By knitting half tubular you can create single jersey knitting that is twice as wide as the machine, which can be useful for garments such as skirts or dresses.
In regular tubular, you alternate between rows of single jersey on the front bed and single jersey on the rear bed. Half tubular is created the same way, except you alternate the rows of front and rear bed knitting in pairs.
Racking the needle bed is unnecessary when knitting tubular because the needles, although opposite of each other, are never in use at the same time. This means there is no risk for colliding needles.
Select the line drawing tool and draw pairs of rows of alternating front bed and rear bed single jersey.
Below a detail of half tubular knitting.