- sheerstrake
- shipper
- shipping bill
- shipping charges
- shipping lane
- shipping line
- shipping note
- shipping port
- shipping terms
- shipping ton
- shipwreck
- shipwrecked
- shoal
- shock recorder
- shop track
- shoulder cleaning
- shroud
- shuttle service
- shuttle traffic
- side construction
- side sill
- shore leave
- shore up
- shoreward
- Short Tie
- shoulder
- shoulder wing
- shroud ring
- shunter lamp
- shunting
- shunting cost
- shunting locomotive
- shunting yard
- shutter train
- side wall
- sidebearer centre
- sidewalk
- sidewipe
- single ticket
- single-hull
- single-lane
- sink hole
- sinkage
- sidebearer clearance
- sight bill
- sighting distance
- signal book
- signal locker
- signal regulation
- signal station
- signal tower
- silicon rectifier
- silicone compound
- siren
- skeg
- skeleton container
- skew
- skew crossing
- slab track
- sleeper screwdriver
- sliding door
- sliding speed
- sliding window
- slipperiness
- slipstream
- slope height
- slope stabilization
- sluicegate
- smoke gas
- smooth
- skid mark
- skin
- skyjack
- skylight
- sleep
- sleeping car
- slide rail
- sliding body
- snaking
- snap ring
- social insurance
- slamming
- sleeper lifter
- sleeper screw
- sleeper spacing
- sleeper weight
- sling
- slip detector
- slipway
- sliver
- sloop
- slowing down
- smokebox
- sliding wheel
- slot flap
- slow board
- slow down
- slow order
- snow detector
- snowplow