These are practical examples that avoid the use
of the Euler–Eytelwein formula. They are purely
trial-and error methods with good success . . .
so far.
The first example is supposed to demonstrate the
descent of a substantial branch that overhung
the property fence. Unfortunately a stray tiny
branch snagged the rope and due to other pressing
matters and prolonged neglect, the rope
deteriorated/snapped before I resumed filming.
The first video shows how I dismantle a tree/branch
in small stages and how I avoid whiplash or
unanticipated sudden motions that could knock
me off the extension laddder or break something.
I described this method at another post:
https://permies.com/t/24998/woodland/timbertool-tree-jack
I think it is the last post. A diagram and more detailed
description can be found there.
The ladder is secured to the tree via both rope and
chain - I take lots of precautions and it is loose
enough to prevent any storm sway from damaging the
ladder.
With two or three wraps around the capstan (in
this case the top bar of a swing), and a small
weight, the load is unable to move due to the
friction imposed. Adding a second weight in the
middle allows you - with appropriate
manipulations - to advance or reverse while
maintaining a secure hold on the load. the
intention is to lower the branch in increments
as I cut away at the bits reaching the ground.
ascent part2
In the second demonstration, I transport an old
table to the balcony. The table weighs 12.5 kg
and is extremely difficult to manouever through
the house and up the stairs all by myself.
I used two static capstans in this case. The pulleys
are two tyre-less wheelbarrow wheels. The Moringa
outgrew its pot and toppled against the balcony.
I have tied it to the balcony and my remaining cat
Leeseunggi easily scales it to reach the balcony.
She descends via the Neem tree where the extension
ladder is currently positioned.
The photo shows the intended location of the
table.
Why?
It is just a stop gap measure. For some
unknown reason, during the 3 to 5 inch storms,
the gutter overflows there and the waterfall
is enough to overpower the lip of the roof tiles
thus flooding the ceiling underneath.
The rope I used was deteriorated at the bleached
spots and splintered but held together long enough
for the mission. I have retired that.
Do not attempt these unless you can accept the risks.
EDIT:
In hindsight, I should have used captive pulleys because
if the rope escapes one pulley, the load will swing and
almost certainly cause the other to escape and the load
will come crashing down.
The same thing will happen if one rope breaks.
Two ropes gives false security. I failed to include
a safety/failsafe rope.
In reality, the drawing shows the rope at the pulley
drawn incorrectly. There is a limit to simulating scenarios
in the mind. In reality, it is better reversed as the rope
will not have to rub against any surface. You adjust
according to what you find on the ground.
In contrast the captive branch technique has
withstood a dozen trials.
"Every plan fails at the first contact with the enemy."
