The number "1" is to be interpreted as depositing weld metal in the flat position only...
The letter "G" is to be interpreted as a groove weld deposit...
The term "rolled" means that the base or parent metal(s) where the weld is to be deposited on, is "rolling" in a clockwise or counterclockwise progression on top of a set of wheels, or attached to a positioner/turntable or something else to that effect...
When you combine everything just mentioned, it seems to me that the "mechanism" depositing the filler metal is fixtured or held manually above the base/parent metal(s) so that the weld metal is deposited on it in the flat position only...
The exception of this is when GTAW or PAW is the process of choice because, the torch is fixtured or held manually so that the weld puddle is created with a non-consumable electrode (not necessarily directly perpendicular to the groove) below the torch, in the groove of the base/parent metal(s) being joined... The filler metal is then deposited into the direction of the base metal(s) travel or roll, onto the leading edge of the puddle which is within the groove, in the flat position only...
In both cases, the progression of the weld is dictated by the "rolling" of the base metal(s)... The Gun or the Torch does'nt move (unless oscillation is specified), only the base metal(s) will "roll"... I may be incorrect but, the number "1" means flat only as far as I know - which is never enough!
Respectfully.
SSBN727
Run Silent... Run Deep!!!