One of the advantages of being around for a long time is that you get to see trends come and go. Gear and techniques move in and out of vogue over the decades as old makes way for the new only to be discovered years later then it becomes new again. By the same token having been around for a long while, it’s easy to get set in your ways and continue to do things simply because that’s what you’ve always done.

Typically I spend a lot of time thinking about gear, how it’s designed, how it’s used and most importantly how to make it better. I have to, it’s my job. Still there are some things I still do not so much out of logic, even though it was probably logical at some point in time. These tasks are carried on more out of tradition than anything else.

A few days ago I got to thinking about how I pack my pack. For years I’ve subscribed to the notion of “Heavy High” and “Light Low”. It is after based upon years of empirical evidence. Placing heavy things higher does bring them closer to your center of gravity and reduces the tendency to be thrown off balance.

But in the age of UL or SUL frameless packs does this truism still ring true. By far the heaviest thing in my pack these days is my food bag. Its maximum weight for a 5 day hike is no more than 10 pounds. Everything else I carry is measured in ounces instead of pounds.

Carrying food high has a major convenience factor quotient. After all who wants to dump out the contents of their pack on the ground simply to retrieve a candy bar during a break or even lunch for that matter? On the other hand with all the external mesh pockets on UL packs it’s pretty easy to pack all of your days food needs into outside pockets, thus leaving that food bag untouched.

There are many in the UL community who’ve argued over the years for the “Heavy Low” theory. Resolute in my olden ways, I’ve given it little head space. Then I got to thinking about the physics and forces of weight distribution. Except for those who love the pain of pinched backs, fundamentally most of us want to transfer the weight off the shoulders and on to the hips. At best, this requires either a frame or a pseudo or virtual frame. However, even the best virtual frames break down over time, pads weaken, extra care must be applied to the packing process to preserve rigidity, etc.

The best argument I’ve been able to devise for “Heavy Low Theory” is that it places the bulk of the weight directly at the hip zone. With a relatively narrow pack and good hip belt, the weight will be tied directly to the hips and there will be little tendency for it to pull backwards. Also with the weight low, only a minimal amount of support needed to keep the rest of the pack rigid enough to keep it from pulling down on your shoulders.

So which theory Heavy High or Heavy Low do you subscribe and why?

Ron

I find that neither pad or compression alone will create a durable virtual frame. However when the two are combined with a light load then you can get good durable weight transfer.

I subscribe to both theories. On days when the hiking mostly is on wide and level trail then my camp clothes bag is on bottom and the food bag is next. When I need more balance the food bag goes on bottom and the camp clothes is next.

I carry my insulating jacket inside the main compartment. The only time I go into the main compartment during the day is for the jacket or to cook a trail meal.

I would be very tempted to carry the bear can on the bottom in the Essence.

Mr. Moak,

Agreed on the food as i've stated numerous times over the last couple of years. Click my Avatar and read my profile. This area, viz. Non-Conventional Packing systems (implicit in this description is "packing" the Packing System) is one of my interests.

You might have read my numerous posts over the last couple of years on the subject (including the Thread in which a top pack designer construed my words to be an attack on him, though i didn't name him personally, but did make refs to partial statements he had made). Boy, was that a hullabaloo. He makes great packs though - no argument about that.

I subscribe to heavy low and near, using what i would describe geometrically as a triangular loading system which attempts to keep most of the weight below the shoulder blades while attempting to minimize backward pull on the shoulder straps by keeping the heaviest gear/food/water closest to the back.

Reason: minimize deviations above and to the rear from my body's natural unladen CG. Few (none???) would argue that we are most agile without a pack on our back. For the same given pack weight, a poorly loaded pack can be a pain (literally) to carry and make for terrible balance (increasing the workload required by our "core" muscles, producing greater fatigue). The opposite is true of a properly loaded pack.

I've performed both numeric integrations and scaled graphical illustrations which plotted the centroids of geometric shapes of the conventional pack load scheme and my triangular heavy gear/food low and near approach (then measuring the distance from my body's unladen CG to each centroid). My scheme produces lower numerical results and shorter distances to the centroid.

My experience with grappling Martial Arts, where one's CG becomes very important for quick movements and to avoid being thrown or losing one's balance when forces are trying to upset it, when i was a boy caused me to naturally pack this way. It just made sense to me as a kid. Not only did it sound right, it felt right when i tried it.

Proof of this now is that when i use a heavier hunter's lumbar pack vs. a normal UL pack, i feel more nimble and end up less fatigued at the end of the day carrying 15-20lb in (and strapped on) the lumbar pack. The difference is not the weight (the hunter's lumbar pack is marginall heavier), but the balance due to the lower CG. The highest anything reaches is the bottom of my shoulder blades. The light weight of the load does NOT cause too great a moment arm that i feel a backward pull. Besides, i very often don't use shoulder straps with the lumbar pack and the rearward vector is basically at hip level, or just a tad above, so the pack wants to rotate into my hip region (this is really minimal and not really felt; it's more theoretical if you can picture what i'm so poorly describing).

I've also experimented with counterbalancing by placing some water (and gear) in front of me, and also with leg packs (as a kid, and was laughed off the trail, though i see someone is selling them now 40yrs later).

For more details, search the Forums for CG, leg packs, hunter's lumbar pack(s), and other likely terms. I written "volumes" ('ok', an overstatement, but some were weighty tomes) on the subject - probably a lot of repetition though.

There in no doubt that a Hipbelt transfers load to your hips, so in my G pack and my Granite Gear, I'm most comfortable when carrying 7 L plus of Water and food if I place the water high but below my shoulder blades, and food above that.

With belt less packs I think that long term comfort depends more on the moment about your lower back created by the shift of loading from your natural CG. That "Torquing" effect is minimzed when I pack my heavy items next to my back between my waist and shoulder blades. For that reason, I prefer my beltless packs to be thinner in profile. They can be long, but I try to keep my load as close to my natural CG as possible.

My ultralight setup, for example, uses a panel loading simple book bag (foam backing so it also doubles as insulation under my legs when sleeping) with 2 8 L stuff sacks and a 2 L stuff sack. I pack my bag in a 8L ultrasil drybag, my clothes in a 8 L thermarest pillow/stuff sack, both of these are packed vertically in the bottom of my pack, with my gatewood cape and a 2L drybag with all of my essentials/extras packed in it, and my 600 mug and alcohol stove in between the two bags. This makes a formed almost square base in the bottom of my pack. My inflatable 3/4 pad is next to my back, and I have a level platform in the top of my pack for my foodbag and any extra water I need to carry. My Hydration bladder goes in my pack's side pocket, my fuel and extra drink mixing bottle, 45 ft of paracord, my T.P., headnet, backup lighter, and Aqua Mira goes in the back pocket, and the other side pocket I use for my windshirt, groundcloth (for rest breaks), and a backup 2L Platy, with room left over for any extras or an extra Propack for a long weekend (I always carry a couple of extra energy bars).

Entire set up with a weekend of food and 2 L of water comes in at about 15 lbs at the trailhead.

Photon and Whistle are worn Jordan style, and my knife and lighter are carried in my pockets.

Mr. Moak, pj,
I tend to organize my pack with dense items close to the backpanel(frame) without regard for vertical c.g. If we define a 3d cartesian coordinate system fixed in the human body, x axis out of the belly button (about where the human cg is), y axis to the left or right, and z axis up, then plot in this 3-d space the centroids of the pack items, we can see that vertical orientation of those items has little effect on pitching moments about the combined cg when the pack remains basically vertical. The bothersome (to me) pitching moments come from items packed farther from the axis origins in y and/or x directions. When the person starts to bend and lean, even the vertical orientation becomes important, as the sin of that angle becomes significant.

What this means I think, is that for someone who spends a lot of pack time bending, stooping, dodging branches, and generally going off-trail (YDS class 3+ stuff), vertical orientation of cargo becomes important in minimizing the energy expenditures in counteracting the resulting moments. But if you stick to YDS class1, it's not so important.

pj's example of a lumbar pack reducing fatigue was interesting; now maybe I understand why MountainSmith still sells huge lumbar packs; they must be comfortable.

On a related topic, for a long time I have wanted to ask people about their pack densities, to determine if mine is higher, or lower, than the average for a ULer. We have already defined SUL, and SUS as both 'good'; is high pack density good or bad? The answer might be surprising, or irrelevant? I would guess a high pack density is indicitive of someone using the smallest possible pack for the smallest possible load.. pj; this seems to be right up your alley.. ever thought about pack density?

>>"pj; this seems to be right up your alley.. ever thought about pack density?"

Can't say that i think much, Brett, 'bout anything that is.

Well, ok, sometimes. Whether they're good thoughts or not, i'm not always sure. They seem to be at the time. I'm working this out with PacerPoles on steep slopes right 'bout now, and don't know if i can spare any CPU horsepower to simultaneously work on another problem. But, here goes...

i try for a dense pack. regardless of the pack. w/some UL packs, compression is lacking (G5 and G6 Whisper for example), so there's only so much one can do using the innate compression capabilities of the pack. i figure, rightly or wrongly, that dense packs have lower rotational moments. Does that make sense to you? Maybe i'm not expressing it right. I'm just a lowly computer/software engineer, with only a rudimentary understanding of all things mechanical and physical.

Brett, regarding your comments on bending, etc. In my old posts on CG and packing, i've mentioned this very thing. I'm often bending and twisting on some trails, or stepping over and around roots and rocks, and deadfall. I find my unique triangular loading scheme works pretty well. Sure, it involves tradeoffs, but unless one is just going straight line nearly all of the time, i find my scheme works well even if 99+% of trekkers pack conventionally (i.e., hvy-hi) and disagree with me. I'm used to being strange and different (one look in the mirror each morning confirms that assessment).

As far as the bodies natural unladen CG, i'd modify your navel comment slightly, and move the CG half-way back (front to back, that is) into the body (that way it doesn't matter if one has an "outie" or an "innie" :).

Also, to simplify, i view this as a 2D problem and NOT a 3D problem. Why? No one i know disagrees that we should attempt to distribute wt evenly left-to-right. So, i "factor" it out of the equation. The issues are front-to-back and low-to-high; how to optimize that for the type of trek we are going on and the expected pack weight. Climbing (which i really know nothing about), i'm guessing (someone who climbs, please correct me if i'm wrong) keeping it as close to the back as possible is probably good to reduce the rearward moment arm that would tend to pull one away from the face being climbed. Same would go for a very heavy pack, but perhaps not as extreme, just enough to reduce rearward pull on the shoulder straps. L/UL pack weights, unless one is just going straight ahead (and then reducing rearward pull as much as possible might be best) with no bending, leaning, or twisting, i'd say my unique triangular heavy low and nearest the back is best. It feels good when bending, leaning, and twisting.

Your explanation about the vertical moment coming into play when bending, etc, is precisely my reason for packing as i do. Theoretically, it simply makes sense; it's logical and to me intuitive (though perhaps b/c of childhood experiences). Practically speaking, it just plain feels good.

Some of the old posts dealt w/male vs. female CG, and bodybuilder type physique CG vs Sumo CG.

Best CG possible - make a "Sumo Pack" (y'all can stop laughing now; i can hear y'all way out here in New England; don't go gettin' Gimli riled!!) - weight distributed in various pockets around the mid-section just like a wrestler (at least water bladder[s] on side and in front). Obvious limitations include being able to see one's feet for proper foot placement, non-interference with the thighs when stepping up high, and keeping one's body close to rock faces when scrambling or climbing. The Sumo Pack would also have some small volume on the sides of the legs (not too much b/c this makes the legs too wide for squeezing through tight spots; very handy for fetching things easily though), thus distributing some of the wt below the body's natural CG to offset that weight carried above.

I know, some crazy packing ideas.

Edited by pj on 12/15/2006 03:23:48 MST.

PJ,
Not so crazy from my point of view as another lowly software engineer. If you look at where the weight is on a Sumo wrestler, it's mainly around the CG. It's also interesting that lower density fat, for the most part, builds in a layer below the skin and above the higher density muscle. It was interesting to see this in the cadavers I worked with in my anatomy classes, years ago. I'm sure there must be other factors at work in the disposition of adipose tissue but CG does appear to play a role.

Edited by ericnoble on 12/14/2006 14:43:35 MST.

Eric, you're absolutely right about disposition of adipose tissue, primarily being around the CG (ignoring female breast tissue) - a compelling design argument, or if one prefers, a compelling "survival of the fittest"/natural selection argument. Besides what we can obviously see in an overweight person, there can also be significant amounts of fat "packed", so to speak, around organs internal to the body cavity.

Edited by pj on 12/15/2006 03:27:15 MST.

pj, Eric,
Thanks for the detailed posts. pj, Your comments were astute as usual. And as Erik you mentioned, a low and distributed method of carrying the weight (sumo-type) would be best for most situations. In fact, the old military LBE (Load Bearing Equipment) did that, with a butt pack in the back, canteens on the hips, and ammo pouches in front. A little better than everything in back; but then it was heavy canvas or nylon. Subsequent load bearing vests etc.. use the same idea. But of course; don't look to conventional issued equipment for UL or even light ideas; they typically contract for bombproof (forgive the analogy) equipment.

Edited by Brett1234 on 12/17/2006 08:19:34 MST.

Brett,
I am working on a way to support a set of hip belt pouches with my shoulder straps for my new AT Pack. The picture is a set of some of my old military gear. We have talked about and around a setup like this army stuff several times here. This type of setup works well. Mine will be made out of - guess what - Cuben to take advantage of its really light weight and strength.

There is also a good thread about the use of the "vest" idea someplace here.

Edited by bfornshell on 12/17/2006 09:02:49 MST.

I start with my sleeping bag and clothes crammed in the bottom, so that isn't a lot of weight. My heaviest items are water and food. The food is near the top, water on the sides low. So, I guess, if you think about, mine is well balanced, I don't go high or low. For me, if the load is not balanced, I can feel it. For snacks, etc, those mesh pockets are handy!
It seems as the years have passed, I have gotten my packing down to an art, it only takes a couple minutes to shove everything in and go.

The typical backpacking trip lasts a weekend to a few days for most hikers. Here, water is the heaviest item for most of us. And much more often than not, we place it either in the upper region of the pack close to our back (i.e. using our pack's hydration sleeve) -- or we place it near the bottom, one on each side (i.e. using our pack's water bottle pockets).

Considering how we have our water "anchored" -- and how relatively light everything else is in comparison -- so long as we pack our stuff more-or-less balanced and cinched tightly, our lightweight pack load will feel pretty good. In other words, the exact position of our food bag or clothes bag becomes secondary -- in terms of the effect on overall pack comfort. My two cents anyway.

Edited by ben2world on 12/17/2006 11:20:26 MST.

Does anyone out there carry 1 gallon cook pots? If so how do you pack it?

Some folks say you can judge the skill of a packer and the care they give their gear by the lack of dents or bends in their aluminum (no experience with Ti) cook pot.

Let's start with the pack. I think if all of the previous comments were amended to include as a starting point the type of pack used, that would make some difference in the method of packing. Perhaps not a big difference but some.

In my case, for the most part I carry my LT Ghost. Since this is a panel loader I have found that under most conditions, folded flat next to my back is my sleeping pad (either the downmat 7 or BA insulated AC). I pack my sleeping bag horizontally (after compression) in the very bottom. On top of that goes my clothes bag (also compressed) and various small sacks with first aide, personal hygene and emergency kit. Then Stove and cooking gear. Then on top of that and at the apex of the pack is the Ursack food bag or solo bearicade canister(lid facing out). One 40oz nalgene canteen in the bottle pocket and snacks and day use items in the other pocket. Strapped low on the outside is my Rainbow (the pole is lenthwise inside the pack along one outside edge. This panel loader allows me access to anything at any time I take it off without disturbing any of the other gear. So, I could just as easily pack it in any other fashion and it would make no difference in terms of access. The above packing method allows me to use my sleeping bag as part of the hip belt support mechanism.

Even on a 5 or 6 day outing where food is the heaviest packing element starting out(followed by water), my pack never weighs more than 21 lbs. The pack gets lighter as the days count down. Given this reality of carrying at most 21 lbs, I don't think worrying about precise gear placement in the pack makes much sense. Back in the day when we carried 35lbs to 50lbs, it made great sense. Most of the packs we use carry close to the body and carrying 5 lbs of food 10 inches higher or lower on your back at a distance of 2 inches to 4 inches IMHO makes little difference. I pack for convenience and to keep things from making noise when I walk, something I really hate.

I'd like to pack my internal frame packs W/ the heaviest items nearest my back and low to med. low.
BUT... Here's my compromise...

Pack most needed items in side pockets, Dana Wet Rib & top lid of the pack and on top inside main pack.

Top to Bottom in main pack:
Cook set & stove
Food (against my back)
hydration bag (in its compartment against my back)
clothes
tent & Thermarest
sleeping bag

Top Compartment:
rain gear for me and the pack
lunches

Side Pockets:
Fuel, 1st aid kit, toilet kit & TP
water filter IF I bring it instead of Aqua Mira

Front Wet Rib:
Map, compass, headlight, trail munchies in Ziploc, other "possibles" I may need, Kool Aid-type drink in bike bottle in attached bottle pouch.

Mitchell, you make some good points. Think laterally, however. If one is forced to do a lot of bending, as i do on some trails, then it's not the 2-4 inches, but the 10 inches that really comes into play. However, for upright, straight ahead trekking, at 21lb, just like you said, it's probably not too much of a big deal. For shorter treks, which i do - no long hauls with resupplies, it only weighs that much at the start when one is "fresher".

However, from experience, i can tell you that a 20lb pack with weight up high (at or slightly above the top of the shoulder blades) vs. in the lumbar region (no higher than the bottom of the shoulder blades) makes a big difference in agility IF a lot of bending, forward and sideways, is performed. It's "A Tale of Ten Inches".

Now, if only i could get a UL "super-sized" lumbar pack with a REAL ~1400 in^3 capacity.

PJ:
Yeah, I see your point about thinking laterally. I know the general rule is to keep the weight low and at the hips, but I just never seem to notice the difference at the lower overall wieghts I am now carrying. I am going to have to try to consciously pack to see if I can tell the difference on my next outing which is going to be a short overnight of about 8 miles out and back (with a steady 2000 feet of elevation gain and loss and plenty of stream crossings) with my daughter and her boyfriend this weekend. I'll pack more than I usually do to get the pack to 22 lbs.

One thing I have been reading and thinking about which showed up in some recent posts is that putting the sleeping bag on the bottom, even in a internal plastic bag liner, may not be the best place to have your sleeping bag. Although I have never had a problem with water pooling in the bottom of my pack and thus soaking my sleeping bag, it has been pointed out that is may not be the best placement of the sleeping bag because of this possibility. And per a suggestion that Benajimin Tang made, I also now carry my tent on the outside of my pack strapped to the bottom/back for ready access and immediate retrieval in case of rain, so that one does not have to expose the contents of the pack to moisture while setting up the tent in a rain.

Each of these changes in carry position for gear has implications for the weight distribution in the pack.

Edited by mitchellkeil on 01/15/2007 11:33:30 MST.

I subscribe to *neither* theory of packing. Heavy-high leaves your pack pulling down on your shoulders and back from your centre. It also lolls around whilst you walk, and can be quite ungainly. Similar also is the heavy-low packing method, which can exert a backwards rotational force on the user - especially if the hip-belt is not utilised to the full extent possible.

I pack with heavy objects [food, water, fuel, accomodation] in the middle of the pack - closest to your lumbar and centre of gravity. Mid-weight objects are low down [sleeping bag, cookware] and lightweight stuff high-up so your pack doesnt want to pull backwards from your body. This way, you just loosen the shoulder straps all the way, secure the hip belt snugly, and then do the shoulders up so the straps *just* touch your shoulders.

I'd swear by this to the exclusion of all other methods. [If it is relevant, I use a Roman 'Snowy' pack, that has an 'air-frame' back with meshing over a sturdy plastic frame - giving good air circulation and awesome comfort because the pack itself doesnt even touch your spine]

Hvy-Hi & Hvy-lo aren't really theories being put forth here. In fact, read my first Post (the reply to the Thread Initiator - Mr. Ron Moak) and please take note of the BOLD words, viz. "I subscribe to heavy low and near, using what i would describe geometrically as a triangular loading system which attempts to keep most of the weight below the shoulder blades while attempting to minimize backward pull on the shoulder straps by keeping the heaviest gear/food/water closest to the back."

By LOW i mean lumbar & waist area. This is readily understood by L/UL backpackers as most don't carry packs that extend to the bottom of the buttocks. To one coming from a more traditional, heavy backpacking background, this might not be intuitively clear.

In both cases the hvy, regardless of where the hvy is, vertically speaking, it is kept closest to the back. Hence, my preference for a triangular loading arrangement which is a trade-off which minimizes deviation from one's natural unladen CG in ALL directions.

Keeping all gear closest to the spine results in a taller column which is slightly better than a triangular loading arrangement when it comes to longitudinal CG, but far worse when it comes vertical CG. To prove this to oneseld, merely perform a numerical integration of both loading arrangements, or a geometrical analysis, plotting the centroids of a 2D scale drawing of each loading arrangement.

We need to think 3D or 2D (since no one i know of has a diff of opinion on lateral CG loading issues) about this problem and not just 1D - it's more than a 1D problem.

I'm confused a bit by the following comment: "I pack with heavy objects [food, water, fuel, accomodation] in the middle of the pack - closest to your lumbar and centre of gravity." This must be some HUGE pack if the middle is at your lumbar region. In the L/UL packs i use, that would be the lower portion (these packs don't extend below the sacral region); middle at the shoulder blades, and rarely (unless the extension collar is used do smaller vol. L/UL packs extend above the shoulder top, so the upper portion of the pack (the portion above the shoulder blades) is typically very small unless the ext. collar is deployed.

Take a look at some of the pics of people wearing these smaller capacity packs. Your description, in most cases, wouldn't work as there wouldn't be much or anything below the sacral region (which is a very small area in most L/UL packs).

Essentially, what you describe as "middle of the pack" is the lower/bottom portion in my triangular loading arrangement, i.e. there virtually NOTHING (or very little) LOWER in my packs. Using a smaller UL pack and packing in the "middle of the pack" would place that heaviest items at shoulder blade level, not in the lumbar region which is the goal of the triangular loading arrangement. Please search the Forums and you will find very detailed older Posts in which i painstakingly describe the theory and practice. It might prove educational.

In fact i'll often use large capacity Hunter's Lumbar packs which make it very difficult to pack anything much above the lower level of my shoulder blades (or below the lower level of the waist/hip area) - truly excellent in terms of deviation from one's natural unladen CG, making one quite nimble and well balanced when traversing rough terrain. The trick is getting one's kit to fit in the smaller volume. I supplement it with a 450in^3 fanny pack which is worn in front at the area of the navel-to-lower abdomen. Big enough to carry a few things, but not too large to get in the way of leg movement or vision down to my feet and foot placement.

I also take exeption to the statement "Similar also is the heavy-low packing method, which can exert a backwards rotational force on the user - especially if the hip-belt is not utilised to the full extent possible." In a smaller capacity L/UL pack (or a large lumbar pack - in reality a lumbar/sacral pack) the LOWER portion is at the position of the hip-belt, i.e. it is AT the "rotational" point as you might term it. Hence, it doesn't contribute much to any rotational moments as its deviation from that point is minimal, i.e. it has a very short moment arm. I think the problem you are having is my VERY POOR description. For this i apologize for not being clearer. Most long term Forum Participants have read (and are probably sick of) my lengthy detailed descriptions of my triangular loading/packing arrangement.

Edited by pj on 02/03/2007 02:19:51 MST.

I've tried and tried the weight-low way, and I just can't make it work for me. My sister, on the other hand, can't stand weight-high.

This leads to my modest opinion: it depends on how you're built and how you walk. Women are an extreme: generally smaller shoulders, generally much more of their weight in their hips. Thus their walking style, balance, and stabilizer muscles are all geared towards a low CG.

They "expect" a low CG. Raising their CG throws a spanner in the works.

If you're going to increase a person's total weight, do it as close as possible to their CG which is where they're used to having the weight. Where they expect their weight, their body's "swing", their momentum to be.

That's the general case for women. Men, I think, are more varied in their "construction". I think it depends on how you're built *and* how you walk. We generally have more weight up top and our gait is adjusted accordingly. When we stumble, when we speedwalk, when we climb, when we descend, **many** of us expect to feel a high CG. Lowering our CG throws off our gait, screws up our agility, and changes the way we expect our body to move or fall.

That said, for **many other** men, the CG is lower. Pack according to your body and your walk, I say.

Brian

PS another example is my girlfriend: she has the longest torso of anyone I know, for her height. The result is a lighter and more slender upper body and her weight is carried very low. I am the opposite: long legs means my upper body is compacted "up high".

Edited by bjamesd on 02/04/2007 16:50:55 MST.