Lyric discussion by rog27 

Cover art for Sledgehammer lyrics by Peter Gabriel

This song is about sex. And sex is fun.

First off: Sledgehamemr = penis (obviously)

he's saying he'll use his sledgehammer (penis) to nail down her tracks (he wants to NAIL her)....that's a hilarious allusion by the way.

also...more sexual double-entendre in the song:

You could have a steam train If you'd just lay down your tracks (uh yeah)

You could have a big dipper Going up and down, all around the bends You could have a bumper car, bumping This amusement never ends (hahaha - this is great stuff)

Show me round your fruitcage 'Cause I will be your honey bee Open up your fruitcage Where the fruit is as sweet as can be (blatantly ridiculous)

You've been coming through Going to build that powerr Build, build up that power, hey I've been feeding the rhythm I've been feeding the rhythm Going to feel that power, build in you Come on, come on, help me do Yeah, yeah, yeah, yeah, yeah, yeah, yeah, yeah, you I've been feeding the rhythm I've been feeding the rhythm It's what we're doing, doing All day and night (ok i think i've made my point)

About sex. That's it. The music video illustrates this quite clearly, as well.