The two footrests visible in the picture are hinged to the central box. Inside this are two sliding brake blocks.
When the footrests are depressed, these blocks grip the ascent rope threaded through the guide tube. This rope should
be attached to the deck and the upper end secured to a halyard which is then used to hoist it to the masthead. Once
the rope is gripped, the footrests will take the climbers weight and he can lift himself out of the bosun's chair.
His helper then takes up the slack in the chair halyard and the climber again sits down. He raises his feet in the stirrups,
the brake blocks retreat off the rope releasing their grip and he then slides the whole assembly up the line to a comfortable
height and repeats the process. Internal springs apply sufficient pressure on the line to prevent the MastaClimba sliding
back down as the climber changes from pressing to lifting. The springs also prevent the MastaClimba disappearing down
to the deck if the feet are completely removed when transferring to fixed mast steps for instance.
The
MastaClimba can be hoisted as far up the mast as the attachment to the halyard and the turning block position allow.
In most full rigged boats, this permits the climber to rise head and shoulders above the masthead;- handy for changing lightbulbs
and the like.
New! Single-handed ascents.
To
ascend, use the MastaClimba in conjunction with an Ascendeur, Jumar, Prussic knots or the like attached to the chair or harness.
Belay the chair around the ascent line with a shackle. At the point of attachment of the ascent line to the hoisting halyard,
also attach another line free hanging and reaching the deck. Ascend in the usual way;- sit,slide, stand. On descent,
thread the free hanging line through a figure of 8 attached to the harness, unclip the Ascendeur and abseil down. Once
the shackle hits the guide tube on the MastaClimba, they will slide down together.
An alternative
giving greater control, is to use the figure of eight at the masthead with one end of the free line attached to the chair
the other being fed by hand upwards through the figure of eight. This gives a 2:1 disadvantage thus halving the speed
of descent and the effort. There is a danger in this. A figure
of eight used in this way can cause a collapse of the threaded line into a cow hitch. You could hang there until the
flesh rots off your bones! Instead use an Anka which is like the figure of eight but has horns preventing the collapse.
