Assertion: scaffold | /r/ObjectUse | used in scaffold casters
Facets:
Source sentences:
text: To prevent movement of the scaffold while it is being used in a stationary position, scaffold casters and wheels must be locked with positive wheel locks Platforms must not extend beyond the base supports of the scaffold, unless stability is ensured by outrigger frames Leveling of the scaffold, where necessary, must be achieved by the use of screw jacks.