chunk loading

Ok, so when building big ships in singleplayer, I build them around 600m, to 1km, long, and when I try to admin load them in, large chunks (like, actual 32 by 32 block chunks) are missing from the ship. If I leave my world, and then join it again, the chunks, again, are missing. They are always...

Is the chunk there? Yes. Is it loaded? No, it's out of the chunk loading range. Is the chunk at least X% full of blocks? Yes. Take the predominant hull color in that chunk and render the entire chunk as a smooth cube of that hull color. Don't bother trying to load the chunk. Just render its...