Here's the quote:
The teaching of Sauron has led to the invention of ships of metal that traverse the seas without sails, but which are hideous in the eyes of those who have not abandoned or forgotten Tol-eressea. — The Lost Road
This appears to be an indirect quote. I don't know whether the original is available. Did Christopher further commented on this anywhere else? Like, what did he think it's implying?
It's mentioned in later texts that Númenóreans devised engines, but it's likely they were only cunning mechanical devices/weapons, as in "siege engines".
For with the aid of Zigûr they multiplied their wealth and they devised many engines, and they built ever greater ships. — Sauron Defeated, DA II
The same narrative doesn't mention self-propelled ships at all when they are needed.
Then Ar-Pharazôn hardened his heart, and he went aboard his mighty ship, Aglarrâma, Castle of the Sea. Many-oared it was and many-masted... there was little wind, but they had many oars and many strong slaves to row beneath the lash. — ibid.