Can a cannon battery form on a rank instead of a file?
These answers restate the rules implemented by our open-source engine, which follows the WXF laws and is regression-tested against the official 110-diagram repetition casebook. Where an answer refers to a specific position, that position lives on the linked reference page, where the build verifies it against the engine before publishing.
Direct answer
Yes. Nothing about the screen rule cares whether the line is a file or a rank, a cannon's capture works identically in both directions. Two cannons stacked along a rank, one acting as the other's screen, threaten sideways exactly as 重炮 threatens down a file.
Why the file version is the famous one
重炮 is named for the mate against the general, and the general only ever sits on a file relative to a cannon attacking down it in the standard pattern. A rank-based battery is mechanically identical but usually shows up as pressure against a rank of defenders, the back rank, most often, rather than as a named mating pattern of its own.
Where it is genuinely useful
A pair of cannons stacked along the opponent's own back rank can threaten several defenders in sequence, since whichever piece the front cannon screens for, the rear one is aimed straight at it. It is the same idea as a bottom-rank cannon, doubled.
Related questions
Does this need the same three conditions as 重炮?
The mechanism is the same, so yes: the front cannon needs to be defended, and there needs to be no way to interpose safely.
Is a rank battery weaker than a file battery in general?
Not inherently weaker, just usually aimed at different targets, since a rank rarely has the general sitting on it.
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