Well, I can not even start to pretend I know what this poem means, or what its theme is, so I'll simply critique the technical side behind it, and its structure.
The most obvious poetic device you use is that of repetition, most notably of the syllable sound "layd". You use this eight times (and "lay" once), but the poem seems uneven for it. You use it three times in the first and second stanza, and twice in the fourth stanza ("lay" comes in during the third stanza). It feels slightly unbalanced as a poetic device for this reason, but does not deeply effect the read. It might, perhaps, lessen the impact, but other than that, hardly harmful.
Unfortunately, the poem is so vague, it's impossible to relate to any of the imagery, so any potential power behind these vehicles is either lessened or eliminated. In other words, because I don't really understand where you're coming from, I can't understand the technical side of the poem itself either in relation to the theme.
As a poem, technically, it was quite sound. The phrase "And knee to balls" was a bit awkward, seeming grammatically incorrect, but again, because I do not understand the context, I can not really pass judgment on it.