B-2 Bomber SDB Carrying Capacity

I was reading the article below about the USAF integrating the SDB into the F-22 and F-16 (Blocks 30-50) then caught this little piece...

Eventually Air Force experts plan to equip the B-2 long-range strategic bomber to carry as many as 216 Small Diameter Bombs on each mission.

Link

The first two words that came to mind, appropriately, were "Holy...". Currently the largest load the B-2 can carry is 80 500 lb JDAM's. With this load it can attack eighty individual targets, obviously, or an entire area, like an airfield. With a possible 216 however it can take out much more than that, multiple defense instillations and military targets in one attack. To put that in prospective, a mission that would take 27 F-15E Strike Eagles each dropping eight bombs would only take one B-2, simply incredibl.

More on the Small Diameter Bomb (GBU-39).

GBU-39 variant of the Small Diameter Bomb has guidance from the satellite Global Positioning System (GPS), as well as from an inertial gyro. The future GBU-40 variant will have a terminal seeker with automatic target recognition capabilities for mobile and relocatable targets.

The bomb measures 5.9 feet long and weighs 285 pounds, and is to increases the number of weapons an aircraft can carry, as well as reduce collateral damage. The bomb has a range of more than 60 miles, and can operate in bad weather.

Other Sources.

The F-22, for example, will carry up to eight GBU-39s in its two internal weapons bays for attack missions. The B-2 could potentially deliver up to 216 SDBs in one load.

Interesting Read On the SDB Program

At the risk of sounding stupid (well... I suppose thats nothing new for me ) would this actually be of much use?


The B-2 is a strategic platform, the SDB essentially a tactical weapon.

B-2s are not going to be doing CAS missions - they'll be going after bridges, power stations, command facilities etc.

Does an SDB have the punch to take out such things? Or are bigger bombs with a bit more bite the norm?

Originally posted by kilcoo316
The B-2 is a strategic platform, the SDB essentially a tactical weapon.

B-2s are not going to be doing CAS missions - they'll be going after bridges, power stations, command facilities etc.

Well, the SDB, due to it's new technological and design innovations can be used against strategic targets even though it is relatively small. Of course (as I'm about to show) it's not the end all be all hence why the B-2 can still carry the GBU-31 (2,000 lb), EGBU-28 (5,000 lb), JASSM, JSOW, GBU-38 and in the near future the Massive Ordnance Penetrator (30,000 lb).

Originally posted by kilcoo316
Does an SDB have the punch to take out such things? Or are bigger bombs with a bit more bite the norm?

Due to the design of the SDB penetrator and charge it still has the 'kick' to take out large or reinforced targets.

Although the SDB is significantly smaller than existing bombs, its warhead is still adequate for many typical targets. E.g. its steel and concrete penetration capability is similar to that of the much larger 2000 lb BLU-109/B warhead. Therefore the SDB enables USAF bombers to attack more targets per sortie. The smaller warhead will also tend to reduce collateral damage.

Link

The US Air Force is developing a Focused Lethality Munition warhead for the Small Diameter Bomb. The new warhead employs multi-phase blast explosive and a composite carbon fiber warhead case, allowing for pinpoint strikes with low collateral damage. The FLM warhead technology was developed at the Lawrence Livermore National Laboratory and the U.S Air Force Research Laboratory.

Link

The small-diameter bomb is a 250-pound class munition, providing the warfighter with a four-fold increase in weapons per aircraft station. It can penetrate more than 13 feet into a target and can be accurate from up to 70 miles away.

Link

Video Of SDB Penetration Test

The Small Smart Bomb is a 250 pound weapon that has the same penetration capabilities as a 2000lb BLU-109, but with only 50 pounds of explosive. The 250 pound-class warhead that has demonstrated penetration of more than 6 feet of reinforced concrete. With the INS/GPS guidance in conjunction with differential GPS (using all 12 channel receivers, instead of only 5) corrections provided by GPS SPO Accuracy Improvement Initiative (AII) and improved Target Location Error (TLE), it can achieve a 5-8m CEP. The munition, with a smart fuze, has been extensively tested against multi-layered targets by Wright Laboratory under the Hard Target Ordnance Program and Miniature Munitions Technology Program. The length to diameter ratio and nose shape are designed to optimize penetration for a 50lb charge.

In early ground testing, the weapon's ability to penetrate six feet of reinforced concrete was demonstrated. In subsequent testing, a total of five weapons were dropped against targets with surveyed aim points (no target location error). The bombs' accuracy was achieved through the use of a Differential Global Positioning System (GPS) guidance unit. A few tests demonstrated the abilityof the Munitions Directorate-developed Hard Target Smart Fuze to initiate bomb detonation at the optimum location duringpenetration.

The miniaturized munition concept was a weapon that is six feet long, six inches in diameter, and weighs only 250 pounds with approximately fifty pounds of Tritonal explosive material. The weapon is effective against a majority of hardened targets previously vulnerable only to munitions in the 2,000 pound class.

Link

SDB Specifications

Small Diameter Bomb

As you can see the SDB was designed from day one to have good penetration and destructive capability yet still be small and have long range. It will expand and increase the B-2's strike capability because it will allow it to attack many different targets in one mission and with one load. From mobile tactical systems to fixed strategic ones, with a load out of 216 it will also have more of an immediate and devastating affect on the battlefield, it also improves the B-2's survivability.

The SDB offers the latest developments in GPS guidance, data links, fuse/penetrators, (future seekers) and overall reliability as well. The B-2 however does not have to be loaded entirety with SDB's, you can also have a mixed force of some with SDB's and some with other weapons, depending on what the mission requires. And finally, due to the large load and enhanced accuracy/fuse the B-2 can "ripple fire" if need be to destroy a target with multiple SDB's without drastically reducing it's overall weapons load as would be the case with GBU-31's for example.

[edit on 23-12-2006 by WestPoint23]

Video of SDB air burst detonation, this is footage from the first picture with the rocket launcher.

Link

I was not aware that it had an airburst mode, apparently it's warhead can be set to explode at different times. It can be delayed, explode on contact or air burst.

SDB's are impressive...and needed, since today is all about keeping the collateral damage to a minimum.

If memory serves a B-1 can hold like twice the amount of the B-2....but I guess then it comes down to size...I dont think the B-1 could literally hold (internally anyway) over 400 small bombs, but that would sure make the enemy quiver.

Physical size, volume and weight capacity of the internal bays does matter, but the configuration and internal attachment points are also important. The B-2 has 80 attachment points for the BRU-61/A SDB rack, I don't know how many the B-1B has, some figures I've seen say 96-144 SDB's for the Lancer.

WP23,

>>
Physical size, volume and weight capacity of the internal bays does matter, but the configuration and internal attachment points are also important. The B-2 has 80 attachment points for the BRU-61/A SDB rack, I don't know how many the B-1B has, some figures I've seen say 96-144 SDB's for the Lancer.
>>

Uhhhh, no. This is a photo of the BRU-61 SMER in a B-2 weapons bay-

kr.img.blog.yahoo.com...

As you can see, it's 8 per rotary and thus 16 per jet which equates to a maximum of 64 GBU-39.

I frankly don't know where they came up with the '216' number. As that is on the order of 66,000lbs in munitions alone and the Batarangs maximum payload metric is in the low 40s. A fully loaded BRU-61 with four GBU-39 aboard runs about 1,600lbs so either they planned on a CBM type (large scale) rack. Or the 216 is based on a false understanding of how the payload:weight issues are truly resolved.

In any case, the big differences to keep in mind here are as follows:

1. Despite 'promises to the contrary' (expeditionary inflateable hangars and the like) the B-2 continues to fly almost entirely out of Whiteman AFB in Missouri. Which means that you are looking at 40+ hour trips to the ME/SWA region.

2. An F-15E is seldom more than about 8hrs out from any target it can realistically be expected to reach, just on the sheer un-comfort factor of sitting on those damn ACES II. The longest I recall hearing of was a single flight from Dharan to Kabul that was about 17hrs and they had to peel the pilot/WSO out with a blotter at the end of it.

3. If you end up paying 'X4' (due to nascent corruption) for something to be rebuilt after you blow it up, it makes sense to /deny it temporarily/ rather than hit high value targets that cost a lot more to replace. U.S. Desert Storm tacair idiots being a case point where the "Ho Boyee Big Building!" effect was what they aimed for in blowing up turbine generator halls rather than transformer pads and powerline distribution junctions. Partly this was because they just couldn't see anything much smaller. Partly it was because the weather and the enemy were all making life complicated. And mostly it was just little-boy-make-big-boom psychology. But if you /can/ attack individual point targets, be they loading ramps and approach roads to a Yugo factory or the pumps at a cracking tower, you can still blackmail the local yokels into seeing their bank accounts go flat without having to _literally_ destroy the infrastructure on which the 'next government' will still depend to keep their city-state from defaulting on multiple loans.

4. As someone else stated, the ability to stand off is important. Right now, even from 50,000ft, the B-2 is /terribly/ vulnerable as a more or less laydown-as-target-overflight type bomber. Indeed, at operational heights and speeds, it may well take 20 miles to turn a bomber around in and this, when combined with the changes in radar observation aspects may well put you in a damned-if-do-thrashed-if-don't scenario whereby the threat WILL SEE YOU BEFORE IMPACT if you maintain current course. But they will also track you if you try to 'break away' (which is particularly difficult in the Spirit because GTW mode halves the control deflection authorities). Indeed, if anything, the adoption of the GBU-39 may signal an acknowledgment of what Rumsfield I think it was admitted way back in 2000 when he came back from Russia with the news that "Yes, they can track us...". Standoff as _Better Bullet Theory_ is now driving the threshold to which stealth can usefully perform.

CONCLUSION:
Probably the critical factor here is that the GBU-39, when allowed full spectrum use -with it's parent or a remote targeting platform- undertake to reduce TLE or Target Location Error factors by differential compensation over a 2-way datalink. For the B-2, such a continuous emission would be death and while I have no doubt that it can do better (with it's GATS system and ultrahigh resolution APQ-181) at 'zeroing' the satellite propogation errors as stereo bias before launch, it remains true that the majority of GBU-39 use, especially in the later spiral upgrades, will be against _tactical_ targets developed on a time-critical basis. Such is something that the B-2 cannot really contribute to and probably (HDLD) never will.
As such, you need a functional UCAV which may only have 8 bombs onboard but which can loiter for 4-6 hours at 700nm radii and just /cover/ a country with airpower as both a bombardment and mosaic ISR system.
Something which neither the B-2 nor the Fastmover community can match.
Of course we're saddled and ridden by the worthless flyboys so when and if this will ever realisitically happen is attributable solely to the development and proliferation of DEWS as skyknight killers.


KPl.

That picture doesn't really show me anything, the B-2 can carry 80 500-lb GBU-38's which means 80 attachment points, the BRU-61/A rack does not cover that much more area than a GBU-38 bomb. Also, the 40k figure for the B-2 is it's standard and most economical load out, it does not mean it cannot hold more; albeit with the sacrifice of fuel and therefore un-refueled range...

Modifications currently under way will allow each B-2 to carry 80 500-pound GBU-38 JDAMs. The B-2 can also carry eight of the massive 5,000-pound GBU-37 bunker-buster bombs, and may eventually carry a pair of the 30,000-pound Massive Ordnance Penetrators. Proponents claim that by 2007 the B-2 could carry 216 [some accounts say as many as 324] of the 250-pound SDBs. Each BRU-61/A smart pneumatic carriage holds four SDB weapons, the rack weighs 320 pounds (145 kg) empty, and 1,460 pounds (664 kg) loaded with four 285 pound (130 kg) bombs. In principle, the B-2 has a total of 80 attachment points for the 500-lb MK82 GBU-30 JDAM, each of which could accommodate a single BRU-61/A rack, for a total of 320 SDB weapons. In practice, the resulting 117,000 lbs (53,000 kg) weight would exceed the B-2's nominal 40,000 pound (18,000 kilogram) payload by some wide margin. The bomber could of course trade up for somewhat more payload by trading off against fuel and un-refueled range. The widely cited 216 SDB carriage would result in 54 BRU-61/A racks, 27 in each bomb bay, for a total 78,800 pound (35,800 kilogram) payload, roughly double the nominal value.

Link

WP23,

>>
That picture doesn't really show me anything,
>>

Sure it does. It shows you the standard carriage format for the GBU-39 _on the B-2_.

The only way to get even /close/ to the numbers implied would be to modify the SBRA or Smart Bomb Rack Assembly which, like the CBM unit for the B-1B is a ladder rack of some 10,000lbs weight.

Even given that the SBRA on the B-2 is capable of carrying 40 GBU-38 per side instead of the 26 or so on the B-1 rack AND the GBU-38 carriage box is defined by it's 17" finspan instead of the 7.5" over the GBU-39 (folding tail controls) diamondback; you _cannot_ achieve a 2.7:1 carriage number increase because 2.7 GBU-39 = 20.25 inches.

Now, further add to this the complexities of wiring up EACH station attachment for 1760 class wiring (power plus high speed bus) and the certainty that it takes upwards of THREE HOURS to load a single CBM with ordinary Mk.82 (30 minutes to decart and clean, 15 minutes to check electrical connects, 15 minutes for the first bomb and 5 minutes per bomb thereafter) and it rapidly becomes obvious that USAF is serving up another bellringer 'as if it were true'.

It's not possible. It's not practical. It's not necessary. Because the B-2 will not /generate/ sufficient targeting during it's limited time in theater to employ 216 weapons well. It either won't have the targets or won't be _over_ the target area where a TCT pops up.

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...the B-2 can carry 80 500-lb GBU-38's which means 80 attachment points, the BRU-61/A rack does not cover that much more area than a GBU-38 bomb.
>>

The BRU-61/A is not going to be the rack that they use to attach 108 GBU-39 per bay too. It will be an SSBRA and that ladder rack will be a major hassle to wire and hang ordnance from in the weapon densities implied.

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Also, the 40k figure for the B-2 is it's standard and most economical load out, it does not mean it cannot hold more; albeit with the sacrifice of fuel and therefore un-refueled range...
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Crap. You overload an airframe and you instantly bite into it's service life. Nor does 'shifting weight' from gas to bombs change the absolute structural loadpath values for any given area of weight -distribution- on the primary frames.

The B-2 is too valuable and too materials unique to risk cracked composite spars due to overload conditioned flight _when there is no need_.

What's more, the Batarang carries 180-220,000lbs of fuel, depending on which source you read and achieves only 6,000nm range with it. Comparitively the B-52 achieves 8,800nm with 330,000lbs.

You chop half the B-2s gas out from under it to pay for the additional warload and you WILL PAY THE DIFFERENCE. Either in further reduced time over the target area or added tankers to bring it /allllll the way around/ the world. Or both.

When tacair or even 'regionally local' bombers on a 500-1,500nm radius could double it's BOTOT numbers AND be 'more present' for the _same amount of gas_. Simply because they are both more numerous and operating at shorter distances with fewer international flyover politics of divert and prestaged gas-pass.

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Modifications currently under way will allow each B-2 to carry 80 500-pound GBU-38 JDAMs. The B-2 can also carry eight of the massive 5,000-pound GBU-37 bunker-buster bombs, and may eventually carry a pair of the 30,000-pound Massive Ordnance Penetrators.
>>

Fine.

80X500lbs = 40,000lbs + 10,000lbs (SBRA) X2 = 60,000lbs.

8X5,000lbs = 40,000lbs + 5,000lbs X2 (MPRL) = 50,000lbs.

2X 30,000lbs = 60,000lbs (parent loaded like the B-53 to the upper roofmounts)

216 X 285 = 61,560lbs + 10,000lbs X2 (SBRA _without BRU-61 addition) = 80,000lbs.

i.e. You are pushing the absolute weight of the other loadout options JUST with the munition totals of the SDB alone. Even before you include the SBRA/BRU-61 weights.

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Proponents claim that by 2007 the B-2 could carry 216 [some accounts say as many as 324] of the 250-pound SDBs. Each BRU-61/A smart pneumatic carriage holds four SDB weapons, the rack weighs 320 pounds (145 kg) empty, and 1,460 pounds (664 kg) loaded with four 285 pound (130 kg) bombs.
>>

And 8X 1,460lbs = 11,680lbs. Which is more than reasonable for a jet looking to go from 16 to 64 shots WHILE GAINING a 50nm standoff option unavailable with the GBU-38. Nobody wants to see a B-2 come like a falling leaf down ala F-117 because the ballistic munition requires target overflight into the heart of the defensive envelope + sensor crosscoverage!

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In principle, the B-2 has a total of 80 attachment points for the 500-lb MK82 GBU-30 JDAM, each of which could accommodate a single BRU-61/A rack, for a total of 320 SDB weapons.
>>

NO IT DOES NOT! The B-2 has _two_ primary bay attachments into which you 'clipload' either an MPRL or an SBRA.

The SBRA has _40_ attachment points for Mk.82 class munitions of which the GBU-38 is carriage factor typified by it's 92.64" length, 17" finspan and 558lb weight.

The BRU-61 is _143"_ long and (empty) weighs 320lbs. Loaded it weighs 1,460lbs and is probably another 16" longer yet as the GBU-39 protrudes beyond BOTH ENDS by a good 6-8 inches.

As such, I doubt if you can even manage what they do on the B-1B when carrying Mk.82 AIR munitions which is to stagger the bomb rows at the cost of a couple weapons per rack.

Indeed, the closest I can compare to is when they 'reconfigured' a few CBMs to carry SUU-60 class TMDs and ended up permanently restressing the rack and derating it from 26-28 to 10 munitions on a weight change of only about 400 pounds per bomb.

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In practice, the resulting 117,000 lbs (53,000 kg) weight would exceed the B-2's nominal 40,000 pound (18,000 kilogram) payload by some wide margin.
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No freakin' kidding.

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The bomber could of course trade up for somewhat more payload by trading off against fuel and un-refueled range. The widely cited 216 SDB carriage would result in 54 BRU-61/A racks, 27 in each bomb bay, for a total 78,800 pound (35,800 kilogram) payload, roughly double the nominal value.
>>

I doubt it, seriously.

Wiring up the B-1's CBM for WCMD and JDAM carriage was originally supposed to be a plug'n'play 'ECBM' enhancment. Now I understand it to be a completely new rack with a different wiring group and computer interface as the 'ACBM'. The old modules are still capable of dumb + cluster release. But only those with the current 1760 wiring TO THE INDIVIDUAL RACKS are able to handle the precision weapons of Block-E.

CONCLUSION:
It being worth noting that the B-1 is also going to carry GBU-39 on the CRLs _not_ in the CBMs and given that there are roughly 3 times as many B-1Bs as B-2As with an order of magnitude greater signature vulnerability, the automatic question must be "Why not double their standoff bombload configuration through CBM carriage too?"

...

The answer is that the CRLs are cheap and easy go-to fixes that give you either-or on IAMs in the 250 or 2,000lb class with 1760 already imbedded in the spindle. While the GBU-38 has, by definition, only two 'other' class alternatives in the form of cluster weapons which we will not use in collaterals dense areas. Or dumb-iron 82s which we will not unload on ONE target just to play Arclight all over again.

Given that you cannot opposed-load SBRA and MPRL assymetrically on the Batarang and the MPRL provides _automatic_ improvements in multi-weapon class options for both standoff, suppression, hard target and multistrike/collateraled conditions; it makes sense that you would employ IT as your baseline for the SDB. Because, even more than the B-1B, the alternative 'smart bomb' isn't worth the associated platform risk of FDOW direct delivery (the only time the B-2 is useful as a platinum bullet force) and 64 vs. 80 is 'close enough' for DMPI trades.

What sucks is that the USAF is trying to trump up their hood ornament platform at the cost of real warfightering to begin with. Stealth is the worst of the bombers for HDLD low presence by virtue of their long radius lags limited inventory. And unlike the B-52 which can at least accomodate significant relief crew as well as quick-load external cruise for either FDOW or long endurance OBAS-as-gun-cabinet type missions; the B-2 crews are still vulnerable to excessive fatigue factoring.

Tacair may or may not quadruple the sortie rate and total TOI coverage areas but has so little COP loiter as to be equally worthless. And the UCAV whose TOTAL mission fuel for an 8 ship flight is less than ONE bomber's effect on the tanker stream with endurance numbers 3 and 4 times that of 'fighters' is being ignored altogether as the '8X8 = 64' equivalent solution to the B-2s _real GBU-39 delivery capability_. In which having targets under your nose is worth having bombs you don't drop because your crews are dead on their feet and/or the ONE jet is 200 miles from the popup target that it might kill, 'if only' it weren't 30 minutes out.

Moral Of The Story: Don't buy at face value what a corrupt organization sells only to further their own ends of force sustainment as a union job.


KPl.