Fig. 179.—Form Used by Mr. Hennebique for Rectangular Columns.
Fig. 180.—Form for Rectangular Column for a Factory Building, New York City.
The form shown by Fig. 180 is an extreme example of nailed construction throughout, no yokes or clamps being used. It was used in constructing a factory building in New York City. Horizontal lagging nailed to vertical studs was used for all four sides; three sides were built up full height and the fourth side was placed a board at a time as concreting progressed. This form required 7⅓ ft. B. M. of lumber per foot length of 12-in. column, which is probably about as low in lumber as column form construction can be got. The labor of tearing down and re-erecting the form would be high as also would the waste of lumber. Nailed forms of this type are rarely used.
Fig. 181.—Form for T-Section Wall Column.
Fig. 182.—Form for Corner Wall Column.
The form shown by Fig. 181 was used for molding T-section wall columns for a power station. It is noteworthy for its section; because of the provision for molding grooves in the two sides to which the curtain walls join, and because of the manner in which three of the eight sides were built up as the concreting progressed. The sides a b c, d e and f g h were erected in full column units and the sides c d, e f and h a were erected in sections 2 ft. high as concreting progressed. The yokes were spaced 2 ft. apart. Using 1¼-in. stuff for yokes and lagging this form as built required about 16 ft. B. M. per foot length of column. Except for the beveling of the mold for the curtain wall recesses, the framing is all plain saw and hammer work.