Author Topic: Fires and Magazine Explosions  (Read 5782 times)

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Offline cjblack

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Re: Fires and Magazine Explosions
« Reply #15 on: February 20, 2009, 12:57:31 PM »
I wonder what the ignition temperature of Duranium is?
 

Offline schroeam

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Re: Fires and Magazine Explosions
« Reply #16 on: February 20, 2009, 02:50:54 PM »
I'm sure Steve will come up with an appropriate level of technobable for the DC requirements, but seriously, as much as we want to go back and forth on how realistic/unrealistic the requirement may be, he is still writing this game for him.  It is our privilege to play for free...

Adam.
 

Offline Erik L

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Re: Fires and Magazine Explosions
« Reply #17 on: February 20, 2009, 03:43:50 PM »
Sorium is the volatile element. That's why it's fuel and used in warheads :)

Offline MWadwell

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Re: Fires and Magazine Explosions
« Reply #18 on: February 21, 2009, 02:28:35 AM »
Quote from: "adradjool"
As long as there is oxygen present a fire will burn, well below the limit for humans to stay conscious, or live, therefore lowering the oxygen available in the space is not an option, totally eliminating oxygen to the fire is the only option, or cooling it.

<SNIP>

You might want to check this - as a INERGEN system is able to put out fires, but still allow people to enter the room afterwards.

From Wikipedia (http://en.wikipedia.org/wiki/Inergen):
"Inergen is used at design concentrations of 40-50% to lower the concentration of oxygen to a point that cannot support combustion.

A component of Inergen is carbon dioxide, which allows the human body to adapt to the environment of reduced oxygen that is present after discharge of agent. Discharge of Inergen results in an approximate 3% concentration of carbon dioxide within the space. This directs the human body to take deeper breaths and to make more efficient use of the available oxygen."
Later,
Matt
 

Offline SteveAlt (OP)

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Re: Fires and Magazine Explosions
« Reply #19 on: February 21, 2009, 04:28:11 AM »
Quote from: "jfelten"
So no matter how much fuel you have to burn, the amount of air/oxygen available is probably what is going to limit the fire.  I just don't think there is enough air inside a ship to sustain a big fire and allow it to grow out of control even if you have plenty of fuel.  On a wet navy ship there is a limitless supply of air.  
That is an excellent point. I hadn't considered the fact that wet-navy ships wouldn't burn so much without an external oxygen supply. I'll give some thought to how that would affect the idea of fires.

Quote
Quote from: "Steve"
The main reason is that ships blowing up due to magazine explosions is fun (well in a game at least) and fun gameplay is the most important factor. In terms of technobabble, you could argue that the warheads are actually anti-matter and they probably would explode.
There are a couple things I don't like about it.  The game currently tries to be realistic in areas that it can be such as orbital mechanics.  At least to the extent that it can be immersive.  But if something goes totally over the top such as nuclear warheads going off like popcorn, it ruins the experience since nobody will believe it is possible, like a bad movie or such.  Antimatter would be much more believable but I thought you specified somewhere that missile warheads were nuclear based?  
Based on the warhead descriptions they start off nuclear and eventually move to anti-matter. I suppose an alternative could be to base magazine explosions on the missile fuel but if that was the case then hits on fuel storage would be catastrophic.

Quote
Another concern I have is the golden BB effect.  Now that could be believable since there is plenty of historical precedent for it.  Although I would argue that is almost always something like a magazine explosion which gets less and less likely as technology progresses.  But even if believable or realistic, it is a game killer.  As you mention, sometimes gameplay has to come first.  Nobody past puberty wants to play a game where the battle can be totally thrown to a single wildly lucky chance event.  Eventually someone is going to loose the game because a tiny ship gets a lucky "die roll" on the intact enemy super dreadnought.  It might make a good movie when the evil guys death star gets blown up by the heroes,  but it doesn't work in games against evenly matched players.  I've seen many a home brew campaign game die an early death because some sort of golden BB rule resulted in something ridiculous happening.  That is not "fun".  Even the winner looses in the end when the others stops playing the game.

I'm not saying these ideas can't work and add color.  But I want to urge caution because I've seen similar things effectively ruin game systems in the past.  It even crosses game genres.  You can get away with a lucky hit causing extra damage (aka a "critical hit") but if you allow golden BB's to outright destroy intact ships and such, in my opinion it will poison the game.
It isn't just a movie situation; there are a lot of examples in real life. The one that comes to mind immediately is the Hood. In the Battle of the Denmark Strait, she was virtually undamaged when a shell penetrated her magazine and the 48,000 ton ship blew up, killing all but three of her crew. In the battlecruiser action prior to the main Battle of Jutland, the battlecruiser Queen Mary was lost when both of her forward magazines exploded, killing all but 9 of her 1275 man crew. In the same action, involving a dozen ships, Indefatigable was lost after two huge magazine explosions. Later in the main battle, the battlecruiser Invincible was destroyed when a 12" shell detonated the magazine under her Q turret. So the three largest British ships lost in the battle were all destroyed by magazine explosions. On the German side, the only capital ships lost were Lutzow, which got pounded to to destruction and Pommern, which (surprise!) was lost to a magazine explosion. Of the three Armoured Cruisers lost by the British in the battle, one of those, "Defence", was lost to a magazine explosion.

So while losing a ship to a lucky hit might be unfortunate, it is no way unrealistic in terms of naval history. Besides, Aurora ia a game involving fleets rather than single ship actions so the occasional loss of single ships to magazine explosions will hurt but should not be a game killer.

Steve
 

Offline welchbloke

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Re: Fires and Magazine Explosions
« Reply #20 on: February 21, 2009, 04:59:53 AM »
IIRC Admiral Beatty made the comment at Jutland 'Something's wrong with our bloody ships today'.  I agree that the loss of ships to magazine explosions is realistic, but the golden BB effect does deserve some consideration.  As with everything else in Aurora, I'm sure that Steve will introduce a piece of functionality for fire damage that, following first contact with the enemy (us!), matures into another colourful element of what is an excellent game.
Welchbloke
 

Offline IanD

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Re: Fires and Magazine Explosions
« Reply #21 on: February 21, 2009, 11:10:38 AM »
Steve wrote
Quote
the Hood. In the Battle of the Denmark Strait, she was virtually undamaged when a shell penetrated her magazine and the 48,000 ton ship blew up, killing all but three of her crew. In the battlecruiser action prior to the main Battle of Jutland, the battlecruiser Queen Mary was lost when both of her forward magazines exploded, killing all but 9 of her 1275 man crew. In the same action, involving a dozen ships, Indefatigable was lost after two huge magazine explosions. Later in the main battle, the battlecruiser Invincible was destroyed when a 12" shell detonated the magazine under her Q turret. So the three largest British ships lost in the battle were all destroyed by magazine explosions.

So Steve are you saying all our ship designs have a basic design flaw? :)  The German ships in WW1 had better protected magazines because they had already had experience of such a near catastrophe with the Seydlitz, I think at the Dogger Bank action in which the danger of an explosive flash in a turret descending the trunk to the cordite-handling room was exposed.

Does this mean there should be another tech line which governs how well the ships are designed to stand up to battle damage? Which in turn could affect the chance of the power plant, magazine, sorium fuel bunkerage etc detonating and destroying the ship?

Regards
IanD
 

Offline sloanjh

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Re: Fires and Magazine Explosions
« Reply #22 on: February 21, 2009, 02:04:27 PM »
Quote from: "IanD"
Steve wrote
Quote
the Hood. In the Battle of the Denmark Strait, she was virtually undamaged when a shell penetrated her magazine and the 48,000 ton ship blew up, killing all but three of her crew. In the battlecruiser action prior to the main Battle of Jutland, the battlecruiser Queen Mary was lost when both of her forward magazines exploded, killing all but 9 of her 1275 man crew. In the same action, involving a dozen ships, Indefatigable was lost after two huge magazine explosions. Later in the main battle, the battlecruiser Invincible was destroyed when a 12" shell detonated the magazine under her Q turret. So the three largest British ships lost in the battle were all destroyed by magazine explosions.

So Steve are you saying all our ship designs have a basic design flaw? :)  The German ships in WW1 had better protected magazines because they had already had experience of such a near catastrophe with the Seydlitz, I think at the Dogger Bank action in which the danger of an explosive flash in a turret descending the trunk to the cordite-handling room was exposed.

Does this mean there should be another tech line which governs how well the ships are designed to stand up to battle damage? Which in turn could affect the chance of the power plant, magazine, sorium fuel bunkerage etc detonating and destroying the ship?

Regards

Isn't that the internal armor rating?  I assume magazines can be armored.  That does raise an interesting point, though - for purposes of calculating the size of fire, etc, internal armor probably shouldn't contribute to HTK (I don't think it does now, but can't remember).

John
 

Offline Cassaralla

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Re: Fires and Magazine Explosions
« Reply #23 on: February 21, 2009, 03:42:15 PM »
On the matter of magazine explosions, perhaps a tech like the Battletech CASE system (I forget what the acronym stoof for in that game) could be implemented.  If I remember correctly it was a storage system designed to blow just the location of the missiles if a critical caused an explosion and leave the rest of the mech undamaged.  In Aurora this would be like venting the explosion via hull panels that blow out, saving the ship itself from total loss.
 

Offline SteveAlt (OP)

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Re: Fires and Magazine Explosions
« Reply #24 on: February 22, 2009, 09:38:59 AM »
Quote from: "sloanjh"
Isn't that the internal armor rating?  I assume magazines can be armored.  That does raise an interesting point, though - for purposes of calculating the size of fire, etc, internal armor probably shouldn't contribute to HTK (I don't think it does now, but can't remember).
There are no armoured magazines at the moment. Internal armour is out of date anyway after the armour system change so I think it needs replacing with a new concept.

Steve
 

Offline SteveAlt (OP)

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Re: Fires and Magazine Explosions
« Reply #25 on: February 22, 2009, 09:51:36 AM »
Quote from: "Cassaralla"
On the matter of magazine explosions, perhaps a tech like the Battletech CASE system (I forget what the acronym stoof for in that game) could be implemented.  If I remember correctly it was a storage system designed to blow just the location of the missiles if a critical caused an explosion and leave the rest of the mech undamaged.  In Aurora this would be like venting the explosion via hull panels that blow out, saving the ship itself from total loss.

Quote from: "IanD"
Does this mean there should be another tech line which governs how well the ships are designed to stand up to battle damage? Which in turn could affect the chance of the power plant, magazine, sorium fuel bunkerage etc detonating and destroying the ship?

Both of these are good ideas. I think what I may do is replace the existing standard magazine systems with player-designed magazines. This would include size, the efficiency of the mechanism (which would allow more storage space), the resistance to damage (which would replace the concept of internal armour and give the magazine more HTK) and an ejection system (which would be the basis of the chance of a magazine explosion). Larger magazines would be inherently more efficient and the armour for one large magazine would be less than that required for several smaller ones (In the same way that a 10,000 ton ship needs less armour than 2x 5000 ton ships).

The resistance to damage concept could also be built into engines, reactors and fuel storage. Perhaps instead of an actual resistance to damage tech line, you could choose the HTK number and the size/cost of each HTK level would be determined by the current armour technology.

Steve
 

Offline SteveAlt (OP)

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Re: Fires and Magazine Explosions
« Reply #26 on: February 22, 2009, 10:01:58 AM »
Quote from: "welchbloke"
IIRC Admiral Beatty made the comment at Jutland 'Something's wrong with our bloody ships today'.  I agree that the loss of ships to magazine explosions is realistic, but the golden BB effect does deserve some consideration.  As with everything else in Aurora, I'm sure that Steve will introduce a piece of functionality for fire damage that, following first contact with the enemy (us!), matures into another colourful element of what is an excellent game.
Yes, I agree that is what will likely happen. My experience with the 3DG made me a firm believer in the concept that if you get a group of intelligent people together, then it is highly unlikely that any idea supported by the majority will be a bad one. Through their comments, feedback and suggestions, the players of Aurora have made it a far better game than I could possibly have accomplished by myself.

Steve
 

Offline SteveAlt (OP)

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Re: Fires and Magazine Explosions
« Reply #27 on: February 22, 2009, 12:43:28 PM »
Quote from: "SteveAlt"
Quote from: "jfelten"
There are a couple things I don't like about it.  The game currently tries to be realistic in areas that it can be such as orbital mechanics.  At least to the extent that it can be immersive.  But if something goes totally over the top such as nuclear warheads going off like popcorn, it ruins the experience since nobody will believe it is possible, like a bad movie or such.  Antimatter would be much more believable but I thought you specified somewhere that missile warheads were nuclear based?  
Based on the warhead descriptions they start off nuclear and eventually move to anti-matter. I suppose an alternative could be to base magazine explosions on the missile fuel but if that was the case then hits on fuel storage would be catastrophic.
I have been reading up on accidents involving nuclear weapons. As an example, there is an interesting report on twenty-six accidents between 1950 and 1980 on the following webpage: http://www.milnet.com/cdiart.htm

This supports the view that is it is extremely difficult to get a nuclear weapon to explode by accident. However, it also demonstrates that the conventional explosives in the warhead can do a considerable amount of damage by themselves. At this point it occured to me that when an Aurora warship is hit by the nearby detonation of a nuclear weapon, only a fraction of the power of that warhead will actually hit the ship, with the rest of the explosion being wasted on empty space. Therefore the strength of the warhead in game terms really represents the fraction of the explosive power that would affect the ship. Even a single small nuclear weapon detonating inside a ship would apply all its energy against that ship and almost certainly destroy it. Which means that the best way to implement a realistic magazine explosion scenario is for the explosion to represent the conventional explosives within the warheads plus the missile engines, possibly the fuel and possibly a quantity of radioactive material. A large conventional explosion taking place within a ship is still going to go a massive amount of damage. I am tempted to assign an explosive amount equal to either a percentage of the warhead strength or a fixed amount (perhaps 1 point of damage) per missile. The percentage would likely be 10-20%. While the conventional explosives on a nuclear weapon are obviously not equal to 10-20% of the maximum warhead yield, they might be equal to 10-20% of the amount of energy that hits a ship from the nuclear detonation, especially as they would be exploding inside the ship.

Does this sound like a more reasonable scenario?

Steve
 

Offline SteveAlt (OP)

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Re: Fires and Magazine Explosions
« Reply #28 on: February 22, 2009, 02:36:45 PM »
I have created a prelimary design system for magazines. There are five components to each system:

1) Size
2) HTK
3) Armour Type
4) Magazine Ejection System. This is the percentage chance of successfully ejecting the magazine contents in case of damage. Starting chance is 70%. Increments are: 80, 85, 90 (4000 RP), 93, 95. 97, 98, 99
5) Magazine Feed System Efficiency. How much of the internal space of the magazine is used for actual storage rather than the mechanism. Starting efficiency is 75%. Increments are: 80, 85 (4000 RP), 90, 92, 94, 96, 98, 99

Leaving aside armour and HTK for now, you just select the size of the magazine. The ejection and efficiency are set to the best available. For example, I have set the Commonwealth to 90% for the Ejection System and 85% for the Efficiency. So if they select a 3 HS Magazine (same size as the existing Standard Magazine), the storage space available would be equal to 3 HS x 85% efficiency = 2.55HS. As each HS is equal to 20 missile size points, this translates to a magazine capacity of 51 (the existing standard magazine has a capacity of 50). Because of the 90% chance of successful ordnance ejection when damaged, the magazine has a 10% of an internal explosion. If the magazine was 10HS (as per the existing large magazine), the internal storage space would be 10 x 85% = 8.5 HS and the capacity would be 8.5 x 20 = 170. This is less than the existing large magazine (180 capacity). This can be improved with technology and larger magazines also become more attractive when armouring is considered.

The old internal armour system is no longer consistent with the updated external armour system so I decided to replace it with a method of improving HTK (hits-to-kill) instead. All magazines are assumed to have a base HTK of 1, regardless of size. You have the option of choosing a higher HTK if you wish. In this case, an amount of internal armour is added to make the magazine harder to destroy. The amount of internal armour added is based on exactly the same formula as that used for ships, except that for each additional point of HTK you only need armour strength equal to one tenth of the surface area of the magazine. This is because you are only increasing the chance for the magazine to survive a hit rather than adding armour strong enough to absorb hits. The amount of space required for the armour is deducted from the size of the magazine before internal space is calculated. This sounds complex so an example should make it clearer.

Lets assume a 1 HS magazine using the tech of the Commonwealth (90% Ejection System, 85% Efficiency, Composite Armour). With a normal HTK of 1, the magazine has internal storage space of 0.85 and therefore a capacity of 17.

If we increase the HTK to 3, then some internal armour is required. Determing the surface area of the magazine based on its volume (or HS) is straightforward maths

    Radius = ((Magazine HS * 0.75) / PI) ^ (1 / 3)
        Surface Area = (Radius ^ 2) x 4 x PI
In this case the radius is 0.6204 and the surface area is 4.8368

The armour strength required is equal to one tenth of the surface area multiplied by the total HTK - 1. In this case: 2 x (4.8368 / 10) = 0.9674

Once the amount of armour strength required is determined, the actual HS of that armour is a simple matter of dividing the required strength by the strength per HS of the best available armour, which is 8 for composite armour. So, in this case, the amount of armour required in HS is 0.9674 / 8 = 0.1209.

That 0.1209 HS worth of armour is deducted from the size of the magazine before internal space is calculated: 1 - 0.1209 = 0.8791

Which means that when the efficiency of 85% is applied to the remaining space, the capacity of the magazine drops accordingly: Internal Storage: 0.8791 x 85% = 0.7472, Capacity  = 0.7472 x 20 = 14.944, rounded down to 14. So an increase in HTK for the 1 HS magazine from 1 to 3, decreases its capacity from 17 to 14. If the HTK was increased to 5, then the capacity would drop to 12.

As objects get larger, the ratio of their surface area to their volume decreases, which is why in Aurora larger ships require less armour tonnage on a per HS basis for the same thickness of armour than a smaller ship. This also applies to magazines, so the percentage of capacity lost by larger magazines is less for a given HTK. For example, the 3HS magazine with a 51 capacity described earlier would have a capacity of 46 for 3 HTK and a capacity of 42 for 5 HTK. A 10 HS magazine with a 170 capacity would have capacities of 160 and 150 for HTKs of 3 and 5. If you increased it to a HTK of 10, the capacity would fall to 127.

This gives the player some real decisions to make, both in terms of how much research time he wants to spend on magazines and in how much protection against secondary explosion is emphasised over magazine capacity.

Steve
 

Offline waresky

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Re: Fires and Magazine Explosions
« Reply #29 on: February 22, 2009, 02:45:37 PM »
Awesome..u r surely an technician:)..
This "game" become deepest every time u upgrade:)
ty

Giorgio