Saturday, July 16, 2011

Stone or Cast Iron?

Interior View of main Collapse looking North toward Cedar Street, showing Debris on top of Safe Deposit Vaults. The floors above the Security Vault of the Equitable Life Association Society are shown standing in left of picture. From: REPORT ON FIRE IN THE EQUITABLE BUILDING,

All exterior walls were standing after the fire. On the Cedar Street side near Broadway the top of the wall has apparently fallen. This section, however, was built of metal to imitate stone and cannot properly be considered part of the wall. At this point the wall is out of plumb, due to the weakness of the hollow backing and the falling of the floors. The bricks on the inside of this wall are somewhat spalled and the floor beams in falling tore out large sections of the brick work. (See Plate No. 18.) Elsewhere the exterior walls appear to be in good condition. From: REPORT ON FIRE IN THE EQUITABLE BUILDING,

Although the two views depicted above were taken at different points in time during the cleanup process, in what appears to be the earlier of the two, given the amount of roof debris present, the decorative exterior cornice on which sit the remnants of a dormer surround is lacking. Instead we see what looks like cast iron structural supports poking up out of an internal covering of brick and masonry.
Plate 18. Cedar Street Wall, corner of Broadway—Inside View Showing Pipe Channels.

The brick backing to the walls on Pine Street and two-thirds of the Broadway side was solid. On the Cedar Street side of the building and the remainder of the Broadway wall, the brick backing was hollow, containing large pipe shafts, making a weaker wall at these points. (See Plate No. 18.) When the height of the original building was increased the Cedar Street wall was so weak that hollow metal ornamentation had to be used at the top to imitate the masonry used elsewhere. From: REPORT ON FIRE IN THE EQUITABLE BUILDING,

Although the Underwriters' Report sees things differently, in the pier on the right, I also see a vertical structural member, probably cast iron in this earlier remodeled section. This indicates that the Equitable Building was fundamentally a cast-iron fronted building typical of its time and style.

All of the exterior ornament therefore is made of cast iron. However, the Underwriters' report says
The fronts of the building facing on Cedar, Broadway, Pine and Nassau Streets, consisted of massive brick and stone walls, the brick being 40 to 16 inches thick, faced with granite ashlar 8 to 2 0 inches thick. The walls were part bearing and part self-supporting but non-bearing. On the Broadway side ornamental granite columns supported heavy ledges at the levels of the 2d, 3d, 5th and 6th floors; partly projecting columns performed a similar function on Cedar, Pine and Nassau Streets. From: REPORT ON FIRE IN THE EQUITABLE BUILDING,
Ashlar is prepared (or "dressed") stone work. A stone "curtain wall" is cladding supported by an anchoring system and used to protect a building from the elements. Apparently, since the Equitable Building is described in contemporary accounts as being made of stone, its likely that at least the ground floor was faced with granite--certainly on the primary facade facing Broadway.

The Equitable looks very similar to the Gilsey House Hotel at Broadway and 29th Street, in New York City, which opened in 1872, shortly after the first Equitable Building was completed. The Gilsey is a proud example of cast-iron architecture, without an ounce of granite to her name.

There are many references in the record of the firefighting at the Equitable Building on January 9, 1912 to the fact of falling stone work. The Chief of the FDNY operation published a book in 1913, barely a year afterward, and here is some of what he said about granite:
Followed by my aides I returned to Pine Street, where I found that the granite trimmings on the dormer windows of the upper floors were beginning to fly. This told me at once of the intense heat which must be surrounding the unprotected iron columns of which mention has been made, and, in consequence, I ordered all companies to back down and out of the building.

Great masses of granite from its walls were being tossed high in the air like thistledown and exploding a hundred feet above our heads from the intense heat, their fragments falling in meteoric showers about us. A great section of the outer wall burst near the corner of Pine
Street and Broadway, and a piece of stone weighing several tons fell near Mr. Robert Mainzer, with whom I had been speaking, missing him by only a few inches.
From:Fires and Fire-Fighters - A History of Modern Fire-Fighting with a Review of Its Development from Earliest Times By John Kenlon

No comments: