The Indus Dictionary Project
This ideograph is a repetition of the noun span with a track stretched between the two signs. A track that people travel along with the arms is a rope. Hence, this symbol depicts the activity of climbing. It is the verb to climb or the adjective climbing.
Harappa: Seal: H-37 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 177: Collections in India: Suomalainen Tiedeakatemia.
Mohenjo-daro: Seal: M-26 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 15: Collections in India: Suomalainen Tiedeakatemia.
In each of the examples, the symbol is used as an adjective to describe the equipment.
Indus Script Sign Number 2074: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.