The spelling of the word "equippings" is determined by its pronunciation. According to the International Phonetic Alphabet (IPA), the word is pronounced as /ɪˈkwɪpɪŋz/. This means that it is pronounced with a short "i" sound at the beginning, followed by a "kw" sound, then a short "i" sound again, and finally a "ngz" sound at the end. The double "p" in the middle is necessary to indicate that the stressed syllable is the second syllable, as opposed to "equipings" which would indicate the stress is on the first syllable.