science

Rocket net

Rocket net 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 Rocket net rather than just read about it. In short: Rocket nets and cannon nets are types of animal traps used to trap many live animals, usually birds, but they also have been used to catch large animals such as various species of deer. Rocket nets, cannon nets, and other net launching devices are built upon similar principles have been used since the 1950s (Dill and Thornsberry 1950, Hawkins et al. 1968, Grubb 1988 and 1991).

Key takeaways

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

Reference excerpt

Rocket nets and cannon nets are types of animal traps used to trap many live animals, usually birds, but they also have been used to catch large animals such as various species of deer. Rocket nets, cannon nets, and other net launching devices are built upon similar principles have been used since the 1950s (Dill and Thornsberry 1950, Hawkins et al. 1968, Grubb 1988 and 1991). Rocket and cannon nets are used in conservation programs where many live animals need to be captured for analysis, veterinary care or relocation.

Devices

Rocket nets The Rocket Net consists of an accordion folded rectangular net with one edge attached to the ground by short ropes or shock cords. The net can be placed directly on the ground in a line or can be folded and placed in a specially designed box (Grubb 1988). Nets specifically designed for rocket nets can be purchased from several wildlife supply and net manufacturers. The rockets are constructed from heavy gauge metal pipes with caps threaded and welded on one end with a removable cap on the opposite end that contains ports for the expanding gasses to escape. The rocket charges are made from black powder and an electric match enclosed that is used to ignite M6 Howitzer propellant. All three components are enclosed in a larger plastic bag with shunted leg wires extending out of the bag. Currently the primary manufacturer of rockets for rocket nets is Winn-Star in Carbondale Illinois. In addition to the rocket net, other specialty equipment is necessary for the safe firing and storage of rocket nets and their charges. A blasting galvanometer, capacitor discharge machine, and electrical blasting line are recommended for the safe use of this equipment. In addition, an IME-22 container is necessary for the safe transportation of charges and an explosives magazine is required for long-term storage. Transportation and storage of the charges are regulated by the US Department of Transportation; Department of Alcohol, Tobacco, Firearms and Explosives; and by other state and local agencies (ATF: Explosives Law and Regulations, ATF P 5400.7 and 29 CFR, Part 1910.109 and IME Safety Library Publication Numbers 1,3,12, 22, and 14). The US Fish and Wildlife Service and State Wildlife Agencies regulate their use to capture birds and other wildlife.

Cannon nets Cannon nets are similar to rocket net except a cannon-net projectile is a heavy metal barrel which is fired from a launch-rod attached to a metal plate. Cannon propellant is smokeless gunpowder ignited by an electric match. The primary advantage of cannon nets is the lack of explosives, therefore storage and transportation is easier. However, cannon-net projectiles have to be cleaned after every use. A full-sized cannon-net may utilize four or more cannons to pull the net over the target birds. Smaller nets with fewer cannons may also be used.

Air powered cannon The Martin Engineering Net Blaster is a similar device that propels a weight attached to a rocket net via a rope without the use of explosives. The Net Blaster was developed between researchers at USDA APHIS Wildlife Services and Martin Engineering as an alternative to the rocket net where the use of explosive charges would not be advisable, such as capturing oiled birds at an oil spill. The Net Blaster is charged with a portable compressor and set out in a similar fashion to the rocket nets placed in boxes. The air powered cannon is much quieter than rocket nets, but are much more expensive and less powerful.

Use The rocket net or similar-looking item is placed at the target location after days or week of pre-baiting the target species in, or is placed in an area where it is likely to capture the target animals, to allow animals to become accustomed to its presence. When the biologist is ready to use the actual rocket net, the net is folded accordion style in a line or packed in the rocket net bock. The rear or trailing edge of the net is staked to the ground by ropes and the leading edge of the net is attached to a number of rockets (typically 3 or 4) via longer ropes. The rockets are placed on the box, staked to the ground, or placed on post for additional elevation when taller animals are trapped. The charges are placed in the rocket and the wires attached to a shunted electrical blasting line. Once all the charges are connected, the line is tested, and the area is safe, it is attached to the capacitor blasting machine. When the animals are in place, the operator activates the blasting machine and the electrical charge ignites the rockets, propelling the net over the animals. The biologists and their team then remove the animals for whatever study they are conducting.

Catching waders When cannon-netting is carried out for the purpose of catching large numbers of waders or shorebirds for banding and release, it requires an experienced team to coordinate and manage not only the catch itself, but also the subsequent care and processing of the birds to their eventual safe release. Catching is usually conducted on tidal beaches with nutritious tidewrack, or adjacent to coastal mudflats, though occasionally other locations, such as salt lakes or sewage treatment lagoons, are used.

… excerpt ends here. Continue reading the full article.

Illustrations

Rocket net: Net gun being fired by a USDA researcher to capture birds — Net gun being fired by a USDA researcher to capture birds

Worked examples

Example 1 — a first encounter with Rocket net

Start with the simplest possible case. Write down what Rocket net 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 Rocket net 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 Rocket net 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 Rocket net

In research: Rocket net 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 Rocket net 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: Rocket net is common in secondary-school and first-year university syllabi. It links to neighbouring topics Fowling, Nets (devices), Ornithological equipment and methods, so understanding it makes those chapters shorter.
In everyday life: Look for Rocket net 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 Rocket net in 20 minutes

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

Frequently asked questions

What is Rocket net in simple terms?

Why does Rocket net 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 Rocket net?

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 Rocket net.