610 NICHOLAS'S SEAMANSHIP AND NAUTICAL KNOWLEDGE

Fig. 18 shows a simple relieving tackle for small vessels, but in
large vessels this is quite inadequate, and many are fitted with a
friction brake, one of the simplest and most effective being the
" Dunstos " Kudder Brake as illustrated.

Fig 19

Fig. 19 gives a general view of the arrangement. Two brackets
are fitted on deck, one on each side of the quadrant, and a free wheel
rotating on a vertical axis, the foundation of which is bolted to the
middle of the quadrant near to its circumference. The end of a
wire is shackled to one bracket, a turn of the wire is taken round the
pulley, and the other end of the wire is set up tight to the other
bracket by means of a tightening screw.

Frictional resistance to back-kick is obtained as follows (see
Figs. 19 and 20):—

HftNDWHEEL

Fig. 20.
A base plate A with a central axis having a recess all round k
securely bolted to the quadrant, the circular recess in base is fitted
with hardwood in segments B.
A double grooved sheave 0 is fitted, free to revolve on the axis
of the base plate, the bottom o* the sheave rests upon the wood B,