(a)   Description. An off-street loading berth shall be a hard-surfaced area of land, open or enclosed, other than a street or a public way, used principally for the standing, loading or unloading of motor trucks, tractors and trailers so as to avoid undue interference with the public use of streets and alleys. A required loading space shall not be less than ten feet in width, forty-five feet in length and fourteen feet in height, exclusive of access aisles and maneuvering space, except as otherwise specifically dimensioned in this section.
   (b)   Location. No permitted or required loading berth shall be closer than fifty feet from any property in a Residential District unless completely enclosed by building walls, or a uniformly painted solid fence or wall, or a combination thereof, not less than six feet in height. No permitted or required loading berth shall be located within twenty-five feet of the nearest point of intersection of two streets. Loading berths open to the sky may be located in required yards.
   (c)   Measurement. When determination of the number of required off-street loading berths results in a requirement of a fractional berth, any fraction up to and including one-half shall be disregarded, and fractions over one-half shall be interpreted as one loading berth.
   (d)   Surfacing. All open off-street loading berths shall be improved with a compacted macadam base, not less than seven inches thick, surfaced with not less than two inches of asphaltic concrete or some comparable construction material.