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Knacker

Knacker 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 Knacker rather than just read about it. In short: A knacker (), knackerman or knacker man is a person who removes and clears animal carcasses (dead, dying, injured) from private farms or public highways and renders the collected carcasses into by-products such as fats, tallow (yellow grease), glue, gelatin, bone meal, bone char, sal ammoniac, soap, bleach and animal feed. A knacker's yard or a knackery is different from a slaughterhouse or abattoir, where animals a…

Knacker — main illustration
Knacker — illustration

Key takeaways

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

Reference excerpt

A knacker (), knackerman or knacker man is a person who removes and clears animal carcasses (dead, dying, injured) from private farms or public highways and renders the collected carcasses into by-products such as fats, tallow (yellow grease), glue, gelatin, bone meal, bone char, sal ammoniac, soap, bleach and animal feed. A knacker's yard or a knackery is different from a slaughterhouse or abattoir, where animals are slaughtered for human consumption. Since the Middle Ages, the occupation of "knacker man" was frequently considered a disreputable occupation. Knackers were often also commissioned by the courts as public executioners.

Etymology The oldest recorded use of the word "knacker" dates to 1812, meaning "one who slaughters old or sick horses" and in 1855 "to kill, castrate", and is believed to be the same word as the earlier knacker/nacker "harness-maker" from the 1570s, surviving in 18th century dialects. The sense extension is perhaps because "knackers" provided farmers with general help in horse matters, including the disposal of dead horses and animals. The word is of uncertain origin, perhaps from the Scandinavian word represented by Old Norse hnakkur, saddle, and related to hnakki, "back of the neck", possibly relating to neck.

Legal definitions The term is in this literal sense in British English and Irish English, and gained some notoriety during the outbreak of mad cow disease (BSE) in the United Kingdom. The Slaughterhouses Act 1974, the Meat (Sterilisation and Staining) Regulations 1982, and the Food Safety Act 1990 all define a "knacker's yard" as "any premises used in connection with the business of slaughtering, skinning or cutting up animals whose flesh is not intended for human consumption". Knackery by-products are rendered under regulation into fats and meat and bone meal for incineration. Cattle hides may be recovered for leather production. The kinds of animal processing which can occur at knackeries are defined by law, for example, in Australia by the Commonwealth Meat Inspection Act 1983. In the EU, the legislation covering knackeries is Regulation (EC) No 1069/2009 of 21 October 2009. It regulates animal by-products and derived products not intended for human consumption.

Slang use "Knackered" meaning tired, exhausted or broken in British and Irish slang is commonly used in Australia, Ireland, Newfoundland, New Zealand, and the United Kingdom. The word has also been used as a derogatory term against members of the Travelling Community in Ireland. There have been some calls to cease the use of slang terms like "knacker drinking" and "knackered" as a result. In Ireland, "knacker drinking" refers to the practice of consuming alcohol in the open, e.g. in a field or a park, or by a roadside or canal; the drink is typically cheap cider, beer or vodka from an off licence. "Knacker drinking" is commonly done by teenagers or students. The British satirical magazine Private Eye often refers to senior police figures as "Inspector Knacker" or the police force in general as "Knacker of the Yard", a reference to Jack "Slipper of the Yard" Slipper. Automotive junkyards, salvage yards or recyclers may also be referred to as "knackers' yards" or "knackers". "Knackers" is also a British/Australasian vulgar slang for testicles.

References

Illustrations

Knacker: "A Dead Horse on a Knacker's Cart", drawing by Thomas Rowlandson (1757–1827).
"A Dead Horse on a Knacker's Cart", drawing by Thomas Rowlandson (1757–1827).
Knacker: A group of dead pigs awaiting pickup by a local knackery, dumped at the edge of a farm site in Scotland; pig farmers in particular prefer the knackery truck not to come close to where live pigs are kept as this is a way that disease can be spread.
A group of dead pigs awaiting pickup by a local knackery, dumped at the edge of a farm site in Scotland; pig farmers in particular prefer the knackery truck not to come close to where live pigs are kept as this is a way that disease can be spread.
Knacker: Smoke discharging from incinerators at Douglasbrae Knackery, Scotland. The business deals with the disposal of animal carcasses from all over the north-east of Scotland.
Smoke discharging from incinerators at Douglasbrae Knackery, Scotland. The business deals with the disposal of animal carcasses from all over the north-east of Scotland.

Worked examples

Example 1 — a first encounter with Knacker

Start with the simplest possible case. Write down what Knacker 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 Knacker 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 Knacker 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 Knacker

In research
Knacker 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 Knacker 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
Knacker is common in secondary-school and first-year university syllabi. It links to neighbouring topics Animal husbandry occupations, Australian slang, British slang, so understanding it makes those chapters shorter.
In everyday life
Look for Knacker 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 Knacker in 20 minutes

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

Frequently asked questions

What is Knacker in simple terms?

A knacker (), knackerman or knacker man is a person who removes and clears animal carcasses (dead, dying, injured) from private farms or public highways and renders the collected carcasses into by-products such as fats, tallow (yellow grease), glue, gelatin, bone meal, bone char, sal ammoniac, soap…

Why does Knacker 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 Knacker?

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 Knacker.

Tags

  • Animal husbandry occupations
  • Australian slang
  • British slang
  • Cleaning and maintenance occupations
  • Irish slang
  • Pejorative terms for people
  • Scrap collectors
  • Waste collection

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