A full-size concert harp stands over six feet tall, weighs 80 to 90 pounds concentrated along a single curved column, and is genuinely top-heavy in a way that makes casual tipping dangerous to both the instrument and whoever is holding it. A dedicated harp cart and real care around the column are non-negotiable.
Pro tip: If you are hiring specialty harp movers, ask whether they have moved your specific harp maker's model before; column shape and pedal mechanisms vary enough between makers to matter.
Watch out: Never let a full-size harp rest its weight on the soundboard side during a tilt or move; the soundboard is a thin, curved panel not designed to bear the instrument's own weight from that angle.