area for conductors.
  • Target Line
    The pipe or cable intended to be detected.
  • Telco
    A telephone company
  • Telephone Passive
    Provides a wider spectrum for a passive locate from 300 Hz to 3.4 kHz.  This wider spectrum could be detrimental because you would end up detecting a number of other currents as well.
  • Test Hole
    Exposure of a facility by safe excavation practices used to ascertain the precise horizontal and vertical position of underground lines or facilities.  This is typically handled by Vacuum Trucks.
  • Theory of Oblong Field
    Is that other conductors, the depth of the conductor, and weak currents can alter the shape of the EMF.  A round or (perfectly circular) shape is how a typical electromagnetic field would be, but when it is disturbed it will become oblong in shape. The most common cause is depth.
  • Thin Walled Rocket Tubing (TWRT)
    Is a fragile metal pipe that was formerly surplus metal from World War II, and was used as replacement pipes for steel gas mains after the war. They have been known to fail easily because they are fragile and so they have been getting replaced gradually by gas companies.
  • Third Party Damage Prevention
    Third-party damage prevention includes all efforts and programs designed to prevent outside force damage to underground facilities (e.g., pipelines) that can occur during excavation activities. Responsibility for preventing underground facility damage is shared by all stakeholders. Advanced planning, effective use of one-call systems, accurate locating and marking of underground facilities, and the use of safe-digging […]
  • Throughput
    Measurement of the amount of oil or gas product flowing through a pipeline.
  • Tire
    A vertical coil winding in the receiver that provides a peak response.
  • Tolerance Zone
    The space in which a line or facility is located and in which special care is to be taken.
  • Toll Cables
    Run from central office (CO) to central office and often used as dedicated “911” cables.
  • Toneable Duct (Tracer Wire Innerduct)
    Conduit that has a conductive wire embedded in the conduit structure.
  • Total Cost of Incident
    Total property damage as reported on the operator-filed incident report.
  • Trace
    The entire section of a pipe or cable being located.
  • Tracer
    An insulated metal wire that is a good conductor that is laid alongside plastic lines and fiber cables so it can be located later on.
  • Transformer
    Enclosures that are downstream from a junction enclosure that contains both primary and secondary power cables.
  • Transmission Lines – Aka “Feeder”
    Are lines that carry a large capacity of the utility over a long distance.
  • Trench
    Long narrow ditch dug into the ground and embanked with its own soil and used for concealment and protection of line pipe. Trenches are usually dug by a backhoe or by a specialized digging machine.
  • Trenchless Technology
    Newer technologies of placing utilities underground without having to dig a trench.
  • Triangulating Depth
    Determining an approximation of depth by creating 3 marks on the ground: one from pointing the receiver straight down, and one mark to each side of that from 45 degree angled locate.  Measure the distance between the two outside marks, then divide by two.
  • Trunk Line
    Either a transmission or distribution line, or any type of main carrier cable or pipe.
  • Underbuilt
    Utility lines that are beneath the electric primary lines.
  • Upstream
    The direction of stream flow of an utility operation. From your house outward is upstream.
  • Utility
    Any service that originates from a separate location, or has a designation point outside of a building.
  • Vacuum Excavation
    A means of soil extraction through vacuum; water or air jet devices are commonly used for breaking the ground.
  • Vent Pipe
    A pipe that extends out of the ground (off of a buried steel casing of a gas pipe) to vent any possible leaking gases that would otherwise be trapped in the steel pipe casing.
  • Wall Loss
    Is a term used to describe the thinning of a pipe wall, usually due to metal loss by corrosion.
  • Waterproof Crayons
    Used to mark utilities when it is raining
  • Wellhead
    Refers to the point at which oil and natural gas is extracted from the ground.
  • Wrinkles
    Are anomalies that are usually caused by excessive bending or curvature being applied to the pipe. Depending on the severity of the wrinkles, they may represent an undesirable anomaly that can cause localized stress concentrations and must be repaired.