Is there a particular reason why most prison doors’ bars are vertical?

Question

I would assume horizontal bars would make it stronger because they will have to be shorter (assuming normal door proportions)

EDIT: I mean cell doors

EDIT 2: Ok so its a combo of reasons like making it harder to punch thru the bars, exchange goods, use weight to bend the bars, and no climbing to prevent WWE scenarios. Aight thanks guys

In: Other

Answer 1

Imagine someone trying to reach between the bars to either hand off goods or hit someone. Horizontal movements would let them reach more than vertical movements do.