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Octuptarra Magna Tri Gun
Rocket Artillery

Range   Fire Rate   Penetration   Collateral

The towering Octuptarra Magna artillery-droids of the Techno Union carried three artillery guns into battle, arranged into three arcs to ensure that the wardroids could wage war on all fronts. The Octuptarra Magna Tri Droid shown in the image is equipped with three ordnance launchers, though some variations of the wardroid had blaster (or "laser") cannons instead, and could rotate their guns to sustain a higher rate of fire in a given direction; blaster equipped Tri Droids also had a different armour pattern and different limbs compared to the rocket artillery variant. 


The magna rockets calibre hasn't been specified by any source but videos and images show that it was certainly less than 200 mm (8 inch), and might be less than 100 mm (4 inch); the projectiles probably weigh much less than 100 kg (<220 lb) based on their size.


Range

Firepower

Comparison to Real World

Reinforced Concrete Vs. Armour Steel

Concluding Statistics

References

Range

The Octuptarra magna cannon fires rocket assisted munitions, so range is limited by the fuel and navigation of the rockets, & not necessarily by the horizon. 

 In the case of Octuptarra magna droids which have their ordnance launchers replaced with line-of-sight blaster (or "laser") cannons, range is limited by the horizon, which (for example) at 10 meters elevation on an Earth like planet would be ~11 km or 7 mi. 

 

Firepower

Video footage from the battle of Mygeeto shows the Magna tri-gun artillery system in action, firing 6 to 7 rockets over 5 second periods to sustain a fire rate of 72 shots per minute; the magna rockets demonstrated tremendous penetrating power when they totally perforated Mygeeto bridges. This gif image captures the moment in which a magna rocket lands roughly-centre bridge and proceeds to explosively core through ~5 meters (14.6 ft) of reinforced concrete, leaving the structure punctured--with rubble pouring out from beneath, like blood from an open wound: Image 01

The bridge itself was roughly as thick as an UT AT (Unstable Terrain Artillery Transport) stands tall--which is over twice the height of a man--as seen in these photos: Image 01   Image 02   Image 03   Image 04   Image 05   Image 06 -- see gallery

Mygeeto bridges are supported by a network of thick metal bars which further strengthen their structure; concrete interlaced with metal in this way is by definition "reinforced". There is reference to materials with superior properties to their Earthly counterparts in Star Wars lore, i.e "ferrocrete" and "durasteel", and the mighty bridges of Mygeeto stand by virtue of their own strength and without columns for support, which might only be possible using "supermaterials". 

 

Comparison to Real World

For some grounding in reality and to get a sense of scale it can be useful to compare weapons in SciFi to those of real life; for perspective on the concrete penetrating capabilities of the Octuptarra's magna rockets--which greatly exceeds modern tank guns--I looked into modern day and historical concrete piercing weapons, i.e. "bunker busters" and superheavy siege artillery. 

Real Life weapons with LESS concrete piercing capability

Weapon Particulars
 Concrete Penetration &
Kinetic Energy for Penetration
Source 
/
SUPERHEAVY SIEGE ARTILLERY 
\
  • Skoda 305 mm Model 1911
Weight of weapon: 20.83 tons  
Weight of shell: 384 kg (847 lb)
In service until 1945
  • 2 meters (6 ft 7 in)
Kinetic Energy = 22 MJ


"The weapon was able to penetrate 2 m (6 ft 7 in) of reinforced concrete with its special armour-piercing shell, which weighed 384 kg (847 lb)."
  • Karl Gerät, Mörser Karl
Caliber: 600 mm (24 in) mortar
Weight of shell: 1,250 - 2,170 kg (2,760 - 4,780 lb)
In service until: 1945

  • 2.5 - 3.5 meters (8.2 - 11.5 ft)
Heavy AP shell KE = 52 MJ
Light AP shell KE = 89 MJ


The heavy concrete piercing shell could penetrate 2.5 m and the light concrete piercing shell could penetrate up to 3.5 m. The article does not specify "reinforced" concrete.
/
 BOMBS
\
  • Mark 84 bomb
Weight: 925 kg (2,039 lb)
Length: 3.28 meters (10.75 ft)
Diameter: 458 mm (18 in)
Presently in service*
  • 3.4 meters (11 ft)




"[...the Mark 84 bomb] can penetrate up to 15 inches (381.0 mm) of metal or 11 ft (3.4 m) of concrete, depending on the height from which it is dropped..."

/
BUNKER BUSTERS 
  • 2000-lb. SAP (M103) bomb (inert loaded)
No longer in service



  • 1.11 meters (3 ft 8 in)
KE = 50 MJ



Anglo American bomb tests "Project Ruby"
"(9) The inert loaded 2000-lb. SAP (M103) bomb, with a striking velocity of 1030 to 1100 feet per second, will penetrate only 3⁸–1¹¹ into reinforced concrete."
  • 1650-lb. Model bomb
No longer in service



  • 1.4 meters (4 ft 8 in)
KE = 34 MJ



Anglo American bomb tests "Project Ruby"
"(11) The 1650-lb. Model bomb, with a striking velocity of 1000 feet per second, will penetrate 4⁸–4¹¹ into reinforced concrete. With a striking velocity of 800 feet per second it will penetrate 3⁸-3¹¹."
  • 2000-lb. SAP (M103) bomb (picratol filled)
No longer in service




  • 1.8 meters (6 ft)
KE = 50 MJ





Anglo American bomb tests "Project Ruby"
"(10) The Picratol filled 2000-lb. SAP (M103) bomb, fuzed for 0.10 second delay, and dropped from 20,000 feet, wrill scab the underside of the ten foot thick Haligolerd roof. The bomb will blow through lesser thicknesses of concrete, such as the roof overhang, averaging six feet thick."
  • 12,000-lb fabrieated Tall Boy
No longer in service



  • 1.7 meters (5 ft 2 in)
KE = 182 MJ



Anglo American bomb tests "Project Ruby"
"(6) The American 12,000-lb. fabrieated Tall Boy (T10) bomb will penetrate 5²–8¹¹ into reinferced concrete at 850 feet per seond, and 3⁸–5¹¹ at 620 feet per second striking velocity."
  • 12,000-lb British Tall Boy
No longer in service



  • 1.7 meters (5 ft 2 in)
KE = 334 MJ



Anglo American bomb tests "Project Ruby"
"(7) The British 12,000-lb, east Tall Boy will penetrate 5²–7¹¹ into reinforeed concrete at a striking velocity of 1150 feet per second, 3²–9¹¹ at 850 feet per second, and 3²–0¹¹ at 620 feet per second."
  • BLU 109 hardened penetration bomb
Weight: 884.5 kg (1,950 lb)
Length: 2.5 meters (8 ft 2.5 in)
Diameter: 368 mm (14.5 in)
Presently in service*
  • <2 meters (4 to 6 ft)




Global security
"penetration capability of 4 to 6 feet of reinforced concrete"


  • 2000-lb AP bomb
No longer in service


  • 2 meters (6 ft 8 in)
KE = 55 MJ


Anglo American bomb tests "Project Ruby"
"(8) The British 2000-lb. AP bomb, with a striking velocity of 1150 feet per seeend, will penetrate 6⁸–0¹¹ into reinforced conarete."
  • 22,000-lb fabrinated Grand Slam (T14)
No longer in service


  • 2.3 meters (7 ft 8 in)
KE = 1,226 MJ


Anglo American bomb tests "Project Ruby"
"(5) The American 22,000-lb. fabrinated Grand Slam (T14) bomb will penetrate 7⁸–8¹¹ into reiniereed concrete at 1150 feet per second striking velocity..."
  • BLU 116 Advanced Unitary Penetrator [AUP]
Weight 874 kg (1867 lb)
Length: 2.4 meters (7 ft 10 in)
Diameter 370 mm (14.56 in)
Presently in service*
  • <3.66 meters (8 to 12 ft)




"penetration capability of 8 to 12 feet of reinforced concrete
Over twice the penetration of BLU-109
Performance demonstrated through Air Force tests"
 

Real Life weapons with SIMILAR concrete piercing capability

Weapon Particulars
Concrete Penetration &
Kinetic Energy for penetration
 Source
/
SUPERHEAVY NAVAL ARTILLERY
\
  • (406 mm) / 50-caliber Mark 7 naval guns
Calibre: 406 mm / 16 inch
Weight of shell: 1,225 kg (2,700 lb)




  • 6.4 meters (21 ft)
KE = 412 MJ





"The Mk. 8 APC (Armor-Piercing, Capped) shell weighed 2,700 lb (1225 kg)...[and at]...20,000 yards (18 km) the Mk. 8 could penetrate 20 inches (500 mm) of steel armor plate.[24] At the same range, the Mk. 8 could penetrate 21 feet (6.4 m) of reinforced concrete.[24]"
/
BUNKER BUSTERS
\
  • 22,000-lb Amazon bomb
No longer in service




  • 4.77 meters (15 ft 8 in)
KE = 560 MJ




Anglo American bomb tests "Project Ruby"
"(2) The 22,000-lb. Amazon bomb, with a striking velocity of 1100 feet per second, will perforate the 14⁸–9¹¹ thickness of the Farge roof, and can be expected to perforate up to 15⁸–l0¹¹ of reinforced concrete at this striking velocity."
  • 4,500-lb Disney Bomb
Weight: 2,000 kg
Length: 5.03 meters (16 ft 6 in)
Diameter: 380 mm / 15 in (body)
No longer in service

  • 5 meters (16 ft 8 in)
KE = 194 MJ




Anglo American bomb tests "Project Ruby"
"(3) The rocket assisted 4500-lb. Disney bomb, with a striking velocity of 1450 feet per second, will perforate the 14⁸–9¹¹ Farge roof, and can be expected to perforate up to 16⁸–4¹¹ of reinforced concrete at this striking velocity."
  • 5000-lb GBU 28 (BLU 113 super penetrator)
Weight: ~2300 kg (4700 lb)
Length: 5.66 meters (18 ft 7 in)
Diameter: 388 mm (15.3 in)
Presently in service*
  • 6.7 meters (22 ft)




"A sled test on 26 February 1991 proved that the bomb could penetrate over 20 feet of concrete, while an earlier flight test had demonstrated the bomb's ability to penetrate more than 100 feet of earth."
 

Real Life weapons with GREATER concrete piercing capability

Weapon Particulars
Concrete Penetration &
Kinetic Energy for Penetration 
Source
/
BUNKER BUSTERS
\
  • GBU-57A/B Massive Ordnance Penetrator
Weight: 13,600 kg (<30,000 lb)
Length 6 m (20 ft 6 in)
Diameter: 800 mm (31.5 in)
Presently in service*





  • 2.4 - 18 meters (8 to 60 ft) 
May or may not be similar to the penetrative capabilties of magna rockets in Star Wars according to the durability of Mygeeto concrete.

KE = >800 MJ
Exact velocity is classified but is "supersonic"



"(these number seem suspiciously high and may in fact be first in feet, not meters)
60 meters (200 feet) through 5,000 psi reinforced concrete
40 meters (125 feet) through moderately hard rock
8 meters (25 feet) through 10,000 psi reinforced concrete"
(other sources are also skeptical of the 8, 40, and 40 meter figures, claiming exageration)

These real-life concrete piercing weapons are designed to physically penetrate their target before exploding; conversely the tri-gun magna rockets penetrate meters of concrete with highly concentrated explosive force. The Star Wars magna rocket creates lateral blast effects which expand to perhaps a half dozen meters from impact, whereas massive real-life ordinances carrying dozens-to-hundreds of kilos of explosive result in much greater collateral antipersonnel blast effects which sometimes extend for hundreds of meters. 


These facts imply that the magna rocket performs much like an extremely efficient postmodern "shaped charge" with directed explosive force serving in place of the kinetic energy employed by real-life concrete piercing weapons. The magna rockets limited collateral effect renders them less useful for bunker busting and saturation bombardment, but their armour-piercing explosive is suitable for penetrating combat vehicles & fortifications (such as pillboxes, flak towers, etc.) with armour not equivalent to more than several meters of reinforced Mygeeto concrete. Note that in real life this would most likely include the armoured plate of even the largest naval vessels ever built at sea, in addition to all ground vehicles & most above-ground fortifications. 

 

Reinforced Concrete Vs. Steel

Estimating the thickness of steel which a magna rocket from Star Wars might penetrate is pretty much impossible without knowing the properties of Mygeeto reinforced concrete, however the ratio between steel armour piercing and reinforced-concrete piercing capabilities of certain real-world weapons have been published, and could be used to draw a comparison...

Mark 84 bomb

Weight: 925 kg (2,039 lb)

Length: 3.28 meters (10.75 ft)

Diameter: 458 mm (18 in)

Kinetic energy: unknown, likely >100 MJ


RATIO

Concrete Piercing

9 : 1

Steel Piercing

406mm (16 in) Mark 7 naval guns

Calibre: 406mm (16 in)

Weight of shell: 1,225 kg (2,700 lb)

Kinetic energy: 412 MJ


RATIO

Concrete Piercing

12 : 1

Steel Piercing

 

Demolition Shaped Charge

The Charge, Demolition, Shaped, 150mm is designed to make holes of considerable depth and breadth in a variety of materials. It consists of a 150mm diameter conical steel liner with three removable legs which provide a standoff of 145mm. The Charge, Demolition, Shaped, 150mm contains 3.1 kg of HE and its total mass is 4.9 kg.


Target Material Depth of Hole (mm) 

Armour Plate 178

Mild Steel 250

Hard Rock (Granite) 380

Reinforced concrete 760

Soft rock (Sandstone) 910) 

Global Security

RATIO

Concrete Piercing

4 : 1

Steel Piercing

Since the Star Wars magna rocket is effectively an extremely powerful and highly concentrated shaped-charge type ordinance (which penetrates the target with focused explosive force) it seems likely that the ratio between reinforced-concrete-piercing & steel-penetrating capability would be closer to the ~4:1 ratio of the 150mm shaped charge than the ~10:1 ratio of high--speed kinetic penetrators. 

 

Concluding Statistics

Magna Tri Gun Rocket Artillery System

Calibre: ~

Rate of Fire: ~72 rockets per minute per launcher (3)
Range: rocket assisted munition

Magna Rocket

Range: unknown upper limit

Yield: 100 - 1000 MJ AP explosive (25 - 250 kg TNT equivalent) estimated


Penetration capability

Reinforced concrete: 5000 mm (5 m) demonstrated

Non-reinforced concrete: 10,000 mm (10 m) estimated

Steel: 1200 mm (1.2 m) estimated


Deadly blast radius: ~4 m (13 ft)

References

STAR WARS Episode III: Revenge of the Sith

STAR WARS: The Clone Wars Movie

Wikipedia

Anglo American large bomb tests "Ruby Project" - pgs 8 to 9 (download)

GlobalSecurity.org (warning: only 5 free page views per month)

NEW SELF-PROPELLED PENETRATION BOMB - by Alexander Bolonkin & Shmuel Neumann - pgs 3 to 4