Wednesday, September 30, 2015

The Purpose of Stay Chains

Over the years, I’ve talked a lot about the different types of technology employed in early wooden wagons.  For some, these old wheels seem extremely simple.  The original builders and users of the vehicles, though, understood just how difficult it was to keep wood held together correctly and successfully.  After all, virtually all of the outdoor elements worked against it – dirt, moisture, dryness, sun, rough terrain, heavy loads, and more.  With so much stacked against them, I’m sometimes amazed that any of these vehicles have survived.

Because of my intrigue and continual research on this subject, I’m often asked questions related to who did what and when.  I’m also asked the “whys” of different vehicle types and technologies.  Answering some of those questions can be even tougher when the questioner is looking to confirm answers with primary sources.  As an example, some time ago, a reader asked me if I had ever seen references to the purpose of ‘stay chains’ in nineteenth century materials?  It was an unusual question that led me to one conclusion – That at least some of the information many of us believe we know is likely limited to our own modern day experiences or what our grandparents might have passed on.  While both oral history and personal discovery are important, neither can completely take the place of earlier primary sources. 

Even though I haven’t deliberately gone looking for details on stay chains, I have kept the question in the back of my mind.  As fortune would have it, a few months back, while I was reviewing some Civil-War-era records, I came across a reference to a doubletree innovation that mentioned the purpose of stay chains.  For many, the answer may seem obvious.  The fact remains, though, that for any of us to truly connect with the way wagons and western vehicles were looked upon in their time, we must base our understanding in the documentation left within primary sources. 

Stay chains are positioned to work hand-in-hand with the doubletree to optimize the leverage and power efficiencies of draft animals hooked to a wagon.

For those unfamiliar with the location of stay chains, they are typically attached to hooks positioned near the outer ends of a wagon’s front axle.  The other end of each chain (two total) is then attached to the corresponding outer portion of the doubletree. 

The 1865 document I stumbled across detailed the function of a newly-developed doubletree equipped with a counterbalancing center spring.  To digest the full description below, you may have to read it a few times as it does get a bit wordy.  Ultimately, the writer does an interesting job of explaining both the complexity and purposes of a doubletree and stay chains... 

“...From the foregoing description it will be understood that in using my improved doubletree, the changing point of draught will always correspond with the difference in power applied to the ends of the doubletree. In every instance and condition the doubletree will adjust itself upon the fulcrum-block in such a manner as to favor the less powerful horse, because, as the more powerful of the two will keep in advance of the other, the point of draught will correspondingly approach and remain in nearer proximity to the most advanced of the animals.  In other words, the foremost horse will necessarily have the short end of the lever, while the rearmost will draw from the longer end. In the event of the entire suspension of power at one end of the doubletree, then the stay-block will operate to check and hold the doubletree from oscillating to any considerable extent, serving the purpose of stay-chains, which are generally required for the same purpose...”

Simply put, properly-used stay chains help ensure that optimum leverage is available to a team drawing a wagon, thereby allowing for easier pulling and overall wagon operation.  Clearly, the references to technical terms like fulcrums, leverage, power, and point of draught can get a bit complicated.  That said, the description helps demonstrate that quite a bit of math and science went into the design of even the smallest of parts.  Ultimately, the engineered designs were crafted to enable the wagon to function with the greatest efficiency, effectiveness, and longevity while providing the means for draft animals to optimize power.    

Whew!  So much for simplicity.  Sounds more like geometry, physics, science, and algebra classes to me!  I realize today’s blog wasn’t exactly a casual read.  From time to time, though, we’ll share a few pieces like this to help reinforce the contributions of early builders and designers while also highlighting the true complexities of their craft.  

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