other property
(4) Plant or other property. As used in subparagraph (2) of this paragraph, the phrase plant or other property means any tangible property whether or not such property is used in the trade or business or held for the production of income. Such term includes, for example, a papermill, a motor vehicle, or a furnace in an apartment house. (5) In operation before January 1, 1969. (i) For purposes of subparagraph (2) of this paragraph and section 169 (d), a plant or other property will be considered to be in operation before January 1, 1969, if prior to that date such plant or other property was actually performing the function for which it was constructed or acquired. For example, a papermill which is completed in July 1968, but which is not actually used to produce paper until 1969 would not be considered to be in operation before January 1, 1969. The fact that such plant or other property was only operating at partial capacity prior to January 1, 1969, or was being used as a standby facility prior to such date, shall not prevent its being considered to be in operation before such date. (ii)(a) A piece of machinery which replaces one which was in operation prior to January 1, 1969, and which was a part of the manufacturing operation carried on by the plant but which does not substantially increase the capacity of the plant will be considered to be in operation prior to January 1, 1969. However, an additional machine that is added to a plant which was in operation before January 1, 1969, and which represents a substantial increase in the plant's capacity will not be considered to have been in operation before such date. There shall be deemed to be a substantial increase in the capacity of a plant or other property as of the time its capacity exceeds by more than 20 percent its capacity on December 31, 1968.