R & R
(Repeatability and Reproducibility) refers to gauge and test equipment studies. Repeatability is the measurement variation obtained when one person measures the same dimension or characteristic several times with the same gauge or test equipment. Reproducibility is the variation in measurement averages when more than one person measures the same dimension or characteristic using the same measuring instrument.
Number of Repairs per 100 Vehicles
An offset designed into the surrounding body construction to accommodate and assemble glass.
Redbook Assumption Cost Estimating Request
RACK AND PINION GEARBOX
In a rack and pinion gearbox, the Steering shaft is connected to a Sear, or pinion, and the pinion causes a rack (a type of "straight sear") to move the steering linkage In this type of gearbox, the rack performs the same function as the pit man arm.
The term "radial' refers to a direction toward or away from the center of a circle (alerts a radius). Tire construction where cords run at a 90-degree angle to the bead or the tire's direction of rotation. "Radial" has come to mean the more modern of the two basic tire types.
RADIAL PLY TIRE
A radial ply tire is a pneumatic tire in which the ply cords which extend to the beads are laid at substantially 90 degrees to the centerline of the tread.
RADIO CONTROLLED ENGINE
An unmanned engine situated within the train consist, separated by cars from the lead unit, but controlled from it by radio signals.
(r): The distance from the center of a circle to a point on the circumference.
Metal arms attached to frame and axles for alignment.
A length of track, usually thirty nine feet long. Also see track.
An electrical conductor for bridging joints between rails for the purpose of carrying electrical current and part of a track circuit.
A fastening designed to unite a butting ends of rails.
Protection device used on exhaust stacks to prevent rain entry when the engine is stopped. Opens and closes automatically. Opens by the pressure of exhaust gases passing out of the stack. When exhaust stops (with engine shut off), the Ian cap closes.
The angle formed by the intersection of the steered axis and a vertical line while the motorcycle is in an up right position.
Angle created by lines tangent to the static loaded radii of front and rear wheels, converging at the point of lowest ground interference of underside of car - angle of overhang at lower extremities.
Random vibration exists in a system when the oscillation is sustained but irregular both as to period and amplitude.
A serrated edge like that of a saw, sometimes straight and sometimes on a wheel, into which a pawl engages, for producing or (more commonly) restraining motion. See brake ratchet, and pawl.
RATE OF CASTER CHANGE
The change in caster angle per unit vertical displacement of the wheel center relative to the sprung mass.
RATE OF CHAMBER CHANGE
The change of camber angle per unit vertical displacement of the wheel center relative to the sprung mass.
RATE OF TRACK CHANGE
The change in wheel track per unit vertical displacement of both wheel centers in the same direction relative to the sprung mass.
The maximum brake horsepower output of an engine as certified by the manufacturer.
The maximum torque produced by an engine as certified by the manufacturer.
Relation or proportion in magnitude of one quantity to another.
A person's voluntary or involuntary response to a hazard or other situation that has been perceived; the response to a sensory stimulus. Reactions may be reflex, simple, complex, or discriminatory.
The distance moved or traveled by a vehicle or other traffic unit during reaction time.
A backing plate for air cushion deployment.
The delay between the perception of a danger and the beginning of the physical response to that perception.
REAR END BAR FIXTURE
Fixture used to locate rear end panel in body frame.
A seat oriented so that its occupant faces the rear of the vehicle.
REAR OF A SIGNAL
The side of the Signal from which the indication is received.
REAR QUARTER PANEL
The rear fender panel.
REAR QUARTER WINDOW
The rearmost side window located in the rear quarter panel.
REAR SEAT RISER
The rise in the rear floor pan that supports the front edge of the rear seat.
See same-direction collision.
The relative displacement of the sprung and unsprung masses in a suspension system in which the distance between the masses increases from that at static condition.
The maximum displacement in rebound of the sprung mass relative to the wheel center permitted by the suspension system, from the normal load position.
An elastic member which increases the wheel rate toward the end of the rebound travel. The rebound stop may also act to limit the rebound travel.
The return velocity of the occupant after impact with, and reaction to, the air cushion or vehicle interior.
A track used for arriving trains.
The raising of a surface adjacent to a flange as a result of the resistance of the material to the flanging process.
A fiberglass or plaster reproduction of the original clay model as approved.
Identifies the type of data record in a Comma Delimited (CSV) export file. ( Detroit )
A fixed signal to stop. Also see board.
Part I: A publication generated by the Greenbook, but data is further enhanced by preliminary drawings based on studio clay models representing a carline approved concept or theme. Part II: Additional stage of the initial Redbook developed from data after the "hard point" of given components are finalized in design, thus allowing the controllers offices to accurately define a vehicle cost and profit margin.
Prepare to stop short of train or obstruction.
REDUCTION OF GEARS
Used where very slow speed is needed. Two reductions are made in the differential. See gear ratio.
Truck with heavily insulated refrigerated body.
A line, often the edge of a roadway, from which measurements are made to locate spots, especially spots along a roadway.
A point from which measurements are made to locate spots in an area; sometimes the intersection of two reference lines; (RP). A reference point is described in terms of its relation to permanent landmarks.
REFINING IN TRANSIT
The stopping of shipments of sugar, oil, etc., at a point located between the points of origin and destination to be refined.
An involuntary response to a stimulus; an instinctive act resulting from perception of an imminently hazardous situation.
REFRIGERATED CAR / TRAILER
An insulated car, van-type truck or trailer body equipped with a refrigeration unit. Used for carrying perishable goods. Also called a reefer.
To cut new grooves into a tire. This can be done only on tires that are made specifically to be regrooved. They are marked "regroovable."
A train authorized by a time table schedule.
Instrument to control voltage and current in vehicle electrical system.
The ratio of the absolute error to the size of the quantity.
RELATIVE POLAR MEASUREMENTS
A point on a drawing specified in terms of radius and angle from the previous point.
RELATIVE X-Y COORDINATE MEASUREMENTS
A point on a drawing specified in terms of X- Y- offset from the previous point.
RELAY EMERGENCY VALVE
A combination valve in an air brake system, which controls brake application and which also provides for automatic trailer brake application should the trailer become disconnected from the towing vehicle.
RELAY LOGIC SEQUENCING MODULE
An electro-mechanical device employing relays and associated timing, protection and control components which provides logical control of the ignition interlock system.
Valve used to speed up the application and release of the rear wheel brakes.
See release valve.
A small iron rod generally located at the side of a car for the purpose of operating the air brake release valve.
RELEASE VALVE (air brake)
A valve attached to the auxiliary reservoir for reducing the air pressure when the locomotive is detached so as to release the brakes.
See radio controlled engine.
A detailed illustration.
A track used for car repairs.
Date of generated report. ( Detroit )
Basis data collection to identify and classify a motor vehicle traffic accident and the persons, property and planned movements involved. Only strictly factual information is wanted, no opinions. Level 1 of traffic accident investigation.
RESERVOIR (air brake)
A cylindrical container for the storage of air under pressure. Main reservoir of large capacity are located in locomotives and under all motor cars having air compressors; auxiliary and emergency reservoirs are located under the cars.
Prevents the Pro Link Diagnostic Data Reader from resetting DDEC Trip information. Without this lockout feature, trip data can be accidentally erased when a Pro Link is used to service the DDEC ECM. ( Detroit )
A plastic liquid chemical. The two most commonly used are epoxy and polyester.
Opposition to the free flow of electrical current in a circuit.
Any device that "uses up" voltage by opposing, or resisting, the flow of electrical current. Resistors may be current consuming devices such as lamps or motors, or devices which are designed for the purpose of using a specific amount of voltage.
A forced vibration phenomenon which exits if any small change in frequency of the applied force causes a decrease in the amplitude of the vibrating system.
Frequency at which resonance exists.
A feature of the ignition interlock system which after starting allows uninhibited restart, regardless of the belt condition as long as the driver remains seated.
RESTRAINT SURVIVAL DISTANCE (RSD)
The distance between a restrained vehicle occupant in the normal, seated position and the interior surfaces of the vehicle in the direction of the crash forces. When the vehicle slows to a stop during impact it achieves its total deceleration during the crush. Thus all slowing will take place over the time required to produce the dynamic crush. The restrained occupant will not begin to slow at the same time as the vehicle due to the slack in the restraint system. The occupant will keep moving at the pre-crash velocity as the vehicle begins to slow until all the slack and stretch is eliminated from the restraint system. The restraint system will then hold the occupant back and cause him to slow down. If the slack in the restraint is removed before the vehicle comes to a complete stop, then the occupant will be able to slow along with the vehicle during ride down.
Manually operated restraint system including shoulder belts, lap belts, lap and shoulder belt combinations, or child safety seats. Automatic restraint systems include a relatively small number of "passive" belts and air cushion systems.
RESTRAINT SYSTEM LOADING
The process of engaging the restraint system, removing slack from the restraint system, and having the restraint system apply a restraining force to the vehicle occupant.
Types of freight that cannot be handled at all or may only be handled under certain specific conditions.
Proceed prepared to stop short of train, obstruction, or switch not properly lined, looking out for broken rail not exceeding fifteen mile per hour.
RESULTANT AIR VELOCITY
resultant air velocity vector is the vector difference of the ambient wind velocity vector and the projection of the velocity vector of the vehicle on the X-Y plane.
A resultant force is that force which is due to the vector summation of two or more forces. With respect to accident reconstruction the forces acting on colliding vehicles can be combined to give a single resultant force.
That single vector which would display the same effect as a number of original vectors added together.
A small manually positioned valve located near the brake wheel for retaining part of the brake cylinder pressure, to aid in retarding the acceleration of a train in descending long grades.
A metal grip adjacent to the rail, usually operated by compressed air or electrical motors, for regulating speed of a car by pressure on the wheels while rolling down a hump incline.
A belt retractor which automatically locks after the belt has been extended, preventing any further extension.
RETRACTOR VEHICLE SENSITIVE
A belt retractor which automatically locks when the acceleration of the belt relative to the vehicle exceeds a predetermined level.
A loss or impairment of memory of events preceding injury. In a traffic accident, a person who has been unconscious for a considerable time or who has lost much blood at the scene or the person may have no recollection of events immediately preceding the crash.
The lever which controls the direction of motion of the locomotive by reversing the traction motor field connections.
REVISED OCCUPANT SIMULATION
(ROS) A graphic computer simulation of occupant kinematics applied decelerations.
REVOLUTIONS PER MINUTE
The number of turns or rotations the engine makes in a minute (abbreviated RPM). Engine RPM is expressed in hundreds on the tachometer.
The act of incorporating a change or correction in a production part by hand and or temporary tools.
Information summary to assembly plants pertaining to rework required on production parts.
Radio Frequency Interference.
The low frequency (up to 5 Hz) vibrations of the sprung mass as a rigid body.
The maximum displacement in compression of the sprung mass relative to the wheel center permitted by the suspension system, from the normal load position.
The slowing of the vehicle occupant that occurs while the vehicle is still being crushed in an impact. An unrestrained occupant will typically not experience ride down. For a restrained occupant, the amount of ride down achieved is determined by the time required to fully load the restraint system.
The change of wheel load, at the center of tire contact, per unit vertical displacement of the sprung mass relative to the ground at a specified load.
Truck or truck-trailer combination.
RIGHT ANGLE COLLISION
In a right angle collision one vehicle is perpendicular to the other when the collision occurs.
RIGHT OF WAY (RR)
The property owned by the railroad over which tracks have been laid.
The item that supports the tire. It may consist of one piece (tubeless drop center type) or two or three pieces (tube type).
The diameter at the intersection of the bead seat and the flange. (See Tire and Rim Association Year Book.) Nominal rim diameter (i.e., 14, 14, 16.5, etc.) is commonly used.
Actual amount of effort in pounds available at point of contact of tire and road surface.
The distance between the inside surfaces or the rim flanges. (See Tire and Rim Association Year Book.)
Car in need of repair.
A fabric construction for air cushions with intermittent reinforcement.
The part of a trafficway which includes both the roadway, which is the traveled part, and any shoulder alongside the roadway. Where there are unmountable curbs, the road and roadway are the same. If there is a guardrail, the road is considered to extend to the guardrail.
The foundation on which the track and ballast rest; or on which the highway rest.
Not a main road or highway. Usually narrower, less direct, and often more winding than a primary road.
That part of the highway not occupied by road or sidewalk.
The part of the road intended for vehicle travel. It does not include paved or otherwise improved shoulders or what is sometimes called a berm or breakdown lane.
A single tool body framing system employing automatic locating and clamping fixtures with robots performing welding operations to create dimensional control of the total body.
A reprogrammable, multi-functional manipulator used to position parts, tools, or welding guns through a variety of programmed motions.
The sheet metal surface below the door opening, running between front and rear wheel openings.
The motion of a vehicle which has been retarded at the ground level while the remainder of the vehicle continues moving forward without leaving the ground; rollover. One of the three principles axis of a vehicle; along the longitudinal (x), axis.
The line joining the front and rear roll centers.
The camber displacements of a wheel resulting from suspension roll.
ROLL CAMBER COEFFICIENT
The rate of change in wheel inclination angle with respect to change in suspension roll angle.
The point in the transverse vertical plane through any pair of wheel centers at which lateral forces may be applied to the sprung mass without producing suspension roll.
The continuous bend-forming of constant section parts.
Roll steer which decreases vehicle understeer or increases vehicle oversteer.
ROLL STEER COEFFICIENT
The rate of change in roll steer with respect to change in suspension roll angle at a given trim.
ROLL STIFFNESS DISTRIBUTION
The distribution of the vehicle roll stiffness between front and rear suspension expressed as percentage of the vehicle roll stiffness.
A truck or trailer body with a sliding roof to permit overhead crane loading of freight.
Roll steer which decreases vehicle understeer with respect to change in suspension roll angle at a given trim.
roll velocity (p) The angular velocity about the x-axis.
The general term applied to a group of journal bearings which depend upon the action of a set of rollers in order to reduce rotational friction.
ROLLING MOMENT COEFFICIENT
(C M x) is based on the rolling moment deriving from the distribution of aerodynamic forces acting on the vehicle.
(Mx) is the component of the moment vector tending to rotate the vehicle about the x-axis, positive clockwise when looking in the positive direction of the x-axis.
1) Diameter of a tire under the weight of a car. 2) Distance from center of the tire to ground.
The horizontal force required to keep a vehicle in motion on a level surface, with the engine disconnected from the wheels and with no brake application; drag factor produced by friction within the vehicle and deformation of the tires and road surface.
An accident situation where the vehicle rolls at least 90 degrees. The term rollover is also sometimes used to describe a pitchroll. See roll.
A dynamic test used to evaluate body roof crush and occupant anti-ejection characteristics.
The lateral acceleration rate to which a vehicle will begin rotation about its longitudinal axis.
Body seam (joint) where the roof panel and body side panel are welded together. This seam (joint) creates a ditch along each side of the roof.
The kinematics of the impacted pedestrian where the head and torso pivot down toward the hood and the legs rotate up over the torso. The pedestrian then flips up and over the roof of the vehicle falling to the ground behind the vehicle.
A term associated with uni-axial forming and designating furrows of excess metal resulting from unequal wrap dimensions at adjacent areas on the punch.
The equations of motion relating distance, velocity, time and acceleration in a linear system have their exact equivalents in rotary motion. These are angular displacement (degrees or radians), angular velocity and angular acceleration. The equivalent of mass when rotation is occurring is more complex however. It is the moment of inertia. Consider a uniform rod in comparison to a dumbbell. Each is the same weight but the distribution of that weight is different. If both objects are rotating about their geometric centers at the same speed, they clearly have different moments of inertia as a result of the different distributions of weight. The moment of inertia can be measured or calculated for all objects and that parameter (I) replaces mass in calculations involving angular equations. These are equations relating to angular momentum and energy of rotation.
A metal disc used in a disc braking system. (See disc brakes).
A building, circular in design, used to house engines while being serviced or repaired.
1) The course or direction that a shipment moves. 2) To designate the course or direction a shipment shall move.
Revolutions Per Minute, a measure of the engine crankshaft rotational speed per minute.
Drop in rpm between shifts in transmission.
Engine overspeed limit in Revolutions Per Minute. ( Detroit )
Regular Production Option
Request for Procurement Services
(Reliability Standard) specification of the supplemental requirements that both internal production run and model year production run parts must meet to conform to specifications. (Chrysler derived)
A railroad operating rule prohibiting the possession or use of intoxicants or narcotics while on duty.
A side slat on a single-deck stock car made heavier than the usual slats. It is placed about four feet above the floor to resist movement of cattle against the car sides.
Rivulets of liquid debris from a puddle area flowing downhill toward soak-in at the edge of the pavement; frequently the source of tire prints after a collision.
The kinematics of the impacted pedestrian where the pedestrian falls under the vehicle while the vehicle is still moving. This situation can also occur with vehicle occupants or bicyclists who are ejected into the path of a moving vehicle.
A general term applied to and including the wheels, axles, springs, axle boxes, frames and other carrying parts of a truck or locomotive.
Same as clearance or marker lights. Set clearance lights.
1) A track designated in the time table upon which movements may be made subject to prescribed signals and rules, or special instructions. 2) A track reserved for movement through a yard.
That area outside the boundaries of an urban area.
A depression in soft or loose material, such as snow or dirt, made by a rolling tire.
RZEPPA UNIVERSALS JOINT
A disc-type constant-velocity joint.
Caterpillar User's Manual