- streetcar stop
- streetcar tracks
- stress expansion
- stretched aircraft
- strike colors
- striking horn
- string
- strut angle
- stuff
- submarine
- submarine tanker
- subsonic aircraft
- suburban railway
- subway
- succession
- sunk cost
- superconducting coil
- stringer
- stringer angle
- stringer rail
- strip
- structural defect
- suburban traffic
- suffer shipwreck
- stuck joint
- submerged speed
- substandard ship
- subterranean crossing
- suburban train
- stub shaft
- submarine pen
- sun buckle
- superheating coil
- supersonic aircraft
- superstructure
- supplemental brake
- supply reservoir
- supply vessel
- support vessel
- supported monorail
- supporting rack
- supporting rail
- surface
- surface current
- surface flaw
- surface float
- surface irregularity
- surface slip
- surface speed
- surfacing
- surfacing lift
- surge
- supercavitating propeller
- superelevated switch
- superhighway
- survey rod
- surveying
- surveying method
- surveying technique
- surveyor
- suspended monorail
- suspended system
- suspension
- suspension bracket
- suspension hanger
- swash
- sway stabilization
- sweat
- swede car
- sweep angle
- swell
- swept wing
- swing hanger
- switch
- switch adjustment
- switch box
- switch bolt
- switch crank
- switch lamp
- switch lever
- switch parameter
- switch plate
- switch protector
- switch rod
- switch section
- switch sleeper
- switch stand
- switch stroke
- switching
- tail disk
- tail heaviness
- tail rotor
- tailback
- takeoff ability
- takeoff funnel
- tamping machine
- tanker lorry
- swivel
- swivel hook
- synchronized lights