The floating steel-and-concrete jetties and pontoons, hauled across the English Channel, were the only way of unloading tanks and heavy artillery on a coastline (Gold Beach) without natural harbors.
Gold Beach is a coastline which has many natural harbors.
mnli hypothesis: Gold Beach is a coastline which has many natural harbors. premise: The floating steel-and-concrete jetties and pontoons, hauled across the English Channel, were the only way of unloading tanks and heavy artillery on a coastline (Gold Beach) without natural harbors.