Complex sentence: A semicircular duct along the top of the dorsal spine of the fuselage, extending from the rear of the cockpit enclosure to the vertical fin carries electrical and fluid lines around the engine compartment.
Split into simpler sentences: A semicircular duct ran along the top of the dorsal spine of the fuselage, extending from the rear of the cockpit enclosure to the vertical fin. This duct is used to carry electrical and fluid lines around the engine compartment.