In article ,
Vir Campestris wrote:

On 21/02/2017 17:19, Nick Maclaren wrote:
You're missing the point. For a given leg separation, the distance
from the centre (at ground level) to the closest point outside the
triangle is much less than it is for the quadrilateral. Therefore,
the ladder will fall over for a much lower imbalance in the weight
or sideways force.

You're missing the point. Unlike a floor in a house a garden isn't a
flat plane. Which means that one leg of a 4 legged ladder is always off
the ground.

And that means it is _less_ stable than a properly designed three legged
one, as it rocks between the two stable configurations...

I have a step ladder with bars across the base of each step. It's great
indoors. Outdoors I have to fiddle around for ages so it doesn't rock,
sometime putting bricks under it

I've only ever seen (on't'telly) tripod ladders in use with
trees/hedges. One was Monty Don doing his Product Placement thing [he's
good at that] when cutting his 15' tall beech hedge[1], with the odd
leg shoved through into the bottom of the hedge -- you couldn't do that
with a 4-legger. "Damn good!" I thought, as a regular hedge trimmer
myself.

Another was when a programme visited an orchard, and they were using the
tripod to pick apples -- perfect.

In both cases, the tree/hedge is giving extra stability to the lad/lass
at the top of the ladder.

John

[1] You never, ever, see a sign of the small army of "assistant
gardeners" who must inhabit Monty's VAST garden at lovely old Long
Meadow. He wouldn't remotely have time, let alone the energy, to do
everything that gets done there. Bloody annoying.