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Russian wiki (Road of life) provides extensive data with references.
At what point was ice thickness would it stop/start.. and how long were the "windows" in the spring and fall when the ice was not thick enough to support the Road of Life, but the lake was still too frozen for conventional shipping?
In 1941 barges went only until 10th November, but some ships continued routing until 4th December. On 20-21 November they sent the first wagon-train (horses and sledges, about 63 tons). First trucks went on route on 22nd November (only about 100 tons per day in the beginning).
The first ice road was closed on 21st April 1942. But navigation could start only on 21st May because of ice.