CHAPTER 3: EIFFEL AND BUFFINGTON USE IRON TO RESIST THE WIND

Imagine it’s March 1888, and you are either John Root trying to crank out the punchlist to finish the Rookery (while his 13-story Monadnock Block had been sitting in hybernation), or that you are Louis Sullivan feverishly trying to complete the interior of the Auditorium’s hall by June 1. You open the latest issue of Northwestern Architect and, to your utter amazement, there is an article detailing a proposal to erect a 28-story, 350′ high ‘‘Cloudscraper’’ designed by Minneapolis’ LeRoy Buffington. At this moment, the 12-storied Washington Building at 258′ was the tallest building in New York, and the Maller Building stood at twelve stories in Chicago (with the Rookery’s eleven stories nearing completion). How would you react?

LeRoy S. Buffington, 28-story Cloudscraper, Minneapolis, 1888. (*Inland Architect*, July 1888)

3.1. LEROY BUFFINGTON’S 28-STORY ‘CLOUDSCRAPER’

Buffington’s ‘‘Cloudscraper’’ contained more than twice the number of floors in any American building! He was able to design such a tall building because he had developed a system of iron framing that enabled the erection of buildings to almost unlimited heights, for which he was granted a patent two months later on May 22, 1888. News of the patent and the rendering of the ‘Cloudscraper’ had to have greeted Chicago’s architectural community like a cold shower when it was first published in the July 1888 issue of Inland Architect. Buffington had finally succeeded in giving physical form to James Bogardus’ claim in 1856 that with the iron skeleton frame, it was possible “to erect a tower or building many times the height of any other edifice in the world.”

LeRoy S. Buffington, Patent for Iron Building Construction, May 22,1888. (Online)

3.2. A REVIEW OF MULTISTORIED IRON-FRAMED CONSTRUCTION

Although George Post would soon prove that masonry bearing walls could be used to erect skyscrapers to heights over 300’ (i.e., the 309’ high Pulitzer/New York World Building completed in 1890: note that the 215’ tall Monadnock Block WAS NOT THE TALLEST BEARING WALL STRUCTURE), the immense thickness of these walls ate up valuable rental area and reduced the amount of daylight penetrating into a building’s interior. The weight of these thick walls posed a special problem in Chicago, as we have seen, simply because the strength of its soil wasn’t sufficient to support such pressure without excessive settlement. While American architects and engineers had been using iron framing in the interiors of multistoried buildings for decades, these had always relied upon the rigidity of the masonry exterior walls to stabilize the building against lateral wind loads (i.e., “box” construction). In addition, the masonry exteriors provided a fireproof construction. In order to erect a building solely with an iron frame (i.e., “frame” construction) meant that the function these walls had provided (i.e., lateral stability and fire resistance) would have to be provided in a different manner.

James Bogardus, McCullough Shot Tower, New York, 1855. (Silver, *Lost New York*)

James Bogardus was the first to erect such an iron-framed tower with the McCullough Shot Tower in 1856, in which he had supported 12” brick panels on each story of iron beams. His bolted connection of the beams to the columns, in combination with the rigidity provided of the brick walls at the intersection of the columns and beams was sufficient to ensure the tower’s stability. Bogardus had claimed that his cast iron structures were fireproof. Unfortunately, as the 1871 Chicago fire had proved, Bogardus’ cast iron was not fireproof has he had stated, and the iron frame was forced back into its masonry protective coating. Peter Wight had eventually solved this problem, following the 1874 Chicago fire with his terra cotta tile fireproofing casings. As I have documented, George Post was first to detail the exterior walls in the lightcourts of the Equitable Building and Produce Exchange in New York as an iron frame upon which he supported the enclosure’s masonry exterior panels at each level. John Root had followed Post’s precedents a few years later in the Phoenix Building and Rookery. The final problem facing builders who wanted to completely free the iron frame from its masonry bondage in 1888 was how to make the iron frame sufficiently rigid to resist wind loads. As I will describe, Buffington employed a combination of rigid connections at the beam/column intersections and diagonal bracing.

3.3. BUFFINGTON PREPARES HIS PATENT APPLICATION

In Chapter 1, we had seen that Buffington had become the Twin Cities’ leading architect during the first half of the 1880s. By 1885, his office staff had grown to over 30, and it was responsible for buildings from New Hampshire to Wyoming, and from Kentucky to Canada. In addition to the major buildings in the Twin Cities area, including the Minnesota State Capitol, he had also designed the state Capitols for North Dakota and West Virginia. A reporter from the Chicago Times probably summed it up best in 1884, stating that:

“the one architect who more than any other has stamped the impress of his artistic personality upon the finest and most costly structures…[and that] his own abilities… have pushed him to the front in the wild race of competition which is characteristic of the great Northwest, particularly so in Minneapolis, the city whose fortunes and those of a few of her enterprising, hard working citizens, of which number Mr. Buffington is one, are so inseparably connected.”

But following the completion of the lavish West Hotel, potential clients had the perception that Buffington had expensive tastes and commercial developers tended to shy away from him. Hence, the skyscrapers in the Twin Cities constructed in 1885 and 1886 were designed by architects other than Buffington. This initially had little impact on his practice, as he had aligned himself over the years with the rich and powerful in the area and was kept busy designing mansions for these folks during the second half of the 1880s. As we have seen in his Boston Block and the West Hotel, Buffington had always shown a keen and informed interest in using iron framing and Wight’s fireproofing systems, but why and how he developed his patent for iron-framed skyscrapers has always been shrouded in mystery and litigation.

In the years that followed his patent, Buffington would state that he had initially been inspired to develop his system while reading the second volume of Eugène-Emmanuel Viollet-le-Duc’s Discourses on Architecture. While the second volume had been published in France in 1872, following the end of the Franco-Prussian War, although Henry Van Brunt had published the first English translation of the first volume in 1876, the first English translation of Volume II wasn’t published in the U.S. until late 1881. Buffington credited these lines from Volume Two as his inspiration:

“A practical architect might not unnaturally conceive the idea of erecting a vast edifice whose frame should be entirely of iron, and clothing that frame, preserving it by means of a casing of stone…But it cannot be too often repeated, Iron should be left independent. It cannot be allied to masonry.”

The first reports in 1888 of Buffington’s proposal had stressed the uniqueness of the building’s patented construction and described it in detail for those who could not travel to Washington to view the patent drawings:

“It consists of a continuous skeleton of iron, commencing on the iron footings and continuing of iron and steel to the full height. The framework consists of a series of continuous laminated, riveted iron posts, diminishing in size as they ascend; braced diagonally, after the manner of lattice bridge girders, and horizontally braced by the iron beams of each floor, which form an integral portion of the building…[an] important consideration in the iron construction is the reduced thickness of the walls, as those on the exterior of the building do not in any part exceed 22 inches, thereby giving more light and air to the offices… The exterior is formed of stone and copper. The stone is carried at each story, of oftener when necessary, by means of horizontal shelves of iron – the shelves themselves being hidden by the stone.”

Buffington’s patented system incorporated continuous columns that were built-up by riveting together (also known at the time as “laminated”) plates of wrought iron that overlapped the joints of adjacent plates. These would be assembled into a rigid rectilinear grid by iron C-section spandrel beams that were riveted to the columns via iron angles. This created a rigid connection, and thereby, imparted a stiffness to the frame that would be needed to resist the pressure of the wind, if the exterior masonry wall’s structural stiffness was to be eliminated. Wrought iron floor girders sat on these spandrels and were also riveted to the face of the columns.

Similar to Root’s earlier detailing in the lightcourts in the Phoenix and Rookery, Buffington detailed an iron lintel at the exterior face of each column, at each floor, providing a ledge upon which the building’s lightweight exterior enclosure of masonry and windows could be constructed. With the exception of the solid section, built-up columns that had never been used in an American building by 1888, Buffington’s system had simply utilized the best contemporary details in use. The one significant improvement he had made in construction technology was his use of diagonal bracing, one of earliest in an iron-framed skyscraper to increase the frame’s resistance to wind loads. He had specified double-diagonal bracing per each floor, in the form of thin iron plates that were riveted to the columns and to each other where they crossed.