I normality don't have a problem with this, I put the game on hard for the first time and it goes well I taken city and villages but I cant seem to take this castles

it don't matter how much I try, last time I attacked outnumber them like 3 to 1 but every time I attack they will burn all my siege equipment just before it reach the wall, ladder are useless my men get slaughter by the archer it early days so no artillery yet, is there any good tactic to getting my siege equipment to the fucking walls.