[SG,DS] Power Armour Weapon

G'day,

After the comments about water cooled MGs yesterday I was wondering if they
could resurface on power armour, which would be less concerned with the weight
issues. Feasible?

Cheers

Why carry water when you could carry more (pick one or more)
ammo/fuel/armor/?.

Michael Brown

[quoted original message omitted]

Agreed and more importantly a water cooled weapon doesn't pass the most
important it "looks cool and modern", military appropriations test....)

> At 1:45 PM +1100 3/9/03, Beth.Fulton@csiro.au wrote:

Since you've likely got a cooling system already for your fusion bottle or
something, you could build on that for weapon cooling. As you've got a
radiator system and space for circulation pumps, you don't need to have a big
cooling jacket, just a compact shroud around the barrel or perhaps a very
small jacket.

A water cooled (or something liquid) setup in this context could be quite
unobtrusive.

G'day,

Dealing with all in one....

> Ryan wrote:

That's what I was thinking/hoping so as you and Tim think it isn't too
weird I may have to think about this some more;)

> Mike wrote:
ammo/fuel/armor/?.

Well I was thinking more just coolant not necessarily water and depending on
your take on PA they can a) carry large loads anyway (after all some people
have them carrying class 1 vehicle weapons) b) would need their own coolant
systems so it might not be much of an extension

My limited understanding had lead me to believe that the main reasons not to
use it (as outlined in the earlier) posts were coolant/weight/being
static emplacement (this may be missing something subtle though so if I am
please point it out). So if it didn't take a whole heap extra to deal with
these issues then why not use them if their capabilities are such a handy
thing to have?

> Don wrote:

Well I play with WWI tanks and airships as a sci-fi force ;P

Seriously though a "cooled" weapon wouldn't have to look like something from
the past you can always make something look high tech even if the principle is
ancient <just hire a good *designer*;)>...

knight plate armour vs hardsuit... wooden crossbows they've been using in the
congo for thousands of years vs modern hunting crossbows... early gun vs WWI
gun vs vietnam era gun vs those things they use on
Stargate... ;)

Though I freely admit I may be oversimplifying here and if I am please pull me
up!

Cheers

I tend to fall on the opposition side of this issue. It seems to me that if
you are going to have to make choices in wiehgt allocation then why allocate
to water or coolant when a bigger gun, more ammo, a secondary weapon system,
or contermeasures, etc can be taken.  The advantage to water-cooled MGs
isn't all that great anyhow.

Now, if you are talking about a timeline such as a VSF setting, the
advantage of a water-cooled MG would make sense as there aren't too many
other options.

Eli

The thing to remember with water cooling even today is that it's a far better
medium for transferring heat than air is. It is used on larger caliber weapons
that have to have a high rate of fire. Several
naval mounts use them iirc as does the Russian ZSU-23-4 sp AA mount.

If you've got a few centuries of technical development to play with, it'd be a
lot easier to just say they use some sort of ceramic barrels and skip the
cooling entirely. Barrel might get a little warm, though...

(real life: the ceramic engine parts used today to not require cooling, but
are extremely sensitive to thermal and physical shock: in other words, sudden
changes in temperature or being hit).

on 03.3.10 0:15 PM, Ryan Gill at rmgill@mindspring.com scribbleth:
> The thing to remember with water cooling even today is that it's a

maybe I am wrong, but isn't the advantage of a water (or other fluid) cooled
weapon that long bursts can be fired without the need to replace the barrel.
The entire point of a power armoured force is that it can carry pretty much
everything it needs in its suit. Not having to stop and change the barrel on
a weapon would be a huge time-saver (wouldn't it?). Maybe for personal
weapons this would be unnecesary, but with a SAW...

Richard

> I tend to fall on the opposition side of this issue. It seems to me

> maybe I am wrong, but isn't the advantage of a water (or other fluid)
cooled
> weapon that long bursts can be fired without the need to replace the

So you could sort of have a Dune type 'Still-Suit' that has the ability
to use the pilots bodily fluids along with a starting reserviour to cool
weapons down. If your collecting sweat and other fluids from the trooper then
the weight to carry cooling water is reduced.

Just a thought.

Oh and on this power armour note Northstar have a new armoured figure out for
their WWII style range Project X.

http://www.northstarfigures.com/shop/projektx/powersoldat.html

Jeremey

> At 2:07 PM +0000 3/10/03, Germ wrote:

I think you'd need a bit more fluid than your average soldier to produce.
Plus, that fluid is going to have to go back to the user after a recycling
session.

> So you could sort of have a Dune type 'Still-Suit' that has the ability

> I think you'd need a bit more fluid than your average soldier to

How much water do you need to keep a barrel cool? Average fluid loss is 1.2
litres a day. So perhaps recycling and having the trooper share water with the
suits weapons would be for prolonged activity in the field.

Jeremey

> At 4:36 PM +0000 3/10/03, Germ wrote:

A belt of.303 (250 rounds) causes a vickers jacket to loose 1 pint of water.
With 7 pints in the jacket, you've got 7 belts before that jacket is dry. A
circulating system with a small radiator and reservoir could operate more
efficiently.

> A belt of .303 (250 rounds) causes a vickers jacket to loose 1 pint

Well with that kind of demand expecting a contribution from the trooper isn't
going to happen.;)

It's also going to add up to a lot of water per armoured suit just for one
water cooled weapon.

Jeremey

> At 7:33 PM +0000 3/10/03, Germ wrote:

The thing is, you've probably got some kind of cooling system for the suit
already right? If you do, why not add to that system and include the weapon's
cooling system in it as well, or piggy back off the same function.

Cooling circuit for the Guy inside Cooling circuit for the gun Cooling circuit
for the power pack
common fan with a backup for all three with 3 separate heat-sincs for
dumping heat into the surrounding environment at predicted times.

Yes, but with futuristic weapons using futuristic materials, given a normal
battle length and the ammount of long-burst firing that any gunner will
be
throwign out, is it really worth the fuss.  I thought wwater-coolign was
one of those things developed for when the primary use of an MG was for
sweeping open fields and defense. Modern SAW tactics don't really call for
extended burst fire, do they? Another thing to consider is that a coolign
system is just one more thing to break down.

Eli
[quoted original message omitted]

Well, I think mobility is key to modern and likely to futuristic warfare. I
am sure that if a water-cooled MG was more mobile tactics would have
evolved around it, but they haven't. I don't think you'll find anyone
complaining
because their MG doesn't have a cooling system - ammo shortages and
bulkiness yes.

Eli
[quoted original message omitted]

G'day,

> I thought wwater-coolign was one of those things

> At 5:29 PM -0600 3/10/03, staremu wrote:

Umm, they were and they are.

Several vehicles in WWII had water cooled Vickers MGs. Vickers light tanks up
to the Mk VIb and A13s up to the Mk III. Infantry tanks had
them as well. The .50 cal Vickers used in Anti-aircraft roles was
also water cooled, it was mostly a naval mount however. I'd say that the Water
Cooled MG didn't stay in use because of weight, rather it
was replaced in the ground/portable role because of weight and in the
emplaced/vehicle/ship mounted anti-aircraft role because of size of
projectile/range issues. I say this because there are several AA
mounts today that use water cooling to maintain

> At 12:15 PM +1100 3/11/03, Beth.Fulton@csiro.au wrote:

Machine guns in the heavy sustained fire roles were abandoned because the
human wave tactics fell into rarity. I'm sure that at Korea many US troops
were wishing they still had their water cooled M1919s over the air cooled
ones.

In the sustained indirect role, Water cooled MGs have been replaced by mortars
(as John would no doubt argue were he online).

I think, that given off world limitations on supply and that given a supply of
brass (easy to mine), link or cloth, propellant (you need a fertilizer plant)
and lead (also easy to mine) you could keep a water cooled MG in bullets for
years. In fact, the surplus market for.303 British is finally running out of
belted.303 Mk VIIIz from the 40's.

In the infantry role, Water cooled MGs are bloody heavy. They aren't terribly
good for attack, but are killer for defense. Your big problem being displacing
quickly to alternate positions on the defense. If you have to hold a line they
are good for a solid Final Protective Fire line.

For a powered trooper, a water cooled gun with a very streamlined jacket (and
armored), a 400 rpm rate and given a good supply of ammo, could keep the heads
down on a large number of fuzzy wuzzies or what
ever you want to call a nasty group of low tech creatures/people you
want to keep at bay.

> At 5:07 PM -0600 3/10/03, staremu wrote:

Consider human wave tactics and the need to kill lots of creatures before they
get to you and mob you down. Like I said in the other posting, I'll bet the US
troops in Korea were wishing for their water cooled M1919s. Barrel changes
were less of an issue with water cooled Guns.

Ryan Gill schrieb:
> At 12:15 PM +1100 3/11/03, Beth.Fulton@csiro.au wrote:

WWII Germans in Russia do not seem to have had problems over the lack
of a water cooled weapon. With a good barrel-change mechanism and a
skilled crew, the delay on a MG42 is no longer than putting in a new belt.

I have read anecdotes where in an emergency they even dispensed with
the asbestos glove normally used to handle the hot barrel :-(

> I think, that given off world limitations on supply and

"Easy to mine" would depend on the geology of the planet. Also, brass is two
elements (Copper and Zinc) that are not too commonly found together.
Generally, iron is more likely to be easily found.

> In the infantry role, Water cooled MGs are bloody heavy.

Which is indeed a problem as soon as the enemy has spotted the position.
Spotting an MG firing occasional bursts is not that easy, but
a sustained-fire position is something else.

Greetings Karl Heinz

Ryan M Gill schrieb:

> A belt of .303 (250 rounds) causes a vickers jacket to

I doubt it. Evaporation is just about the fastest way to move heat energy.
Heat transfer through conduction (radiator to air) is much slower. With a
radiator, you need either a ventilator to move enough air over a small
radiator or a large surface area with free air access to get rid of the heat.

Greetings Karl Heinz

Ryan Gill schrieb:
> Several vehicles in WWII had water cooled Vickers MGs.

The Russians also used water-cooled Maxims in AA mounts.

> I'd say that the Water Cooled MG didn't stay in use because of

Lots of armies (including the Bundeswehr) still use 7,62 mm or similar
calibres for vehicle AA MGs. I rather think that the AA or general vehicle MG
roles rarely call for sustained fire.

I suspect that water-cooled vehicle weapons were mainly used because
they were the standard weapon in the army at the time.

Greetings Karl Heinz

Only 400 rpm ROF? With modern materials and production I would expect somewhat
high ROF myself. And as for cooling the barrel, which is easier to maneuver, a
barrel with large fins to dissapate the heat to the air or a

barrel with a water jacket and 2 pipes leading to a radiator mounted on the
back of the PA? (after all, the surface area determines the heat disapation
rate, and I would prefere the heat disapation fins somewhere where they will
not interfere with the PAs troopers ability to fight).

Another question is are gataling guns (the multi barreled rotating ones)

rotating to allow the barrels to cool between firing or is there a separate
firing chamber for each barrel and the gun reloads while the barrel is
rotating, so allowing the increadably high ROF the are capable of (thinking
of the modern versions like the Phlanix or the gattaling in the A-10).

BIF

> From: Ryan Gill <rmgill@mindspring.com>

> At 11:13 AM +0000 3/11/03, david smith wrote:

Keep a lower ROF and you're going to have better control and better ammo
conservation. With a low ROF but, steady fire rate, you'll cover the same kind
of ground with better ammo conservation. With a 1200 rpm rate of fire, you're
talking about a lot of link for a small burst.

> Another question is are gataling guns (the multi barreled rotating

Phalanx gets its rate of fire by using multiple barrels and cools
them by moving them through the air. The ZSU 23-4 and the 40mm bofors
mounts use multiple barrels all cycling and water cooling.

> At 11:14 AM +0100 3/11/03, KH.Ranitzsch@t-online.de wrote:

Um, last I checked, they weren't able to turn Russian advances or attacks.
I'll bet that running out of good barrels did hurt things.

> I have read anecdotes where in an emergency they even dispensed with

Not really a problem with a water cooled gun I think.

> > I think, that given off world limitations on supply and

Its minimal enough technology that you can rely on it on most planets I would
expect. Brass cases have survived how long in our current weapons doctrine?
150 years.

> > In the infantry role, Water cooled MGs are bloody heavy.

That's a problem anywhere. One thing we're looking at is that you're giving
your power armor, high sustained rates of fire, minimal barrel changes, and
lower barrel wear (by keeping your barrel cool, you're minimizing wear). The
power armor can carry the weight, the ammo and since water is usually
plentiful, it's easy to add to the closed circuit even accounting for minor
losses of coolant. If water as a coolant were so problematic, why are we still
using it to cool most internal combustion reciprocating engines?

> At 11:22 AM +0100 3/11/03, KH.Ranitzsch@t-online.de wrote:

Close circuit systems seem to do pretty well. All but one of my vehicles has
it as a cooling system. What about your cars?

Radiators are in use in current small arms... For example, the original
version of the Soviet PKM GPMG had a paritaial fluted barrel. The flutes
increase surface area without increasing weight. They also affect barrel
vibration when firing. Fluted barrels are common in the civilian shooting
sector on high accuracy rifles with high rate of fire, such as varmit rifles.
Another current radiator in use is the prominent threads on Steyr AUG barrels.
This thread is a radiator to assist in heat disipation.

Why a hot barrel is such a bad thing is material science. Basically, if a
steel barrel is too hot to touch, it is hot enough to cause
re-crystalization.  This means you are changing the properties of the
steel in the barrel. It was much worse in WWI because the technology and
quality controls were much lower then they were in WWII. This means that heat
was a much worse problem in WWI then WWII. While it is still a problem today,
it is not the overiding conern it was in WWI.

There is an lot of experimentation going on in small arms barrels in the U.S.
civilian shooting industry, such as carbon fiber barrels with titatnium
linners, low friction coating for bullets (internal ballistics), Very Low Drag
bullets (external ballistics), etc. Actually, the VLD bullets aren't
experimental, they are very common now for long range shooting matches
(300+
yards). There's a lot of potential for improved military small arms and
improved amunition, but it languishes (from a military stand point) because
the U.S. military has it's head way up its own "donkey."

[quoted original message omitted]

[quoted original message omitted]

It's a matter of scale. Engines generate a constant, relatively low amount of
heat. Plus it has the mass of several hundred pounds of engine block to soak
up and distribute the heat, plus the mass of the radiator and fluid. This is
combined with dozens of square feet of radiating surface on the radiator (all
those skinny fins).

Comparison numbers - 1 gram of gasoline burns for 11.5 calories of
energy. 1 gram of black powder propellent burns for 718.1 calories per
gram - a roughly 70 fold difference in energy release. (modern
propellents are probably higher energy concentrates)

A gallon of gas weighs approximately 2.8 kg, so if you burn 10 gallons an hour
you have released 322 Kcal of energy. If in one hour you fire a conservative
100 rounds per minute, 1 gram of propellent per bullet, you release 4,308 Kcal
of energy. Multiply by 4 for 400 rounds per minute that is being discussed.

Note that the 1 gram per bullet is probably low, I couldn't find a number for
grains of propellent in 7.62 NATO, but 1 grain is 0.648 grams, so two grains
would be 1.296 grams. For comparison, most.45 ammo is loaded to 5 or 6 grains
of smokeless powder.

Yes, you could have a closed system for an MG, but you'd add a couple hundred
pounds of weight to it with extra pipes, reservoir, pump and fluid. The added
mechanical complexity probably isn't worth it either as you then have to have
flexible hoses, clamps and other parts that can fail.

-Binhan

> -----Original Message-----

Gatling guns work well because the number of round fired through any
particular barrel is a fraction of what a single barreled MG sees - i.e.
a six-barrelled gatling, each barrels sees only 1/6 of the bullets fed
into the MG so it has longer to cool than a single barrelled MG. In addition,
the rotation of the barrels causes increased movement of air which helps in
cooling. You can fire longer than a single barreled MG, but you can't sustain
for minutes on end at high rates because you still will burn out the barrels.

In addition to the added weight of the barrels, the drive mechanism is also
relatively heavy (you need a lot of torque to get 20 pounds of metal spinning
in a second or two). IIRC a 5.56mm minigun weighs over 30 lbs for just the
gun, 1000 rounds of ammo another 35 lbs, a truck battery to run the gun 30
lbs. So for 100 lbs of weight, you get about 10 seconds of firepower.

Assuming you run the power from the PA and quadruple the ammo load - 30
lbs for the gun, 140 lbs for ammo - 170 lbs for 40 seconds of fire. Not
totally unreasonable if you can PSB PA in the first place.

--Binhan

> -----Original Message-----
.
> Another question is are gataling guns (the multi barreled

> At 5:51 PM +0100 3/11/03, KH.Ranitzsch@t-online.de wrote:

Good enough to be the standard on modern high performance reciprocating
engines.

> > All but one of my

And, based on an environmental system, as well as a need to cool the power
supply, the user and other systems on the power armor, adding one additional
cooling circuit to the system doesn't necessarily complicate things. Does a
transmission cooler add that much complexity?

> Only engines with large areas exposed to the air (e.g.motorcycles) or

Rear engined Porche's were air cooled for a long time iirc. So were VW Beetles
and a number of other cars.

> This started off with "A circulating system with a small radiator and

But it incurs a penalty of having to add fluid to the system every so often.

> At 5:56 PM +0100 3/11/03, KH.Ranitzsch@t-online.de wrote:

I'd be willing to wager a fiver that the MG42's barrel and ammo consumption
rate as well as the retention of the Vickers in British and Canadian units in
the Korean war made a difference in both conflicts. Not something easy to
prove either way however.

> At 10:11 AM -0700 3/11/03, B Lin wrote:

This assumes that all the heat is expended into the barrel. Plus there's
frictional issues with both engines and guns. The compression of the Fuel Air
Mixture creates heat as well.

> Yes, you could have a closed system for an MG, but you'd add a

A couple of hundred pounds? A high flow system with a good sized radiator
could deal with heat pretty well I think and not weigh that much. Pumps are
small. Likely you've already got lots of flexible hoses for the man inside as
well as other conduits.

> Ryan Gill wrote:

> Phalanx gets its rate of fire by using multiple barrels and cools them

Some 40mm Bofors mounts use multiple barrels... but the ones in production
today (same gun, different mounts) are all single-barrel ones AFAIK.
Even
the CV4090AAA SPAAG :-/

Later,

> At 8:30 PM +0100 3/11/03, Oerjan Ohlson wrote:

Are the naval mounts still water cooled?

G'day,

> Yes, you could have a closed system for an MG, but you'd add

Water is good because it's cheap and available. There is higher tech stuff
like liquid sodium and such but they are nasty to deal with and
you can't just pour your canteen in the reservoir to re-fill it.  Once
you move away from that convenience, then you might as well use mechanical
cooling (a la those funky new refrigerators for the car) or passive cooling.

For instance, in WWI when running low on water for their MG's it was not
unheard of to contribute to the fluid supply by using recycled human water.
Since there was no active pumps for cooling, you didn't worry about
contaminants (like urea or salt) blocking up the works.

--Binhan

> -----Original Message-----

> A gallon of gas weighs approximately 2.8 kg, so if you burn 10 gallons

There's a big problem with this; you're leaving out a critical variable. The
brass casing acts as a heat sink and absorbs a lot of the heat and removes it
from the system when the casing is ejected. Car engines don't have anything
similar to this.

This is also what made caseless ammo such #$^%$@@ to get to work. HK teamed up
with Dynamite Noble and ended up using a propellent derived from solid rocket
fuel, not traditional gun powder to get a propellant that wouldn't cookoff.

Well, yes there are a lot of variables - temperature of the gasoline and
air as they enter an engine for example can both act as a coolant for an
engine, the circulating oil acts as another cooling system for an engine, the
sheer mass of an engine block as a heat sink, the fact that most engines run
at high energy output (lots of RPM's) also happen to be
traveling very quickly (100 kph+) which aids in cooling. I don't think
that most car manufacturers would suggest that running your car in
neutral at 6000+ RPM for 10 minutes is a recommended practice let alone
hours and hours on end.

In addition, car radiators are not completely closed systems. If they
were, you'd never have to re-fill the reservoir.  In emergency, they are
allowed to boil over - taking excess heat away as the fluid evaporates
and reducing dangerous pressure. The fact that they have this planned in
shows that they are not a total solution - you still fall back on
evaporation to take care of really large heat loads.

--Binhan

> -----Original Message-----

> At 9:20 AM +1100 3/12/03, Beth.Fulton@csiro.au wrote:

Water is good because it's cheap and common. Usually an
anti-freeze/boiling solution is added. Usually there are corrosion
inhibitors as well. Water is better the oil for transferring heat. There could
be more exotic materials but water based solutions are rather good.

> At 5:55 PM -0500 3/11/03, Imre A. Szabo wrote:

...too quickly. I seem to recall reading that they still had cookoff issues
with hot guns.

> On Wed, 12 Mar 2003 Beth.Fulton@csiro.au wrote:

Availability is a big problem, especially on a battlefield. Water is cheap and
plentiful (on Earth, at least), but if your weapon requires ethylene glycol as
a coolant, then you need to carry an ample supply with you.

> In addition to the added weight of the barrels, the drive mechanism is

You can reduce the weight by a thrid and the torque problem by a half by going
with a three barrel design and lower cyclic rate (also about half). Note that
this is a simple modification of the gun by removing half of the
barrels.  A redesigned mini-gun optimized for three barrels would cut
the weight to about 60% of a six barrel version. Example is the GE M61 at 120
kg versus the GE M197 at 66 kg. There are numerous other three barrel gattling
guns in existence, and no reason a 5.56 version couldn't be built.
My personal favorite is the XM188E1 30mm Aden/DEFA at 50 kg and 2,000
rpm...
But the gun I'm basing this idea is the GECAL 50. The six barrel version
(8,000 rpm) weighs 96 lbs, the three barrel version (4,000 rpm) weighs 66 lbs.
Note that the GE XM 214 5.56 mini gun has a maximum rate of fire of 10,000
rpm; but is usually set at 4,000 rpm or less. This means you could expect a
maximum of 5,000 rpm for a three barrel version. This should be more then
enough for most applications...

rpm means rounds per minute

This is a job for Reason [1].

So I've gone to the trouble and expense of putting my troops in powered armour
[2] and then I equip them with an MG designed three hundred years ago?

If I need an area-denial weapon [3], I'll issue a
rapid-fire low-calibre plasma weapon. Ideally it
will be adaptable so a quick adjustment will permit it to fire a bolt capable
of melting through the side of an enemy AFV. If there are overheating
problems with sustained fire, I'll issue a high-
performance low-calibre gauss weapon. Give it a
magentic action and no combustion or friction with the barrel and it'll go as
fast as you want.

If circumstances permit me power armour but force
the use of locally-manufactured medium-technology
ammunition, I'd consider an oversized automatic shotgun or grenade launcher.
If these don't have
the necessary range then I would resort to a low-
calibre gatling weapon. Cue the modern-day
replacements for the Vickers, adding all the suggestions others have posted.
If sustained fire is critical, don't leave just the one trooper on sentry
duty.

For many of these selections, a backup weapon will be necessary to deal with
armoured targets. I'd
pick an anti-tank rifle designed for use with
powered armour. In other words, more recoil and a heavier shell than
unassisted troops would want,
possibly even a man-portable HKP rifle.

Regards vehicle radiators, I don't understand all this enthusiasm for water.
There's something green and slimy slopping about in my radiator, and it isn't
just there to act as antifreeze and rust inhibitor.

1. Ultima Ratio Regum [4] for the Stephenson fans.

2. Two thousand pounds of armour and psuedo-
musulature amplifying the wearer's movements and moderated by negative
feedback, just like Uncle Bob promised us? Needs a checklist of
   three hundred and forty-seven items when
drawn from stores? Item 348: add water to MG?

3. If you want to deny an area and sustained fire isn't necessary, I suppose
the first option
   should be a Y-rack mortar firing scatterable
mines.

4. Termed MD in DS. 3mm strikes me as awfully big for a gauss round. I'd have
thought a lot less would do, as long as the muzzle velocity and rate of fire
are correspondingly high.

"Drama is an ammunition counter thundering down

> At 12:07 AM +0000 3/12/03, CS Renegade wrote:

Umm, no. You've equipped him with a very modern machine gun that uses
principles from 300 years ago because some systems just continue to work.

Again, consider the need to 'hose' down advancing hordes of fuzzy wuzzies,
Posleen, Kra'Vak, Islamic Fed or ESU troopies.

Grenades are great, but what if you need low angle, direct fire?

> Regards vehicle radiators, I don't understand all

Sounds like you aren't changing the fluid every year.
> 2. Two thousand pounds of armour and psuedo-

Add water to entire system. It works for maintaining the user (he drinks water
still right?) cooling the user (he still needs a 75 degree F environment
right?), cooling the power pack (unless you've got something better?) and now,
cooling the support weapon that the trooper uses.

From: "Ryan M Gill" <rmgill@mindspring.com>
> Again, consider the need to 'hose' down advancing hordes of fuzzy

IFed don't usually do the human wave route any more, now that we've got
someplace to put our excess peasants. And our troops are mostly
not all *that* motivated to collect the 70 sloe-eyed virgins.

I think the "heat pipes" I mentioned earlier use some exotic (compared to
water) chemical, ammonia or something like that, plus they're sealed systems.
The ones in laptops use methanol.

The ones that are being used in laptops today move the heat away from the
processor chips, through the body of the laptop without distributing
heat along the heat pipe's path, then dump the head to a heat-sink once
the evaporated gasses are allowed to condense.

Multiple paths have been designed for some implementations to feed to a
single heat-sink, so all the excess heat (limited by the efficiency
and/or capacity of the heat pipe, I guess) is supposed to go where you
want it.

For PA applications, I can see baffling around the heat sink(s) to
reduce IR signature, or possibly the ability use different heat-sinks
positioned in different areas on the PA. (So a PA suit wading through water
could use the sinks in the legs for more efficient cooling).

If the suit starts to overheat, the heat-sinks can be actively cooled by
fans, or in the case of extreme overheating liquid nitrogen (or other liquid
gas) can be vented over them. To those who would dismiss that
idea as being too logistically intensive... that's fine, for _your_
PSB. For my PSB, power armor is a luxury afforded the more elite units, units
that you wouldn't deploy without the logistical support they need any more
than you'd deploy a tank without it's POL (Petroleum, Oil, Lubricants). The
liquid cooling gas would just be part of the POL.

And insofar as it applies to cooling weapons, perhaps heat pipes could be used
to cool the chamber of weapons with caseless ammo, or be used as barrel
cooling jacket when a weapon is used on a vehicle mount or on PA,
allowing higher sustained rates of fire without making the non-jacketed
barrel weapon too heavy for foot sloggers.

I found a bit more information on heat pipes.
http://www.cheresources.com/htpipes.shtml

http://www.sandia.gov/news-center/news-releases/2002/comp-soft-math/hotl
aptop.html

> On Tue, 2003-03-11 at 17:20, Beth.Fulton@csiro.au wrote:

> At 10:51 PM +0000 3/12/03, CS Renegade wrote:

A mumble-glycol pre-mix perhaps?

> At 12:07 AM +0000 3/12/03, CS Renegade wrote:

> So I've gone to the trouble and expense of putting

> From: ~ On Behalf Of Ryan M Gill

> Umm, no. You've equipped him with a very modern

Hmm. If I'm suited and they're not, what's wrong with dropping a chemical
agent? Oh, we did that last year.
(See the [MERCS] Weapons Available [FH] thread, 4/02)

> Grenades are great, but what if you need low angle,

Time-fused flechette? Set for minumum range, it turns
a grenade launcher into a super-shotgun, but maybe I'm
assuming too advanced a round since I mentally slap on rocket assistance and a
smart fuse to transform your humble GL into a miniature rocket launcher.

> Regards vehicle radiators, I don't understand all

> Sounds like you aren't changing the fluid every year.

No, there's two brands, and one goes in pink and slimy and the other goes in
green and slimy. The radiator's smaller than the engine capacity would
normally dictate, so the system needs to be more efficient than plain water
would permit.