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Dutch Barn Preservation Society Dedicated
to the Study and Preservation NEWSLETTER
FALL 2002 Vol. 15, Issue 2STATICS By the time the first American-Dutch Barn was built in 1680, sophisticated science in structural design had been developed in Europe. Buildings up to that time were one of a kind and built by the trial and error method. They evolved without prescience. Structural integrity was a matter of experience. Any departure from the old way was a gamble that might, or might not, end-up with fracture from overload. This possibility still plagues engineers with new concepts, i.e. World Trade Center and the Tacoma Narrows Bridge. CHRONOLOGY 585 BC THALES of Miletus, introduced Egyptian geometry to Greece.
Holland and vicinity, in the 17th century, was a hotbed of activity in the mechanical sciences. Simon Stevin of Bruges, then Netherlands, built upon Euclid and Leonardo mechanics and philosophy. His book, ELEMENTS OF STATICS, in 1586, while largely philosophical, was a first. Then it was Descartes, in Holland, who established science as a physical rather than a spiritual discipline. Scientific societies were begun in London in 1660 and in Paris in 1667. Of special note was Sir Isaac Newton (1642-1727) in England. Among his many discoveries were the "Laws of Similarity." These provided for model analysis. A structure could be built in miniature to exact scale and material, loaded proportionately, and tested for strength. (Complete Book of Science, J.j. Little & Ives Co. Inc. NY, Page 1735) The science of static's, (bodies at rest), received its greatest break through in 1638. Galileo, ostracized from Italy, went to Lieden, in Holland to publish his book, TWO NEW SCIENCESI (figure 1). In those papers, he established principles that affect all of us everyday. He said:
The rule for a beam then became:
This simple statement would dictate the structure of all future barns, homes, skyscrapers, and bridges, exerting a vast influence on civilization. Without the notoriety, it would rival the popular Einstein formula E=MC2, in its effect on humanity. It was indeed the dawn of modern technology. The barn designer could then, with certainty, dimension timbers suitable to the task. With that host of knowledge, and the confidence it generated, its no wonder the American Dutch Barn was the first built in such abundance. The late Vincent Schaefer once told me that he thought that the Dutch Barn was, "over built." He did not elaborate. Galileo's formula and Newton's law will test the anchor beam ofthe American Dutch Barn. Given is a beam of 30' length, a 10" width, and 20" depth.
The bents are Hemlock and on 10' centers. The load will consist
of a crop of sheaves, the poles they sit on and the beam itself.
(See figure 2 below) Galileo's formula designates a relative strength for different beam dimensions. ANCHOR BEAM: Width x Square of Depth = Relative strength 10" x (20" X 20") = 133.3 Newton's model analysis is taken from a piece of the species of wood, 1" x 1", a one foot span of which is subjected to a breaking force at the center. Hemlock will break at a weight of 5000 Lbs. This "Unit Strength" then multiplied,by the relative strength of the beam is what a concentrated Load the Hemlock beam will hold. Figure 2 Click on graphic to view rest of calculations Conclusion Once domestic consumption was satisfied, one could look at exports to gauge the productivity of our country (DBPS N/Ltr Fall 2001). In the 20th century, metals and manufacturing were 60% of all exports. In the 19th century, cotton and cotton products were 64% of all exports. In the 18th century, the expendables tobacco, grain, fish, and rice accounted for 68% of all exports. The success of manufacturing can be traced to the "Assembly line," introduced by Henry Ford. The cotton revolution came about because of the II Eli Whitney Cotton Gin." Where grain was concerned, New York State and the" American Dutch Barn", did their part. So much so, that the US eventually became the leading wheat exporter in the world. Credit was also due to the colonial farmer and that included the 95% of the population engaged in farming. So much of written history concerns the butcher, baker, candle stick maker, politician and soldier. The vast number of country folk received little attention in the history books. The barn was of little use without them. ROBERT J. ANDERSEN BARN SPEAK The following are two interesting letters exchanged between two serious barn watchers. Sept. 25, 2002 Dear Peter: Enclosed are draft drawings and a couple of photographs of the ZIMMERMAN barn, located in Plymouth County, in the northwest corner of Iowa. None of this material need be returned to me, but I would welcome your opinion on any link you see between the Zimmerman barn and the New World Dutch Barns. I've done a little reading in Fitchen now and while this. is clearly from the wrong century and part of the country to be a NWDB, it does seem to me that the Z barn could be derivative. Mr. Zimmerman was born in Germany and this part of Iowa has both a strong ,!utch presence in Orange City and a history of East Frisian immigration to rural countryside. At this point, though, I'm unclear as to exactly how the Dutch relate to the East Frisians and how both relate to Germany (I've been assuming that there is a borderline territory and/or islands over which ownership has varied). The barn's heavy timber frame is of milled wood with pined and nailed mortise and tenon joinery. While I have run across heavy timber frame barns in northwest Iowa before, I continue to think it is unusual for someone to chose to build with this technique when balloon framing and plank and stud lumber were more common, probably cheaper and certainly easier to use. This is the "high prairie" of lowa-not quite the Dakotas, but nearly so-and there were few trees here. The railroad would have been hauling limber to the area for building purposes for at least the 25 years prior to the construction of the Z barn. Also, I think the frame is of fir rather than a native Iowa hardwood or North Woods white pine. Douglas fir would have come from the Pacific Northwest at this time, though it may have been milled in one of the Mississippi River towns prior to distribution. In any event, it's clear to me the barn's framing method was a choice, not a necessity. The H-bents and long sloping roof, terminating in 8-foot sidewalls, just feel like the offspring of a NWDB. I'd be interested in absolutely anything you'd like to comment on! Please feel free to email me or I can call you if you'd like me to. Thank you so much in advance. Sincerely, Sept. 30, 2002 Dear Jan, I received your drawings, photographs and letter about the Zimmerman barn. They are very descriptive. About 10 years ago I spent time looking at and documenting barns in the Holland area of Michigan where timber framing continued well into the 20th century. The next year I took a trip to Pella, Iowa and other places that had mid 19th century Dutch immigrants. The only "Dutch" barns I found were in Michigan and they remind me very much of the Zimmerman barn. A year ago I went on a twoweek tour of Holland and Germany organized by the Arnhem museum and a friend from Breitenheim. The Z barn has the Dutch and north German characteristics of being an aisle barn with low sidewalls that include animals, grain storage, etc. "English" barns are smaller and they tend to have specialized outbuildings. The Z barn is based on the H-bent. In Holland this construction seems very localized around Guilderland. In the rest of Holland and Germany we saw only decbalk (balk=beam) construction where the beam is joined to the top of the column whereas the ankerbalk (anchor beam) is a drop tie mortised to the column to form the H-bent. I found only one decbalk barn in Holland, Michigan; the only one I have seen in America. Since the early 17th century, Hudson Valley frame houses and barns have been based on the Hbent. New England frame houses and barns began being built with what is sometimes called a box frame with flared posts and principal rafters. They were one- or two-story houses where they were story and a half in the Hudson Valley. English framing is very complex and was gradually abandoned, especially in barns, in favor of the drop tie and common rafter. This can be seen as a development that originated in the Hudson Valley (see, Field Guide to New England Barns and Farm Buildings, Thomas Visser, 1997) and became the American timber frame that moved west. I am sure that many people would disagree with this and no doubt the truth is more subtle than I make it sound, but it looks to me that Zimmerman came with his German aisle barn tradition and adopted it to the American drop tie frame. I will copy your material and send it to the Dutch Barn Pres. Soc. and to Bud Miner, NWDB 2000, who is trying to make Midwest links. Friessan barns are very distinct and I used to call the decbalk a Friesan bent but I'm not sure that it is a bent. Their barn is the stolp. Sincerely, Peter Sinclair West Hurley, NY Jan Olive Nash is one of
the Tall Grass Historians of Iowa City, Iowa.
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