Just like any wood, hickory WILL split and splinter is its tensile strength properties are exceeded. CaptA you're correct in that hickory was the preferred wood for FD ladders though today the trend is away from wood and aluminum, (which replaced wood due to lighter weight), and towards fiberglass. Been far too many years for me to recall the trivia as to why the FD's preferred hickory over other woods. I'd have to look that one up.
I've got one stump table that I made from hickory that was blown down by hurricane Opal back in '95. My first table and it's still with me. Heavy as lead still even though it's lost nearly 100 pounds since I first cut it out.