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119:). Since it extends the range by a percentage, it is more useful on longer-range artillery where an increase of approximately 5–15 kilometres (3.1–9.3 mi) can be achieved, and it also was found that the reduced turbulence gave the projectiles a more consistent trajectory, resulting in tighter grouping, and efficient shelling more than 40 kilometres (25 mi) away.
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called "reatil". Their goal was to increase the range of coastal artillery. By 1966, it had been concluded that a small slow-burning charge at the base of the projectile would alleviate the low pressure behind the shell, hence increasing the range by lessening the difference between the pressure due
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on the nose of the shell and the low pressure behind the base. The first full-scale tests took place in 1969 with modified 10.5 cm steel shells, with excellent results, and the
Swedish patent was granted to FOA in 1971 although both application and patent were classified. Since the development
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effectively reduces this component of drag; however, in regular flat-base artillery shells, the other large component is the so-called "base drag", caused by the low-pressure ("suction") area created directly behind the shell as it travels through the air.
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Base bleed technology was developed in Sweden in the mid-1960s but took some time to spread and find its niche between cheaper classical ordnance and even more expensive rocket-assisted projectiles. It is now a fairly common option.
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Diagram of a base bleed unit. The top diagram shows the bottom of the shell and the location of the gas vents. The bottom diagram is a cut-away view showing the gas generator mechanism.
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on an artillery shell derives from the nose portion of the shell. Artillery shells travel through the air at supersonic speeds; as the shell pushes the air out of its way, it creates
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293:. Department of the Army. Office of the Project Manager for Combat Ammunition Systems. Archived from the original on 13 May 2015
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shells to increase range, typically by about 20%–35%. It expels gas into the low-pressure area behind the shell to reduce
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was removed from the patent. Shortly thereafter the international rights were sold, eventually ending up with the
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Base drag can be reduced --without significantly extending the base of the shell or profiling it (as is done with
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fixed coastal artillery gun, and then rapidly into all anti-ship shells in the
Swedish military.
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This means that, at a cost of only very little space to fit the gas generator in the casing,
185:(abbreviated FOA) and the Artillery bureau at the Kungliga Materielförvaltningen (later the
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was done, the patent was transferred to FMV for procurement to the armed forces of Sweden.
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Since FMV was to contract a company in the US to manufacture the gas generator for the
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less propellant is needed to achieve the same effective range as with normal munitions
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151:-- by adding a small ring of metal extending just past the base, and placing a small
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By the end of the 20th century, the technology was generally available world-wide.
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a longer effective firing range can be achieved with the same amount of propellant
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Simplified diagram of a base-bleed artillery shell reducing turbulent vortices
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that bleed off the shell's kinetic energy and therefore reduce its airspeed.
372:. FOURTH ASAT CONFERENCE. CAIRO, EGYPT: MILITARY TECHNICAL COLLEGE. MF-366.
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to the rear part of the shell. The gas generator provides little to no
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288:"M1128 Insensitive Munition High Explosive Base Burn Projectile"
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The principles were developed in Sweden in the mid-1960s by the
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YAKOUT, HASSAN; ABDEL-KADER, MOHAMED S. (14–16 May 1991).
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Pages displaying short descriptions of redirect targets
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heavier shells can be fired to the same effective range
115:(it does not produce thrust; if it did it would be a
403:Gibson, Chris (2023). "It's All About that Base".
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311:: CS1 maint: bot: original URL status unknown (
221:fixed coastal artillery gun, the classification
217:(12 cm anti-ship shell m/70), used in the
206:(7.5 cm anti-ship shell m/66) used in the
465:Army researchers add power, range to artillery
202:The concept was quickly implemented into the
248:XM1128 showing bleed propellant cavity (red)
229:(SRC), then owned by aeronautical engineer
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443:(in Swedish). Nyköping: LAH Bunkertours.
441:ERSTA - Från svarvspån till byggnadsminne
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256: – 155 mm base bleed artillery round
69:Learn how and when to remove this message
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32:This article includes a list of general
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16:Method of increasing artillery range
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38:it lacks sufficient corresponding
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286:Nguyen, Ductri (30 August 2011).
424:(in Swedish). Stockholm: Liber.
379:from the original on 2019-04-29.
366:ASSESSMENT OF ERFB-BB PROJECTILE
339:"155 mm HE ER FB-BB (OFd M3-DV)"
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204:7.5 cm sjömålsgranat m/66
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215:12 cm sjömålsgranat m/70
187:Försvarets Materielverk (FMV)
183:Försvarets forskningsanstalt
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420:Grenander, Gunnar (1987).
263:Rocket-assisted projectile
227:Space Research Corporation
191:rocket-assisted projectile
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141:Shaping the shell properly
117:rocket-assisted projectile
107:is a system used on some
53:more precise citations.
439:Hansson, Lars (2008).
405:The Aviation Historian
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189:) while working on a
131:Most (50–60%) of the
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481:Artillery ammunition
208:7.5 cm tornpjäs m/57
422:Vapenlära för armén
486:Swedish inventions
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467:Picatinny Arsenal
450:978-91-977297-0-3
254:XM1128 projectile
149:sabot projectiles
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231:Gerald Bull
137:shock waves
51:introducing
475:Categories
270:References
98:Base bleed
34:references
413:2051-1930
389:Grenander
343:MSM GROUP
113:base drag
109:artillery
102:base burn
374:Archived
307:cite web
240:See also
127:Function
348:29 July
297:7 April
177:History
47:improve
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223:secret
157:thrust
36:, but
377:(PDF)
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291:(PDF)
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445:ISBN
426:ISBN
409:ISSN
350:2022
313:link
299:2023
133:drag
105:(BB)
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