There is also evidence of distinctive stone wheelhouses and small underground souterrains. Several have been associated with wheelhouses or their outbuildings. Beyond Roman influence, there is evidence of wheelhouses and underground souterrains. Wheelhouses and companionways, where fitted were of varnished wood. Excavations have uncovered a multi-period settlement with broch, wheelhouses and later dwellings. These two differed from "Lady Cutler" in having reverse sloped wheelhouses. This includes a smithy, a cluster of wheelhouses and a later broch. In the 1920s, all four had officers' cabins attached to their wheelhouses. The vessel's stability had been affected by the new heavier steel superstructure and larger wheelhouses. Larger RIBs can have hard-tops or wheelhouses made of GRP or aluminium. The steel superstructure rises to sun deck level, with teak decks and wheelhouses. At each end of the upper deck were the wheelhouses. Elsewhere in Scotland wheelhouses were constructed, probably for ritualistic purposes, in the west and north. During this, her bridge wings and wheelhouses were plated over to form one single bridge. Whereas the "Binggarra-class" vessels would have their wheelhouses at either end of their promenade decks.