What this song renders
The ship is documented in unusual detail. Heimskringla gives the build at Hlaðhamrar in the winter before Olaf’s last voyage, calls the vessel larger than any ship in the country, and records thirty-four benches, the gilt head and arched gilt tail, and bulwarks as high as in sea-going ships. The lyric’s sixty-eight oars is plain arithmetic on the benches, a rowing pair apiece. They planed her sides till the wood ran bright is the Thorberg Skafhogg episode compressed into a line — the craftsman who deliberately wounded the king’s masterpiece, owned it to his face, and repaired it into something better.
What the song adds is the listener. No source says Sigrid heard of the ship, questioned a messenger about it, or reasoned about its turning circle; the sources credit the coalition, not her, with the mechanics of the ambush. But the inference underneath the invention is strong and it is the reason the track exists: the coalition demonstrably knew the ship by reputation before they ever saw it, because at Svolder they spend the morning mistaking lesser ships for it. Somebody carried those measurements east. The song puts the queen at the receiving end of that journey.
The turning-circle argument is the album’s own. A hull that long does not come about in a narrow place, a hull that heavy does not run, and a king who builds a thing that big has published his own position. Svolder’s site has never been identified, so I found the place she could not turn is a claim the record cannot support and the album makes anyway — deliberately, and flagged.
The ship, its dimensions, its gilding and the Thorberg Skafhogg episode are documented in Heimskringla. That the coalition knew the vessel by reputation before the battle is documented by implication, at the ambush itself. That Sigrid heard about it, interrogated a messenger, or reasoned her way to a coordinate is the album’s claim and not the record’s — the inference is strong, the scene is ours.