SADDLE BAGS
Term applied to front-end side vent ducts in
conventional ventilation system.
SADDLE TANKS
Barrel type fuel tanks that hang from the sides of
the tractor's frame.
SAE
Society of Automotive Engineers.
SAIL
Portion on rear quarter panel that extends above
the belt line and forms part of the boundary of the backlight and the side
window or door openings.
SAM
Semi-Axis Manipulator, computerized numerical
control machine used primarily to automate welding operations.
SAME DIRECTION COLLISION
A collision between two traffic units moving in the
same direction on the same roadway.
Sometimes called a rear-end collision.
SANDERS
Devices operated by air for applying sand to the
rail in front of or behind the driving wheels of the train.
SANDWICH PANEL
Composite panel usually formed by high-density
skins and low-density core or filler.
SCALAR QUANTITY
A quantity which has associated with it only a
magnitude.
SCALE HOUSE
Structure erected to house weight recording
mechanism used in weighing freight cars.
SCALE TEST CAR
A compact car equipped with weights for the testing
of track scales.
SCALES TRACK
A storage track for cars needing to be weighed.
SCANNER DRAWING
A drawing created by computerized equipment during
a scan of a three-dimensional clay modeled surface.
SCAR
Any sign that the road, roadside, or fixed object
has been damaged or marred by a traffic accident.
SCAVENGE
Discharge of exhaust by means of air pressure.
SCENE
The location of a traffic accident while people and
vehicles involved are still there.
SCHEDULE
That part of a time table which prescribes class,
direction, number, and movement for a regular train.
SCOOP
A device to catch air; may be either functional or
merely ornamental.
SCORING
Surface scratches on panels caused by cold welding
between a flange die steel and the sheet metal part. Also known as galling.
SCRAPE
A broad area of a hard surface covered with many
scratches or striations made by a sliding metal part without great pressure.
SCRAPER
A clay-molding tool used to rough in the surface of
a model and shaped like a short-handled rake with the straight or curved blade
crosswise to the handle. The blade can vary from one inch to six inches wide.
It has two sharpened sides, one of which has serrations or teeth and the other
a smooth edge.
SCRATCH
A light and unusually irregular scar made on a hard
surface, such as paving, by a sliding metal part without great pressure.
SCUFF MARK
A tire friction mark made by a tire that is both
rotating and slipping on a road or other surface.
SCUFF PLATE
Cover over door sill, usually rubber or metal.
SEAL
1) A security device to assure that truck doors
have not been opened in transit. 2) Metal strips, designed for one time use,
applied to the hasp of closed freight car / trailer doors. To remove, they must be broken. They are used to indicate whether or not the
contents have been tampered with while in transit. They must be stamped with a name, initial and / or number for
identification.
SEAL GAP
Distance from seal mount surface to seal plane.
SEAT SENSOR SWITCH
A switch at each front seating position which
senses the condition of the seat (occupied or unoccupied).
SEAT SIDE
A metal or plastic molding or applique on the outer
edge of the seat cushion and, in some cases, the seat back.
SEATING BUCK
A mock-up of the interior of a car used to evaluate
entrance and egress, seating room, comfort, instrument accessibility, etc.
dimensions are usually accurate to plus or minus .03 inch.
SEATING/PACKAGE BUCK
A simulated body shell (normally of wood
construction) equipped with seats, steering wheel, instrument panel and related
interior vehicle components as required to provide a three-dimensional and
visual evaluation of ingress and egress conditions, interior passenger room,
comfort, accessibility of controls, etc.
This property is used to establish and prove-out Engineering and Styling
proposals affecting package arrangements prior to the availability of running
prototype vehicles.
SECONDARY SHOES
Secondary shoes in a drum brake system are the shoes
which are mounted on the brake plate in a rearward position Each wheel has a primary (front) shoe and a
secondary (rear) shoe Sometimes the
primary is top mounted and the secondary is on the bottom, but this is not a
common type of configuration.
SECONDARY TRACK
A designated track upon which trains or engines may
be operated without timetable authority, train orders or block signals.
SECTION
View of any component at 90 degrees to a plane cut
through the component.
SECTION HEIGHT
Distance between the rim base and surface of the
tread. The unloaded section height at the "top" of the tire will be
greater than the loaded section height being compressed against the pavement.
SECTION MODULUS
Measure of beam strength in frame rails; must equal
the bending moment imposed.
SECTION WIDTH
Section width is the linear distance between the
exteriors of the side walls of an inflated tire, excluding elevations due to
labeling, decoration, or protective bands .
SECURE
(1) To guard or protect, such as to secure the
scene of an accident (2) to make firm
or tight, such as the cargo tie-downs or to secure the truck after parking (3) to obtain, such as to obtain help (4) safe and free from danger, such as
secure place to stop.
SEDAN
Two-door or four-door car having stationary window
frames in its doors.
SELF ALIGNING COUPLER
A coupler which has a taper shank rather that a
straight shank to prevent the jackknifing of cars.
SELF-EXCITED VIBRATION
Vibrations are termed self-excited if the vibratory
motion produces cyclic forces which sustain the vibration.
SEMITRAILER
Any vehicle with or without motive power, other
than a pole trailer, designed for carrying persons or property and for being
drawn by a motor vehicle, and so constructed that some part of its weight and
that of its load rests upon or is carried by another vehicle.
SENIORITY
1) The rights of passenger trains over freight and
of express over locals. 2) The right of
way in one direction on a single track line.
SEPARATION, POINT OF
The point in the collision sequence where collision
forces have been dissipated and the objects in contact have the opportunity to
physically separate from each other
SEQUENTIAL FACTORS
Factors which must follow one another to contribute
to the cause of an accident; generally, operational factors.
SEQUENTIAL INTERLOCKING
a feature of the ignition interlock system which
prohibits starting on the initial start if the belt is fastened at any seating
position before the seat is occupied.
SERIES CIRCUIT
A circuit in which all controls and current
consuming devices are connected in a single line, so that current must pass
through each device in sequence. (See
parallel circuit.)
SERIES-PARALLEL CIRCUIT
A circuit that is made up of combination of series
and parallel circuits.
SERIOUS INJURY
Injury severity of AIS 3 or greater, including for
example, compound fractures and internal organ injuries. Unless otherwise noted, summary statistics
in this report include all fatally injured persons as seriously injured, but
exclude those with unknown severity levels. ( see AIS )
SERVICE APPLICATION
(air brakes)
1) A reduction of air pressure in the brake pipe at a rate that will
produce an application of the locomotive and train brakes and a gradual speed
reduction. 2) An application of air
pressure in the brake pipe at a rate that will produce braking at all service
brakes and a gradual reduction of speed.
SERVICE BRAKES
The service brakes on a vehicle are the brakes (or
more accurately, the braking system) used to stop the vehicle in normal
use. Service brakes are usually air or
hydraulically operated.
SET - UP
A term denoting that an article is put together in
its complete state. Not knocked down.
SEVERITY INDEX
(SI) A measurement of the accelerative forces at
the center of gravity of the anthropomorphic test device during vehicle impact.
SHACKLE
Pivoting link between spring eye and frame bracket.
SHAKE
The intermediate frequency (5-25 Hz) vibrations of
the sprung mass as a flexible body.
SHALLOW ENTRY ANGLE COLLISION
Any collision between two objects in motion in
which the angle between their respective directions of travel is less than 15
degrees.
SHANTY
Small building erected along right of way to
provide shelter.
SHEET METAL
All areas of a car not glass, bumpers, grille,
lights, or trim, that comprise the body; I.e., hood, fenders, quarter panels,
instrument panel, decklid, etc.
SHIFT FORKS
Y-shaped components located between the gears on
the mainshaft which, when actuated, cause the gears to engage or disengage via
sliding clutches. Shift forks are located between low and reverse, first and
second, and third and fourth gears.
SHIFT TOWER
Consisting of a gearshift lever, pivot pin, spring
and boot and housing, it is the main interface between the driver and the
transmission.
SHIM STOCK
Extremely then metal pieces used as dividers in the
making of a mold.
SHIMMY
A self-excited oscillation of a pair of steerable
wheels about their steering axes, accompanied by appreciable tramp.
SHIPPER
Person or firm for whom shipment originates. Also called consignor.
SHIPPER'S LOAD AND COUNT
Indicates that the contents of a truck were loaded
and counted by the shipper and not checked or verified by the transportation
line.
SHOCK
A frequent condition of accident victim in which
there is a lack of sufficient blood circulation.
SHOCK ABSORBER
A generic term which is commonly applied to
hydraulic mechanisms for producing damping of suspension systems.
SHOCK TOWER
Structural pedestal constructed to support shock absorber loads and provide
for required plunger travel.
SHOP
Term applied to a structure where building and
repairing of equipment is performed, e.g., cars, trailers, tractors or
locomotives.
SHORT CIRCUIT
See circuit.
SHORT SILL COWL
Assembly sold to custom body builders consisting of
a portion of the floor pan assembly and rockers and the front end assembly.
SHORT TON
2,000 pounds.
Also called a net ton.
SHOULDER
That portion of the road contiguous with the
roadway for accommodation of stopped vehicles, for emergency use, and for
lateral support of the roadway structure; The line between the roadway and the
shoulder may be a painted edge line, a change in surface color or material.
SHOW CAR
A car having features or shapes not offered in
production cars, and designed for display.
SHROUD
Housing located around engine fan for the purpose
of utilizing full drawing power of fan.
SHUT-DOWN VALVE
1) (manual type)
Located on top of the fuel pump used to shut off fuel supply to the
engine. When the plunger is pushed in,
the fuel passage to the injectors is opened.
When it is pulled out, the fuel passage is closed. It is important to keep the valve pulled out
in the "Off" position whenever the engine is not running. 2) (electric solenoid) Permits the fuel to be shut off or turned on
through the use of a switch key similar to that used in automobiles.
SIDE ACCELERATION
The component of the vector acceleration of a point
in the vehicle in the y-direction.
SIDE FORCE COEFFICIENT
(C y) is
based on the aerodynamic force acting on the vehicle in the y-direction.
SIDE FRAME FIXTURE
Fixture used to locate and hold major panels and
assemblies together for welding and line operations.
SIDE GUARD BEAM
Beam inside of doors extending from hinge pillar to
lock pillar for added side impact protection.
SIDE SKID
A skid mark is a tire mark left by a locked,
braked, or rotating wheel sliding sideways to its original direction of travel
SIDE SLIP ANGLE
The angle between the heading direction and the
velocity direction of the vehicle. This
is because when the pre-collision skidding occurs, the heading direction of the
skidding vehicle is generally not aligned with its velocity direction at the
point of impact.
SIDE TRACK
A track adjacent to the main track for purposes
other than for meeting and passing trains.
SIDE VELOCITY
side velocity (v)
of a point in the vehicle is the component of the vector velocity in the
y-direction.
SIDE WALL
(of a tire)
The side wall is that portion of a tire between the tread and the bead
SIDE WALL SEPARATION
Side wall separation is the parting of the rubber
compound from the cord material in the sidewall of the tire
SIDESLIP ANGLE
(Attitude Angle) is the angle between the traces on
the X-Y plane of the vehicle x-axis and the vehicle velocity vector at some
specified point in the vehicle.
SIDESLIP ANGLE GRADIENT
The rate of change of sideslip angle with respect
to change in steady-state lateral acceleration on a level road at a given trim
and test conditions.
SIDEWALK
That
portion of the street between the curb lines, or the lateral lines of a
roadway, and the adjacent property lines, intended for use by pedestrians.
SIDING
A track adjacent to a main or a secondary track for
meeting or passing trains.
SIGHT ANGLE
The angle of a line tangent to the lowest exposed
surface of the body and the edge of the rocker or quarter pinch-weld flange.
SIGHT GAUGE
A glass window for determining fluid levels, as in
a radiator.
SIGHT SIDE
The side of the tractor visible by the driver on
the driver's side. Opposite of blind
side.
SIGNBOARD
Information stenciled on side of car pertaining to
empty car movement instructions.
SILL (car)
The main longitudinal members of a car under frame.
SILL PLATE
Finishing panel on top of rocker in door opening
areas.
SIMPLE HARMONIC VIBRATION
Vibration at a point in a system is simple harmonic
when the displacement with respect to time is described by a simple sine
function.
SIMPLE REACTION
A pre planned reaction to an expected hazard or
other stimulus. Time 0.75 sec, + or -.
SIMULTANEOUS FACTORS
Factors which must be present at the same time to
contribute to the cause of an accident; generally condition factors.
SINGLE AXLE (SLANG):
Slang for either a tractor with one front axle and
one rear axle or a semi-trailer with only one axle.
SINGLE DROP FRAME:
A drop frame trailer with one drop, immediately
behind kingpin. See drop frame.
SINGLE TRACK
A main track upon which trains are operated in both
directions.
SINGLE TRACK VEHICLE
A term used to describe a vehicle whose front wheel
tracks in front of the rear wheel.
Lines left on the road to mark the path of the tires would appear as a
single track.
SINGLE-REDUCTION REAR AXLE:
A rear end that reduces the drive line rpm in
relation to the rear wheel rpm by means of a single combination of gears.
SIPES
Sipes are the slits and slots often found on the
circumferential ribs of a tire.
SISSY BAR
A decorative metal bar mounted on the rear fender
at the back of the seat.
SITE
The location of a traffic accident after vehicles
and people involved have gone.
SITUATION HAZARD
A circumstance that more or less endangers a
traffic unit on a trip and which must be avoided to prevent an accident.
SIX-WHEELER
Reference to three-axle truck
SKATE
A metal skid placed on rail in hump yard to stop
cars from running out the lower end of the classified yard.
SKEW BRIDGE
A bridge which crosses a passageway at other than a
right angle.
SKID LINE
A visible surface defect caused by movement of the
blank over a sharp feature line during the drawing operation.
SKID MARK
A skid mark is a mark left on the road surface, or
on any surface, by a wheel in a skid
The term "skit mark" includes all evidence of skidding such as
scuffing of a concrete coat surface, even if no rubber is left behind
SKID NUMBER
Skid number is the frictional resistance of a
pavement measured in accordance with the American Society for Testing and
Materials, Method E-274-65T, at forty miles per hour omitting water
delivery This is the official
definition contained in Federal Motor Vehicle Safety -Standards The term skid number is defined as the ratio
of skid resistance to normal load on a wheel, multiplied by 100 It can also be defined as the coefficient
of friction multiplied by I00
SKID RESISTANCE
Skid resistance is the frictional force which
resists the motion of a skidding wheel or tire
SKINS
Reference to vehicle tires.
SKIP SKID
A braking skid mark interrupted by frequent
intervals; the skid mark made by a bouncing wheel on which brakes keep the
wheel from turning. Compare with gap skid.
SKIVE
To slice or cut off in thin layers.
SLACK ADJUSTER
An adjustable device located on the brake chamber
push rod that is used to compensate for brake shoe wear.
SLAVE FLASH
A supplementary photo-flash placed at a distance
from the master flash to increase the illuminated field in the photograph and
fired by a photoelectric device actuated by light from the master flash.
SLAVE UNIT
See radio controlled engine.
SLED PULSE
a deceleration signal used as a model to simulate
the barrier crash pattern of a particular vehicle.
SLED RUNNER CHASSIS FRAME
Type of chassis frame in semi-integral frame cars
that extends from the front end to the front seat area.
SLED TEST
A dynamic test in which a test system is mounted on
a sled which is either accelerated or decelerated to simulate a vehicle crash
condition.
SLEEPER
Truck with a sleeping compartment in the cab.
SLEEPER BERTH
Area in a tractor where a driver can sleep. Sleeper berths must meet standards set by
the Federal Motor Carrier Safety Regulations.
SLICK
A thin piece of plastic with the edges ground free
of all nicks and scratches. It is used to:
1. Smooth a clay surface. 2.
Smooth aluminum foil onto clay of fiberglass to simulate chrome trim on
bumpers, moldings, etc., and to apply Di-Noc.
SLIDE TO
STOP-DISTANCE
(dss): The
distance required to decelerate in a skid from an initial
velocity to a velocity of zero (0).
SLIDE TO STOP-TIME
(tss): The
time required to decelerate in a
skid from an initial velocity to a
velocity of zero (0).
SLIDER TUBE
A lower fork component into which slides the fork
tube. This component carries the axle
and disc brake assembly.
SLIDING FIFTH WHEEL
A fifth wheel assembly capable of being moved
forward or backward on the truck tractor to obtain desired load distribution
between tractor and trailer axles.
SLIDING TANDY
An adjusted bogies beneath the trailer that can be
moved forward or backward to distribute the weight between tractor and trailer
axles.
SLIP
Slip is defined as the ratio of the difference
between the angular wheel velocity of a tire which is both rolling and sliding
and the angular wheel velocity when the tire is only rolling. Slip is usually expressed as a percentage
found by multiplying the ratio by 100
SLIP ANGLE
The additional amount of steering angle that is
applied to the front wheels of a vehicle in order to generate additional
friction force to assist the vehicle in negotiating a turn
SLIP COAT
Reduce Friction
SLIP JOINT
Adjustable driveshaft component.
SLIP RATIO
Slip ratio is a parameter which expresses the
amount of slippage between the tire and the road, defined by the equation: Vs = Va - Vp Va Where: Vs = Slip
Ratio; Vp = Peripheral speed (the speed the vehicle would go if the tire where
rolling without slipping. Va = Actual
speed of the vehicle.
SLIP TORQUE
Engine torque required to slip wheels.
SLOPE
The ratio of a vertical distance change to the
horizontal distance change (See Grade ).
SLOW BOARD
A signal identification to proceed at slow
speed. See board.
SLOW SPEED
Not exceeding 15 miles per hour.
SLR
Surface Layout Release
SLUG MARK
(Slugged) A visible surface defect in a stampling
(usually an out ding) caused by the imbedding of foreign particles in the punch
surface of a draw or flange die.
SNARD
Special Notification Anticipating Receipt of
Direction
SNORKEL
The extension of pipe for the air intake side of
the air cleaner. It enables clean air
to be taken in from on the top of the cab.
SNUB
A snub is a braking deceleration of a vehicle from
a higher reference speed to a lower reference speed that is greater than
zero It is a slowing of the vehicle by braking, but not a stop.
SNUBBER
A generic term which is commonly applied to
mechanisms which employ dry friction to produce damping of suspension systems.
SNUB-NOSE
Conventional style tractor with the engine
protruding into the cab in order to shorten overall length of the tractor.
SOAK-IN
An area on the shoulder or roadside saturated with
liquid debris either at the end of run off or as a puddle marking the rest
position of a vehicle after a collision.
SOFT TOP
Convertible.
SOFT TRIM
The soft or yielding portions of an interior; I.e.,
seats, door panels, carpets, head-lining, arm rest, padding, etc.
SOLENOID
An electromagnetic device that can be used to open
and close a circuit (like opening or closing a valve, or engaging the gear of a
motor).
SOLID INJECTION
Injection of solid fuel in diesel engines.
Solid State Floppy
Portable miniature computer disk with extraordinary Disk Card storage capacity (memory). See SSFDC. ( Detroit )
SOLO
Reference to single vehicle only.
SOMERSAULT
The kinematics of the impacted pedestrian where the
pedestrian is struck by the front of a vehicle and then tumbles to the ground
ahead of the vehicle.
SPADE LAY-OUT
Layout drawings or sketches from body engineering
at beginning of model year. (XPs)
SPATTER
The collection of marks on a road made by liquid
from a vehicle or its cargo squirted from containers on the vehicle by force of
collision. Spatter areas are irregular
n shape and often consist of many spots.
SPC
(Statistical Process Control) is the use of
statistical techniques such as control charges to analyze a process or its
output so as to take appropriate actions to achieve and maintain a state of
statistical control and to improve the capability of the process. Prevention
oriented.
SPECIFIC GRAVITY
Weight of given volume of substance compared to
that of an equal volume of water.
SPEED
(s): A scalar quantity equal to a distance
traversed divided by the time
required. s = d/t
SPEED CHANGE
The vector change in velocity of an object involved
in collision.
SPEEDOMETER
Instrument to indicate velocity.
Speeding A
The Speeding A condition is met when the vehicle is traveling between the Speeding A and the Speeding B values (default thresholds are 66 mph and 71 mph). ( Detroit )
Speeding B
The Speeding B condition is met when the vehicle is traveling above Speeding B (default threshold of 71 mph). ( Detroit )
Speeding Percent
MPH-A Speeding Time> MPH-A divided by Driving Time
MPH-B Speeding Time> MPH-B divided by Driving Time ( Detroit )
SPIDER
Spider-like casting or forging containing axle
differential or brake parts.
SPIDER ASSEMBLY
Usually refers to that portion of the floor pan
assembly consisting of rocker inner panels, crossbars and reinforcements minus
the floor pan.
SPIKE
A very sharp acceleration pulse on a graph of test
results.
SPIN AXIS
The axis of rotation of the wheel.
SPIN VELOCITY
The angular velocity of the wheel on which the tire
is mounted, about its spin axis.
SPINOUT
What happens when the maximum drive slip resistance
has been exceeded by its tractive effort and a sudden increase in driven wheel
speed occurs.
SPINOUT GRADE
See Traction-Limited Grade.
SPLICE BAR
See joint bar.
SPLINE
Series of parallel keys cut along the driveshaft
that mate with corresponding slots in hub or fitting.
SPLIT RATIO
Total reduction in next lower step of transmission.
SPLIT SERVICE BRAKE SYSTEM
A split service brake system is a hydraulic brake
system in which e master cylinder having two pistons supplies pressure to the
front and rear brakes through two independent hydraulic systems Thus, loss of pressure on the front brakes
does not cause loss of pressure on the rear brakes, and vice versa
SPLITTER
Mechanism that divides a gear into two or more
ratios such as direct, overdrive, or under drive.
SPM
(Statistical Process Management) is a term used to
describe a six phase approach using statistical and related methodology to
understand and control the variability of product quality.
SPOILER
A spoiler is an upturned ramp or wing-like device
mounted at the rear of a vehicle for the purpose of increasing rear wheel
traction, or decreasing drag, or both.
SPOKE WHEEL
A casting with 3,5, or 6 spokes that attaches to
the axle and provides a means of attaching a demountable rim to a vehicle. Also
called "Cast Spoke Wheel".
SPOT
To place a car in a designated position or specific
location, usually for loading or unloading, such as at a warehouse door.
SPOT FOR AIR
To position the cars in the yard so as to utilize a
central compressed air supply to charge the brake system.
SPOT SYSTEM
A system in which cars and locomotives under going
repairs are classified and then moved progressively from one spot to
another. At each spot different items
of work are done by a unit force.
SPOTTING
The fitting of one part of a die to another by
applying oil pigment to the surface of the finished part and bringing into
contact with the intended mating part, the high spots being marked by the transfer of pigment through
contact. High spots are removed until surface is finished to desired
smoothness.
SPOTTING (car)
The placing of a car where required to be
accessible for loading or unloading.
SPRAY-UP
The application of resin and roving with a spray
gun.
SPREAD TANDEM
A two axle assembly in which the axles are
separated by distances substantially greater than that in conventional
assemblies.
SPRING
Flexible or elastic member supporting sprung weight
of vehicle with recovering properties of returning to original shape when
released after being distorted.
SPRING BACK
Angular amount a metal returns toward its former
position after being bent a specified amount.
SPRING BRAKE
A device that consists of a conventional brake
chamber and an emergency or parking brake mechanism for use on vehicles
equipped with fir brakes. The service
brake chamber portion of the spring brake is identical to, and functions the
same as a brake chamber. The rear
portion of the spring brake, sometimes called the "piggyback," houses
a large and powerful spring and diaphragm, which under normal conditions, is
held in the released position (spring compressed) by air pressure. If air is exhausted from the spring cavity,
the spring expands, forcing the diaphragm, push plate, and rod forward,
applying the vehicle brakes. A
mechanical release bolt at the rear of the chamber is provided to mechanically
cage the spring and release the brakes, if necessary.
SPRING BRAKE CONTROL
Controls spring-loaded parking brakes.
SPRING CENTER
The vertical line along which a vertical load
applied to the sprung mass will produce only uniform vertical displacement.
SPRING CLIP
U-bolts anchoring spring to axle.
SPRING RATE
The change of load of a spring per unit deflection,
taken as a mean between loading and unloading at a specified load.
SPRING SEAT
Seat or support on which spring is anchored.
SPRING SWITCH
A switch equipped with a spring mechanism arranged
to restore the switch points to normal position after having been trailed
through.
SPRUNG MASS
Considered to be a rigid body having equal mass,
the same center of gravity, and the same moments of inertia about identical
axes as the total sprung weight.
SPRUNG WEIGHT
The sprung weight of a vehicle is the weight (or
mass) of the vehicle which is supported by the springs It normally consists of the body, frame,
engine and accessories (See Unsprung
Weight ).
SPUD
A tool about 2 to 21 feet long with a flat steel
chisel edge, used for heavy digging or clay removal.
SPUR GEAR
A gear having the teeth positioned straight across
the face of gear.
SPUR TRACK
A stub track extending out from a main or other
track.
SQA
(Supplier Quality Assurance/Assistance) Ford
prefers Supplier Quality Assistance. OEM activity primarily responsible for
contacts with outside suppliers on quality.
SQC
(Statistical Quality Control) is the measurement of
finished rather than in-process product using statistical methods. This method
of analysis is normally used on historic data to establish a base-line..
Detection oriented.
SQE
(Supplier Quality Engineering) OEM activity that
combines the SQA, supplier feasibility analysis and tooling liaison functions.
(Ford derived)
SQI
(Supplier Quality Improvement) design dates an
activity that works intensively on quality improvement with selected outside
suppliers during eh prototype and launch phases of new products. (Ford derived)
SQUARE PORTABLE GRID
A sturdy material rectangle which can be placed on
the road or other flat surface and included in the foreground of certain
photographs.
SQUIB
An electric igniter.
SREA
(Supplier Request For Engineering Approval) Ford
form number 1638 that producers use to obtain approval of design and process
change.
SRL
Scientific Research Lab
SRPC
(Supplier Request for Product Change) a method used
by the supplier to document requests
for engineering changes for minor dimensional or standard variations from
specifications. (Chrysler derived)
SSFDC
Solid State Floppy Disk Card (ProDriver Data Card) Stop Idle Stop Idle is collected when idle time has surpassed a certain preset value (default time is five minutes). It is often a measure of unnecessary idling. Stop Idle Percent Trip Stop Idle Time divided by Trip Time. ( Detroit )
STABILITY RATIO
The term is descriptive of the relative stability
of a vehicle. The higher the number,
the better the stability. The lower the
number, the lower the stability.
STABILIZED ACCIDENT SITUATION
The condition prevailing after motion and other
action constituting the events of an accident has ceased and no further harm
will ensue unless a new series of events is initiated by some means.
STABILIZER
Device used to stabilize vehicle during turns. Also called a sway bar.
STAKE BODY
Truck or trailer platform body with readily
removable stakes which may be joined by chains, slats, or panels.
STANDARD GAGE
A distance of 4' 8.5" between the heads of the
rails. See board gage, narrow gage and
gage of track.
STANDARD LOADS AND INFLATIONS
Those combinations of loads and inflations up to
the maximum load and inflation recommended by the Tire and Rim Association and
published in the yearly editions of the Tire and Rim Association Year Book.
STANDARD RADIAL
Tire with aspect ratio above 80 (75 for tiers using
North American standard designations), and usually in the 90s.
STARTER
An electric or air powered motor used to set the
crankshaft in motion in order to start the engine.
STATIC AMPLITUDE
Static amplitude in forced vibration at a point in
a system is that displacement of the point from its specified equilibrium
position which would be produced by a static force equal to the maximum value
of exciting force.
STATIC CRUSH
The deformation as measured on a vehicle after the
event has occurred. A Reconstructionist
would measure this damage on a subject vehicle in a salvage yard.
STATIC ELECTRICITY
An electrical charge produced by the gathering of
free electrons in one place. The
electrons remain at rest until they find a conductor that provides a path to an
opposing charge.
STATIC LOAD RADIUS
The loaded radius of a stationary tire inflated to
normal recommended pressure. NOTE: In general, static loaded radius is
different from the radius of slowly rolling tire. Static radius of a tire rolled into position may be different
from that of the tire loaded without being rolled.
STATIC MARGIN
The horizontal distance from the center of gravity
to the neutral steer line divided by the wheelbase. It is positive if the center of gravity is forward of the neutral
steer line.
STATIC RATE
Static rate of an elastic member is the rate
measured between successive stationary positions at which the member has
settled to substantially equilibrium condition.
STATIC TOE
(in (mm))
Static toe-in or toe-out of a pair of wheels, at a specified wheel load
or relative position of the wheel center with respect to the sprung mass, is
the difference in the transverse distances between the wheel planes taken at
the extreme rear and front points of the tire treads. When the distance at the rear is greater, the wheels are "toed-in"
by this amount; and where smaller, the wheels are "toed-out".
STATIC TOE ANGLE
(deg) The
static toe angle of a wheel, at a specified wheel load or relative position of
the wheel center with respect to the sprung mass, is the angle between a
longitudinal axis of the vehicle and the line of intersection of the wheel
plane and the road surface. The wheel
is "toed-in" if the forward portion of the wheel is turned toward a
central longitudinal axis of the vehicle, and "toed-out" if turned
away.
STATION LINE
A reference line along which measurements are made,
from predetermined reference points ( in a given direction) and from which
measurements are made at right angles ( in a given direction).
STEADY-STATE
Steady-state exists when periodic (or constant)
vehicle responses to periodic (or constant) control and/or disturbance inputs
do not change over an arbitrarily long time.
The motion responses in steady-state are referred to as steady-state
responses. This definition does not
require the vehicle to be operating in a straight line or on a level road
surface. It can also be in a turn of
constant radius or on a cambered road surface.
STEADY-STATE RESPONSE GAIN
The ratio of change in the steady-state response of
any motion variable with respect to change in input at a given trim.
STEADY-STATE VIBRATION
Steady-state vibration exists in a system if the
displacement at each point recurs for equal increments of time.
STEERING ANGLE
The angle of motion of the fork assembly about the
steering axis measured from a longitudinal axis of the frame point to the
direction that the front wheel is pointed while turning.
STEERING ARM
A steering arm is a lever, attached to the front
wheel Of a vehicle, which rotates the wheel about a vertical axis for the
purpose of controlling the direction of the vehicle The steering arm is actuated by a linkage element of the
steering system
STEERING AXLE
An axle through which directional control of the
vehicle is applied. A steering axle may
be powered or non-powered. A tractor
may have more than one steering axle.
STEERING COLUMN
The steering column is the structural housing that
surrounds a steering shaft
STEERING CONTROL SYSTEM
A steering control system is defined (FMVSS No 203) as the basic steering mechanism and its
associated trim hardware, including any portion of a steering column assembly
that provides energy absorption upon impact
STEERING DAMPER
A damping device which produces a torque about the
steer axis to reduce wobble.
STEERING GEAR RATIO
The steering gear ratio is the ratio of the sector
shaft output torque (that is the output of the Sears) to the steering wheel
input torque.
STEERING KNUCKLES
The steering knuckles are arms, connected rigidly
at one end to the front wheel spindle
and connected at the other end to the tie rods The steering knuckles are the end of the steering linkage
"chain," the steering -linkage comprising the drag link, the tie
rods, the idler arm, and the steering knuckles
STEERING LINKAGE
The steering linkage is defined as the assemblage
of connected parts and pivot joints between the steering Sear and the arm
attached to each of the front wheels
STEERING RESPONSE
The vehicle motion resulting from an input to the
steering (control) element.
STEERING SENSITIVITY
(control gain)
The change in steady-state lateral acceleration on a level road with
respect to change in steering wheel angle at a given trim and test conditions.
STEERING SHAFT
A steering shaft is the component of a steering
system that transmits steering torque from the steering wheel to the steering
STEERING WHEEL ANGLE
Angular displacement of the steering wheel measured
from the straight-ahead position (position corresponding to zero average steer
angle of a pair of steered wheels.)
STEERING WHEEL ANGLE GRADIENT
The rate of change in the steering wheel angle with
respect to change in steady-state lateral acceleration on a level road at a
given trim and test conditions.
STEERING WHEEL TORQUE
The torque applied to the steering wheel about its
axis of rotation.
STEERING WHEEL TORQUE GRADIENT
The rate of change in the steering wheel torque
with respect to change in steady-state lateral acceleration on a level road at
a given trim and test conditions.
STEERING, CENTER POINT
Front axle having kingpin perpendicular to the
ground line and intersecting centerline of it.
STEPOVER HEIGHT
The maximum height of the rocker, including trim
and moldings, in the door openings to ground.
STINGER
V-shaped configuration of rear frame rails to
accept tow bar or trailer coupling.
STIPPLES
Stipples are small mounds of projections of oil and
tar which are left by a rolling tire after it has passed through an oil spot on
the road.
STOCK CAR
A car for transportation of live stock, equipped
with slatted sides, single or double deck, and sometimes with feed and water
troughs.
STOP (ENGINE) AND EMERGENCY STOP
Some tractors are equipped with a starter button
and an "engine stop" switch.
The engine stop is used to shut off the engine. Some tractors are equipped with an
"emergency engine stop" switch to be used only when the engine starts
to "run away" (exceeding the safe upper RPM limits). Once the ever agency stop has been used, the
engine will not start again until a mechanic has mite repairs.
STOPPING DISTANCE
Stopping distance is the sum of the reaction
distance plus the distance the vehicle travels while the brakes are applied.
STORAGE TRACK
A track on which cars are placed when not in service.
STORED GAS INFLATOR
An ACRS inflator which contains high pressure gas
(i.e. argon).
STOVEPIPE VENTILATION
Front-end ventilation system with air entering the
passenger compartment through vertical ducts in bottom of plenum chamber.
STRAIGHT ACTING GUN
Describes a type of weld gun.
STRAIGHT FREE-ROLLING TIRE
A free-rolling tire moving in a straight line at
zero inclination angle and zero slip angle.
STRAIGHT TRUCK
A truck with the body and engine mounted on the
same chests. (As contrasted to a combination
unit such as tractor-trailer).
STRAIN
To effect a change in size or form by application
of external force.
STRATEGY
Adjusting speed, position on the road, and
direction of motion, giving signals of intent to turn or slow, or any action in
situations involving potential hazards; any maneuvers while on a trip which
increases the chance of success in avoiding an actual hazard.
STRESS
The forces exerted on, within, or by a body during
either tension or compression.
STRESS RELIEF
A process involving heat treatment for the purpose
of reducing internal residual stresses in a metal.
STRIATION MARK
Narrow, light, parallel stripes or streaks usually
made by friction or abrasion on the roadway or vehicle parts.
STRING
(slang) Two more freight cars coupled together, as
a string of cars.
STROKE
The distance traveled by the piston from top dead
center to bottom dead center of crankshaft.
STUB PILLAR
Rear-door hinge pillar concealed behind and below
beltline on four-door hardtops; a pillar that extends only from the rocker
panel to the beltline.
STUB TRACK
A track connected at one end only.
STUD MOUNT WHEELS
Wheels that are designed to center on the studs of
a hub. These wheels have chamfers at the bolt holes into which a ball seat or
conical nut is installed to center the wheel. The center bore of the wheel is
only for clearance of the axle end.
STUD WELDER
Type of weld gun to weld studs automatically to
outer panel to retain moldings and glass.
SUBMARINING
Movement of the occupant forward and under the
restraining device during vehicle impact.
SUGAR SCOOP
A depressed surface leading to an air scoop.
SUPER ELEVATION
The degree to which the outside edge of a roadway
is higher than the inside edge at a specified point on a curve; the change in
elevation per unit distance across the roadway from inside to outside edge;
bank.
SUPERCHARGER
A type of blower, connected to the engine
crank-shaft, that forces air into the intake manifold at higher than
atmospheric pressure to increase engine power and performance. See blower.
SUPERIOR TRAIN
A train having precedence over another train.
SUPPLY LINES (FUEL)
The lines that carry a supply of fuel to each
injector. Fuel enters the inlet
connection and then the injectors.
SURFACE PLATE
A flat cast-iron plate with five-inch grid lines,
inscribed; used as a base to take all dimensions.
SURPANEL
An extra panel adjoining a main panel, as in the
sheet metal under the grille and between the front fenders.
SUSPENSION
Attaching parts including springs for securing axle
or axles to chassis frame.
SUSPENSION RATE
(wheel rate)
The change of wheel load, at the center of tire contact, per unit
vertical displacement of the sprung mass relative to the wheel at a specified
load. If the wheel camber varies, the displacement should be measured relative
to the lowest point on the rim centerline.
SUSPENSION ROLL
The rotation of the vehicle sprung mass about the
x-axis with respect to a transverse axis joining a pair of wheel centers.
SUSPENSION ROLL ANGLE
The angular displacement produced by suspension
roll.
SUSPENSION ROLL GRADIENT
The rate of change in the suspension roll angle
with respect to change in steady-state lateral acceleration on a level road at
a given trim and test conditions.
SUSPENSION ROLL STIFFNESS
The rate of change in the restoring couple exerted
by the suspension of a pair of wheels on the sprung mass of the vehicle with
respect to change in suspension roll angle.
SUSPENSION SYSTEM
The term suspension system of a vehicle usually
refers to some type of spring arrangement plus a damping arrangement in the
form of a shock absorber, along with their support elements. However, the term can also include all of
the components which so to make up the Unsprung weight.
SWEEP
A plastic, metal or wood guide used in drawing an
irregular or flowing contour.
SWERVE
A slight deviation from a straight ahead path.
SWING
1) The degree to which the upper and lower edges of
the film in a camera deviate from horizontal when a photograph is made. Swing should be avoided in traffic accident
photography because it may misrepresent grades and elevations. 2) Brakeman in the middle of a freight train
in charge of setting out cars and braking between the sections of the train
handled by head and rear brakemen.
SWING ARM
A rear fork with a rear wheel attached, which
pivots vertically at the point where it is connected to the frame and whose
travel is controlled by one or two springs and shock absorbers.
SWING CENTER
That instantaneous center in the transverse
vertical plane through any pair of wheel centers about which the wheel moves
relative to the sprung mass.
SWING-ARM RADIUS
The horizontal distance from the swing center to
the center of tire contact.
SWINGING MEAT
Sides of slaughtered beef, pork, lamb, etc. that
are suspended from special racks in a refrigerated trailer.
SWITCH
1) A connection between 2 lines of track to permit
cars or trains to pass from one track to the other track. 2) To move cars from
one place to another within a definite territory such as an industry, a yard,
or a terminal.
SWITCH BACK
Track constructed in a series of zig zag curves in
mountainous terrain to reduce rate of climb or decent.
SWITCH ENGINE
A locomotive used for switching cars in yards and
terminals. Sometimes termed
switcher. Usually built to carry all
its weight on the driving wheels.
SWITCH LOCK
A fastener, usually a spring pad lock, used to
secure the switch or derail stand in place.
SWITCH STAND
A device by which a switch is thrown, locked, and
its position indicated. It consist
essentially of a base, spindle, lever and connecting rod, as is usually
furnished with a lamp and a banner signal.
SWITCH TARGET
A visual day signal fixed on the spindle of a
switch stand, or the circular flaring collar fitted around the switch-lamp
lens, and painted a distinctive color to indicate the position of the switch.
SYNCHRO-MESH
A synchronizing mechanism to slow down the faster
gear, so that engagement of the sifting mechanism can be made quickly and
noiselessly without double clutching.
SYNCHRONIZE
Two or more events or operations occurring at the
proper sequence in relation to each other.
SYSTEMS INTEGRATOR
Supplier who "packages" separate
components to sell to automotive manufacturers, i.e., instrument panel cluster,
interior packages.
References
Detroit Diesel
Caterpillar User's Manual