A common type of scaffold for smaller jobs is a single pole or putlog scaffold which consists of a platform resting on horizontal putlogs (called transoms in independent scaffolds) fixed at 90° to the face of the building (figure 15).
Source: wiktionary
The platform in this type of scaffold is supported by putlogs and not transoms.
Source: wiktionary
Where putlogs are not required to support boards, a putlog must occur within 300mm of each standard. / When bracing is connected to a putlog, the putlog must be connected to a ledger.
Source: wiktionary