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Yamhill River lock and dam

Yamhill River lock and dam is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Yamhill River lock and dam rather than just read about it. In short: The Yamhill River lock and dam was completed in 1900. It was built near Lafayette, Oregon, to allow better river transport on the Yamhill River from Dayton, to McMinnville, Oregon.

Yamhill River lock and dam — main illustration
Yamhill River lock and dam — illustration

Key takeaways

  • Yamhill River lock and dam belongs to engineering; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Yamhill River lock and dam to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Yamhill River lock and dam from memory before moving on to harder problems.

Reference excerpt

The Yamhill River lock and dam was completed in 1900. It was built near Lafayette, Oregon, to allow better river transport on the Yamhill River from Dayton, to McMinnville, Oregon. While the Corps of Engineers had recommended against construction of the lock, it was built anyway, largely as a result of political effort by the backers of the project. For almost forty years prior to the lock construction there had been efforts made to construct a lock and dam on the Yamhill River. The lock was a single-lift chamber 210 feet (64 m) long and 40 feet (12 m) wide, located on the west side of the river. The dam extended from the east bank of the river to the eastern lock wall, and when the lock gates were shut, acted to back up the Yamhill river and raise the water level sufficiently to allow ready steamboat navigation to McMinnville during the summer dry season. During the winter, the lock and dam were more of an obstruction than a navigational aid, as they were frequently overtopped by freshets and floods, sometimes as high as or higher than twenty feet above the lock walls. The lock ceased to be used in any significant way soon after it was built. There was an upsurge in use of the river during the 1930s and 1940s primary for transport of logs. The lock continued in operation until the 1950s, when the U.S. government concluded that the little amount of traffic on the river no longer justified the expense. The lock and dam were then turned over to Yamhill County. The county lacked the funds to maintain or restore the lock, and the dam, having been viewed as a barrier to spawning salmon, was eventually destroyed with use of explosives. The lock walls remain to this day. The lock keeper's residence, built at the same time, and now in private hands, also remains. A county park is nearby from which the lock structure can be viewed. Some other remains of the work, such as pilings, are also visible at low water. While not particularly remarkable as an engineering project, the lock was one of only three lock and dam projects commenced in Oregon and indeed in all of the Pacific Coast states by the United States government during the 19th century. The lock and dam are also representative of the results of local pressure for expenditure of funds from the national government for works of a local nature. A substantial portion of the project remains visible to this day, and has been said to be "one of the last tangible remnants in the Upper Willamette Valley of a time when river navigation played an important role in transporting freight and passengers." The lock is sometimes referred to as the Lafayette Lock. The Lafayette Locks Park, maintained by Yamhill County, Oregon now occupies the site of the old lock and dam.

Location The lock was (and is) located about one mile downriver from the town of Lafayette and about five miles upriver from the confluence of the Yamhill and the Willamette Rivers. The fall of the Yamhill river between McMinnville and the lock was 13 feet (4.0 m). The river in its natural state had a stretch of rapids running from Lafayette, which was originally called Yamhill Falls, downriver to the lock site, over which the river fell nine feet. The source of the Yamhill River was the Coast Range in Oregon. The river flows to the east about 45 miles (72 km), to a point about 40 miles (64 km) upriver from Portland, Oregon, where it joins the Willamette River. Light-draft steamboats routinely ran to Dayton, about five miles above the river's mouth. The town of Lafayette was about 8 miles (13 km) up from the river mouth. At Lafayette there was a stretch of rapids over which the river fell 8.8 feet (2.7 m) in 1 mile (1.6 km). From the foot of the rapids to the mouth of the river the fall was just 1 foot (0.30 m). High water in the Yamhill River, or a rise of 10 feet (3.0 m) in the Willamette River would submerge the rapids. From Lafayette the river ran about 9 miles (14 km) to McMinnville, the seat of Yamhill County, a prosperous agricultural region. This stretch of the river was from 40 to 100 feet (12 to 30 m) wide, and obstructed with snags and overhanging trees. The snags were particularly bad for a stretch running from McMinnville 3 miles (4.8 km) down river. If the snags and overhanging trees were removed, steamboats drawing 2.5 to 3.0 feet (0.76 to 0.91 m) of water could proceed to McMinnville. The season in which boats could pass over the rapids was limited to about five months a year. In December 1892 there had been no preparation at all for use of the river to ship products by water. No roads led to the river, and there were no storehouses on the banks. There seemed to be very little interest taken in the recent clearance of the river. One steamer regularly ran the whole year between Portland and Dayton, and made a good business. This steamer could have extended its route to McMinnville if there had been sufficient business on the river to make it worthwhile. In 1892, a rail line crossed the Yamhill river at McMinnville and at LaFayette, which were only 5 miles (8.0 km) apart by wagon road. Lafayette and Dayton were only 2 miles (3.2 km) apart by road, and all of the country was flat. In 1910, the Yamhill river was described as "a limpid stream of shallows and deeps in Summer, a brawling torrent in Winter." In 1874, the Yamhill was examined by the engineering department of the U.S. army, which found that the river would vary from a shallow chain of pools in the summer to a "river of great power and strength" whose waterlines along the banks showed a rise, sometimes, of over 60 feet (18 m) during winter and spring floods.

… excerpt ends here. Continue reading the full article.

Illustrations

Yamhill River lock and dam illustration
Yamhill River lock and dam illustration
Yamhill River lock and dam: Sketch showing work being done on the foundation for the dam.
Sketch showing work being done on the foundation for the dam.
Yamhill River lock and dam: The locks in operation, as imagined by a sketch artist in 1900.
The locks in operation, as imagined by a sketch artist in 1900.
Yamhill River lock and dam: Completed Yamhill lock and dam.
Completed Yamhill lock and dam.

Worked examples

Example 1 — a first encounter with Yamhill River lock and dam

Start with the simplest possible case. Write down what Yamhill River lock and dam claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Yamhill River lock and dam before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Yamhill River lock and dam ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Yamhill River lock and dam

In research
Yamhill River lock and dam appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Yamhill River lock and dam in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Yamhill River lock and dam is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1900 establishments in Oregon, Buildings and structures in Yamhill County, Oregon, Dams on the National Register of Historic Places in Oregon, so understanding it makes those chapters shorter.
In everyday life
Look for Yamhill River lock and dam outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Yamhill River lock and dam in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Yamhill River lock and dam means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Yamhill River lock and dam out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Yamhill River lock and dam in simple terms?

The Yamhill River lock and dam was completed in 1900. It was built near Lafayette, Oregon, to allow better river transport on the Yamhill River from Dayton, to McMinnville, Oregon.

Why does Yamhill River lock and dam matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Yamhill River lock and dam?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Yamhill River lock and dam.

Tags

  • 1900 establishments in Oregon
  • Buildings and structures in Yamhill County, Oregon
  • Dams on the National Register of Historic Places in Oregon
  • Dams with fish ladders
  • Locks on the National Register of Historic Places in Oregon
  • Parks in Yamhill County, Oregon
  • Transport infrastructure completed in 1900
  • Transportation buildings and structures in Yamhill County, Oregon
  • United States Army Corps of Engineers dams

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