I'm doing research on the Battle of Svolder. The one thing that I find hard to understand is how the Iron Ram was used by Eiríkr to 'peel off' Olaf's ships one by one, until only the Long Serpent was left.
How would this 'peeling' work? Did Eiríkr literally wedge his ship between the last two ships in Olaf's line, thereby physically separating the last ship from the rest and then boarded it with superior numbers?
Or was this the case that Eiríkr simply flanked Olaf's line, followed by other support ships, then boarded the furthers ship on the flank and picked off the crews one by one until he reached the Long Serpent?
I've read sources that focus more on this being a flanking maneuver, while others mention wedging in-between Olaf's ships on the flanks. What I find most problematic, I guess, is the plausibility of Eiríkr's ship maneuvering around during the course of the battle to peel off Olaf's ships one by one. What am I missing?
Any chance someone here might be able to clarify this a bit more for me?
I 'suppose' the latter was the more likely, but I afraid that we don't have enough extant sources for such details of the battle that occured more than 1,000 years ago.
I'm sure you've done research much extensively and in-depth than I just did, but the following are the main relevant sources for the question you've posted above:
+++
Contemporary Accounts to Witness the Naval Battle: Skaldic Poems
The skaldic poem is a less known, but only one of the two contemporary types of the contemporary primary sources (also by the Norsemen themselves) from the Viking Age. The Norse skalds (poets) composed the poem as an eulogy for the ruler they served. The poem had been transmitted at first orally, but was later cited as 'evidences' in the prose narrative texts of the royal biography (kings' saga) and extant as a part of the royal biography. I'm also sure you've already familiar some of these 'cited evidences' poem in the saga narrative like Heimskringla, Fagrskinna, and further, Oddr Snorrason the Monk's Óláfs saga Tryggvasonar, oldest of the famous three and customarily dated in the end of the 12th century (ca. 1180-1200: by Theodore M. Andersson).
The standard work of skaldic poems, Judith Jesch summarizes the source value of the skaldic poem for the sea battle as following, citing late Bjarne Fidjestøl, the pholologist authority in skaldic verses:
'Fidjestøl has pointed out (1982, 216) that, although the most skaldic poems are descriptice or enumerative, those which concenrate on one particular historical event, such as a sea-battle, have a clear narrative structure, with events told in sequence and using appropriate syntactic markers (Jesch 2000: 205)'.
As for the battle of Svolder in 999/1000, we have three of such skaldic poems, Eiríksflokkr (Sts. 1-6) by Halldórr ókristni, Eiríksdrápa by Þórðr Kolbeinsson (St.8 only), and Erfidrápa Óláfs Tryggvasonar by Hallfræðr vandræðaskáld Óttarsson (Sts. 1-28: though he was not at the battle according to the later tradition, so its trustworthiness as eye-witness accounts can be somewhat dubious than the first two).
Of these poems, only two stanzas (Sts. 3 & 5) in Eiríksflokkr narrates the ship(s) battle between the flagship of Jarl Eirik of Lade and the Long Serpent (flagship of King Olaf Tryggvason), as I cite below together with St. 4:
'(Eiríksflokkr, St. 3: translation in English only) Last year Ormr inn langi ("The Long Serpent") underwent a rather harsh [trial] - reeds of gore [>swords] crashed together; moons of the tongs of prow-boards [shields] were cut then - , when the Reginn <dwarf> of the byrnie-troll-woman [axe>warrior>Eiríkr] brought the high-sided Barði ("Prow") alondside Fáfnir [Ormr inn langi]; the jarl fought a storm of the helmet [battle] near the island (Whaley 2012: 475, ed. & trans. Kari E. Gade)'.
'(Eiríksflokkr, St. 4) A tumult of sharp swords took place on Ormr inn langi ("The Long Serpent"): warriors demolished the peace for a long time where golden spears resounded. They said that Swedish men and Danish bushes of battle [warriors] follow him [Eiríkr] forward in the south at the flytning of the glittering leg-biter [sword>battle] (Whaley 2012: 478)'.
'(Eiríksflokkr, St. 5) I do not believe there was mercy during the onslaught [or that] the battle-hard one [Eiríkr] spared himself - the retinue attacked the prince; last year, the jarl obtained the land - when, war-hard one, you brought Barði ("Prow") onto the path of fjord-lump [skerry>sea] against Ormr inn langi ("The Long Serpent"); the Sóti <horse> of Sif [Wolf] was hardly hungry (Whaley 2012: 479)'.
That's all we have as contemporary near eye-witness accounts for the ship handling in midst of the battle of Svolder, occurred in more than 1,000 years ago.
+++
Later Traditions of the Battle:
Although not so widely known, these are some early historical writings from 12th century Scandinavia, and the royal biographies (kings' sagas) in the 13th century often build their narrative also based on the information in them.
I've checked all the three of them, namely A History of Norway (Historia Norwegie: ca. 1150-75), A synopsis of the history of the kings of Norway (Ágrip af Nóregskonungasögum : ca. 1190), and Theodricus Monachus' Ancient History of the Norwegian Kings (before 1188) in the section of the battle of Svolder: While these three work shares the basic development of the sea battle (like the clear out of the Norwegian warships and the Long serpent withstood to the last together with King Olaf), neither did they inform us of the ship tactics in detail, narrated in the sagas.
Thus, I suppose that the narrative part of your question in the saga (s) are largely the later adaptation of the skaldic poems (cited above) by the saga 'author(s)' who lived at least 150 years than the sea battle had actually happened, and were sometimes not so specialized in the arts of battle, so to speak, though some part of their narratives could be traced into the oral traditions surrounding the battle, as Andersson notes (Andersson 2003:19)'. I couldn't indeed trace the source of your question's 'Iron Ram', a mechanical devide used by the instruction of Jarl Eiríkr to damage the Long Serpent further back than the oldest saga account on the battle of Svolder, Oddr Snorrason, a monk in Þingeyjar in Northern lceland (Chap. 73, in Andersson 2003: 130). While Oddr and his collegue Gunnlangr were familiar with Jón Loptsson of Oddi, the southern cultural center of the 12th cenrury Iceland, I'm not so sure whether Oddr himself knew so much about the sea battle.
Someone more knowledgeable (especially with the naval battle) may tell you different story, but that's almost all I can inform you of, based on the basic source criterion of this period.
+++
References (only listed the translations for convenience):
+++
Jesch, Judith. Ships and Men in the Late Viking Age. Woodbridge: Boydell, 2000.
[Edited]: some typo fixes, and standalized the spelling of some person names in Old Norse.
[Edited 2]: typo fixes (again, sorry)