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Log driving

Log driving is a science 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 Log driving rather than just read about it. In short: Log driving is a means of moving logs (sawn tree trunks) from a forest to sawmills and pulp mills downstream using the current of a river. It was the main transportation method of the early logging industry in Europe and North America.

Log driving — main illustration
Log driving — illustration

Key takeaways

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

Reference excerpt

Log driving is a means of moving logs (sawn tree trunks) from a forest to sawmills and pulp mills downstream using the current of a river. It was the main transportation method of the early logging industry in Europe and North America.

History

When the first sawmills were established, they were usually small water-powered facilities located near the source of timber, which might be converted to grist mills after farming became established when the forests had been cleared. Later, bigger circular sawmills were developed in the lower reaches of a river, with the logs floated down to them by log drivers. In the broader, slower stretches of a river, the logs might be bound together into timber rafts. In the smaller, wilder stretches of a river where rafts couldn't get through, masses of individual logs were driven down the river like huge herds of cattle. "Log floating" in Sweden (timmerflottning) had begun by the 16th century, and 17th century in Finland (tukinuitto). The total length of timber-floating routes in Finland was 40,000km.

The log drive was one step in a larger process of lumber-making in remote places. In a location with snowy winters, the yearly process typically began in autumn when a small team of men hauled tools upstream into the timbered area, chopped out a clearing, and constructed crude buildings for a logging camp. In the winter when things froze, a larger crew moved into the camp and proceeded to cut trees, cutting the trunks into 5-metre (16 ft) lengths, and hauling the logs with oxen or horses over iced trails to the riverbank. There the logs were decked onto "rollways." In spring when snow thawed and water levels rose, the logs were rolled into the river, and the drive commenced. To ensure that logs drifted freely along the river, men called "log drivers" or "river pigs" were needed to guide the logs. The drivers typically divided into two groups. The more experienced and nimble men comprised the "jam" crew or "beat" crew. They watched the spots where logs were likely to jam, and when a jam started, tried to get to it quickly and dislodge the key logs before many logs stacked up. If they didn't, the river would keep piling on more logs, forming a partial dam which could raise the water level. Millions of board feet of lumber could back up for miles upriver, requiring weeks to break up, with some timber lost if it was shoved far enough into the shallows. When the jam crew saw a jam begin, they rushed to it and tried to break it up, using peaveys and possibly dynamite. This job required some understanding of physics, strong muscles, and extreme agility. The jam crew was an exceedingly dangerous occupation, with the drivers standing on the moving logs and running from one to another. Many drivers lost their lives by falling and being crushed by the logs.

Each crew was accompanied by an experienced boss often selected for his fighting skills to control the strong and reckless men of his team. The overall drive was controlled by the "walking boss" who moved from place to place to coordinate the various teams to keep logs moving past problem spots. Stalling a drive near a saloon often created a cascade of drunken personnel problems. A larger group of less experienced men brought up the rear, pushing along the straggler logs that were stuck on the banks and in trees. They spent more time wading in icy water than balancing on moving logs. They were called the "rear crew." Other men worked with them from the bank, pushing logs away with pike poles. Others worked with horses and oxen to pull in the logs that had strayed furthest out into the flats. Bateaux ferried log drivers using pike poles to dislodge stranded logs while maneuvering with the log drive. A wannigan was a kitchen built on a raft which followed the drivers down the river. The wannigan served four meals a day to fuel the men working in cold water. It also provided tents and blankets for the night if no better accommodations were available. A commissary wagon carrying clothing, plug tobacco and patent medicines for purchase by the log drivers was also called a wangan. The logging company wangan train, called a Mary Anne, was a caravan of wagons pulled by four- or six-horse teams where roads followed the river to transport the tents, blankets, food, stoves, and tools needed by the log drivers. For log drives, the ideal river would have been straight and uniform, with sharp banks and a predictable flow of water. Wild rivers were not that, so men cut away the fallen trees that would snag logs, dynamited troublesome rocks, and built up the banks in places. To control the flow of water, they built "flash dams" or "driving dams" on smaller streams, so they could release water to push the logs down when they wanted. Each timber firm had its own mark which was placed on the logs, called an "end mark". Obliterating or altering a timber mark was a crime. At the mill the logs were captured by a log boom, and the logs were sorted for ownership before being sawn. Log drives were often in conflict with navigation, as logs would sometimes fill the entire river and make boat travel dangerous or impossible. Floating logs down a river worked well for the most desirable pine timber, because it floated well. But hardwoods were more dense, and weren't buoyant enough to be easily driven, and some pines weren't near drivable streams. Log driving became increasingly unnecessary with the development of railroads and the use of trucks on logging roads. However, the practice survived in some remote locations where such infrastructure did not exist. Most log driving in the US and Canada ended with changes in environmental legislation in the 1970s. Some places, like the Catalan Pyrenees, still retain the practice as a popular holiday celebration once a year. In Sweden legal exemptions for log driving were eliminated in 1983. "The last float in southern Sweden was in the 1960s, with the floating era in the rest of the country ending completely with the last of the many log drives in the Klarälven river in 1991."

Popular culture

… excerpt ends here. Continue reading the full article.

Illustrations

Log driving: Log drivers at Klarälven in Sweden.
Log drivers at Klarälven in Sweden.
Log driving: A sawmill with floating logs in Kotka, Finland.
A sawmill with floating logs in Kotka, Finland.
Log driving: Log jam at Berlin, New Hampshire.
Log jam at Berlin, New Hampshire.
Log driving: Log driver working for the Brown Company in New Hampshire.
Log driver working for the Brown Company in New Hampshire.
Log driving: River drivers in Germany with a crude pike pole the Germans call a rafters' hook (Flößerhaken, as in rafting logs), probably one or two pickaroons and a ring dog for rolling logs over.
River drivers in Germany with a crude pike pole the Germans call a rafters' hook (Flößerhaken, as in rafting logs), probably one or two pickaroons and a ring dog for rolling logs over.

Worked examples

Example 1 — a first encounter with Log driving

Start with the simplest possible case. Write down what Log driving claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 Log driving 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 Log driving 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 Log driving

In research
Log driving appears in science 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 Log driving 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
Log driving is common in secondary-school and first-year university syllabi. It links to neighbouring topics Forestry occupations, Log transport, Timber rafting, so understanding it makes those chapters shorter.
In everyday life
Look for Log driving 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 Log driving in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Log driving 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 Log driving out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Log driving in simple terms?

Log driving is a means of moving logs (sawn tree trunks) from a forest to sawmills and pulp mills downstream using the current of a river. It was the main transportation method of the early logging industry in Europe and North America.

Why does Log driving matter?

Because it connects several science 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 Log driving?

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 Log driving.

Tags

  • Forestry occupations
  • Log transport
  • Timber rafting
  • Water transport
  • Wood

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