Friday, January 28, 2011

Heavier is Sometimes Lighter

How can heavier be lighter? The title sounds like an oxymoron perhaps, but I think when focusing on reducing pack weight, most people tend to focus solely on base weight, i.e. pack weight minus consumables (food, water, and fuel). Reducing your base pack weight is a good start, but if you don't consider everything that goes into your total pack weight, you may be increasing your load without even knowing it.  Sometimes a heavier base pack weight can result in a lighter total pack weight. Let me explain...



These 3 stove systems from Trail Designs are all lightweight, but the ounce counter would have to go with the lightest one, right?

      Ti-Tri Keg-H, 2.70oz
      Sidewinder .6L, 4.50oz
      Sidewinder .9L, 5.25oz

The solution seems obvious, go with the Keg-H. That is until you look at the big picture. With both the Keg-H and the Sidewinder .6L, I use a technique called FBC or freezer bag cooking. This requires me to carry a freezer bag cozy and a quart size freezer bag for every meal. I have really embraced this method over the years because it makes trail cooking easy and it works great. The only issue is that you end up carrying all of the additional freezer bags (including the empties with some scraps of food in them when you are done), plus a cozy to keep the food hot while it is rehydrating.

Now consider the designs of the 3 different systems. The lightest is tall and narrow, leaving less surface area that the flame directly hits. The .6L being much wider uses less fuel, and the .9L is wider yet and uses even less. These factors all play a role in Total Pack Weight. The following chart details these weights (based on bringing 2 cups of water to a boil twice a day using my fuel of choice - Esbit).

Cooking Systems
oz Stove
oz Cozy
qty fuel/day
oz fuel/day
qty fbg/day
oz fbc/day
Ti-Tri Keg-H
2.70
0.70
2.00
1.00
2.00
0.44
Sidewinder.6L
4.50
0.70
1.50
0.75
2.00
0.44
Sidewinder.9L
5.25
0
1.25
0.63
0.00
0.00

The heaviest cooking system is large enough to cook my FBC meals right in the pot, so I can eliminate the cozy and the freezer bags. That and the fuel savings over the length of a 3 day trip actually makes the heaviest stove system end up being the lightest (calculations assume you are carrying the empty used freezer bags the entire trip).

3 day trip
Cooking Systems
Day 1
Day 2
Day 3
Ti-Tri Keg-H
7.7
6.7
5.7
Sidewinder.6L
8.8
8.0
7.3
Sidewinder.9L
7.1
6.5
5.9

On a 3 day trip, the heaviest and lightest stove systems end up adding about the same Total Pack Weight. But all things being equal, I prefer simplicity in the backcountry. The .9L has less stuff to bring (i.e. no pot cozy or freezer bags to "cook" in). Now consider a longer trip of 7 days and the weight difference starts to become more significant.

7 day trip
Cooking Systems
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Ti-Tri Keg-H
13.5
12.5
11.5
10.5
9.5
8.5
7.5
Sidewinder.6L
13.5
12.8
12.0
11.3
10.5
9.8
9.0
Sidewinder.9L
9.6
9.0
8.4
7.8
7.1
6.5
5.9

While most people don't carry much more than 7 days worth of food with them, many carry lots of fuel on long trips including multi-month thru-hikes. This is because it can be difficult to find places to resupply your fuel of choice, while food can be found at small markets and even gas stations in a pinch. The same goes for freezer bags...if you intend to use this method on longer hikes, you will probably find yourself carrying some extras with you.

14 day trip
Cooking Systems
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Day 8
Day 9
Day 10
Day 11
Day 12
Day 13
Day 14
Ti-Tri Keg-H
23.6
22.6
21.6
20.6
19.6
18.6
17.6
16.6
15.6
14.6
13.6
12.6
11.6
10.6
Sidewinder.6L
21.9
21.1
20.4
19.6
18.9
18.1
17.4
16.6
15.9
15.1
14.4
13.6
12.9
12.1
Sidewinder.9L
14.0
13.4
12.8
12.1
11.5
10.9
10.3
9.6
9.0
8.4
7.8
7.1
6.5
5.9

The moral of this discussion...when considering what gear to pack, don't forget to think about how it will affect your Total Pack Weight. Food for UltraLight thought!




13 comments:

  1. Good logical argument. I just stuff my stove in a friends pack when they aren't looking and follow them to the next shelter. That way I don't care how much it weighs.

    ReplyDelete
  2. Great post, good food for thought John. It's for this very reason that I've never really taken to alcohol, the fuel weight adds up really quick. There is one convenience to living in an arid environment like mine, dry tinder is abundant.

    I use a FBC method but it delineates slightly from yours- cozy is my merino Buff wrapped around the food in bag, thrown in the now empty pot, then wrapped with my down jacket or quilt. Why do you pack extra empty freezer bags in your pack?

    ReplyDelete
  3. John,
    Great article. I've been thinking some of those same things. What would you recommend for a husband and wife team? Also, even when traveling alone, I would still need bags to store my food. What do you use for cleaning your pot? Because I am a really bad person I usually just burn my empty bags.
    David Noll

    ReplyDelete
  4. If you would compare average weight you carry, all methods are quite even. With the .9L you save weight in the end, but carry more at the start. But you have to clean your dish every time and wasting water you have to carry additionally for dish-cleaning.

    ReplyDelete
  5. Jolly Green Giant, I'll try and remember that in case we ever have the opportunity to hike together :)

    Eugene, I've never really caught on to alcohol either (except for some red wine on occasion). I've never liked the idea of having food smells on my clothing, so I've always carried a cozy. The extra bags were for my 14 day trip example...you would probably resupply sooner than 2 weeks, but might carry all the food and freezer bags unless you are doing mail drops. The sidewinder you recently picked up...if it's the .9L, try cooking right in it. I just had a couscous breakfast with my wife this morning on a hike, and it worked very well.

    David, there is a 1.3L pot that would work well for two people, and Trail Designs sells them along with their Sidewinder setup. For storing your food, just 1 bag per food type if you don't mind repeating the same types of meals, and if you use a grocery store produce type of bag, they weigh virtually nothing. 3 of these weigh about the same as 1 freezer bag, which I typically carry in case I have one that leaks while cooking in it. I won't lecture on burning plastic bags, but it's definitely not LTN.

    Thrush, the weight is very close on shorter trips, but on a 7 day trip, there is a substantial difference. If you are not able to eat by water sources, you would need to use some water weight to clean the pot out, but since you are not cooking in it and just heating/rehydrating food, there is really very little mess. And it doesn't have to be perfect...you can rinse it out at the next water source, but if you don't, the heat from boiling water will kill any germs the next time you use it.

    Thanks for all the comments and the challenges. I really like the simplicity of the .9L and cooking the FBC right in the pot. I also prefer eating out of a pot over a plastic bag. My gear preferences are intended to work on a multi-month thru-hike, which I intend to do some day. I just can't see me doing FBC on that type of a trip.

    ReplyDelete
  6. John,

    I grabbed the 1.3L, the .4oz. weight penalty over the .9L Evernew seemed pretty insignificant to me when in light of the additional volume and flexibility. I'm confident this will make a great "do all" stove+pot combination for solo and duo use.

    With that said, I'm now a one pot owner with the exception of my BPL Trappers Mug, so this guy is going to have to pull all my cooking duties and I think it's up for the task. Eventually I'd like to look for something in the 550-700ml range for strictly solo boil only use. I'm not much of a stove guy but they're growing on me.

    ReplyDelete
  7. The 1.3L sounds like a good option Eugene. For solo boil only, I think the Keg-H is a great option. Especially if you get it in the Ti_Tri version.

    ReplyDelete
  8. Hi,
    Clue me in, but even if you don't cook in qt zip- locks, you still need to package meals in zip-locks anyway,correct? So how do you save on weight, by cooking in the pot?

    ReplyDelete
  9. Hi,
    Good question! I figure all food will fit in 2 or 3 total bags so I can package several meals in just 1 bag. I use grocery store produce bags for this, which are extremely light. 3 of them probably weigh about the same as 1 quart freezer bag (.22oz), and when I do FBC cooking I always bring an extra freezer bag in case 1 breaks (has happened a time or two), which is my logic for not counting it. I got the idea from a great article called Groovy-Biotic Cooking (google it) by Mike Clelland on www.backpackinglight.com (membership required).

    Thanks for the question!

    John

    ReplyDelete
  10. I'm going from my .9 Evernew pot to the 1.3 pot. I can't fit everything into the .9. So, its worth the extra weight and size, having a pot that will hold everything with the sidewinder system, cone, alcohol stove, and stakes, all nested inside the pot. The 1.3 is only about .7" wider in Dia. and approx. .5" taller. The wider pots are definitely more efficient compared to narrow pots, when using the alcohol stove.

    ReplyDelete
  11. Hi Anon, I think the 1.3L is a great alternative if you're looking for something bigger than the .9L!

    ReplyDelete
  12. Thanks John, great article - I've been wondering about this same question which you've addressed. It seems it is the total kitchen system we must weigh over a period of time, not just the individual parts.

    ReplyDelete
  13. John, thank you for addressing this topic. Great post. I tried to address it on my blog, as well... http://www.joshspice.com/2011/06/ultralight-stove-systems-whats-lightest.html
    I agree with you on the Evernew .9L pot
    Keep it up!

    ReplyDelete