EarthForce Warships

Omegas have numerous weapon emplacements.  Some are turrets and some are fixed-axis weapons.  The forward emplacements are fixed-axis, but are equipped with both interceptors and beam weapons.  The interceptors have a high rate of fire, at 3 shots per second, and are very effective anti-starfighter batteries as well as active defense devices against incoming destructive pulses.

Aft-mounted weapons are also fixed-axis, and include at least 4 interceptors and two (possibly four) beam weapons.  Pulse weapons mounted along the narrower sections of the ship are turret-mounted.  In the accompanying animation, they are destroying enemy Starfuries with pulse fire.

The "fixed" emplacements can still fire at significant angles from their bore orientation, as seen in this image from A Spider in the Web.  However, the existance of turret weapons implies that they have a wider angle available than these fixed weapons.

The heaviest weapons are mounted on the bow and stern of the ship, implying that they are designed to do most of their fighting while approaching the enemy or retreating from the enemy.  This arrangement makes sense, because the ship presents the smallest target when pointed directly toward or away from the enemy.  This is in contrast to the ancient "broadside bombardment" tactic.

In Severed Dreams, several Omega-class destroyers engage in combat against each other and Babylon 5.  The Churchill destroys one (the Roanoke) by ramming it, and Babylon 5 and the Alexander destroy another (the Agrippa by the visuals, the Roanoke by the dialogue, in a minor inconsistency).  In the case, the Alexander closes to point-blank range and fires with one of its powerful forward beams.

• The hull of the Agrippa is constructed from a type of steel. This allows us to use the thermal properties of iron to determine how much energy is used to melt the hull.  We use iron because it is a good construction material; it is widely available, and its thermal properties are easy to obtain.

• The beam weapon has a circular cross-section with a diameter of 10 meters.  We determined this value by comparing the weapon port and beam to the size of EarthForce fighters.
• The beam melted a line of hull 250 meters long.  This is approximately one fifth to one sixth of the length of the ship.
• The beam melted the hull to a depth of 2.11 meters.  This is proportionate-by-length to the depth of the thickest armor on a 20th-century Iowa-class battleship.
• No allowance has been made for airspaces since this is a measure of energy used to melt armor.
• The result is a lower-limit estimate of the power delivered to the target by the heavy beam weapons mounted on each side of the ship's bow.

Calculations The ability to deliver several kilotons of energy per second is consistent with the fact that Earthforce warships carry tactical nukes of 2 megatons yield each, as seen in In the Beginning.  Otherwise, there would be little need for the bombs in question.  If we assume that the heavy forward weapons on an Omega can deliver approximately 40 terawatts of sustained firepower, it would take just under 2 minutes (approximately 105 seconds) to deliver as much energy as the nuke.  Since a bomb delivers only a fraction of its energy to a single target, it would take only several seconds to deliver equal energy to that target with the beam weapons alone.  For example, if the bomb delivers 10% of its energy to the target, it would take approximately 11 seconds for a single beam weapon to the same amount of equal energy.  Thus, the above lower limit must be accurate within an order of magnitude.

Estimated Range

The maximum range of the weapons carried on an Omega is implied twice in canon events.  In Severed Dreams, we join Ivanova in her Starfury cockpit, and her computer quantifies the distance to the enemy.  When it reaches 700 kilometers, we cut back to C&C on Babylon 5, where an officer reports that the two forces are now entering firing range.  As both forces had launched fighters, which were closing more rapidly than the opposing warships, we can assume that an Omega's weapons have a maximum effective range on the order of a few times 700 kilometers.  This is supported by the fact that Sheridan ordered interceptors set to "long range dispersion pattern" to intercept incoming fighters in that same battle.  The pulses themselves did not diffuse, so it is likely that he meant for each turret to fire in a different direction. The second quantifiable event takes place in the Crusade episode The Long Road.  A Technomage on the surface of a planet builds power in a mine in hopes of destroying an Omega-class destroyer in orbit.  The Captain of the vessel informs Captain Gideon that he does not have the capability of killing this technomage in time to prevent the attack, and requests assistance.  Captain Gideon orders Excalibur's main guns to fire on the mine.  In A Call to Arms, combined events establish Excalibur's weapons range as less than 10,000 kilometers.  In that event, Sheridan ordered weapons to fire in dispersion (as above, the beams themselves did not diffuse, but each one fired a different direction), trying to map the structure of the Shadow Planet Killer.  Later, after considerable time for the forces to close, Sheridan ordered to fire "once we are in range," implying that the effective range is less than 10,000 kilometers.

This series of events implies that the weapons on an Omega-class destroyer have a maximum effective range of much less than 10,000 kilometers, as it cannot match Excalibur's range.  This is further supported by the planetary assault in GROPOS, where troops were landed with air support instead of beginning with a bombardment from orbit by the warship present.  It is also consistent with the upper limit of Whitestar range, established as less than 3,000 kilometers.

Omegas with Shadow Technology

EarthForce was able to at least partially replicate Shadow technology to retrofit a small fleet of Omega-class destroyers with techno-organic hull armor and advanced weaponry.  The Clark administration intended to use these advanced destroyers to attack the conventional Omegas that had defected to Sheridan's rebellion.  Learning of this plan, the White Star Fleet moved ahead of the rest of the fleet to spring the trap and engage the advanced destroyer force in Between the Darkness and the Light.

The exact advantages of the modified ships are not clear, but they were apparently more resistant to fire from Whitestars than conventional Omega-class destroyers (several of which were disabled in moments by Whitestars in orbit over Mars in Endgame).  They also used turret-mounted beam weapons not seen on conventional Omegas, and these weapons seemed to be more effective against Whitestars than the pulse cannons used against them in Battle of Proxima 3 (No Surrender, No Retreat).  Despite their enhancements, the advanced destroyers were unable to defeat the Whitestars, which outmaneuvered them and effectively concentrated their fire to eliminate the advanced destroyer fleet.  The advanced destroyers did, however, inflict more damage on the Whitestar fleet than any other Young Race fleet did onscreen (it is unclear if the Rangers, onboard Whitestars, participated in the Minbari Civil War).

Size

In this image, a lower limit on the forward section of an Omega can be estimated, since it is more distant from the camera than the station (B5's shadow is cast on the Omega).  If the front of Babylon 5 is 333 meters in diameter, then the front section of an Omega is at least 225 meters tall.

Since the ship is closer to Babylon 5 than either object is to the camera, this lower limit is close to the actual value.

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If the front section is over 225 meters tall, then the vessel is at least 1155 meters long in this image from Severed Dreams.

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In this image, the front section of the Omega closest to the bottom is 29 pixels tall.  The entire ship is 166 pixels long, indicating a lower limit close to the actual value of 1288 meters.

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If the front section of the ship is at least 225 meters tall, then the bay opening is around 30 meters tall.  A fighter is exiting the bay, but is difficult to see in this image.

If we assume that the bay opening is the same size as B5's bay opening (65 meters wide, 35 meters tall), the front section of the ship is around 270 meters tall, and the entire ship is around 1400 meters long.  This is not an unreasonable assumption, as Earthforce would likely dictate a certain standard for bay openings, so that ships of different class could dock at all EA facilities.

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In this image from Severed Dreams, the Alexander, and Omega Class Destroyer, is between the camera and Babylon 5.  The front of Babylon 5's rotating section is 54 pixels in diameter, and the front section of the warship is 48 pixels tall.  If this part of Babylon 5 is 333 meters in diameter, the front section of the Alexander is no more than ~296 meters tall.  This results in an upper limit of 1520 meters in overall length of the ship.  A direct measurement of the image above points toward a ~1260 meter overall length, but the ship is not perfectly presenting its broadside.  This upper limit is consistent with the assumption above about the dimensions of the bay opening.

Omega-class Estimated Length: 1288 - 1520 meters

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"Nova-class" Destroyers

“Nova” is a class name found in secondary sources; the term was never used in the series. These older destroyers (called “dreadnaughts” in secondary sources, even though “destroyer” is the standard term for large capital ships in the series) have many design similarities to the newer Omega-class, which was presumably designed and built by the same manufacturer. Novas fought in the Earth-Minbari war, but in far smaller numbers than heavy cruisers. Like the heavy cruisers, Nova-class destroyers were probably almost wiped out during the war; only one ship of the class was seen in the regular series (GROPOS).

Nova-class destroyers are substantially shorter than the newer Omega-class destroyers, but the forward hangar section is not noticeably smaller than the hangar of an Omega, indicating that they probably have a similar fighter complement. There is no evidence of beam weapons, but Nova’s mount large dual turrets along their length, which are presumably pulse cannons. Like heavy cruisers, Nova-class destroyers have no rotating sections to simulate gravity for the crew or passengers.

In 2259, a Nova carrying 25,000 EarthForce ground troops visited Babylon 5 to rest the troops and upgrade the station’s defense grid before moving on to support Earth’s allies in a civil war on the planet Akdor. This incident indicates that the Nova has enough hangar space for all of their troopships, since the destroyer did not emerge from hyperspace surrounded by a swarm of troopships.

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Size

In this image, a Nova is on the far side of the station from the camera, the front section having a lower limit of about 108 meters in height.

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In this image, the same ship is now closer to the camera than the station, the front section having an upper limit of about 300 meters in height in this angled image.

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In this image, the ship is approximately the same distance from the camera as the station.  This is demonstrated by the above images, the ship's shadow on the station, and the fact that the bay openings measure the same width within a pixel.  The station's docking ring is 208 pixels in diameter, and the Nova's front section is 141 pixels tall.  This results in approximately 226 meters, a nice match to the Omega scaled above.

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This image shows a broadside view of a Nova.  The front section is 263 pixels tall, and the visible portion of the ship (most of the ship's length) is 960 pixels long.  If the front section of the ship is approximately 225 meters tall, the ship is a bit more than 820 meters long.

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This image is severely angled, but does present the ship closer to the camera than the station.  The docking area of the station is 170 pixels in diameter, and the angled view of the ship is 378 pixels long.  This results in an upper limit of 740 meters in length of the current angled view.  The true upper limit from a broadside view would be some percent higher, but this measurement is relatively consistent with the one immediately above.  Unfortunately, a full broadside view is difficult to locate, but it seems likely that this warship is on the order of 750-1000 meters long.

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Weapons

Novas appear to be very heavily armed.  Although the relative amount of power available to each weapon is unknown, the gun mounts on a Nova dwarf those of an Omega.  These gun mounts appear to be approximately 41 meters wide and 85 meters long to the end of the barrel in the first image scaled above.  They appear to carry at least 16 such emplacements, with some facing forward and some facing aft.  It is unknown if these weapons are turret-mounted or fixed-axis.

Combat Role

Novas have no rotating sections, and thus no artificial gravity of any kind.  Along with updated equipment, this may be the primary advantage of Omegas over Novas.  The particular warship pictured above was used by Earthforce "Gropos" in the episode of the same name, and General Franklin was adamant that his troops would not spend several days in the transports.  It seems unlikely that the warship would be used for orbital fire support, as the more advanced Omega could not threaten ground targets easily in the Crusade episode The Long Road, discussed above.  It is possible that the warship's primary purposes in that conflict were to carry troops and supply a jump engine for escape.

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Heavy Cruisers

Earth Alliance heavy cruisers are often referred to as the "Hyperion-class" by some fans because the first ship of this type ever seen in the series was named the Hyperion and the B5 Wars game ran with this name and called the EA heavy cruisers "Hyperion-class" in their publications, even though it's both unproven and unlikely that the Hyperion was actually the first ship of its class.

Earth Alliance heavy cruisers were the most common EarthForce warships at the time of the Earth-Minbari War, and hundreds were gathered to defend Earth at the Battle of the Line. At that time, heavy cruisers were armed with turret-mounted pulse cannons and each carried a squadron of Starfuries. By 2258, the armament of at least some heavy cruisers included interceptors, as demonstrated by the Hyperion in A Voice in the Wilderness; these defensive weapons may have always been standard equipment.

During the war, EarthForce purchased new weaponry from the Narn Regime. EarthForce upgraded at least some heavy cruisers to carry heavy beam weapons similar to those mounted on Narn heavy cruisers. The heavy cruiser Clarkestown carried such weapons and inflicted considerable damage on the Omega-class destroyer Alexander in the early stages of Earth's Civil War (Severed Dreams) before being destroyed by return fire from the Alexander. The beams on heavy cruisers were probably similar in firepower to the beam weapons of Narn heavy cruisers and – later – on Omega-class destroyers.

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Note: Some behind-the-scenes comments suggest that interceptors may have a grid-like component that protects ships from beam weapons like electronic defense shields in other fictional stories, and the above event was referenced.  While an interesting concept, it is not Babtech policy to count behind the scenes comments as primary evidence, and no such effect was ever seen onscreen.  In strictly intrinsic terms, Clarkestown is a smaller and less heavily-armored vessel than Alexander, and it makes sense that it is more easily destroyed by a weapon of similar magnitude.  However, since an officer on the Alexander observed that Clarkestown's interceptors were down and that they could penetrate the hull because of this, there is reason to believe that interceptors do provide some kind of defense against beam weapons. It is also important to note that the beam struck a Starfury before impacting Alexander's hull.

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By around 2260, heavy cruisers were few in number as Omega-class destroyers became the workhorse capital ships of EarthForce. A couple of heavy cruisers were part of the task force that attacked Babylon 5 in 2260 (Severed Dreams), but their role in the battle was so negligible that they weren't even seen on screen after the shooting started. Furthermore, the EarthForce fleet gathered at Mars to defend against Sheridan's attack in 2261 (Endgame) did not include any heavy cruisers.

It's likely that the number of heavy cruisers available to EarthForce declined sharply during the Earth-Minbari war and that only a few were left after the Battle of the Line. EarthForce never replaced these losses, preferring to spend its resources on Omega-class destroyers, instead. By the end of the civil war, attrition had essentially removed the heavy cruisers from service.

EarthForce heavy cruisers had no rotating sections to simulate gravity. Their crews would therefore suffer losses of bone mass and muscle tone on prolonged deployments. EarthForce would have to rotate the crews frequently to keep them healthy, requiring them to keep standby crews available at bases. The use of a rotating crew section on the Omega-class allows the destroyers to remain deployed for longer periods without detrimental effects on the crew; this improvement, in addition to greater power and a larger fighter complement, probably convinced EarthForce to phase out its heavy cruisers.

Note: In his commentaries on A Voice in the Wilderness, Straczynski corroborates our conclusion that Earth’s heavy cruisers were almost all destroyed during the Earth-Minbari war and never replaced.