Izikhathi ezibalulekile ezisetshenziswa kakhulu ezinezimfuneko zokunemba, kanye nangaphansi komthelela omkhulu, ukudlidliza noma umthwalo oshintshanayo.Isetshenziswa kakhulu emigwaqweni emikhulu namabhuloho wesitimela, izakhiwo zezimboni nezomphakathi, imibhoshongo, ama-cranes.