The state of New Jersey sought to tax as real property cranes used in the loading and unloading of ships designed to carry freight in containers. These large cranes were mounted and movable on tracks at the pier. Each crane weighed one million pounds and required special concrete piles for the base of the piers. Each crane was 50 feet wide and stood 170 feet above the rail. The boom could be raised to 245 feet. Complex electrical systems were required for operation of the cranes. Were the cranes fixtures and thus taxable as part of the real estate? Explain.