How to harvest ice
photo courtesy Tim Graf CollectionIce was harvested throughout the northern states where lakes and rivers developed ice at least 6-8 inches thick. Farm families would harvest ice on a farm pond, or local lakes or rivers. A small harvest could be done with a handful of workers, a minimal tool set, and would only take only a day or two. Even a small operation would yield a harvest of 5-20 tons - enough to fill a small 9 x 12 foot ice house and last a small farm for the entire year. Large commercial operations needed crews of dozens, multiple teams of men and horses using specialized ice plows, and mechanized equipment to move the ice into enormous ice houses capable of storing up to 100,000 tons of ice.
Whether the harvest was large or small, the steps needed to harvest were similar: prepare the surface to get to clean ice, mark out a grid to define the cakes, plow or saw along the marked grooves, and move the ice to the collection point at shore.
Preparing the field
Good harvesting requires good ice: thick enough to safely support men and horses, and clean enough on top to yield solid ice cakes without a surface of snow.
How thick is the ice? To ensure a thick enough ice layer to yield usable blocks and to work safely, an early step in harvesting is measuring the thickness of the ice in multiple places all across the field to be worked. A hand auger drills through the ice fast; the depth is checked using a measuring stick with a hook to catch the bottom of the ice in the drilled hole. The minimum thickness that can be worked safely is about four inches, but 6-12” is more typical and easier. In colder areas of the country, standard ice thickness for harvesting might be up to 20 inches or more thick.
Clearing the surface. Since scraping thick layers of snow off of a large ice filed is labor- and time-intensive, it is preferable to flood the ice surface by chopping holes in the ice. The flooded surface will refreeze into ice suitable for harvesting. Since this isn’t always possible, the ice surface can be scraped clear with a horse-drawn scoop or scraper. Keeping up with removal of new snow layers in the weeks before harvesting minimizes field preparation time when the harvesting begins.
Laying out the field
Lay out the first two lines. Before any cutting is started, the field is marked to define the size of ice blocks, or cakes, to be harvested. The initial lines are carefully marked by scoring the surface with a cutting tool, or hand plow guided by a long straightedge board, and a large wood square.
Mark the grid. After these first two lines are made, the rest of the marking uses a horse-drawn marking plow to define a grid for standard sized cakes of ice – typically 22 inches square. The marking plow has a guide to fit in the previous groove and a row of cutters to mark the new row.
Plowing down
A horse-drawn grooving plow deepens the marked grooves to one-half to two-thirds of the ice thickness with multiple passes; grooving plows can cut 2-3 inches deep on each pass. It’s critical to not cut the grooves too deep; leaving four inches of ice at the bottom of the grooves leaves the grooved field strong and safe for men and horses. Using the grooving plow as much as possible greatly reduces the need for laborious sawing. Large ice operations had multiple grooving plows with various length teeth; teams of men and horses would follow one another to quickly cut deep grooves through thick ice.
Cutting ice cakes and breaking off floats
Cutting begins by hand-sawing out and then pushing the first ice cakes (“sinkers”) under the ice to make a channel opening. Small harvesting operations might not plow grooves but instead do all the cutting by hand with ice saws. In these cases, individual cakes are floated through a channel to the collection point.
Breaking off floats. Large ice cutting operations did as little sawing as possible and used plows as described above. Long rafts of unseparated cakes called "floats" are hand-sawn at the ends and split on a long side by repeatedly striking a chisel along the groove. The floats are moved down channels toward the collection point and split into individual cakes before pulling out of the channel.
Out of the water
Grapple and tow hooks are used to drag the block from the water up a ramp into the ice house or a wagon for transport. Tongs are used to lift the blocks into the ice house and arrange them in piles with sawdust between layers and between blocks to insulate them as well to keep them from coalescing into one large mass of ice. Large commercial operations had huge ice houses close to the ponds and rivers that were harvested; mechanical conveyors and elevators were used to move thousands of ice cakes into the massive storage houses.
A 1902 film by Thomas Edison shows a commercial crew of dozens of men and many teams of horses plowing down and moving ice floats during ice harvesting in Groton, Massachusetts. The plowmen on ice skates are a treat to see!
source: The Library of Congress
Small scale ice harvesting in Hillsboro, New Hampshire in 1938. Plowing down, hand-sawing, and loading ice cakes by hand onto a wagon to move to the ice house.
A series of three short videos on ice harvesting with excellent narration by Philip C. Whitney (New England Tool Collectors Association) to explain key points and processes. South Portland, Maine in 1943.
References
Gifford-Wood Company. How to harvest ice. 1912.Bowen J.T. Harvesting and Storing Ice on the Farm. USDA Farmers Bulletin 1078. 1920.
Trowbridge, J. T. Lawrence's Adventures Among the Ice-Cutters, Glass-Makers, Coal-Miners, Iron-Men, and Ship-Builders. Philadephia, H. T. Coates & Co., 1898. A funny little 19th century boy’s book that explains various trades to young readers. On pp. 14-26 an ice company man explains ice harvesting to young Lawrence. A surprisingly good description of the process.
Hiles, Theron. The Ice Crop. New York: Orange Judd Co. 1893. Steps and tools for cutting and storing ice on pp. 14-42, 83.