Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 05-04-2015, 04:52 AM   #91
Pomphis
 
Join Date: Oct 2004
Default Re: Operation Brünnhilde

Quote:
Originally Posted by Icelander View Post
Reichkannslei.Weltmittpunkbunker
Reichskanzlei

Weltmittelpunktbunker (unless you really mean "punk")
Pomphis is offline   Reply With Quote
Old 05-04-2015, 05:02 AM   #92
Icelander
 
Icelander's Avatar
 
Join Date: Mar 2006
Location: Iceland*
Default Re: Operation Brünnhilde

Quote:
Originally Posted by Pomphis View Post
Reichskanzlei

Weltmittelpunktbunker (unless you really mean "punk")
Thank you. My German was awful at school and has only gotten worse in the decades since.

Not that troopers from the SS-Sturmkommando Totenkopf; who always wear their gas masks, move stiffly but inexorably and appear impervious to pain and injury, are not very Dieselpunk.
__________________
Za uspiekh nashevo beznadiozhnovo diela!

Last edited by Icelander; 05-04-2015 at 06:31 AM.
Icelander is offline   Reply With Quote
Old 05-04-2015, 11:05 AM   #93
Icelander
 
Icelander's Avatar
 
Join Date: Mar 2006
Location: Iceland*
Default Chemical Weapons and Delivery Systems

Germany had stockpiles of tabun and sarin nerve gasses (among others). If these were used in combat in a Weird War II scenario, what options for delivery systems exist at the technology level of the time?

I'm particularly interested in a hypothetical situation where the German side can send in troops with reliable Sealed* and the opposition is limited to TL3 or lower tech countermeasures. That seems to address the issues that made chemical weaponry have questionable utility at our real TL7.

Limiting the Germans in our hypothetical situation, however, is that deploying aircraft is impossible, vehicles** are extremely hard to get to the engagement area and any artillery not man-portable is out. We're essentially arming infantry going into a target-rich environment with hostile life forms all around them, some intelligent, some not.

So, could someone effectively deliver sarin or tabun using light mortars, grenades, sprayers or similar methods?

What would the GURPS stats be?

How large does your chemical warhead need to be to fill x number of hexes with nerve gas?

How does spraying it work, if at all?

What about chloride and phosgene gas?

How much can you usefully compress those gasses, to use them in backpack gas dispensers (a.k.a. tactical herbicide sprayers)?

Would you get improved range by using an inert compressed gas, like nitrogen, to propel the chloride or phosgene?

Does early TL7 offer any realistic way to keep the phosgene or chloride extremely cold until it is sprayed?

Would there be a significant range benefit to propelling the chloride or phosgene in liquid form*** by means of compressed nitrogen, so that the backpack sprayer works somewhat like a flamethrower?

How would the range of poison gasses propelled under their own power compare to modern backpack riot gas dispensers? What about if we use nitrogen to propel them?

What about area of effect?

Do you need more or less volume of phosgene or chloride to affect a given number of hexes than you need with tear gas/CS/CN/OC?

*Because of... reasons.
**And those that might be moved there are mostly scout motorcycles, with perhaps one or two light automobiles.
***Becoming gaseous as soon as the temperature rose above minus lots, of course.
__________________
Za uspiekh nashevo beznadiozhnovo diela!
Icelander is offline   Reply With Quote
Old 05-04-2015, 11:33 AM   #94
johndallman
Night Watchman
 
Join Date: Oct 2010
Location: Cambridge, UK
Default Re: Chemical Weapons and Delivery Systems

Quote:
Originally Posted by Icelander View Post
I'm particularly interested in a hypothetical situation where the German side can send in troops with reliable Sealed* and the opposition is limited to TL3 or lower tech countermeasures. That seems to address the issues that made chemical weaponry have questionable utility at our real TL7.
Yes... If the opposition breathes and uses neurochemistry anything like ours, then this is pretty much an "I win" button. There aren't any practical countermeasures to nerve gasses at TL3-.
Quote:
So, could someone effectively deliver sarin or tabun using light mortars, grenades, sprayers or similar methods?
Nerve gasses are on B.439. Tear gas weapons that could be re-used for nerve gas are on High-Tech p103, 142, 143, 180, 192, 199 and Pulp Guns 2 p28-30. If you really trust your protective gear, you could refill flamethrowers or other sprayers with nerve gas, but it will use up a lot of the stuff.
Quote:
Does early TL7 offer any realistic way to keep the phosgene or chloride extremely cold until it is sprayed?
Liquid nitrogen.
Quote:
How would the range of poison gasses propelled under their own power compare to modern backpack riot gas dispensers? What about if we use nitrogen to propel them?
Use nitrogen.
johndallman is offline   Reply With Quote
Old 05-04-2015, 11:38 AM   #95
johndallman
Night Watchman
 
Join Date: Oct 2010
Location: Cambridge, UK
Default Re: [WWII/TS/Covert Ops/Weird War II] Götterdämmerung on Walpurgisnacht

If you're willing to use crazy science, there was a weapon proposed by an Austrian chemist in 1944 or so that used gaseous fluorine to burn powdered aluminium. This makes a blowtorch that will go through ferroconcrete like an ordinary blowtorch through butter, but the protective clothing and respirator requirements are severe, to say the least. The US Army looked at it after the war for dismantling fortifications but felt it was too dangerous.
johndallman is offline   Reply With Quote
Old 05-04-2015, 12:08 PM   #96
Icelander
 
Icelander's Avatar
 
Join Date: Mar 2006
Location: Iceland*
Default Re: Chemical Weapons and Delivery Systems

Quote:
Originally Posted by johndallman View Post
Yes... If the opposition breathes and uses neurochemistry anything like ours, then this is pretty much an "I win" button. There aren't any practical countermeasures to nerve gasses at TL3-.
Well, fantasy TL3, so there are some who are able to counter it and accordingly must be dealt with carefully. It has been decided that certain beings encountered in the engagement area are useful potential allies, but anyone incapable of harnessing mysterious energies to shield himself is a nuisance to be cleared out, not someone to negotiate with.

Quote:
Originally Posted by johndallman View Post
Nerve gasses are on B.439. Tear gas weapons that could be re-used for nerve gas are on High-Tech p103, 142, 143, 180, 192, 199 and Pulp Guns 2 p28-30.
Thanks, I was in the process of having Adobe Acrobat search my eletronic library.

I found generic nerve gas rules, but no way to distinguish between tabun, sarin or VX gas.

Looks like sarin might be modelled by the generic resistable cyclic toxic effects given for nerve gas on p. B439, with Symptoms as follows:

More than 1/3 HP: Moderate Pain (p. B428);
More than 1/2 HP: Moderate Pain[1] (p. B428) + Nausea (p. B428);
More than 2/3 HP: Coughing (p. B428) + Severe Pain[2] (p. B428) + Nausea[1] (p. B428);
More than HP: Coughing (p. B428) + Severe Pain[2] (p. B428) + Retching[2] (p. B428);
More than 1.5xHP: Coughing (p. B428) + Terrible Pain[3] (p. B428) + Retching[2] (p. B428);
More than 2xHP: Coughing (p. B428) + Terrible Pain[3] (p. B428) + Retching[2] (p. B428);
More than 3xHP: Coughing (p. B428) + Terrible Pain[4] (p. B428) + Seizure (p. B428);
More than 4xHP: Choking (p. B428) + Terrible Pain[4] (p. B428) + Seizure (p. B428).

[1] Lasts for as many hours as the margin of failure on the HT check.
[2] Lasts for as many minutes as the margin of failure on the HT check, but persists in the form of the next lower form (i.e. Moderate Pain or Nausea) for as many hours as the margin of failure on the HT check after that.
[3] Lasts for as many minutes as the margin of failure on the HT check. Is then reduced to Severe Pain, which which lasts for as many hours as the margin of failure on the HT check after that. Moderate Pain persists until all HP caused by the gas are healed.
[4] Lasts for as many hours as the margin of failure on the HT check. Is then reduced to Severe Pain, which persists until all HP caused by the gas are healed.

Other Symptoms than those with special notes last for as long as the character is exposed to the gas, as well as many minutes as the margin of failure on the HT check to resist.

This is for someone exposed through both dermal and pulmonary means. Dermal exposure only adds an Onset time of 2d minutes and drops the Coughing (p. B428) Symptom.

A gas mask adds +1 to HT checks to resist. Heavy clothing with full body coverage can give a further +1 bonus, but only for someone wearing a gas mask or not exposed long enough to need to breathe. Purpose-designed and specially-treated capes/ponchos combined with gas masks (or Doesn't Breathe) give a total of +3 bonus to HT to resist, for a modified roll of HT-3 against sarin gas.

Increase the cycle time and give a bonus to the HT check for lesser concentrations than typical weaponised payloads in the immediate target area. Massive concentrations can count as more than one cyclic attack, requiring multiple HT checks and doing damage independently. Total damage for multiple doses for the purposes of Symptoms.

I suppose tabun would be similar, but be resisted at HT-5 instead of HT-6 and do 1d+2 tox instead of 2d per hourly cycle.

Does anyone care to propose a write-up of phosgene or chloride gas?

Quote:
Originally Posted by johndallman View Post
If you really trust your protective gear, you could refill flamethrowers or other sprayers with nerve gas, but it will use up a lot of the stuff.
Gear?

Oh, no. Members of the SS-Sturmkommando Totenkopf do happen wear a gas mask at all times, but there are... other reasons why they do not need to worry about being poisoned. :)

Quote:
Originally Posted by johndallman View Post
Liquid nitrogen.

Use nitrogen.
Cool. How much shorter than the range of the base weapon would the range be for an adapted flamethrower which used liquid nitrogen to propel chloride or phosgene?
__________________
Za uspiekh nashevo beznadiozhnovo diela!

Last edited by Icelander; 05-05-2015 at 06:28 AM.
Icelander is offline   Reply With Quote
Old 05-04-2015, 01:43 PM   #97
johndallman
Night Watchman
 
Join Date: Oct 2010
Location: Cambridge, UK
Default Re: Chemical Weapons and Delivery Systems

Quote:
Originally Posted by Icelander View Post
It has been decided that certain beings encountered in the engagement area are useful potential allies, but anyone incapable of harnessing mysterious energies to shield himself is a nuisance to be cleared out, not someone to negotiate with.
Ah, the traditional SS way of making friends!
Quote:
I found generic nerve gas rules, but no way to distinguish between tabun, sarin or VX gas.
They aren't very different in their effects. They differ in ease of manufacture and storage, ability to be turned into binary gasses (two relatively safe chemicals that get mixed-on-launch and react to produce the weapon), persistence, and so on.
Quote:
Cool. How much shorter than the range of the base weapon would the range be for an adapted flamethrower which used liquid nitrogen to propel chloride or phosgene?
It's a bit more complicated than that. If you just fill the gas tank of a flamethrower with liquid nitrogen, it won't keep the fuel tank cold: it's too small and doesn't surround the fuel. You'll also start out with little or no pressure, and it will steadily increase as the LN evaporates until the safety valve blows.

You need to arrange some kind of vessel surrounding the fuel tanks and fill that with LN, allowing it to boil away without developing any pressure. You fill the gas tank with gaseous nitrogen, and try not to let it get too cold; this may involve re-arranging the plumbing to move it outside the LN jacket.

Here's a page about the Flammenwerfer 41. One of the tanks is for fuel and the other (probably the smaller) for gas. Somebody needs to do an Armoury job to move the tanks apart a bit and wrap a larger tank round the fuel tank.

Last edited by johndallman; 05-04-2015 at 01:46 PM. Reason: straighten out terminology
johndallman is offline   Reply With Quote
Old 05-04-2015, 03:37 PM   #98
Icelander
 
Icelander's Avatar
 
Join Date: Mar 2006
Location: Iceland*
Default Re: Chemical Weapons and Delivery Systems

Quote:
Originally Posted by johndallman View Post
Ah, the traditional SS way of making friends!
In their defence, there are pretty terrible biological organisms with Bestial and (generally) IQ 6 or lower in the operational area. Like, super-terrible.

Quote:
Originally Posted by johndallman View Post
They aren't very different in their effects. They differ in ease of manufacture and storage, ability to be turned into binary gasses (two relatively safe chemicals that get mixed-on-launch and react to produce the weapon), persistence, and so on.
I'm happy enough with sarin, above.

But now I have to stat chlorine/phosgene 80/20 mix. Himmler had to obtain a lot of something toxic without Hitler raising eyebrows and while pure phosgene might have worked even better, I'll rule that this was easier to obtain and/or had some minor operational benefits.

The real reason is that the Sanitätswerfer-Pioniere of SS-Sturmkommando Totenkopf would not work if they advanced ponderously through a cloud of colourless gas. The sickly green colour is vital. Vital!

Quote:
Originally Posted by johndallman View Post
It's a bit more complicated than that. If you just fill the gas tank of a flamethrower with liquid nitrogen, it won't keep the fuel tank cold: it's too small and doesn't surround the fuel. You'll also start out with little or no pressure, and it will steadily increase as the LN evaporates until the safety valve blows.

You need to arrange some kind of vessel surrounding the fuel tanks and fill that with LN, allowing it to boil away without developing any pressure. You fill the gas tank with gaseous nitrogen, and try not to let it get too cold; this may involve re-arranging the plumbing to move it outside the LN jacket.

Here's a page about the Flammenwerfer 41. One of the tanks is for fuel and the other (probably the smaller) for gas. Somebody needs to do an Armoury job to move the tanks apart a bit and wrap a larger tank round the fuel tank.
Himmler's had a few months and most of the SS to call upon for resources, as long as he's careful not to do anything that will tip Hitler off that he's using gas weapons.

I suppose it wouldn't be out of the question that they'd have designed a weapon based on the Flammenwerfer, but with a jacketed cylinder lined with liquid nitrogen.

As the troops this is being designed for will be minimum ST 14 and won't mind discomfort or fatigue, I think it would be an excellent idea to have two jacketed gas-mixture tanks and one (smaller) nitrogen propellant one. Total weight around 78 lbs. or so.
__________________
Za uspiekh nashevo beznadiozhnovo diela!

Last edited by Icelander; 05-04-2015 at 03:55 PM.
Icelander is offline   Reply With Quote
Old 05-04-2015, 04:30 PM   #99
johndallman
Night Watchman
 
Join Date: Oct 2010
Location: Cambridge, UK
Default Re: Chemical Weapons and Delivery Systems

Quote:
Originally Posted by Icelander View Post
But now I have to stat chlorine/phosgene 80/20 mix. Himmler had to obtain a lot of something toxic without Hitler raising eyebrows and while pure phosgene might have worked even better, I'll rule that this was easier to obtain and/or had some minor operational benefits.
Actually, a 50/50 mixture was used during WWI. The chlorine apparently helps spread the phosgene. The chlorine also takes effect much faster, while the phosgene kills more surely.
Quote:
As the troops this is being designed for will be minimum ST 14 and won't mind discomfort or fatigue, I think it would be an excellent idea to have two jacketed gas-mixture tanks and one (smaller) nitrogen propellant one. Total weight around 78 lbs. or so.
OK.

You don't want to use N-stoff, which makes a wonderful self-igniting flame-thrower, but will burn almost anything, notably including concrete and flesh.
johndallman is offline   Reply With Quote
Old 05-04-2015, 06:05 PM   #100
Icelander
 
Icelander's Avatar
 
Join Date: Mar 2006
Location: Iceland*
Default Re: Chemical Weapons and Delivery Systems

Quote:
Originally Posted by johndallman View Post
Actually, a 50/50 mixture was used during WWI. The chlorine apparently helps spread the phosgene. The chlorine also takes effect much faster, while the phosgene kills more surely.
Ah. I found a reference to a German WWI 80/20 mix, but didn't know if a 50/50 mix was practical.

Quote:
Originally Posted by johndallman;1897189You don't want to use [URL="http://en.wikipedia.org/wiki/List_of_stoffs"
N-stoff[/URL], which makes a wonderful self-igniting flame-thrower, but will burn almost anything, notably including concrete and flesh.
While flamethrowers would be in the arsenal of the Weltmittelpunktbunker, it's not certain the PCs will encounter troops armed with them. They are probably inferior to StG44s and grenades for defending tunnel strongpoints.

Could you use N-Stoff in a Flammenwerfer and if so, what would it do to the stats?
__________________
Za uspiekh nashevo beznadiozhnovo diela!
Icelander is offline   Reply With Quote
Reply

Tags
covert ops, special ops, tactical shooting, weird war ii, world war ii, wwii

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 02:51 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.