02 The Empire State Building

21 months from title to the site, 18 months from first sketches,  6 months from first steel to 86th floor steel complete.  11 months from first steel to 102 story equivalent building complete and ready for tenants.   How’d they do it?  Should all projects go this fast?

 

How Diseconomies of Scale introduce us to Stochastic Analysis

Let me start with another illustrative short story.  Company PC was undertaking what we call a mega-project, one big enough to get into what we call dis-economies of scale.  We are talking $12 billion or so; a 10,000 person peak workforce.

Economies of scale are well understood: cost per unit go down as you get bigger due to efficiencies that can be designed in at size.  But there are also diseconomies of scale as you get too big.  I worked on a large oil sands project where the project manager invented a novel way to solve this. He called it: er… Silo Management!

His thinking went thus.  Let’s break this project down into 7 smaller projects.  And ignore all of the work needed to coordinate them, or at least make this coordination a separate silo which does not interfere with individual silo schedules.  Then the elapsed schedule should just be the longest duration of each of the individual silos. A much shorter schedule.

My rough, first pass analysis of the schedule was for 44 months, based on the number of total construction manhours  against Jamie Bent’s data, among other empirical analyses.  The PM’s response: they built the Empire State Building in 13 (sic) months!  Certainly we can do better than 44.

Sam Savage could have helped me, had I known of his work back then.

Let’s start off with a simple everyday example in which most people’s intellects fail. Imagine that you and your spouse have an invitation to a ritzy reception with a bunch of VIPs. You must leave home by 6 p.m. or risk being late. Although you work in different parts of town, each of your average commute times is 30 minutes. So if you both depart work at 5:30, then you should have at least a 50/50 chance of leaving home together for the reception by 6 o’clock. This thinking sounds right. But your instinct warns that you will probably be late. Which is correct: your brain or your gut?

Your gut is correct, but not being particularly good with words, it may have difficulty winning the argument intellectually. So here, in terms that even a brain can understand, is why you’ll probably be late. Suppose there really is a 50/50 chance that each of you will make it home by 6:00. Then the trip is like a coin toss in which heads is equivalent to arriving by 6:00 and tails to arriving after 6:00. Four things can happen: • Heads/tails: You are home by 6:00 but your spouse isn’t. • Tails/heads: Your spouse is home by 6:00 but you aren’t. • Tails/tails: Neither of you is home by 6:00. • Heads/heads: Both of you are home by 6:00. The only way you can leave by 6:00 is if you flip two heads, for which there is only one chance in four. Now imagine that your brother, who also works 30 minutes away, is going to join you. The chance of your all leaving on time now drops to one in eight. Or suppose you, your spouse, and five friends and relations all plan to pile into your minivan for the trip to the reception. Assuming that everyone leaves work at 5:30 and has a different 30-minute route to your house, then the chance of leaving on time is the same as flipping 7 heads in a row; that’s 0.5 raised to the 7th power, or 1 in 128. No wonder people are always late! (1)

So, the PM might have been right 1 in 128 chances.  Not solid.  My 44 months would probably have been pretty close, but has yet to be tested (the PC Company sold out to Suncor, who I suspect will eventually execute this project, likely close to my schedule).

 

The Empire State Building

 

The Issue:  How did they build it so fast?  What can we learn?

 

Bold Decisions:

Design:

The Empire State was built towards the tail of the golden age of skyscrapers.  Maybe Chicago was first, but Manhattan had quickly caught up.  The Building Contractor had recently finished a seventy story building in 11 months.  Basic design parameters were well understood, the bold step was in how to design efficiently and to choreograph the trades – this was where constructability and construction sequencing became integral with design.

Construction Sequencing (Constructability):

Team design.  With a concrete goal.  At the time, all commercial leases expired and were renewed on May 1 of each year.  Hence the timing so as not to lose 12 months of rent and save $10,000 per day of financing fees was for a May 1 completion (April 9, achieved).  Many give lip service to team design but it was achieved here.  And all this possible because the managing contractor had a well thought out, detailed floor by floor framework from which each craft and trade could plug in.  And by engaging material suppliers, fabricators and subcontractors in design, also had their buy in to responsibility in erection.

Materials:

Not since the time of Sneferu has such been seen!  A single foundry for all of the steel, two fabricators, both subsidiaries of US Steel made the shapes, tagged each by floor and location and sent to a marshalling yard across the Hudson in Bayonne, NJ from which the pieces were litered across the river by ship and trucked to the building site on the day each piece was to be erected. Likewise for the 67 elevators, the 10 million bricks, the 6,400 windows, the miles of electrical cable and plumbing pipes, the limestone facing blocks, etc.  At peak there would be 500 trucks making deliveries a day!  And internal (safer and more weather resistant than external!) cranes and  lifts, even miniature train-type tracks on each floor.  Clever.

People:

A small thing, but typical on this job: the builders selected from among several bidders a top restaurant chain to do catering at reduced prices, making sodas and sandwiches, etc available on the several working floors each day.  There is not a lot of documentation explaining the training and abilities of each craft, but the builders typically selected two companies for each craft, and possibly awarded additional work between the two based on performance.  I’m speculating on that.  A 3,500 peak workforce: manageable.  And let us not neglect the motivating force of participating in one of the world’s preeminent construction endeavors.  But mostly, if not a “great man”, a “great team” with overall coordination and synchronization responsibility- a small group with a vision of the overall building, competent and decisive even at the level of details and specifics.

 

Resolution:

“This incredible schedule could be kept for two key reasons: a team-design approach that involved the collaboration of the architects, owners, builders, and engineers in planning and problem-solving, and the organizational genius of the general contractors. (2)

 

Overview:

 

I am indebted to a book which includes 77 pages of  notes from the original construction, “Building the Empire State: a rediscovered 1930s notebook charts the construction of the Empire State Building” edited by Carol Willis, W. W. Norton & Co. New York London in association with the skyscraper Museum copyright 1998 by the skyscraper Museum

A book worthy of purchase!  Excerpts below:

Reproduced here for the first time, notes on construction of Empire State building was compiled and the offices of Starrett Brothers and Eken the general contractor for the Empire State building, probably in late 1930 in 1931. The notebook seems to have been intended simply as an in-house project – even a labor of love – by someone or several people in the company.

The Empire State building is New York signature skyscraper. The tallest building in the world was completed in April 1931, the Empire State broke every record in the book. At 1252 feet, is surpassed the Chrysler building’s quirky crown by 200 and the spire of the Manhattan Company building at 40 Wall Street, the tallest 1930 in more than 300 feet. Gargantuan in scale, it boasted  2,100,000 ft.² of rentable space, compared to the 850,000 ft.² of the Chrysler building. The most astonishing statistic of the Empire State, though, with extraordinary speed with which it was planned and constructed.

There are different ways to describe this feat. Six months after setting of the first structural columns on April 7, 1930, the steel frame topped off on the 86th floor. The fully enclosed building, including the mooring mast that raised the site to the equivalent of 102 stories, was finished in 11 months, in March 1931.  Most amazing, though, is the fact that within just 20 months – the first signed contracts with the architects in September 1929 to opening day ceremonies on May 1, 1931 – the Empire State was designed, engineered, erected and ready for tenants. Within this time, the architectural drawings and plans were prepared, the Victorian pile of the Waldorf – Astoria hotel was demolished, foundations and grillages were dug and set, the steel columns and beams, some 57,000 tons, were fabricated in milled to precise specifications, 10 million common bricks were layed, more than 62,000 yd.³ yards of concrete were poured, 6,400 windows were set and 67 elevators were installed in 7 miles of shafts.

At peak activity 3,500 workers were employed on site in the frame rose more than a story a day.  No comparable structure has since matched that rate of ascent.

The incredible schedule could be kept for two key reasons: a team – design approach that involved the collaboration of the architects, owners, builders, and engineers in planning and problem – solving: the organizational genius the general contractors, Starret Brothers and Eken.

Although the Empire State is often described as 102 stories tall, the building is really in an 85-story, 1050 foot-high building surmounted by an essentially ornamental tower. The so – called  mooring mast for dirigibles rose an additional 200 feet, the equivalent of 17 stories. Of the office tower, 80 floors are served by the main banks of elevators, while for floors 81 through 85 and for the 86th floor observation deck, visitors must transfer to such a separate short shaft of elevators.  In other words, the Empire State was designed as an 80 story office building: that was his economic height.

Securing the title of world’s tallest building was clearly the name of the Empire State’s developers. The Empire State was not just taller than all other skyscrapers, it was decisively bigger by almost every measure. It’s not rentable area 2,100,000 ft.² as opposed to the 850,000 ft.² of the Chrysler building. There were 64 passenger elevators versus 32. The skeleton frame required 57,000 tons of steel compared to 21,000 tons for the Chrysler building.

The scale of the building makes all the more impressive is record for speed of construction. Erected in 11 months from the first steel columns to the physician billing building, the Empire State Rose at the same rate as a Chrysler building but it was twice the size. This record is less known and appreciated than the very visible fact of the buildings great height.

Having reigned as the world’s tallest building for 40 years, the Empire State was eclipsed in the 1970s, first, from the twin towers of the World Trade Center in New York, then, by Sears Tower in Chicago. But even today it’s record speed of construction remains an unequaled achievement.

Team design

As summarized in the article and entitled “Paper Spires” in a 1930 issue of Fortune:

These various elements fixed the perimeter of an oddly shaped geometric solid, bounded on one side by 83,860 ft.² of land, on the other by $35 million, on the other by the law of diminishing returns, on another by the laws of physics and the characteristics of structural steel, and on another by the conical exigencies of the zoning ordinances, and on still another by May 1, 1931.

A design with these disparate dimensions could not be planned by the architects alone. A team of experts – including the owners, builders, architects, structural and mechanical engineers, elevator consultants, and rental agents – was required to collaborate first to define the problem then to solve it.

The directors move quickly to sign on their team. First hired were the architects, Shreve, Lamb and Harman.  Selecting the builder came next. Only a few general contractors had significant experience with this scale of operation and the capital necessary to cover the high cost of equipment and labor. Starret Brothers  and Ekin were selected.  From the outset, the owners, architects, and builder worked in committee to develop the builders program. This method avoided mistakes in design and costly delays in construction and to achieve significant economies to the design process.

The group met regularly to work closely with consultants and technical problems. The initial planning sessions occupied about four weeks in September 1929, and produced a complete technical planning document, and the economic requirements for the project. These guidelines became the basic program of the building.

William Lamb: “the program was short enough – a fixed budget ($35 million), no space more than 28 feet from the corridor, as many stories of such space as possible, an exterior of limestone, a completion date of May 1, 1931, which meant a year and six months from the beginning of the sketches”.

Within this basic program, the team searched for the most efficient and profitable design, developing several different versions of massing and height, each supported by cost estimates. Their 17th version,  “scheme K.”, was adopted at a meeting of the executive committee on October 3, 1929.

If the keys are in the details, let’s look at the design of the facade and its window-spandrel-wall system.  The outer shell, what is seen of the building from the outside, would be recognized “as a wrapping and not as a load-bearing structural element” (note: unlike the World trade towers…).  This was solved during design, especially in the critical months of September through November 1929 when major decisions about massing and height were made.  Some design examples:

  • Of the 5,704 metal spandrels, there were only 18 variations, because “the aim was to standardize as much as possible, creating a sort of kit of parts that would speed both the fabrication and the erection”.
  • In determining the length and width of the chrome-nickel steel for the continuous mullions and the mooring mast, the method of jointing and bracing, the means for attaching the metal form to the frame of the structure, etc – the architects, builders and engineers called in the subcontractors who rolled the material, representatives of the metal works fabricating it, , those who were to erect it, the inspectors who were to test at several stages of preparation among others.  Such a conference “made possible decisions based on instant comparison of recommendations and the establishment of responsibilities of all those involved”.

Organizational genius of the builders

Bill Starrett took a very proprietary view of his role as the builder and general contractor:

“an owner turns over the plans and specifications for a building to a single agency, and the agency binds itself to deliver within a time limit a completed structure ready for the tenants to move in.  The contractor buys and assembles the materials, lets subcontracts himself, may himself perform certain of them, such as foundations, masonry, structural steel and carpentry, supervises and administers the whole and protects the owner against all contingencies, except the contingency of the owner himself changing his mind”

In other words, management – of men, materials, and money – is the essential role of the general contractor.  Bill Starrett also cited another definition he found apt:

Contrary to popular conception, the principal function of the general contractor is not to erect steel, brick, or concrete, but to provide a skillful, centralized management for coordinating the various trades, timing their installations and synchronizing their work according to a predetermined plan, a highly specialized function the success of which depends on the personal skill and direction of capable executives.

As a note, Starret Brothers worked under a fixed fee contract of $500,000 (1/70th total cost) as opposed to a cost-plus structure which increases fee as the cost of the building increases.

 

Materials and Construction Sequencing

 

Even the 77 pages of detailed notes barely scratch the surface of all the clever work that was done in coordinating and synchronizing the work.  One aspect that does shine through, though, is the pride in which the executives take in their innovations and the fact that they tested in real life to work for the project:

  • We handled and distributed all material by industrial cars on narrow gauge tracks, running completely around the perimeter of the building on each floor, with the tracks extending across the platform of the hoist, so the cars loaded, for instance, in the basement, could readily run on the hoist and load off at the proper floor and deliver at almost the spot where the material is to be used.
  • Bricks arriving at the job on the first floor level were dumped into large bends in the first basement.  The cars deposited the bricks along the layers without having been handled from the time they came into the building until the bricklayer placed them in the wall. Under the old method of wheelbarrows we could place only to borrows contain 100 bricks per trip on a standard platform. With the industrial car in the same hoist to carry 400 bricks per trip.
  • For the setting of our stonework, we cut out altogether the customary derrick. The stone trucks drove into the building with the stone in crates, which we call skips or slings, marked for its proper section of the building.  Each crate was lifted off the truck by a small crane, operating from a monorail on the ceiling, and delivered to the flatcars  of the industrial railway. Taken to the proper floor, it was unloaded at almost the exact location it was to be set.  We not only beat the stone setting schedule by 14 days, but for one period of 10 consecutive days averaged 1.4 stories per day.
  • Eken called the Empire State essentially ” a vast scheduling job” and claimed: “we ran trucks for that one the way they run trains in and out of Grand Central. If a truck missed its place in line on Tuesday, it had to wait until Wednesday to get back in”.  The ground floor of the building was kept free of temporary structures so that trucks could drive in to deliver their materials. The notes recorded that at peak operation about 500 trucks a day unloaded inside the building. That was nearly one truck every minute of the eight hour workday — and that does not count the structural steel hoisted by outside derricks.
  • In the summer of 1930, construction hummed with over 3400 men on the site daily. There were established standards for efficient construction: for steel 3 1/2 stories per week; for brick walls, a story a day; and for stonework, one to two stories a week.
  • 1929 Starret Brothers and Eken had maintained a fast pace in the erection of the  Manhattan Company building at 40 Wall Street.  But as Paul Starret explained in his autobiography: ” it was clear to us at once that the Empire State could never finish the building on time by any such progress. We decided to discard all these plans of operations and determined to erect the Empire State at the rate of a story a day”.

 

People

In reviewing claims for an Exxon Modular project in Korea, I once wrote back to the contractor: “we are not willing to pay this claim until you have exhausted all possible remedies to resolve this problem”.  To which they replied: “you cannot expect us to work our people this hard!”.  Unfortunately for Mr. Paul Starret, according to his autobiography: “after 40 years of intense activity, the strain of building the Empire State Building in 11 months was too much for me and I suffered a rather severe nervous breakdown”.

It has been my experience that successful projects have this in common: all parties feel they are in it together: we all win with a successful project or we all lose together.  And we want to win. There is very little finger-pointing or deflecting the blame. It seems to me that was a theme of the Empire State Building.  there is also the issue of competence and confidence, and it seems the key players in building the Empire State building were pros.

But let them speak for themselves from the last of the 77 notebook pages:

Conclusion:

A quotation from Ruskin, which has been used frequently as an inspirational thought in connection with this building, follows:

“Therefore, when we build, let us think that we build forever. But not be for present delight, nor for present use alone, let it be such work as our descendents will thank us for, and let us think, as we lay stone on stone, that a time is to come when the stones will be held sacred, because our hands have touched them, and that men will say as they look upon the labor and the wrought substance of them — See this our fathers did for us.”

At the moment, however, we are astounded at the marvel of its birth. Title to the old hotel was acquired by the owners on June 1, 1929. Demolition of the old buildings with started on September 22, 1929 and completely finished on March 12, 1930. The first steel columns of the new Empire State building were set on April 7, 1930 in the building was completely finished on March 1, 1931.  Within a period of 21 months, the entire project was conceived and brought to successful execution.

This massive building now stands as majestic symbol of the enterprise and efficiency of our age — offering mute tribute to the promoter, financier, architect, engineer, builder, artisan and everyone who toiled to make it a reality — down to the humblest laborer.

Viewed in the light of Faith, it stands out clearly against the sky is a noble monument reflecting the glory of God, who had given such power to man.

 

 

 

 

Notes

(1) Savage, Sam L.; Jeff Danziger (2009-06-03). The Flaw of Averages: Why We Underestimate Risk in the Face of Uncertainty (Kindle Locations 334-347). Wiley.

(2) “Building the Empire State: a rediscovered 1930s notebook charts the construction of the Empire State Building” edited by Carol Willis, W. W. Norton & Co. New York London in association with the skyscraper Museum copyright 1998 by the Skyscraper Museum, page 12.

 

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