Hubbry Logo
FlareFlareMain
Open search
Flare
Community hub
Flare
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Flare
Flare
Flare
View on Wikipedia
from Wikipedia

Illumination flares being used during military training exercises
Flares being fired from a ship during a fleet review

A flare, also sometimes called a fusée, fusee, or bengala,[1][2] bengalo[3] in several European countries, is a type of pyrotechnic that produces a bright light or intense heat without an explosion. Flares are used for distress signaling, illumination, or defensive countermeasures in civilian and military applications. Flares may be ground pyrotechnics, projectile pyrotechnics, or parachute-suspended to provide maximum illumination time over a large area. Projectile pyrotechnics may be dropped from aircraft, fired from rocket or artillery, or deployed by flare guns or handheld percussive tubes.

Origin

[edit]
See also: History of gunpowder and Fireworks

The earliest recorded use of gunpowder for signaling purposes was the 'signal bomb' used by the Chinese Song Dynasty (960–1279) as the Mongol-led Yuan Dynasty (1271–1368) besieged Yangzhou in 1276.[4] These soft-shelled bombs, timed to explode in midair, were used to send messages to a detachment of troops far in the distance. Another mention of the signal bomb appears in a text dating from 1293 requesting their collection from those still stored in Zhejiang.[4] A signal gun appears in Korea by 1600. The Wu I Thu Phu Thung Chih or Illustrated Military Encyclopedia, written in 1791, depicts a signal gun in an illustration.[5]

Civilian use

[edit]
A conventional flare pistol. This particular model uses 26.5-millimeter (1.04 in) flares (manufactured by Patel Ballistics).

In the civilian world, flares are commonly used as signals, and may be ignited on the ground, fired as an aerial signal from a pistol-like flare gun, or launched from a self-contained tube. Flares are commonly found in marine survival kits.

Maritime distress signal

[edit]

Distress rockets (aka "rocket-propelled parachute flares"[6]) have been mentioned in the modern era for civilian maritime emergencies since at least 1856. The U.S. Nautical Magazine of that year mentions the use of "rocket stations" for ship related emergencies.[7] White rockets were solely used until 1873, when commander John Yorke of the Royal Navy suggested that rockets for distress should have a distinctive color. The request was made to help ease confusion between ships in distress and rockets used by pilot ships.[8] By 1875, the UK Board of Trade had issued regulations for captains in regards to night signals. Rockets containing at least 16oz of composition were only to be used as a sign for a ship in distress. Passenger ships at the time were required to carry 12 of these rockets.[9] The Merchant Shipping Act 1894 further stated that these rockets were to be fired one at a time in short intervals of approximately one minute apart.[10] Distress rockets continued to be used in different colors, as was the case with RMS Titanic. At the time shipping companies had "a particular kind of distress rocket (that differed by color)". Each ship was also given a guide of colors to use depending on what signal was to be sent.[10][11]

Modern red distress signals are mentioned by the United States Bureau of Mines as early as 1959, where they state "12 handheld rocket-propelled parachute red flare distress signals" are to be used by ocean going ships.[12] The color red was eventually incorporated for use in the United States on 17 December 1979 as part of a "Universal color language".[6] Red distress rockets and/or flares are now internationally recognized symbols that indicate a ship in distress.[13][14] The International Convention for the Safety of Life at Sea (SOLAS) has standards for visual signals, including both handheld and aerial flares. Handheld flares must burn for at least one minute at an average luminosity of 15,000 candelas, while aerial flares must burn for at least 40 seconds with a 30,000-candela average luminosity.[15]

While rockets and flares are still an option for signaling distress, they have since been surpassed by improved technology. Distress signals can now be sent using automated radio signals from a search and rescue transponder. Other internationally recognized methods include the radio message SOS, which was used during the 1912 sinking of the Titanic, and the emergency procedure word "Mayday", which dates to the 1920s.[13][16][17]

Roadside and rail

[edit]
Three road flares burning

Another type of flare is the fusee, which burns with a bright red light.[18] These come in two main types which are used for roadways and rail transportation. The first type are fusees used for roadways which are known as highway flares or road flares.[19][20] These are commonly used to indicate obstacles or advise caution on roadways at night and are found in roadside emergency kits.[21] Law enforcement also may use these flares (either propped on a biped or laid flat) to signal traffic hazards or that a road is blocked, often as a more visible replacement for traffic cones.[22][23][24] Law enforcement in the United States usually use magnesium-based flares that last from 15–30 minutes.[24]

Fusees used for rail are known as railroad flares, they are commonly used to perform hand signals or used as torches in rail transport applications.[18][25] Railroad flares can burn for at least 10 minutes, are not fastened to train cars, and are handheld by railroad personnel for protection at night.[18] It was argued during an Appeals case that railroad flares are much more visible than lanterns.[18] In general: trains that encounter a lit railroad flare are required to stop until it burns out.[26] Fusees made specifically for railroad use can be distinguished from highway fusees by a sharp steel spike at one end, used to embed the fusee upright in a wooden railroad tie.

Forestry and firefighting

[edit]

In forestry and firefighting, fusees are sometimes used in wildfire suppression and in the ignition of controlled burns. They ignite at 191 °C (376 °F) and burn as hot as 1,600 °C (2,910 °F).[27]

Protests

[edit]
Antifa protestors using flares

Flares are used by law enforcement agencies such as the United States National Guard, and police as a form of riot control.[28] This practice dates back to at least the 1940s where they are mentioned as being "useful in night operations".[28] Handheld flares are also counter used by protestors at demonstrations.[29]

Military use

[edit]

Maritime signal flare

[edit]

In 1859, Martha Coston patented the Coston flare based on early work by her deceased husband Benjamin Franklin Coston.[30]

Illumination

[edit]
Further information: Battlefield illumination

In 1922, a "landing flare" was an aerial candle attached to a parachute and used for landing an airplane in the dark. The flare burned for less than four minutes and the candlepower was about 40,000 lumens.[31] During World War II, the U.S. Navy tested underwater flares for use in detecting submarines.[32]

Countermeasure

[edit]
Main article: Flare (countermeasure)

A special variety of flares is used in military aircraft as a defensive countermeasure against heat-seeking missiles. These flares are usually discharged individually or in salvos by the pilot or automatically by tail-warning devices and are accompanied by vigorous evasive maneuvering. Since they are intended to deceive infrared missiles, these flares burn at temperatures of thousands of degrees, incandescing in the visible spectrum as well.

Tripflares

[edit]
Main article: Tripflare

Flares connected to tripwires are used to guard an area against infiltration. The flare begins burning when the tripwire is triggered, providing both alarm and illumination.

Regulation

[edit]

Under the UN hazard number system, pyrotechnic flares are designated class 1.4 explosives.[33]

Several U.S. states, including California and Massachusetts, have begun regulating levels of potassium perchlorate, which can be unsafe at certain levels in drinking water. Contaminated drinking water can lead to such symptoms as gastric irritation, nausea, vomiting, fever, skin rashes, and even fatal aplastic anemia (a reduction in all types of blood cells).[34]

Chemistry

[edit]

Flares produce their light through the combustion of a pyrotechnic composition. The ingredients are varied, but often based on strontium nitrate, potassium nitrate, or potassium perchlorate, mixed with a fuel such as charcoal, sulfur, sawdust, aluminium, magnesium, or a suitable polymeric resin.[35] Flares may be colored by the inclusion of pyrotechnic colorants. Calcium flares are used underwater to illuminate submerged objects.

Perchlorate flare health issues

[edit]

Many in-service colored signal flares and spectrally balanced decoy flares contain perchlorate oxidizers. Perchlorate, a type of salt in its solid form, dissolves and moves rapidly in groundwater and surface water. Even in low concentrations in drinking water supplies, perchlorate is known to inhibit the uptake of iodine by the thyroid gland. While there are currently no US federal drinking water standards for perchlorate, some states have established public health goals or action levels, and some are in the process of establishing state maximum contaminant levels. For example, the US Environmental Protection Agency has studied the impacts of perchlorate on the environment as well as drinking water.[36] California has also issued guidance regarding perchlorate use.[37]

US courts have taken action regarding the use of perchlorate in manufacturing pyrotechnic devices such as flares. For example, in 2003, a federal district court in California found that the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) applied because perchlorate is ignitable and therefore a "characteristic" hazardous waste.[38] Flares manufactured in the United States no longer use potassium perchlorate as an oxidizer and do not contain aluminium or magnesium.[39]

See also

[edit]

References

[edit]

Further reading

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Flare

View on Grokipedia
from Grokipedia
A flare is a pyrotechnic device that produces intense , , or heat through controlled without a significant , primarily used for visual signaling in distress situations, , or as countermeasures. Originating from early applications in 13th-century for signaling, modern flares trace their development to the , with Martha Coston's 1859 patent for colored signal flares revolutionizing maritime and military communication during the and subsequent conflicts. These devices gained prominence for enabling nighttime naval coordination and distress alerts, evolving from basic fusees to sophisticated parachute-deployed variants that extend visibility over miles. Flares serve diverse roles across civilian and applications, including handheld red smoke or light emitters for boating emergencies, aerial rocket-launched signals for rescue, and magnesium-based decoys ejected from to divert infrared-guided missiles by mimicking engine heat signatures. In contexts, illumination flares provide overhead for operations, while civilian fusees mark roadside hazards; however, their use demands caution due to scorching residues that can ignite flammables or cause burns. Despite regulatory requirements for carriage on vessels and , flares' classification as low-hazard explosives underscores ongoing safety and environmental scrutiny, particularly regarding residues.

History

Early Origins and Maritime Beginnings

In the medieval period, European sailors utilized rudimentary fire-based signals, igniting flames or generating to alert nearby vessels or coastal observers to distress situations. These methods capitalized on fire's inherent visibility, particularly at night, serving as precursors to more refined pyrotechnic devices. Such practices built upon ancient signaling traditions originating with beacons codified around 350 BC, which Romans advanced using paired torches for modulated messages over distance. While primarily terrestrial, these systems informed maritime adaptations, where elevated deck fires extended line-of-sight detection beyond the horizon's —typically limited to 10-15 nautical miles for low-elevation observers—enabling potential rescuers to alter course toward the signal's origin. The saw a shift toward pyrotechnic enhancements, with naval forces employing compositions like blue lights: open-pan mixtures yielding intense, short-duration illumination for coordinated signaling. These gunpowder-derived formulations, managed by ship gunners, provided brighter output than open flames, sustaining visibility over 3-5 miles in clear conditions and demonstrably aiding operational responses in fleet maneuvers, though pre-radio attributions remain anecdotal due to sparse contemporaneous logs.

19th-Century Innovations

Martha Coston developed a system of pyrotechnic signal flares in the , drawing from incomplete notes left by her deceased husband, Benjamin Franklin Coston, to create reliable maritime communication devices capable of producing colored lights at night and smoke signals by day. Over a decade of iterative experimentation addressed key engineering obstacles, including inconsistent ignition and vulnerability to damp weather, through refinements in chemical formulations and casing designs that ensured self-sustained once fired from signal pistols. These advancements prioritized causal mechanisms of reliable pyrotechnic reaction over rudimentary prototypes, yielding flares that maintained and color distinction across distances exceeding several miles under varying atmospheric conditions. The core invention, encompassing red, white, and green night signals for encoding messages via combinations, received U.S. Patent No. 23,536 on April 5, 1859, with Coston credited as administratrix due to patent office restrictions on female inventors at the time. The U.S. Navy adopted the Coston system during the Civil War (1861–1865), contracting for over one million signals that facilitated coordinated blockades and fleet maneuvers by minimizing nighttime miscommunication errors previously reliant on less precise flags or lanterns. Operational records document the flares' effectiveness in real-world applications, such as guiding rescue operations for distressed vessels and signaling during engagements like the 1865 Battle of , where they enabled precise Union naval positioning and contributed to tactical successes by clarifying orders amid darkness and fog. Post-war evaluations confirmed the system's role in averting collisions and enabling timely interventions, with empirical data from naval logs attributing hundreds of vessel saves to its deployment, underscoring the causal link between enhanced signal reliability and reduced maritime losses.

20th-Century Standardization and Military Adoption

During , military adoption of flares accelerated for aerial observation, ground signaling, and illumination, with the standardizing the 25mm Mark IV Very pistol—a direct adaptation of a French design—for launching signal flares from aircraft. British forces incorporated the Holt landing flare, an early parachute-assisted pyrotechnic device, to support nighttime landings and tactical maneuvers, marking a shift from rudimentary ground-based signals to more reliable aerial deployment. Production scaled rapidly to meet demands, as evidenced by contracts awarded to manufacturers like Harrington & Richardson for shoulder-fired flare projectors, enabling infantry units to provide on-demand visibility in where fixed lighting exposed positions to enemy fire. This adoption highlighted flares' tactical edge over alternatives like searchlights, offering portable, instantaneous overhead illumination without revealing static troop locations. In , flare usage expanded across theaters for night bombing support, , and battlefield illumination, with production reaching industrial scales to equip Allied and Axis forces alike. The U.S. military deployed flares such as the AN-M26, which ignited via to deliver approximately 800,000 of yellowish light for about three minutes while descending slowly, proving effective for illuminating targets over fixed lights by minimizing ground exposure and enabling dispersed operations. German forces similarly refined flare guns for signaling and early anti-tank adaptations, underscoring ' versatility in resource-constrained environments compared to bulkier electrical systems. Field applications demonstrated flares' efficacy in sustaining visibility during assaults, where their brief but intense output outperformed searchlights in mobility and reduced vulnerability to , though limited burn duration prompted ongoing refinements. Post-World War II military standardization efforts, documented in U.S. Army pyrotechnics handbooks, focused on enhancing parachute flare reliability and integration with artillery and aviation systems. Developments extended effective burn times beyond wartime baselines, incorporating improved compositions for sustained output in reconnaissance and search-and-rescue, with trial data validating their superiority for temporary area denial and target acquisition over emerging electronic alternatives in low-infrastructure theaters. In parallel, the U.S. Coast Guard formalized flare mandates for vessel safety through the mid-20th century, requiring approved pyrotechnic signals on boats over 16 feet by the 1970s to address distress visibility gaps informed by maritime incident analyses. These evolutions cemented flares' role in joint military-civilian signaling protocols, prioritizing empirical performance in survival and operational scenarios.

Design and Physics

Basic Principles of Operation

Flares are typically ignited through percussion or mechanisms that generate localized exceeding the ignition of the pyrotechnic primer, initiating a self-sustaining of the combustion front via and gas-phase reactions. Percussion ignition, common in aerial flares launched from guns, involves a impacting a primer cap to produce a spark and hot gases, while ignition, used in hand-held types, employs a striker scraped against a rough surface to ignite a match-like head. This rapidly escalates to a pyrotechnic at temperatures of 1000–2000°C, where exothermic oxidation sustains a high-energy front, converting into predominantly in the through incandescence. The resulting luminous intensity spans 10,000–1,000,000 , with maritime hand flares standardized at a minimum of 15,000 and parachute types at 30,000 or higher, enabling detection over extended distances. In aerial configurations, is prolonged by deployment post-ignition, which dramatically increases the effective cross-sectional area exposed to , thereby amplifying aerodynamic drag to counterbalance gravitational and achieve a low . The vtv_t is determined by the equilibrium vt=2mgρCdAv_t = \sqrt{\frac{2mg}{\rho C_d A}}
Add your contribution
Related Hubs
User Avatar
No comments yet.