Heaney’s use of alliteration in the first stanza is suggestive of the man’s character.
The use of plosive sounds such as the repeated ‘t’ in “juts like a gantry’s crossbeam” and in the line “Cowling plated forehead and sledgehead jaw”, reinforce his tough and threatening demeanour.
Heaney uses the materials and tools associated with shipbuilding in the metaphor “Cowling plated forehead and sledgehead jaw”, again highlighting his tough exterior.
The metaphor, "Speech is clamped in the lips’ vice" further reinforces this hard character. The line suggests that his physical appearance reflects his silent repressed personality.
In the second stanza the imagery becomes more violent.
His hatred of all things Catholic is conveyed in the metaphor describing the head of his “sleek pint of porter” as “The only Roman collar he tolerates”.
God is compared to “a foreman with certain definite views”. Heaney merges the idea of a strict boss at work with an unforgiving Old Testament God.