Hennessy Hammock in winter

Check out Douglas Frick’s excellent posts on this subject, as well as Carol Crooker’s great article on SUL hammock use.

Thanks those are very informative post.

Tommy

Eric, thanks for posting those URLs.

>are the underpad’s worth it in cold weather, or would a cheap closed cell foam pad work just as well.

For temperatures below freezing the Hennessy under-pad/under-cover system would work fine with your sleeping bag. The advantages over a typical closed-cell sleeping pad are that it covers more bottom area (most sleeping pads are 24″ wide so you will need to glue or tape two to make a wider pad), and it’s a whole lot easier to deal with slung insulation than in-hammock insulation. However, a Gossamer Gear ThinLight Evazote sleeping pad (Wide-Long if available) slung in a Jacks R Better Weather Shield bottom cover (at present, only their top cover is out of stock) is much cheaper, lighter and almost as warm as the Hennessy under-pad/under-cover system. The JRB Weather Shield has the advantage of being able to sling a quilt as well as a sleeping pad (see below).

>lows at high elevations run around -5-0 at the very least.

For temps of -5F to 0F, I don’t think a Hennessy under-pad/under-cover or a sleeping pad-based system will cut it. I consider that system comfortable down to +25F with a quilt and insulated clothing. I’m just guesstimating, but compressed sleeping bag is probably a bit warmer than compressed Patagonia Micropuff, so you might be able to go as much as 10F to 15F lower with a 0F synthetic sleeping bag; that might keep you warm into the teens. YMMV, however. If you can test your hammock configuration where you can bail home if you freeze, it might be worth trying an under-pad system.

For -5F to 0F temps I’m comfortable with a Jacks R Better Nest quilt slung underneath the hammock–a full 2″ of down loft. Since the Hennessy under-pad is only 3/4″ of open-cell foam (generously overlooking the 1/2″ dimples), there is clearly quite a difference in the amount of insulation I need. If you have a down or synthetic comforter or quilt that is about 2″ thick, then you could try slinging that underneath (easy with the JRB Weather Shield bottom cover). If it works for you, then you could replace it with a lighter quilt.

> also what about the over covers?

I think the Hennessy over-cover does help a bit, especially if you don’t have a heavy enough top-quilt. I’ve used mine several times, and there is always frost condensed on the over-cover; it doesn’t work like a double-wall tent. If there is a cold breeze blowing under your tarp then the over-cover will really make a difference. However, in winter I usually stake my tarp down close to the mesh, so that does about the same thing. I do bring the over-cover when it’s below the teens.

> I thought I would get the proper gear now for next year.

The proper gear for hammock-hanging is harder to determine than for ground sleeping. The sleeping bag/tent environment is fairly well understood, and the top-quilt in a hammock is similar. But bottom insulation seems to be much more variable. As they say, YMMV. Considering the consequences of temps in the teens, let alone below 0F, I suggest testing in a safe environment first. There’s nothing I hate more than waking up shivering and then stopping, wondering as I fall back asleep if I just warmed up a bit or if I’m going into severe hypothermia.

Check out http://www.hammockforums.net/. This is a forum of and for Hammock users.

So how would a JRB Nest underquilt and a HH overcover do? I would be in a down +10 sleeping bag and I sleep in Capolene long underwear, fresh wool socks. and ususally a Polypro longsleeve with a 70% down 30% waterfowl longsleeve jacket.(it was my wifes and is light blue…sad enough it fits me and was free!)

am I going over kill? I am wanting to shave the Oz's where possible, but the JRB nest seems the best in the way of warmth. also how does the JRB nest do in rain?

Thanks for the hammock site. it has given me good ideas to work with.
Tommy

>So how would a JRB Nest underquilt and a HH overcover do? I would be in a down +10 sleeping bag and I sleep in Capolene long underwear, fresh wool socks. and ususally a Polypro longsleeve with a 70% down 30% waterfowl longsleeve jacket.

I’d be comfortable taking that setup down to the -5F – 0F range. I’ve been out as low as -15F with that hammock rig and similar clothing, but I won’t say it was comfortable. I recommend adding down booties (or wear your ski boot liners) and some kind of insulating pants (I either wear my BMW Cocoon pants and/or uninsulated 3-layer snow pants), as well as a neck gaiter or full balaclava and a hat or two (e.g., a fleece hat and a Ray-Way Bomber Hat). I either wear my ski goggles or an airline sleep eye mask (0.3 oz), and a 3M dust mask (0.1 oz) although next time I’m going to try sleeping in my Psolar balaclava.

>am I going over kill? I am wanting to shave the Oz’s where possible, but the JRB nest seems the best in the way of warmth.

I don’t think the above is overkill for -5F to 0F. That rig would be fine as-is for a bit below freezing; you might not need to wear the jacket or use the over-cover.

> also how does the JRB nest do in rain?

The JRB Nest doesn’t have a problem when exposed to cold snow. But if blown rain or sleet is a possibility, I recommend the Jacks R Better Weather Shield bottom cover. This will protect the JRB Nest nicely, and it’s a made from waterproof/breathable material (unlike the silnylon HH under-cover) so the down quilt can pass moisture out through it.

In TN we get much more sleet and rain then snow… even at high(6000ft) elevations. the JRB sounds like the way to go. what would happen if I was to buy the JRB weather bottom and stored my gear/down jacket in that instead of the nest? I am looking to down my weight and stay in my current pack if possible year round, so I atleast need to ask…lol.

Tommy

>what would happen if I was to buy the JRB weather bottom and stored my gear/down jacket in that instead of the nest?

It depends on which temps you're expecting. If -5F to 0F, I wouldn't risk it; in the teens, with your 0F sleeping bag, it would be worth slinging gear and a sleeping pad and testing it in a safe-bail environment; near or just below freezing the addition of a 1/8" sleeping pad to your jacket and gear might be sufficient. YMMV–test it! IME, below +40F I'm not comfortable without full-length insulation underneath. The loft of your down jacket is probably similar to the JRB Nest (2"), so that portion of the area underneath you should be warm enough (place it, uncompressed, under your torso). "Gear," however, generally is neither lofty nor insulating. I don't think an empty pack and spare underwear will do much to keep the rest of you warm. Also, consider that the insulation needs to not only cover underneath you but a bit up the sides as well. I just don't think you're going to be comfortable even above freezing without a sleeping pad or other good-quality insulation below. Again, be sure you are prepared for seasonal-low temperatures by testing it out before you go. It's not overkill if it could be needed. As they say here, "any day of the year…."

I will def. test it. and now with temps hitting 80 this week it will be a year until I need it. so that gives me time to work out bugs.

Tommy