Glen,

Regarding your question of September 9th @ 7:31 p.m.

‘’I’ve just bought some three-handled steel G.I. cans, but they don’t say how much they hold. I’ve been told it’s either 5 fl.gal., or 5 1/4 fl.gal., but nobody can tell me for sure. Do you know?’’

Glen, you first have to determine whether you have a ‘’G.I. can’’ or a ‘’jerrican’’.

At first glance both cans look pretty much the same, but if you look at the can bottom, you can always tell the difference.

The ‘’G.I. can’’ is like a soup can or cornbeef can. So it has a horizontal rolled seam all around the bottom edge. The horizontal top edge can either have a horizontal rolled seam or a horizontal weld, depending on the manufacturer of the ‘’G.I. can’’.

But the ‘’jerrican’’ is made of two vertical halves that are welded together in one complete straight weld across the bottom, up the side, across the top, and down the side to the bottom again.

If you’re still unsure, then pour into the ‘’G.I. can’’ or ‘’jerrican’’ 5 fl.gal. of the liquid you intend to store in it. Whatever you do, do not pour into a drinking water G.I. can, or jerrican, any gas, diesel, oil, solvent, or anything else, other than drinking water ONLY.

If it takes 5 fl.gal., you’ve got yourself a ‘’G.I. can’’.

But if it takes 1 fl.qt. extra, you’ve got yourself a ‘’jerrican’’.

And just to make sure that you don’t forget, stick an indelible label on the ‘’G.I. can’’ or ‘’jerrican’’.

A few years ago when the Queen, at the suggestion of the United Nations, decided to disband the Royal Canadian Navy, Canadian Army, and Royal Canadian Air Force, a large number of ‘’G.I. cans’’ came onto the market. The all had the following indelible label stuck on just one side only:

5.00 fl.gal.
4.17 imp.gal.
18.9 nap.qt.

‘’nap.qt.’’ stands for ‘’napoleonic quart’’. I hadn’t known that the napoleonic scheme had quarts, but apparently it does in the Dominion of Canada.

You could easily make up such an indelible label yourself, and stick it on the side of the ‘’G.I. can’’. Possibly even altering it as below:
5 fl.gal.
4 1/6 imp.gal.
18.88 nap.qt.

or:

5.000 fl.gal.
4.166 imp.gal.
18.88 nap.qt.

If you instead have the ‘’jerrican’’, then you could make up the following label:

5 1/4 fl.gal.
4 3/8 imp.gal.
19.82 nap.qt.

or:

5.250 fl.gal.
4.375 imp.gal.
19.82 nap.qt.

‘’G.I. cans’’ and ‘’jerricans’’ have been painted various colors in the past, but recently there has been an attempt to restrict the use of the colors below:

red – gasoline ONLY
yellow – diesel ONLY
light blue – drinking water ONLY

But don’t rely on those colors for second hand or foreign containers, as some dark blue foreign G.I. cans and jerricans are for gasoline only. Dark blue might fade to light blue, and all of a sudden you’ve got polluted water and real troubles. Although yellow is now used for diesel, in the past yellow or sand colored foreign G.I. cans or jerricans were used for drinking water only.

Always have a look inside the ‘’G.I. can’’ or ‘’jerrican’’, and if you can see that it is completely filled with honeycombed extruded aluminium, then it’s definitely not a drinking water container, no matter what color it is and no matter what you’ve been told.

Without the honeycombed extruded aluminium interior the drinking water ‘’G.I. can’’ or ‘’jerrican’’ capacity is a little more than what is stated in the container stamping, or on the container label. So if you’re travelling in desert conditions, you might want to re-label the can. It’s only a 1/2 fl. cup of water, but it could be a matter of life or death.

water ‘’G.I. can’’
5.029 fl.gal.
4.190 imp.gal.
18.99 nap.qt.

water ‘’jerrycan’’
5.280 fl.gal.
4.400 imp.gal.
19.94 nap.qt.

Although the above are the correct capacities, they are not the correct interior volumes. All ‘’G.I. cans’’ and all ‘’jerricans’’ are designed to have a substantial remaining interior airspace when filled up to the pouring spout with liquid. There are a number of reasons for this, one of them being that a full gasoline G.I.can or jerrican, will float in water, salt or fresh.

The idea of the ‘’G.I. can’’ or ‘’jerrican’’ is to have a robust re-usable large liquid container that can be backpacked many miles on one man. A fit foot soldier carries a maximum load of about 1 av. bushel, and in extreme circumstances about 1 av. firkin or even 1 av. blackjack. The ‘’G.I. can’’ or ‘’jerrican’’ can be backpacked many miles on a foot soldier carrying minimal equipment. In circumstances of:

Stranger,
now passing by,
go,
and tell the Spartans,
that here,
according to their laws,
we lie.

Then a foot soldier stripped of all equipment should be able to backpack two ‘’G.I. cans’’ or ‘’jerrycans’’ for some miles, if he can get over the terrain, or through the weather, or past the enemy.

The ‘’jerrican’’ was invented by Gen. John ‘’Blackjack’’ Pershing, 10th United States Colored Cavalry.

Info @

http://www.weights-and-measures.com

And topics:

Common Fluid Measure & Common Dry Measure
Britanic Explicit Measure & Britanic Improved Measure
Napoleon Emperor’s Republic of Europe Decadent Small-Fluid Measure & Napoleon Emperor’s Republic of Europe Decadent Full-Dry Measure

Modern ones, and probably the German originals, appear to all be 20 L, and are even advertised that way in the US. Early WWII copies from the US were 5 US gal.

They were so named from the slang name for the Germans during the war - "Jerries".

Apparently the German 20 litre fuel can that was used in the Western Desert was well designed, unlike the Allied fuel cans. I have heard that some arabs in the dessert are still using jerricans that haev swastikas on them!

All of the wassted bandwidth just to tell us the cans hold EXACTLY 20 L. And some people insist more information is better? This should be proof it isn't.

I don't so much mind when bandwidth is wasted on CORRECT information instead of XCOLE information. In that vein, I found an odd site that has a substantial file of photos of historic jerry cans from WWII.
http://ww2jerrycans.com/

Click on country, then manufacturer (if it is a link). You will get a photo.
CAUTION: Probably not "dial up friendly"

The German cans are all explicitly stamped 20 L, so of course, XCOLE is wrong on the numbers absurdly close to but not equal to 20 L (there's a shock.) The reinforcement "X" has a center box and could be taken as a stylized swastika or not, as you prefer.

The US cans are unclear, They contain a "20" which may or may not be liters and usually a clear 5.25 gallons, which is pretty close to 20 L. Most use an "X" for reinforcement.

The British cans seem to copy the German stamping exactly, but the capacity isn't stamped or is "coded." 20 L would be extremely close to 4.4 Imperial gallos, and I didn't see that either, but they all have year of manufacture.

So, I conclude "real" jerry cans are 20 L, and may be mislabelled 5 or 5.25 (US) gallons or 4.4 Imp. gallons in non-metric countries.

Since WWII, the designs have proliferated and 5, 10, 20 L cans are available in plastic or metal, with various variations, but still "jerry can style." Even the US ads (mostly) reflectly liter capacities.

Hugh,

Regarding your comments of September 13th @ 7:13 p.m.

‘’Why don’t they just label the G.I. can as 0.6666 cu.’, and the jerrican as 0.7000 cu.’? Instead of having five different measures of gallons and quarts, there would only be one measure.’’

Hugh, it’s an idea.

Info @

http://www.weights-and-measures.com

And topics:

Common Fluid Measure & Common Dry Measure Cylinders
Common Fluid Measure & Common Dry Measure Equivalents
Britanics Explicit Measure & Britanics Improved Measure Cylinders
Britanics Explicit Measure & Britanics Improved Measure Equivalents
Napoleon Emperor’s Republic of Europe Decadent Small-Fluid Measure & Napoleon Emperor’s Republic of Europe Decadent Full-Dry Measure Equivalents
Liquid Measure & Bulk Measure Equivalents

Maybe because 20 L, the correct capacity of a German jerrycan is 0.706 293 cu ft. If you don't have four correct figures, you shouldn't claim 4 significant figures. How about 0.7 cu ft?

Better answer john is that 20 L is a legal unit in every country and feet and its derivatives is not. Plus, nobody would have a clue as to what a cubic foot is.

BTW, are you suppose to be Hugh?

<<BTW, are you suppose to be Hugh?>>

Damned if I know. He muddles names as well as facts. One time, I was apparently Jomo. Even if the numbers were RIGHT, I agree no one would like to label their gas cans in cubic feet, but I am trying to make a point about accuracy, precision, and significant figures. His numbers are virtually NEVER right to the precision claimed.

Naturally, 5 gal ISN'T 0.6666 cu ft, either, it is 0.6684 cu ft. Although I am pretty partial to the 0.6666 cu ft can, "The Can of The Beast." :)
I guess "numerology significance" is more important than accuracy.

20L is a legal unit?

On which planet?

Steve,

20L is cerainly a legal unit (OK "20 L" if you prefer it). Such a representation is certainly in accordance with the BIPM recomendations, teh EU directives and UK law.

So there is a unit called "The 20L"?

Please re-read Daniel's spittle and my response.

I think we should change your name from "Stimpy" to "Picky." :)

"Legal capacity statement" might be better (but longer) than "legal unit." While cutting my grass yesterday, I was amused to note that my gas can (not a jerrican design) which I had always considered as 5 gallons was marked 5.25 GAL 20 L. It's amazing what you learn reading labels.

<<I think we should change your name from "Stimpy" to "Picky." :)>>

Actually Dangly has made many errors that point to him not being very "metric-savvy".

I bet he goes through about 5 calculators a day!

409,

Regarding your comments of September 18th @ 11:53 p.m.

----------------

I think Hugh’s suggestion of labelling all gas cans as 0.666 cu.’ or 0.700 cu.’ should be followed. If all gas is already purchased by the cubic foot, then why, when gas is put into gas cans, is gas then suddenly purchased by the fluid gallon?

----------------

409, I will assume you are being serious.

‘’gasoline gas’’ is ‘’gas’’.

‘’natural gas’’ is ‘’natural gas’’

Info @

http://www.weights-and-measures.com

And topic:

Common Capacity Measure
Common Fluid Measure & Common Dry Measure