trans-Alaska pipeline vs Trans-Alaska Pipeline System

trans-Alaska pipeline and Trans-Alaska Pipeline System both are nouns.

Word	Noun	Adjective	Verb	Adverb
trans-Alaska pipeline	Yes	No	No	No
Trans-Alaska Pipeline System	Yes	No	No	No

As nouns, trans-Alaska pipeline and Trans-Alaska Pipeline System are synonyms defined as:

trans-Alaska pipeline and Trans-Alaska Pipeline System: an oil pipeline that runs 800 miles from wells at Prudhoe Bay to the port of Valdez

Other synonyms of trans-Alaska pipeline include Alaskan pipeline.

trans-Alaska pipeline (noun)	Trans-Alaska Pipeline System (noun)
an oil pipeline that runs 800 miles from wells at Prudhoe Bay to the port of Valdez	an oil pipeline that runs 800 miles from wells at Prudhoe Bay to the port of Valdez