cog railway vs rack railway

cog railway and rack railway both are nouns.

Word	Noun	Adjective	Verb	Adverb
cog railway	Yes	No	No	No
rack railway	Yes	No	No	No

As nouns, cog railway and rack railway are synonyms defined as:

cog railway and rack railway: railway for steep mountains; a cogwheel on the locomotive engages cogs on a center rail to provide traction

cog railway (noun)	rack railway (noun)
railway for steep mountains; a cogwheel on the locomotive engages cogs on a center rail to provide traction	railway for steep mountains; a cogwheel on the locomotive engages cogs on a center rail to provide traction