Warmth, again and again

If you want real warmth in clothing, it needs to block air flow like a fine bed sheet.

With knit wool that means lots of twist in the yarn, and yarns knit tightly together.

Lots of twist means very fine plies. For most things, I like singles of ~5,600 ypp.

Then I do not ply yarn very tightly, so that as yarn is knit, the yarn deforms and "fills" all gaps.

The commercial yarn that this concept is built on is the old Lions Brand Fisherman's Wool.  This yarn is no longer made. Production was moved to China, and the new  Lions Brand Fisherman's Wool is different.  The new Fisherman's Wool is much more pleasant to knit, but the resulting fabric is not as warm or durable.

To block air flow through the yarn, the wool fibers must be between 20 and 40 microns apart.  Closer and they tend to conduct heat. Farther apart and air flows between the fibers carrying heat.  Keeping fibers that close together takes a lot of twist.

For wet weather, I like long wool, spun worsted at 5,600 ypp.  Twist is about 9 tpi. These singles get loosely plied up into a sport weight (1,000 ypp) yarn.

Once you get below freezing, things can get really cold.  There, I like fine wool, spun woolen at 5,600 ypp and 12 tpi. These get plied up into 5-ply at 1,000 ypp or Aran weight at 500 ypp for Arctic  (or Antarctic) conditions.

Ok, these yarns are a bit of extra work, but they are warm, and nothing is worse that being really cold.

The the yarn needs to be knit so tightly with fine needles, so there are no gaps in the fabric.

If you knit with 2 or 3-ply yarns there will not be enough twist to hold the individual wool fibers close together and the wind will blow right through the yarn.

If you use a 5-ply with enough ply twist to hold the yarn round, then there will be gaps between the yarn and the wind will blow through the fabric carrying heat away from the body.

Hand spun, hand knit fabrics can be so warm that they feel like magic.  Most do not make the cut.

Shackleton

Last night there was this thing on PBS about retracing Shackleton's open boat voyage.

They claimed to be using authentic period knit clothing. They were not.

Look at the photos from Shackleton's trip and the modern re-enactment.  Shackleton's knit clothing was knit using knitting sheaths that provided the leverage to knit much tighter and more weatherproof clothing.  The modern replicas were knit much more loosely, and were not as weatherproof and warm.

Likewise, Shackleton's knit clothing provided a great deal more padding between the sailor and points corners that attack the sailor in a small boat in rough weather.  This is something that one must experienced to appreciate.  A well knit gansey pads against against corners and blows to the body in ways that are qualitatively different from modern, looser knitting.  I had been wearing my Mustang Survival coat for reefing in foul weather.  Then, one day I wore my gansey.  That night - no bruises across my chest from the boom banging against me.  It was a revelation of the virtues of a well knit gansey.

The re-enactment expedition was poorly served by their textile consultants.  The knitters, who knit the modern garments did not know the craft of knitting for sailors in polar conditions.  Their stupidity and ignorance caused hypothermia that increased sea sickness and dehydration.  Hypothermia decreases mental judgement.  Hypothermia decreases physical dexterity.

Shackleton's knit clothing was much, much warmer than the clothing worn by the enactors.  This is what happens when knitters and textile historians do knot know their physics and do not do their math home work.

One can look at the photographs of Shackleton's men, and estimate fabric thickness and density.  From that one can calculate  the "warmth" of the fabric.  Then, one produces fabric of similar warmth. The responsible knitters then tests to fabric to ensure that it is warm enough.  Testing garments for warmth is easy.  Find a good polar vortex storm, put on the garment, and sit in storm while you knit. If the garment won't keep you warm as you sit on the quay knitting (watching for a boat carrying a loved one to come out of the storm), then it is not warm enough to sail the Southern Ocean.

When I replicated such sweaters, I used McAusland heavy 3-ply knit on US#3  long steel needles with a knitting sheath. It was about 200 hours of very hard work, and it was the single most difficult knitting project I ever did.  I later wore that sweater to prune an apple orchard during a week of snow, wind, and freezing rain - that included sustained gale winds - It was below freezing, raining, and the wind was blowing trees down. The only other people out were the rescue workers and linemen working on downed power lines. That gansey kept me warm and toasty all day, every day for more than a week's work in the storm.  I had ice climbing gear from Patagonia in my baggage, but the gansey was warmer and more comfortable in those  extreme conditions.  (These trees held my mother's collection of  300 antique apple grafts, and careful judgement was required to prune them. These were full sized trees, and everything was icy so physical dexterity was critical.)

When new, that sweater was as warm as the sweaters that Shackleton and his crew wore.  However, it was not as durable.   Shackleton's knit wear endured on the ice. I respect that greatly.  The kind of mill spun yarns used to knit Shackleton's clothing are no longer available.

That is why I took up hand spinning.