Editing Steamroller (section)

==Configurations==
[[File:Robey Tandem Great Dorset Steam Fair.jpg|thumb|right|1925 [[Robey & Co|Robey]] tandem roller #42693, now owned by the Robey Trust<ref name="robey-tandem" />]]
The majority of rollers were of the same basic 3-roll configuration, gear-driven, with two large smooth wheels (rolls) at the back and a single wide roll at the front (in actuality, the wide roll usually consisted of two narrower rolls on the same axle, to make steering easier). However, there was also a distinctive variant, the "tandem", which had two wide rolls, one front, one rear. Those made by [[Robey & Co]] used their standard [[steam wagon]] engine and [[pistol boiler]] fitted in a girder frame with rolls and a chain drive to produce a quick-reversing roller suitable for modern road surfaces such as [[tarmacadam]] and bituminous [[Asphalt concrete|asphalt]].<ref name="robey-tandem" /> A number of Robey & Co. tandem rollers were modified to make a further variant, the tri-tandem, which was a tandem with a third roll, mounted directly behind the rear one. Robey supplied the parts, but the modification was undertaken by Goodes of Royston.<ref name="robey-tandem">{{Cite web |title=Tandem roller 42693 of 1925 - The Robey Trust |url=http://www.therobeytrust.co.uk/Stocklist%20tandem%20roller.htm |publisher=The Robey Trust}}</ref> Ten tandem and two tri-tandem Robey rollers survive in preservation,<ref>{{Cite web |title=Tri-tandem roller 45655 of 1930 - The Robey Trust |url=http://www.therobeytrust.co.uk/Stocklist%20tri-tandem%20roller.htm |url-status=dead |archive-url=https://web.archive.org/web/20110722134904/http://www.therobeytrust.co.uk/Stocklist%20tri-tandem%20roller.htm |archive-date=2011-07-22 |publisher=The Robey Trust}}</ref> and one of the tri-tandems is known to have been used to construct parts of the [[M1 motorway]].

A variation of the basic configuration was the "convertible": an engine which could be either a steam roller or a traction engine and could be changed from one form to the other in a relatively short time – ''i.e.'', less than half a day. Convertible engines were liked by local authorities, since the same machine could be used for haulage in the winter and road-mending in the summer.