Here is a post from C.E. Harris on the U.S. Military Natick cookers and Alcohol stoves. This time I have taken the liberty of addin a few comments at the end.
I have several of the US Army “Natick cookers” NSN 8465-01-250-3632, aka the “canteen cup warming stand” which nests with the US 1 qt. canteen and cup in the canteen cover. http://www.bestglide.com/canteen_cup_stove.html I keep one of these sets in each car emergency kit.
I decided to do some impromptu testing to compare their heating efficiency with the Trangia alcohol burner I normally use. The results are interesting. I will describe my test methodology so that others can follow similar procedures to compare their cookers. In earlier testing of my Trangia burner, I had started with a measured 16 ozs. (500ml), or about 2/3 of a US canteen cup full of water, the amount required to heat and hydrate one LRP-CW ration. http://www.freezedryguy.com/default.aspx?tabid=91&categoryid=31&pageindex=1&sortid=3&sortdir=asc
Canteen water was stabilized overnight, outdoors, at a temperature of 40 degs. F (~5 degs.C). Using undiluted denatured alcohol fuel, a full tank in the Trangia set up in its Swedish issue windscreen burned a little over 15 minutes, bringing the water to a slow boil, using exactly the right amount of fuel with no waste.
I repeated the test using the “Natick” cooker on a colder morning when water in the canteen had started to freeze. I strained enough liquid water out of the canteen to fill a Nalgene bottle to the 500ml mark, then transferred this into the canteen cup, measuring its temperature at 33 degs. F (1 deg C).
Directions on the Trioxane fuel bar box say to “start with 1/3 of a bar” (the bars come segmented that way). The 1/3 bar recommendation must be for temperate weather, or to use a partial bar for fire starting. The solid fuel is packed three bars to a box, the usual unit of issue, supposedly 1 box per day. I have never had any success warming water in the field using less than a full bar. I placed a whole fuel bar under the windscreen and lit it with a match. Wind velocity, according to the nearby flight service weather station at the 167th Airlift Wing was 15 mph with gusts to 22 mph with temperature 31 degs F. and wind chill of 20 degs. F.
My Natick cooker was set up in the open with no other shelter. The trioxane bar and windscreen were being fanned noticeably by the wind, so the first bar was consumed quickly, in about 5 minutes. The canteen cup water which had started at 33 degs. F was brought up only to a “comfortable washing temperature” of 102 degs. F, far short of boiling. A second and a third bar were similarly consumed with alacrity. After the entire 3-bar box was consumed, the water temperature in the canteen cup was 160 degs. F (70 degs.C), short of a boil, but “pleasantly warm and steamy,” adequate to make instant coffee, cocoa or tea, or to hydrate a freeze-dried LRP-CW ration to make hot chow. Its design intent is met.
Because I wanted to know how much more heat it would take to actually get a boil, I started feeding sticks into the cooker, poking pencil and finger-sized sticks under my cup as my last trioxane bar was burning out. The little wood fire did the trick and boosted the temperature to a slow boil in a total elapsed time of 20 minutes, vs. 15 for the Trangia on another test day starting at 40 degs. F ambient water temperature with less wind.
So, there you have it.
As i said I want to add a few comments. I agree with everything that is said in the above post. I have and like both of these stoves and think they are great items to have in your bug out kit. Both do not create odors from the burning fuel and smoke is almost nonexistent. They also show very little light if used at night.
The other thing I wanted to mention is the Esbit Alcohol Stove. After having spent a considerable amount of time with both the Esbit and the Trangia stove. I feel that the Esbit is a bit better and quicker to heat. It is also smaller and takes less room in your pack. It also comes with a simmer ring that lets you control the flames and makes it easier to extinguish. But the difference is small enough that if you have a Trangia i would not run out and buy an Esbit, the difference is not that big. But if you are a new buyer look at the Esbit.