View Full Version : Effective blast radii of FB/PF ordnance

09-16-2006, 03:28 AM

For lack of anything better to do, I decided to test the effective blast radii of pretty much all the ordnance available in game. When I say 'Effective' I mean the ability to destroy a truck.

To test the level of effectiveness I lined up a hundred trucks spaced exactly 10m apart, with a pattern of lights leading up to the first vehicle to aid in dropping the bombs/rockets in the correct place every time.

I only tested ordnance available to players, no AI only ordance (ie FAB5000) was tested. I have only tested ordnance that can be delivered with a single drop (a single click), ie single bombs and bomb pairs (all rockets are obviously pairs too). I have not tested fragmentation, or incendary devices.

Some people will no doubt think "well done youve proven that big bombs do more damage than little bombs". Well, thats not strictly true, some of the results were a bit surprising, and so I retested until I was sure I had a valid result. Anyway, heres the table of results :


So the statement "big bombs do more damage than little bombs" is not always true. Check the Japanese 600kg and 800kg results. the 800kg does LESS damages than the 600kg.
And for many other bombloads the relationship between weight and blast radius is not always obvious.

Why, for example are two SC250s not as effective as one SC500?
Why is the effectiveness of 2000ks of FAB the same as 4000kg of SC?
Why is the RAF/USAAF 1000lb bomb more effective than two 500lbs?
Why are two SC500s only as effective as one?
Why are two Japanese 250kg bombs over twice as effect as two SC250s, and over three times more effective than two FAB250s?

Anyway, as an ardent bomber/Jabo-ist, this gave me food for thought. I will consider my bombloads a little more carefully. I hope someone else finds this useful.


09-16-2006, 03:43 AM
Good work, kind of obviouse when one think about it. Strange that no one thought about it earlier. ( as far as i know ) http://forums.ubi.com/images/smilies/25.gif

09-16-2006, 04:56 AM
Is the 600kg a GP bomb and the 800kg an AP? I.e. possibly same explosive content, but different case thickness?

09-16-2006, 09:29 AM
Interesting piece of work. http://forums.ubi.com/images/smilies/clap.gif

09-16-2006, 10:28 AM
Nice work!

What I find the most interesting is the effectiveness of the Russian FAB500's. They are twice as effective as anything else in thier weight class.

On another note: I can understand how 2 x500 are not as good as 1 x 1000. A 1000 will always have twice the radius (roughly) as the 500 no matter how many 500's you put together. A 500 is still a 500 no matter how many there are.

09-16-2006, 11:06 AM
Great stuff, excellent info to have long discussed.

09-16-2006, 11:11 AM
How do those numbers stack up compared to real life?

09-16-2006, 11:12 AM
great work! http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif
and LOL @ mistel blast radius

i belive the damage if PF is nearly all todo with blast, or charge to weight ratio.

and one big bomb is normaly better than 2(or more) smaller bombs of the same weight.

one of the guys who designed the lancaster favoured biger bombs over the then raf policy of lots of light bombs. he reasoned even if u miss then atleast u will still break the windows http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

09-16-2006, 11:28 AM
Originally posted by luftluuver:
How do those numbers stack up compared to real life?

Very small.......I was reading up about a type of cluster bomb the Japanese used, they were mentioning how the bomblets were spreading out to if I recall a 300m radius. Most reports I've read give effective ranges MUCH higher then what we have.....I'll try and find the links again.

09-16-2006, 12:04 PM
Glad you like it guys and gals.

It was a bit of a night mare doing the Mistel blast. I had to extend my lines of trucks by about 300m beacause it simply just blew the whole of the first 400m line clean away! http://forums.ubi.com/images/smilies/784.gif

Interesting that you should mention cluster type bombs, LEBillfish.
Ive always rated the AB series of bombs, but think they are underused generally. They certainly have their place, and Im working on some numbers from in-game to show that. Watch this space.


09-16-2006, 12:33 PM
Great work, Hanglands.


* _54th_Speeder *

09-16-2006, 04:59 PM
I think it's important to note that the weight of a bomb has little to do with it's design or explosive content.

Also, since you only tested against one target type, you can't get a full understanding about the role of a particular bomb.

For example, the SD500 has smaller radius than SC500. It is supposed to be that way, as the SD500 is an AP bomb, and would do more damage against an armored target that it hit.

The same may be true for the comparison of the SC and FAB bombs. Perhaps FAB is less metal and more eplxosive, making it more effective against trucks.

09-16-2006, 05:21 PM
Remember that not all bombs are created equal.

I don't know if its modelled, but different nations used different high explosive fillers, with varying levels of 'activity' in their bombs. The British had relatively low activity filler during the beginning of the war, but swapped to higher activiey fillers as pre-war stockpiles were exhausted and new bombs manufactured. The Germans used quite a high activity filler for most of the war.

Then there is the differences in charge to weight ratio; i.e the ratio of explosives to bomb weight.

For example, the RAF started the war with the 'GP' serise of bombs, which ranged from 40-500lbs in size as well as a 1900 bs bomb, which had a charge to weight ratio of between 30-35%, which was quite poor. Disappointed with the results of these bombs, they created the MC, or Medium Capacity, serise of larger bombs in 1940-41. These has a CTW of 40-55% and ranged from 250-4,000 lbs and were considered far more effective (the GP serise of bombs were )

The RAF also created the HC, high capacity, bombs, which had a charge to weight ratio of around 75-80%. They came in 4,000 lbs, 8,000 lbs and 12,000 lbs flavours.

The Tallboy and Grandslam bombs had a charge to weight ratio of about 40%.

The standard German general purpose bomb of the war was the SC (Sprengbombe Cylindrich), wth a CTW of about 55% (which is quite high).

The PC (Panzerbombe Cylindrich) was the German armour piercing bomb, with a CTW of about 20%.

The SD (Sprengbombe Dickwandig) were Semi-AP bombs, which had a CTW of about 30-35% (which is roughly similar to the British GP serise of bombs from the start of the war).

The US GP series had a charge to weight ratio of around 50-55%. US AP bombs have a CTW of 15%, which is really low. The US also copied the British HC 4,000lbs bomb as the AN M56 (Light Case), but I can find no references to operational use.

09-16-2006, 09:11 PM



Here's a start, and a very minor one, I myself did not re-read the pages yet you may find some info there.

09-16-2006, 09:23 PM
i thought there was a 2000lb HC aswell? moot point considering theres no aircraft in our planeset that would take it. http://forums.ubi.com/images/smilies/16x16_smiley-sad.gif

09-17-2006, 01:54 AM
Some Luftwaffe stuff:



09-17-2006, 04:16 PM
Thanks for taking the time to do this. http://forums.ubi.com/images/smilies/25.gif

09-18-2006, 07:46 AM
Originally posted by FritzGryphon:
For example, the SD500 has smaller radius than SC500. It is supposed to be that way, as the SD500 is an AP bomb, and would do more damage against an armored target that it hit.

Isn't the SD a fragmentation bomb, although the flying fragments might be more dangerous to light armour than the pure blast wave. I've noticed the SD is slightly less effective against soft targets than the SC bomb, but wondered whether it might be different against hard targets. Never got around to testing that though.

Did do some extensive testing with the weapons that can be carried by the Il-2, A-20 and B-25. What you've found pretty much ties in with what I found. A few points:<UL TYPE=SQUARE>The BRS rockets are anti-armour rockets; they do no damage unless they hit, but they are the only Soviet rockets that will kill heavy armour. In RL pilots especially liked the BRS-132, but I found in-game that the BRS-82 will penetrate the front turret on a King Tiger and just one hit will kill it. As I doubt any tank has heavier armour and you need a DH anyway just use the BRS-82 for a lighter load.

My info says the M-13 was an improved BRS-132 and I certainly found it to be like other armour-piercing rockets, despite the game graphics indicating a napalm type weapon. I found you needed to hit to have any effect, but maybe it has some residual area effect, judging by what you found. An AP rocket with some gen-purp' utility, perhaps?

I also found that the added frag' effect with the ROFS-132 made them the best gen-purp' rocket. Armoured half-tracks can survive a near miss (~5 m) from an RS-132, but not near misses from an ROFS-132. That seems to accurately reflect the reason why the ROFS was developed in the first place.

I tested pairs of FAB bombs against Tigers and found FAB-50s need to hit or land within a metre, FAB-100 is lethal to Tigers within 5 m and FAB-250 can kill out to 10 m.

AO bomblets are useless against armour. I have a screenshot showing 5 from a stick of AO-10s land on a Pz.III and it survives.

Final point from a one-off online experience the other day. I'd been tank-killing with 4.5" rockets in a P-38. Most targets must have been Pz.IVs and if I hit they were destroyed. Started a run on a fresh target and went for the biggest target there. Saw the rockets explode against the side of a Tiger, but it survived. Good against most armour, the 4.5" seems to be ineffective against the really heavy stuff. Don't recall ever having a problem with the 60-lbers, OTOH.[/list]
Nice work, Hanglands, I'll be taking a copy I think.

Interesting to see they've modelled the PC-1600 with little blast effect, as may befit an armour-piercing bomb, while the SC-2000 is - not surprisingly - awesome in this respect. Unfortunately big armoured targets are not modelled quite so correctly. You might expect the PC to come into its own against a battleship, for example. However, a pair of PC-1600s dropped onto a BB will damage it; a pair of SC-2000s sinks it.

09-18-2006, 08:02 AM
Originally posted by Hanglands:
Ive always rated the AB series of bombs, but think they are underused generally. They certainly have their place, and Im working on some numbers from in-game to show that. Watch this space.

Actually the AB-250 is one of my prefered weapons for the Fw-190 in the jabo role. Especially against the parked aircraft that are now such a tempting target in Spits v 109s. I use my very own '4-2 rule' for a weapon release at around 1 km. Approach at 2-3 km; ID target; start a shallow dive-attack at high speed, keeping the target area in sight under the gunsight; as the target gets close at 1 km alt let it slip out of sight under the nose; count to 4 and drop the bomb with a 2 sec delay setting; some sort of result every time http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif Bug out low and very fast. Possibly not the ultimate in precision, but effective nevertheless and very survivable.

09-18-2006, 08:50 PM
It would be very interesting to see this test repeated against tanks.

09-24-2006, 09:23 AM
Originally posted by Hanglands:
Why, for example are two SC250s not as effective as one SC500?
Why is the RAF/USAAF 1000lb bomb more effective than two 500lbs?

I've always thought the big bombs were disproportionately effective in IL-2 and that's what you've found here. Taking your results and working out the area of destruction makes it even more obvious.

Looking at the results for pairs of FAB bombs and taking the 50s as the benchmark, you find:<UL TYPE=SQUARE>50s destroy 1 unit of area

100s destroy 2.25 units

250s destroy 4 units

so far things are roughly linear, so that x times more 'bang' destroys x times more area - fair enough - and there's even some evidence of 'diminishing returns' in the case of the FAB-250, which is what you might expect... but,

500s destroy 64 units

1000s destroy 156 units[/list]
Packing 20 FAB-50s into one bomb is as effective as spreading 156 evenly over the target area!! http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

In RL it was found that making standard bombs bigger was not the answer most of the time, which is precisely why cluster bombs and other area-effect weapons were developed.