Maquinaria Naval

2. Conventional equipments
• Conventional type of equipments are
1. Mooring windlass. Normally either an electric or Hydraulic motor drives 2
cable lifter and 2 warp ends. There are many designs but due to slow speed of
cable lifter(3-5rpm) a slow speed worm gear and a single step spur gear
between cable lifter and warp end is used
2. Anchor Capstans. Vertical capstans use a vertical shaft, with the motor
and gearbox situated below the winch unit (usually below decks. With larger
cables the capstan barrels is mounted separately on another shaft
3. Winch windlasses. This arrangement uses a mooring
winch to drive the windlass. Both port and starboard units
are interconnected to facilitate standby and additional power
should the situation arise

3. Control of Windlass
• As the location is very vulnerable, the equipment shall
demand less maintenance and the design and layout shall
reflect this.
• Design on adequate margin of the strength rather than on life
is the main criteria while on the planning stage. Slipping
clutches safe guard against shocks. Enclosed oil lubricated
and open gears are common depending on sizes
• Normally these are controlled locally like starting and manual
application of brake while letting go the anchor etc.
• But remote controls are getting popular in the recent times

4. Anchoring equipment
The anchoring equipment
fitted to the majority of
vessels consists of two
matched units, offering a
degree of redundancy.
These units consists of an
anchor, chain (or for
smaller vessels wire), a
gypsum or chain lifter
wheel, brake, lift motor and
various chain stopper
arrangements.
When not in he use the
chain is stowed in a chain
locker.
Systems fitted with wire are
stowed on a drum in the
same way as winches.
1. The windlass must be capable of pulling the
anchor from a depth of 25% of the total cable
carried, i.e. 50% of the length of chain on
one side
2. It should be capable of lifting the anchor from
82.5m to 27.5m at 9m/min.

5. Chain locker
A false bottom is fitted to the
chain locker consisting of a
perforated plate. This allows
water and mud to be
removed from the space.
The end of the chain is
attached to the hull by a
quick release mechanism
known as the 'bitter end'.
The strength of this will not
be sufficient to prevent a run
away unbraked chain. The
arrangement must be easily
accessible.

6. Chain stopper
For anchoring operations the stopper
bar is locked upright. When it is
required to fix the position of the
chain the stopper is lowered into the
position shown. This allows the
brake to be released and is typically
used for stowing the anchor. chain
stopper arrangements are not
designed to stop a runaway chain.
Alternately an arrangement known
as the 'devil's claw' may be used
which has a forked locking piece. For
smaller vessels, and where extra
security is required bottle jacks with
wire straps passed though the chain
may be used.

7. Chain
End pull will cause the link to collapse in. This repeated
many times will lead to fatigue failure. Hence, stud linked
chain is insisted upon
Here a stud is welded on one side in the link to brace it
against deformation. An alternative to this albeit in limited
use is shown below.
Chain sizing
Each vessel is given an equipment number which is
calculated with use of a formula and takes into account the
vessels size, underwater area and sail area. From this a
'look-up' table may be used to give an appropriate size of
cable. The diameter of the chain may be read from this
table and differs depending on the grade of steel. This
grade of steel varies from U1 ( mild steel), U2 (Special
Steel) to U3 (extra special steel).

8. Ranging Anchor Chain
Ranging Anchor Chain
During docking the anchor chain is
lowered from the chain locker to the
dock bottom and laid out for
inspection.
This allows the inspection of the
chain for broken or lost chain studs. A
random set of links are measured
from each shackle length ( Shackle
refers to a standard length- nominally
27.5m), of chain joined to other
shackle lengths by a splitable link.
There is an allowable wear limit
allowed nominally 12%.

9. Anchor designs
Anchor shown below is of the 'flipper' type. Regulations allows these to be
smaller than standard types used in many small to medium sized tankers