End of Phase I production to release.
A test sled which is decelerated to simulate a crash condition (see Holloman tests).
DAMAGE FREE CAR
Car equipped with special bracing devices to decrease the possibility of damage to lading. Usually called "DF" car.
Damped systems are those in which energy is dissipated by forces opposing the vibratory motion. Any means associated with a vibrating system to balance or modulate exciting forces will reduce the vibratory motion, but are not considered to be in the same category as damping. The latter term is applied to an inherent characteristic of the system without reference to the nature of the excitation.
As distinct from specific types of damping, damping devices refer to the actual mechanisms used to obtain damping of suspension systems.
The ratio of the amount of viscous damping present in a system to that required for critical damping.
A board on the fore part of a buggy or other vehicle to intercept water, mud or snow. Sometimes used, incorrectly, as a synonym for instrument panel.
DDEC Detroit Diesel Electronic Controls. ( Detroit )
Detroit Diesel Electronic Controls. ( Detroit )
An un-powered axle used to increase the legal weight capacity of a vehicle.
A second set of tracks over a scale used when cars are not being weighed.
1) Fireman's term for brakeman. 2) Employee riding on a company pass or on company business. 3) Train and / or engine crew moved without performing service, from one terminal to another at railroad convenience and for which they are paid.
Running empty, without cargo.
A buried timber, log or beam designed as an anchor to which a guy wire or cable is fastened to support a structure, as a wood or steel column, derrick or mast.
A foot pedal or brake valve which must be kept in a depressed position while the locomotive is operating. A release from this depressed position initiates an air brake application after a short time delay.
Any accumulation of broken and detached matter. Debris can be left in a pile or scattered over a large area. Usually a poor indicator of area of impact but can sometimes be an indicator of velocity and direction of travel.
(Decalcomania) A decorative or informative transfer sheet used for wood graining, labeling, etc.
Measures the intensity (loudness) of sound.
Determination of what action to take after perceiving a situation; choice of driving strategies or evasive tactics.
Floor of locomotive cab or cars.
A hinged panel providing access to the luggage compartment.
DEFECT CARD RECEPTACLE
A small metal container, placed underneath the car for protection from the weather, in which defect cards are placed.
Driving in a way that avoids conflicts that may be caused by the mistakes of others while making no mistakes yourself.
(static) The radial difference between the undeflected tire radius and the static loaded radius, under specified loads and inflation.
Generally refers to rate of spring deflection in inches per 1000 lb.
The alteration of form or shape, as a result of collision.
DEGREE OF CURVE
The number of degrees of central angle subtended by an arc of 100 feet on the circumference; 5730 feet. Divided by the degree of a curve equals the radius the curve.
DEGREE OF FREEDOM
The number of degrees of freedom of a vibrating system is the sum total of all ways in which the masses of the system can be independently displaced from their respective equilibrium positions. Examples: A single rigid body constrained to move only vertically on supporting springs is a system of one degree of freedom. If the same mass is also permitted angular displacement in one vertical plane, it has two degrees of freedom; one being vertical displacement of the center of gravity; the other, angular displacement about the center of gravity.
Delayed perception is a phrase which expresses the fact that the point of actual perception does not coincide with the point of possible perception, but rather, actual perception is delayed owning to driver inattentiveness. Delayed perception does not include reaction time.
1) The carrier which delivers a shipment to the consignee. 2) The transportation company that delivers a shipment.
The act of transferring possession of a shipment. This could be from consignor to carrier, one carrier to another or carrier to consignee.
A rim with valve locaters which is used with a cast spoke wheel to provide the method of attaching tires to the vehicle.
detention of a freight vehicle or container beyond a stipulated time. Also the payment made for such delay.
The weight of an article per cubic foot. The ratio of mass to bulk or volume.
DEPARTMENT OF TRANSPORTATION (DOT)
The federal agency responsible for the administration of the Federal Motor Carrier Safety Regulations. See Bureau of Motor Carrier Safety.
The level of crash severity at which ACRS system actuation should occur.
An imprint consisting of material deposited on the road surface from tire grooves. Sometimes found where a tire stops sliding.
Pre trial questioning of witness, under oath, subject to cross examination for the purpose of discovering evidence or perpetuating testimony; a document in which a deposition is recorded.
DEPRESSED CENTER FLAT CAR
A flat car with the section of the floor between the trucks depressed to permit loading of high shipments within over head clearance limits. Also called a well flat.
DEPTH OF FIELD
The range or distance from the nearest object to the farthest object in a scene that must be clear in a photograph; desired zone of sharpness.
DEPTH OF FOCUS
The range of distances which are in acceptably sharp focus for any lens setting; the effective area of sharpness.
The ability to Judge distances.
A track safety device designed to guide a car off the rails at a selected spot as means of protection against collision or other accidents; commonly used on spurs or sidings to prevent cars from fouling the main line.
Designation of an object, a condition, or an event according to the appropriate category in each of a number of classifications.
A full size model of a vehicle, or portion thereof, with components simulated of the most practical materials (wood, plastic, etc.). This is the first three-dimensional representation of designs (well in advance of prototype vehicles) and is updated with facsimiles of the latest designs until prototype or design check vehicles are available. One of the prime objectives of the design aid is to provide design visibility to promote early design concurrence between the various areas. Another prime objective is to provide a mock-up where wiring harness routing and component location can be experimentally determined.
DESIGN CHECK VEHICLE
An experimentally assembled vehicle consisting of prototype and current production material. This vehicle, or portion thereof, is used for the design check of components for fit, clearance and functions not requiring the total operation of the vehicle. All RPOs and accessories are also included as port of the design check vehicle specifications. It is the intent that these vehicles will provide the affected design activities with the visibility required for the determination and investigation of design discrepancies and potential production and service problems.
The plies to which a shipment is to be delivered.
A concise written summary of what a particular person has to say about a traffic accident or circumstances connected with it. A detailed statement is usually not a verbatim report of the information obtained from an informant.
A switch used in the ACRS sensor assembly which responds to "G" forces.
Sharp knock resulting from too rapid burning of fuel charge in combustion chamber.
An electronically actuated percussive device (I.e. to open the ACRS inflator valve).
Design for Assembly - Design to make assembly easier.
(Design for Manufacture and Assembly) is the pursuit of product simplification by evaluating and improving products in the design stage. Part features which affect ease of assembly, cost and productivity.
(Design Failure Mode and Effects Analysis) is a disciplined analysis of the part design with the intent to identify and correct any known or potential failure modes before the first production runs occur.
Diag Records indicates the count of Diagnostic Trouble Codes that became active during the trip. ( Detroit )
Electronic means of checking ACRS system electrical continuity and inflator pressure.
Mating metal part containing desired form impressions.
Forcing molten metal into steel die to form casting.
A three-dimensional representation made of hard wood from approved engineering drawings and aluminum templates.
Commonly referred to as diesel-powered vehicle.
DIESEL ELECTRIC LOCOMOTIVE
A locomotive in which one or more diesel engines drive electric generators which in turn supply electric motors (usually series D.C.) which are geared to the driving axles.
An internal combustion engine that uses compression to raise air temperature to the igniting point, whereas fuel is ignited by a spark in a gasoline engine.
The part of the power train that permits one wheel to turn at a different rate of speed from the other, as occurs when going around a turn.
DIFFERENTIAL LOCK, INTERAXLE TYPE
Used on twin-screw tractors, this valve can be set to lock both rear axles together so that they pull as one for off-the-road operation. Never used for over-the-road operation.
A tube with slotted ports to distribute the inflating gas into the air cushions.
To render more liquid or weaken solution.
(slang) A small engine used around round house or back shops for switching.
Trade name for a decal material consisting of three layers - decal, glue and paper. The outer portion can be painted with a special elasticized paint. When applied to the surface of a model, the Di-Noc is first soaked in warm water. The wet paper backing is separated from the decal, which takes the form of the clay surface and gives the model the effect of a painted car.
Electrical current that always flows in one direction only and is the type used in automotive equipment.
Is the definition associated with displacement of sheet metal and / structure under the direct contact of collision forces.
Refers to a condition in which the transmission is in a gear having a 1:1 ratio, that is, when the engine crankshaft is turning at the same rate as the vehicle drive shaft. See overdrive and under drive.
DIRECTION OF FORCE
The direction of the principle force sustained by a vehicle at impact and resulting in the vehicle damage. (See collision deformation classification SAEJ244).
A motorcycle designed for off highway use.
Disc brakes are a type of brake system wherein the friction material is a flat pad. The friction pads bear against a flat brake disc, or rotor, mounted in a plane perpendicular to the axle axis.
A single unit that combines a rim and a wheels
A reaction to perception of an unfamiliar hazard or other situation, which requires additional information than that immediately available to make a decision or which presents several choices of possible evasive tactics. Time required is 1.5 seconds or more, possibly much more.
The final touching of objects in a collision before separation; the time and place on a traffic unit or traffic way where this touching occurs. If colliding objects do not separate, there is no last contact.
Person in charge of dispatching.
The stroke of the piston multiplied by the area of the cylinder bore, the product multiplied by the number of cylinders in the engine.
DISTANCE TO SWERVE
(d): The longitudinal distance necessary to change direction and return to a parallel course while traversing a given lateral distance(dlat).
An engine-driven device in ignition system to produce, time, and deliver spark to the spark plugs.
The vehicle motion resulting from unwanted force or displacement inputs applied to the vehicle. Examples of disturbances are wind forces or vertical road displacements.
Divergent instability exists at a prescribed trim if any small temporary disturbance or control input causes an ever increasing vehicle response without oscillation.
(Day Light Opening) - line defining the areas through which light will pass in glazed areas.
A platform where trucks load and unload.
Receipt given for a shipment received or delivered at a pier or dock. When delivery of a foreign shipment is completed, the dock receipt is surrendered to the transportation line and a bill of lading is issued.
Anything printed, written, etc., relied upon to record or prove something.
(1; the supplying of documents (2) the documents that are supplied.
Design of Experiment - Evaluate key criteria to evaluate contribution to problem.
A relief crew went out to bring in a train which can not be legally moved by its own crew.
A right-angle bend, as in the angle made by the side and bottom of windshields of the mid-fifties.
A small platform mounted on wheels that is used in a warehouse to move objects. Also used in reference to (1) The coupling device composed of one or two axles and a fifth wheel used to convert a semi-trailer to a full trailer so it can be coupled to the rear of a tractor-trailer unit, making the combination into a double-bottom rig; (2) landing gear on a trailer.
Coupling device between leading trailer and dolly consisting of pintle hook and drawbar connection.
A device, part of the door hinge assembly, to prevent the door from opening beyond the designed full-open position.
Federal Department of Transportation
DOUBLE CAP NUT
The inner and outer nuts used to secure stud-mount wheels to a vehicle. The inner dual wheel is attached by an inner cap nut with a spherical radius and the outer dual wheel is attached by an outer cap nut with a spherical radius.
DOUBLE DECK (stock car)
A car with a second floor (often made removable) half way between the ordinary floor and the roof, to increase the carrying capacity of the car for small livestock, such as pigs as sheep.
DOUBLE DROP FRAME
A drop frame trailer with one drop behind the kingpin and one in front of the rear axles. See drop frame.
See tandem axle.
Shifting the gears of a non synchronized truck transmission without clashing them, by depressing and releasing the clutch pedal twice.
DOUBLE-REDUCTION REAR AXLE
A rear end that reduces the drive line rpm in relation to the rear wheel rpm by means of a double. Dual gear reduction generally used in rear axles.
A combination vehicle consisting of a tractor, a semi trailer and a full trailer, coupled together. Also called twins, twin trailers and most often double bettors.
A pin aligning or securing two parts to prevent movement between them.
The lower frame portion extending from the steering head down and under the engine to the swing arm pivot.
A shift which results in an increase in torque ratio and decrease in speed ratio.
Vertical or diagonal structural pillar between roof and body at the rear corner of a station wagon.
Lowest point on a manikin's buttocks contour.
Daily Problem Status Report
DQR DRAG TEMPLATE
Durability, Quality and Reliability. A pattern or guide of a particular of the body section - bumper, molding, etc.
A unit which forms the connection between the coupler rigging and the center sill. The purpose of this unit is to receive the shocks incidental to train movements and coupling of cars, and so cushion the force of impact.
Lowest part of flask used in casting.
(f): A number representing the acceleration or deceleration of a vehicle or other body as a decimal fraction of the acceleration of gravity; the horizontal force needed to produce acceleration in the same direction divided by the weight of the body to which the force is applied. When a vehicle slides with all wheels locked, on a level surface, the coefficient of friction and the drag factor have the same value.
A method of moving freight carts around a carrier's terminal. Refers to a moving cable (the line) that operates either from a suspended position overhead or in a slot in the floor. The line supplies the motive power (drag) to the carts when they are attached to the line.
The term "drag link" in a typical steering system is a rod connected at its end points to the idler arm and the pit man arm. The drag link, the tie rods, the idler arm and the steering knuckles comprise the steering linkage.
In some fuel systems, unburned fuel is returned to the supply tank through the drain lines. Not found on all tractors.
An operation in which a flat sheet metal blank is restrained around its periphery and caused to flow into a female configuration. Action may be air or toggle.
To form parts from flat stock by distortion or stretching in a die.
The inner extreme of draw marks caused by the blank traversing through spleens, binder radii, and steps in the cavity (female) of draw dies. Objectionable surface defect if it carries into an exposed area of a panel.
The head of an automatic coupler, exclusive of the knuckle, knuckle pins and lock.
DRAWING QUALITY STEEL
(DQ) Cold reduced, box annealed last (also tempered in exposed grades) drawing quality sheet steel for parts having a severe draw.
The charge made for carting, draying, or trucking freight.
Liquid debris from a vehicle or its cargo that drops to the ground, often leaving a trail, if the vehicle is moving, from a spatter area to a puddle.
The time required for a vehicle or combination to coast, with engine disengaged, from a specified higher speed to a lower specified speed, without the use of brakes.
A track connecting with the ladder track, over which engines and cars move back and forth in switching.
The handling or switching of cars in freight yards.
The hook or ring latch located in the vicinity of the occupants shoulder, often on the B or C pillars and used for directing the shoulder belt from the retractor mechanism over the shoulder.
(Drips) an exposed channel applied to the roof over the side windows to direct water away from the windows and to cover structural welding.
Every person who drives or is in actual control of a vehicle.
An axle that transmits power to the wheels. A drive axle is a powered axle that actively pulls the load.
A heavy-duty tube that connects the transmission to the rear end assembly of the tractor.
A series of connected mechanical parts for transmitting motion.
A fiberglass body mounted on a chassis and used to evaluate the model in motion.
The universal joints, any bearings, and the driveshaft(s) that transmit power from the transmission to the drive axle.
Driver Identification at the time of the data extraction. ( Detroit )
An air cushion restraint system used to protect the driver in a vehicle crash.
Latest driver incidents recorded, up to five. ( Detroit )
DRIVER INCIDENTS TOTAL
Total number of driver entered incidents. ( Detroit )
The use of steering or brake release and reapplication or combination of both to maintain directional stability.
DRIVER PERCEPTION REACTION TIME
The interval of time lapse between the instant a driver first perceives a reason to stop or maneuver his vehicle and the instant he takes action.
(Slang) The drive wheels of a tractor.
Transistors used as amplifiers. Taking a small current from an integrated circuit to control the much larger current of the interlock relay or the elt warning system.
DRIVER'S DUTY STATUS RECORD BOOK
See log book, driver's dally.
See log book, driver's dally.
DRIVERS PERCEPTION REACTION DISTANCE
The distance traveled by a vehicle during the time that elapses from the instant the driver detects a hazard until he applies the brake or makes an evasive maneuver.
A roadway by which motor vehicles may enter or leave a trafficway and limited to that portion that is entirely within the confines of the trafficway.
Engine on time when the vehicle speed was greater than 1.5 mph. ( Detroit )
Trip Distance divided by Driving Fuel. ( Detroit )
The longitudinal force resulting from driving torque application.
DRIVING FORCE COEFFICIENT
The ratio of the driving force to the vertical load.
Trip fuel minus Idle Fuel. ( Detroit )
Driving Time divided by Trip Time ( Detroit )
Trip time minus Idle Time. ( Detroit )
A long-wheelbase tractor with a cargo body placed between the fifth wheel and the cab.
Switching movement in which cars are cutoff from an engine and allowed to roll free into a track.
DROP BOTTOM CAR
A gondola car with a level floor, equipped with a number of drop doors for discharging the load.
DROP BRAKE SHAFT
A brake shaft for flat cars which normally extends above the floor, but can be dropped down should conditions of the lading require.
DROP END GONDOLA CAR
A gondola car with end doors which can be dropped when the car is used for shipping long material which extends over more than one car.
A trailer frame that drops downward to increase cargo capability without increasing the vertical clearance of the vehicle. Consists of two types: single drop and double drop.
DROP IT ON THE NOSE
Uncoupling a tractor from a semi-trailer without lowering the landing gear to support the trailer's front
The edge of pavement where it is more that about 2 inches (about 5 cm) higher than the abutting shoulder.
DROP THE BODY
(Slang) Unhook and drive a tractor away from a parked semi-trailer.
Generally refers to rear axle gear assembly located in axle housing by drop-in.
Drum brakes are a type of brake system wherein the friction material of the brake shoes is arranged cylindrically around the axle, and bears against a cylindrical brake drum.
Freight that does not need to be shipped at a specific temperature to prevent spoilage.
Part of brake system. Air passes from wet tank to dry tank. Dry tank is the air reservoir from which the air is drawn for operating the brake system.
Tandem axle or two axles in combination.
Lateral distance from wheel centerline to wheel centerline in a dual wheel arrangement. It is determined by adding two offsets (disc wheels) or two offsets plus one spacer bandwidth (demountable rims).
An air cushion inflator comparing two magnitudes of inflating energy which can be timed to provide variable inflation.
A pair of wheels and tires mounted together on the same side of one axle.
A fitting used to seal the opening in an air brake hose connection (glad hands) when the connection is not in use. Sometimes called a dust cap.
DUMP BODY (CAR)
Truck, car or trailer body of any type which can be tilted to discharge its loads
The material used to protect or support freight in trucks. The weight of dunnage is shown separately on the bill of lading since it is material used around a cargo to prevent damage. Often it is transported without charge.
DURABILITY AND FINAL
Certifies that durability, reliability and all other program requirements not met at the time of sign off.
An instrument which measures the hardness of rubber. Measures hardness by the deflection of a steel probe into a material. ( see ASTM D2240 )
The beginning of darkness in the evening.
See dummy coupler.
Sheet metal shield on brake assembly used to keep debris from brakes.
A tax levied by a government on imports and exports.
DVP & R
Design Verification Plan and Report
A statement made by the victim of a homicide while about to die, in expectation of death and without any hope of recovery, and concerning the facts and circumstances under which the fatal injury was inflected.
The balance of an object when it is in motion.
A means of braking a locomotive or car having electric motors or by using the motors as generators and dissipating this power through resistors. It may be used to control train speed and to brake a train to low speed after which air brakes bring it to a full stop.
The maximum exterior deformation suffered by a vehicle in impact with another vehicle or object and, due to the elastic properties of vehicle bodies, will be slightly greater than the post impact measurement. The maximum deformation that a vehicle would experience during the event. The dynamic crush is often 10 - 20 % greater than the static crush. The difference being the bounce or coefficient of restitution.
(k /ab ratio) is the square of the radius of gyration (k) of the sprung mass about a transverse axis through the center of gravity, divided by the product of the two longitudinal distances (a and b) from the center of gravity to the front and rear wheel centers.
Dynamic rate of an elastic member is the rate measured during rapid deflection where the member is not allowed to reach static equilibrium.
The physical behavior of an object in motion.
A device for measuring the work output of an engine. See brake horsepower.
Caterpillar User's Manual