English has no literal word-to-word equivalent to this - this french "à" is used to describe the main property of a noun, and the translation in English when no original word exists is via a nominal group or a concatenation of nouns. An "avion à hélice" is a propeller plane, a "bateau à vapeur" is a steamboat, or an "étui à lunettes" is a glasses case. So a "train à grande vitesse" is similarly just a high-speed train.
"of" in English here sounds like you're describing what the object is made of instead of its property. A "boat of steam" is made of steam, it's not the same as a steam boat.
"of" in English here sounds like you're describing what the object is made of instead of its property. A "boat of steam" is made of steam, it's not the same as a steam boat.