How does a Thule Harpoon Work?

Before Christmas, I promised that I'd describe how a Thule harpoon works. I wanted to take a few new photos of the harpoons to illustrate the different components, but we've had such mild weather that the backyard was full of green grass. This weekend, we finally got snow, so here's a few appropriately wintry shots.

Materials: From tip to base, the materials used in the harpoon are nephrite (endblade), walrus ivory (harpoon head, finger rest, and butt), whale bone (foreshaft, socket, tension piece and tension peg), spruce (main shaft), seal skin (harpoon line, lashing line), baleen (finger rest lashing), and sinew (lashings on harpoon line).

Finger Rest: A Thule hunter would probably be wearing mitts when they threw a harpoon like this, so having a finger rest at the balance point of the harpoon keeps your icy mitt from sliding along the shaft when you go to throw. In the photo on the left, the finger rest is the little sharks fin that my fingers are resting against. The finger rests were secured both by being fit into a rectangular slot in the mainshaft and tied down to the shaft. I like to use baleen lashings to secure the finger rests. The baleen are those two black bands underneath the tension piece.

Tension Piece and Tension Peg: The harpoon head is firmly held onto the foreshaft by having the first 3 feet or so of the line attached to the mainshaft. A bone or ivory tension piece was attached to the line. The tension piece has one or more holes in it that fit over a peg placed midway down the mainshaft. When the line gets wet, it will stretch, so having two holes in the tension piece gives you different settings for the tension in your line depending on the season and weather conditions. With the tension piece in place, the harpoon head can not be removed, so how does it detach when you strike your prey?

The answer is in the design of the foreshaft - its a breakaway design that is built to roll out from its socket, when the weight of the thrown harpoon hits the target. When the foreshaft bends at the socket, it creates enough slack in the line that the harpoon head can detach and toggle in the animal. At the same time the tension piece falls off the peg and the harpoon line detaches itself from the mainshaft.

Socketed Foreshaft: The foreshaft fits into a socket on the end of the mainshaft. The socket and foreshaft were usually made from ivory or whalebone. I've used whalebone in this reproduction. Ivory sockets are pretty cool, because the base of the tusk was used and the pulp cavity of the tooth forms a natural hollow that fits over the end of the wood mainshaft. If you find the right size and shape of tusk to start with, then most of the work is done for you. If you are really lucky, the rest of the tusk can be worked into a foreshaft and harpoon head. One tusk will give you all of the ivory that you need for one harpoon.

Unlike the fixed foreshafts used by the earlier Palaeoeskimo groups, the Thule developed the socketed foreshaft so that its rigid when thrown, but bends when it impacts the prey. Kind of like the crumple zone on a car. The shape of the socket and the foreshaft prevents it from rocking forward or back, so the only way it can bend is right or left. The hunter could even determine whether the foreshaft would roll out to the right or left, by varying the placement of the lashing holes in the foreshaft and mainshaft and by adjusting the tension in the leather lashing. You can preset the foreshaft to bend whichever way you want, to take full advantage of the barbs and the toggling action of your harpoon head.

Thule vs. Palaeoeskimo Harpoons: The photo below shows the difference in size between the larger Thule harpoon reproduction and the smaller Palaeoeskimo harpoon. Both are toggling harpoons that would have been used for seal hunting, although the Thule harpoon may have also been used for larger seals and sea mammals like walrus.

Photo Credits: Tim Rast

Photo Captions:
First, A complete Thule Inuit Harpoon Reproduction
Second, The finger rest is there to keep your mitt from sliding when you go to throw the harpoon
Third, Note the tension in the line between the tension piece and the harpoon head in the distance
Fourth, The harpoon head in place on the foreshaft
Fifth, A side view of the foreshaft in the socket, without the harpoon head and line in place
Sixth, The foreshaft rolls out of the socket on impact, creating slack in the line
Seventh, With slack in the line, the harpoon head can detach and toggle
Eighth, Side by side comparison of a Dorset Palaeoeskimo and Thule Harpoon reproduction