Over the period 1910–1915 the Imperial Russian Navy's Arctic Ocean Hydrographic Expedition aboard the icebreakersTaymyrandVaygachwas engaged in charting the Northern Sea Route. After a brief initial foray into the Chukchi Sea in the late summer of 1910, the two ships pushed progressively farther west over the following three summers, returning to Vladivostok each fall. In 1914 the plan was for the two ships to make the through‐passage to Arkhangel'sk but heavy ice conditions forced them to winter in the eastern part of the Kara Sea, and hence they did not reach Arkhangel'sk until the summer of 1915.