LAUNCHING AND EMBARKATION APPLIANCES
PART I
LIFEBOAT AND RESCUE BOAT DAVITS AND WINCHES
Section 1
Prototype tests
1
General
1.1
Lifeboat and rescue boat davits and winches shall comply with the
requirements contained in Part 1, as applicable, and Part 2 of Schedule 6 of MSN
1676 (M) as appropriate.
1.2
The surveyor should be satisfied with the designed stability and strength,
ensuring that the statutory factors of safety are achieved. Where davits are of welded
steel construction, the thickness of plates and steel sections used in the davit arms
and stand frames should not be less than 6 mm and should be fabricated under
suitable conditions using electrodes suitable for the type of steel used. The davits
should be adequately protected against corrosion.
2
Davit tests
2.1
Proof load
2.1.1
Each davit arm should be tested with a static load of 2.2 times the working
load with the davit arm in any position which gives a maximum stress
concentration. The direction of the load should be such that it simulates the 20° list
and 10° trim conditions. With the davit arm at the full outboard position, where
practicable, the load should be swung through an arc of approximately 10° to each
side of the vertical in the intended fore and aft plane. This test should be carried out
first in a plane simulating the ship in the upright position, followed by tests
simulating a shipboard condition of list of 20° both inboard and outboard. The
davit arm and frame must not be deformed or damaged. Any cast components of
the frame and arm should be hammer-tested to determine that they are sound and
without flaw.
2.1.2
Attachments for the standing part of the wire rope falls and other parts from
which the boat is suspended, should be proof load tested with a static load of 2.2
times the working load on the attachment or other part.
2.2
Stability
2.2.1
A mass equal to 1.1 times the maximum working load should be
suspended with its centre of gravity approximating that of the boat and its full
complement, from the lifting points with the davits in the stowed position. The load
should be moved from full inboard to full outboard position using, where
practicable, the means of operation that is used in the ship. The test should be
repeated with the davit positioned to simulate a combined list of 20° and trim of
10° in both high side and low side list conditions. In moving the davit from the
inboard to the outboard position there must be no evidence of the block leaving the
horn prematurely.
2.2.2
Where gravity (trackway or pivot) davits are being tested all the tests in
paragraph 2.2.1 should be repeated with a mass equal to the fully equipped
lifeboats, without persons, to ensure the satisfactory functioning of the davit under
very light conditions. There must be no evidence of significant deformation or other
damage as a result of the tests. Where identical sets of davits are manufactured the
stability tests need only be carried out on the prototype set of equipment.
2.3
Hoisting load
A mass equal to the maximum designed hoisting load should be hung from the
davit head and the davit should be moved to the satisfaction of the surveyor from
the outboard to the inboard position without causing permanent deformation or
other damage to the launching appliance. This test should be carried out with the
launching appliance in the upright position.
2.4
Luffing equipment pressure
The pressure parts of hydraulic luffing davits should be hydrostatically tested to 1.5
times the design pressure.
3
Winch tests
3.1
Overload lowering
3.1.1
Winch drums should be wound to the maximum number of turns
permitted and a static test load of 1.5 times the maximum designed pull exerted on
the winch should be applied and held by the brake or equivalent device. This load
should then be lowered for at least one complete revolution of the winch barrel
(drum) shaft and held.
3.2
Winch fall end fastenings
3.2.1
The method of attaching the wire rope falls to the winch drums should be
acceptable to the MCA, and samples of the arrangement should be subjected to a
proof load test of 2.2 times the working load on the drum. Where the design allows
for a minimum number of turns to remain on the drum, the test may simulate such a
condition. Where identical end fastenings are incorporated in winches approved
for the same working load this test need only be carried out on the prototype winch.
3.3
Brake
3.3.1
A test load of 1.1 times the maximum designed pull should then be
lowered at the maximum speed in accordance with Schedule 6 Part 1, paragraphs
5.3 and 5.4 of MSN 1676 (M), through at least 3 metres and stopped by applying
the hand brake, or braking device, sharply. The test load must drop no more than 1
metre when the brake is applied. If the winch design incorporates an exposed
brake, a test should be carried out with the brake wetted, but in this case the
stopping distance may be exceeded. The various tests must achieve a cumulative
lowering distance of at least 150m.
3.4
Light lowering
Operation of the winch with a load of a mass equal to a fully equipped lifeboat or
rescue boat, without persons, should also be demonstrated.
3.5
Recovery
3.5.1
Where a powered winch is installed on a set of davits to which a lifeboat is
attached it should be demonstrated that the lifeboat with its launching crew of at
least two persons and its full equipment, or a mass equivalent to that weight, can be
hoisted at a rate of not less than 0.05 metre per second. It should also be
demonstrated that this mass can be hoisted by means of the hand gear.
3.5.2
Where an unpowered winch is installed on a set of davits to which a
lifeboat is attached, it should be demonstrated that the lifeboat with its launching
crew and equipment, or an equivalent mass, can be hoisted at a rate of at least 0.01
metre per second.
3.5.3
In the case of launching arrangements for rescue boats it should be
demonstrated that the rescue boat with its full rescue boat complement of persons
and equipment can be hoisted at a rate of not less than 0.3 metre per second. It
should also be demonstrated that this mass can be hoisted by means of the hand
gear.
Section 2
Production tests
1
Davit tests
Each davit is to be static load tested in accordance with Schedule 6, Part 2,
paragraph 6 of the MSN 1676 (M).
2
Winch tests
Each winch is to be satirically and dynamically load tested and the boat lowering
speed determined in accordance with Schedule 6, Part 1, paragraphs 5.2, 5.3 and
5.4 of MSN 1676 (M). See also note at end of Section 3, paragraph 3 of these
instructions for optimum speed.
3
The Nominated or Notified Body will make random inspections of
manufacturers' premises to ensure that the quality of the materials and associated
equipment used in the fully completed davit and winch comply with the
specification of the approved prototype item.
4
Manufacturers are required to institute a quality control procedure to
ensure that the davit and winch or equipment are produced to the same standard as
the prototype approved by the Nominated or Notified Body and to keep records of
any production tests carried out in accordance with the Nominated or Notified
Body's instructions.
5
As part of the monitoring process of Nominated and Notified Bodies,
appointed by the MCA, a MCA surveyor may make random inspections of the
manufacturers premises to ensure that the appointed Bodies are carrying out their
duties in accordance with the Bodies instructions.
Section 3
Installation tests
1
General
The launching appliance arrangements should be inspected to ensure that they
have been installed in accordance with the approved drawings. Tests should be
made to ensure that all lifeboats and rescue boats can be re-stowed safely when
loaded with the required equipment and persons.
2
Light lowering
The lifeboat or rescue boat loaded with its normal equipment, or an equivalent
mass, should be released by operation of the launching control on deck to
demonstrate that the lifeboat's mass is sufficient to overcome the frictional resistance
of the winch, falls, block and associated gear. The speed at which the lifeboat or
rescue boat is lowered into the water should be within limits as required by
Schedule 6, Part 1, paragraphs 5.3, 5.4 and 5.5 of MSN 1676 (M).
3
Loaded lowering
The lifeboat or rescue boat loaded with its normal equipment, or an equivalent
mass, and a distributed mass equal to the number of persons, each weighing 75 kg,
it is permitted to accommodate plus 10% of the working load should be released by
the operation of the launching controls on deck. When the craft has reached its
maximum lowering speed the brake should be abruptly applied to demonstrate that
the attachments of the davits and winches to the ship's structure are satisfactory.
The speed at which the lifeboat or rescue boat is lowered into the water should be
within limits as required by Schedule 6, Part 1, paragraphs 5.3 and 5.4 of the MSN
1676 (M).
(Note The jolt on the boat lowering system due to sudden braking can be
reduced if the winch centrifugal brakes are adjusted to satisfy just the minimum
required speed by the Regulations. Sudden jolt due to the davit arms coming
against a stop (especially if the boat is being remotely lowered as described in
paragraph 4, from inside the boat, where the operator cannot see the winch hand
brake lever position) can be further reduced by a spring loaded damping
mechanism fitted to the davit arms. The manufacturers should be consulted for this
purpose and the arrangements should be satisfactory to the operators and the
surveyor).
4
Remote controlled lowering
Such lowering is required by regulations for lifeboats and rescue boats (unless
exemption or equivalence is granted) and surveyors should check the items listed in
Schedule 6, Part 1, paragraph 5.10 of MSN 1676 (M) to ensure that they are
complied with.
5
Recovery
5.1
Where a powered winch is installed on a set of davits to which a lifeboat is
attached it should be demonstrated that the lifeboat with its launching crew of at
least two persons and its full equipment, or a mass equivalent to that weight, can be
hoisted at a rate of not less than 0.05 metre per second. It should also be
demonstrated that this mass can be hoisted by means of the hand gear.
5.2
Where an unpowered winch is installed on a set of davits to which a
lifeboat is attached, it should be demonstrated that the lifeboat with its launching
crew and equipment, or an equivalent mass, can be hoisted at a rate of at least 0.01
metre per second.
5.3
In the case of launching arrangements for rescue boats it should be
demonstrated that the rescue boat with its full rescue boat complement of persons
and equipment can be hoisted at a rate of not less than 0.3 metre per second. It
should also be demonstrated that this mass can be hoisted by means of the hand
gear.
5.4
Where davits are recovered by power, it should be demonstrated that the
power is automatically cut off before the davit arms come against the stops.
6
Luffing davit
When luffing type davits are turned out by means of hydraulic cylinders a test
should be carried out under `dead ship' conditions to ensure that the lifeboat or
rescue boat can be safely launched from the stowed position. (Note: Strictly 'dead
ship' conditions mean failure of both electrical power (to generate hydraulic
power), and hydraulic power (e.g. burst hydraulic hose or leaky cylinder etc.),
however provision of hydraulic accumulators has been accepted if hand luffing is
not possible.)
PART II
LIFERAFT LAUNCHING APPLIANCES
Section 1
Prototype tests
1
General
1.1
Liferaft launching appliances should comply with the requirements
contained in Schedule 6, Part 1, as applicable, and Part 3 of MSN 1676 (M).
1.2
The surveyor should be satisfied with the designed stability, where
applicable, and strength, ensuring that the statutory factors of safety are achieved.
Where launching appliances are of welded steel construction, the thickness of
plates and steel sections used in the davit arms and stand frames should not be less
than 6 mm and should be fabricated under suitable conditions using electrodes
suitable for the type of steel used. The appliances should be adequately protected
against corrosion.
2
Davit
2.1
Static load
Each launching appliance should be tested with a static load of 2.2 times the
working load with the appliance in the full outboard position. With the launching
appliances at the full outboard position, where practicable, the load should be
swung through an arc of approximately 10° to each side of the vertical in the
intended fore and aft plane. This test should be carried out first in a plane simulating
the ship in the upright position, followed by tests simulating a shipboard condition
of list of 20° both inboard and outboard. The appliance arm and frame must not be
permanently deformed or damaged by this test. Any cast components of the arm
and frame should be hammer-tested to determine that they are sound and without
flaw.
2.2
Slewing
Where the launching appliance is a mechanically controlled single arm davit, the
davit should be loaded with a mass equivalent to the weight of the liferaft
equipment and container, or 185 kg, whichever is the greater, and should be tested
on a platform tilted at 20° in both directions to demonstrate that the davit can be
freely turned out.
2.3
Luffing equipment pressure
The pressure parts of any hydraulic luffing device incorporated in a launching
appliance should be hydrostatically tested in 1.5 times the design pressure.
3
Winch
3.1
Overload lowering
The winch drum should be wound to the maximum number of turns permitted and
a static test load of 1.5 times the maximum design pull exerted on the winch should
be applied and held by the brake. This load should then be lowered for at least one
complete revolution of the winch barrel/drum shaft.
3.2
Brake
A test load of 1.1 times the maximum designed pull should be lowered at the
maximum speed in accordance with paragraphs 5.2 and 5.3 of Part 1, Schedule 6
of MSN 1676 (M) through at least 3m and stopped by applying the hand brake
sharply. The test load must drop no more than 1 metre when the brake is applied. If
the winch incorporates an exposed brake, a test should be carried out with the
brake wetted, but in this case the stopping distance may be exceeded. The various
tests must achieve a cumulative lowering distance of at least 150m.
3.3
Light hoisting
If the winch is designed for quick recovery by hand with no load, a load equivalent
to 1.5 times the mass of the release hook and fall at its lowest position should be
hoisted in the quick recovery mode by hand.
Section 2
Production tests
1
Davit tests
Each davit is to be static load tested in accordance with Schedule 6, Part 3,
paragraph 3 of the MSN 1676 (M).
2
Winch tests
Each winch is to be satirically and dynamically load tested and the liferaft lowering
speed determined in accordance with Schedule 6, Part 1, paragraphs 5.2 and 5.3 of
MSN 1676 (M).
3
The Nominated or Notified Body will make random inspections of
manufacturers' premises to ensure that the quality of the launching appliance,
materials and associated equipment used in the fully completed liferaft comply with
the specification of the approved prototype item.
4
Manufacturers are required to institute a quality control procedure to
ensure that the launching appliance or equipment are produced to the same
standard as the prototype approved by the Nominated or Notified Body and to
keep records of any production tests carried out in accordance with the Nominated
or Notified Body.
5
As part of the monitoring process of Nominated or Notified Bodies,
appointed by the MCA, a MCA surveyor may make random inspections of the
manufacturers premises to ensure that the appointed bodies are carrying out their
duties in accordance with the bodies instructions.
Section 3
Installation tests
1
General
The launching appliance arrangements should be inspected to ensure that they
have been installed in accordance with the approved drawings.
2
Operational
If more than one liferaft is served by any launching appliance effective successive
launching of at least 3 fully loaded liferafts should be demonstrated in the case of
passenger ships and the number served by the launching appliance in the case of
cargo ships to determine that the requisite number of liferafts can be launched
within 30 and 10 minutes respectively.
3
Loaded lowering
The liferaft loaded with its normal equipment or an equivalent mass and a
distributed mass equal to the number of persons, each weighing 75 kg, it is
permitted to accommodate plus 10% of the working load should be released by the
operation of the launching controls on deck. When the craft has reached its
maximum lowering speed, the brake should be abruptly applied to demonstrate
that the attachments of the davits and winches to the ship's structure are satisfactory.
The speed at which the liferaft is lowered into the water should be within limits as
required by Schedule 6, Part 1, paragraphs 5.3 to 5.5 of MSN 1676 (M).
4
Remote control lowering
If the lowering of the liferaft is controlled from within the liferaft by means of a
control wire paid off from an auxiliary drum on the winch, the items listed in
Schedule 6 Part 1, paragraph 5.9 of MSN 1676 (M) should be checked to ensure
that they have been complied with.
(Note "pull and go" (i.e. no further control when the descent starts) type of
winches have been accepted for liferafts under the SOLAS Convention and MCA's
regulations in which case paragraph 4 will not be applicable).
5
Luffing device
When a hydraulic luffing device is incorporated in a launching appliance, a test
should be carried out under 'dead ship' conditions to ensure that the appliance arm
can be fully extended so that liferafts can be safely lowered to the sea.
(Note Strictly 'dead ship' conditions mean failure of both electrical power (to
generate hydraulic power), and hydraulic power (e.g. a burst hydraulic hose or
leaky cylinder etc.), however provision of hydraulic accumulators have been
accepted if hand luffing is not possible).
PART III
INFLATED BOAT LAUNCHING DEVICES
Section 1
Prototype tests
1
General
1.1
Inflated boat launching appliances should comply with the requirements
contained in Schedule 6, Part 1, as applicable, and Part 4 of MSN 1676 (M).
1.2
The surveyor should be satisfied with the designed strength, ensuring that
the statutory factors of safety are achieved. Where the launching appliances are of
welded steel construction, the thickness of plates and steel sections used in the davit
arms and stand frames should not be less than 6 mm and should be fabricated
under suitable conditions using electrodes suitable for the type of steel used. The
appliances should be adequately protected against corrosion.
2
Davit
2.1
Proof load
Each launching device should be tested with a static load of 2.2 times the working
load with the arm of the device in the full outboard position. The direction of the
load should be such that it simulates 20° list and 10° trim conditions. With the arm
at the full outboard position, where practicable, the mass should be swung through
an arc of approximately 10° to each side of the vertical in the intended fore and aft
plane. The launching device arm and frame should not be permanently deformed
or damaged by this test. Any cast components of the arm and frame should be
hammer-tested to determine that they are sound and without flaw.
2.2
Luffing equipment pressure
The pressure parts of any hydraulic luffing equipment incorporated in a launching
device should be hydrostatically tested to 1.5 times the design pressure.
3
Winch
3.1
Overload lowering
The winch drum should be wound to the maximum number of turns permitted and
a static test load of 1.5 times the maximum designed pull exerted on the winch
should be applied and held by the brake. This load should then be lowered for at
least one complete revolution of the winch barrel (drum) shaft.
3.2
Brake
A test load of 1.1 times the maximum designed pull should be lowered at the
maximum speed in accordance with paragraphs 5.2 and 5.3 of Schedule 6 Part 1 of
MSN 1676 (M) through at least 3m and stopped by applying the hand brake
sharply. The test load must drop no more than 1m when the brake is applied. If the
winch incorporates an exposed brake, a test should be carried out with the brake
wetted, but in this case the stopping distance may be exceeded. The various tests
should achieve a cumulative lowering distance of at least 150m.
3.3
Recovery
It should be demonstrated that the inflated boat with a launching crew of at least
two persons, its engine and full equipment can be hoisted by means of hand gear.
Where a powered winch is fitted it should also be demonstrated that the boat,
launching crew, engine and full equipment, or an equivalent mass, can be hoisted
at a rate not less than 0.05 metre per second.
Section 2
Production tests
1
Launching appliance tests
Each launching appliance is to be static load tested in accordance with Schedule 6,
Part 4, paragraph 4 of MSN 1676 (M).
2
Winch tests
Each winch is to be satirically and dynamically load tested and the inflated boat
lowering speed determined in accordance with Schedule 6, Part 1, paragraphs 5.2,
5.3 and 5.4 of MSN 1676 (M).
3
The Nominated or Notified Body will make random inspections of
manufacturers' premises to ensure that the quality of the materials and associated
equipment used in the fully completed launching appliance comply with the
specification of the approved prototype item.
4
Manufacturers are required to institute a quality control procedure to
ensure that the launching appliance or equipment are produced to the same
standard as the prototype approved by the MCA, Nominated or Notified Body and
to keep records of any production tests carried out in accordance with the MCA,
Nominated or Notified Body.
5
As part of the monitoring process of Nominated or Notified Bodies,
appointed by the MCA, a MCA surveyor may make random inspections of the
manufacturers premises to ensure that the appointed bodies are carrying out their
duties in accordance with the bodies instructions.
Section 3
Installation tests
1
General
The launching device arrangements should be inspected to ensure that they have
been installed in accordance with the approved drawings.
2
Operational
Tests should be made to ensure that any inflated boat served by any launching
device when loaded only with its full equipment can be lowered by gravity into the
water.
3
Loaded lowering
The inflated boat loaded with its normal equipment or an equivalent mass and a
distributed mass equal to the number of persons, each weighing 75 kg, it is
permitted to accommodate plus 10% of the working load should be released by the
operation of the launching controls on deck. When the boat has reached its
maximum lowering speed, the brake should be abruptly applied to demonstrate
that the attachments of the davits and winches to the ship's structure are satisfactory.
The speed at which the inflated boat is lowered into the water should be within
limits as required by Schedule 6, Part 1, paragraphs 5.3 and 5.4 of MSN 1676 (M).
4
Remote control lowering
If the lowering of the inflated boat is controlled from within the boat by means of a
control wire paid off from an auxiliary drum on the winch, the items listed in
Schedule 6, Part 1, paragraph 5.8 of MSN 1676 (M) should be checked to ensure
that they have been complied with.
5
Luffing device
When a hydraulic luffing arrangement is incorporated in a launching device, a test
should be carried out under 'dead ship' conditions to ensure that the appliance arm
can be fully extended so that the boat can be safely lowered to the sea.
(Note Strictly `dead ship' conditions mean failure of both electrical power (to
generate hydraulic power), and hydraulic power (e.g. a burst hydraulic hose of
leaky cylinder etc.), however provision of hydraulic accumulators have been
accepted if hand luffing is not possible).
PART IV
MECHANICALLY CONTROLLED SINGLE ARM DAVITS
Section 1
Prototype
1
General
1.1
When mechanically controlled single arm davits are installed for use with
inflated boats or other boats, they should comply with the requirements contained
in Part 1, as applicable, and Part 4 of Schedule 6 of MSN 1676 (M) except that they
need only operate in the upright or low side list condition of up to 20° list unless
the boat is used for marshalling liferafts in an emergency in which case full
compliance is required.
1.2
The surveyor should be satisfied with the designed stability, where
applicable, and strength, ensuring that the statutory factors of safety are achieved.
Where the mechanically controlled single arm davit is of welded steel construction,
the thickness of plates and steel sections used in the davit arms and pedestal should
not be less than 6 mm and should be fabricated under suitable conditions using
electrodes suitable for the type of steel used. The davit should be adequately
protected against corrosion.
2
Davit tests
2.1
Static load
2.1.1
A mechanically controlled single arm davit should be tested with a static
load of 2.2 times the working load with the davit arm in the full outboard position.
The direction of the load should be such that it simulates 20° low side list and 10°
trim conditions.
2.1.2
With the davit arm at the full outboard position, where practicable, the
mass should be swung through an arc of approximately 10° to each side of the
vertical in the intended fore and aft plane. The davit arm and pedestal should not
be permanently deformed or damaged by this test. Any cast components of the
davit arm and pedestal should be hammer-tested to determine that they are sound
and without flaw.
2.2
Slewing
The prototype davit should be loaded to 1.25 times the working load and tested on
a platform tilted at 20° low side list to demonstrate that the davit arm can be freely
turned out. The same test should be repeated for 20° high side list condition if the
boat is to be used for marshalling liferafts in an emergency.
3
Winch tests
3.1
Overload lowering
The winch drum should be wound up to the maximum number of turns permitted
and a static test load to 1.5 times the maximum designed pull extended on the
winch should be applied and held by the brake. This load should then be lowered
for at least one complete revolution of the winch barrel (drum) shaft.
3.2
Brake
A test load of 1.1 times the maximum designed pull should be lowered at the
maximum speed in accordance with paragraph 5.2 and 5.3 of Part 1 of Schedule 6
of MSN 1676 (M) through at least 3m and stopped by applying the hand brake
sharply. The test load must drop no more than 1m when the brake is applied. If the
winch incorporates an exposed brake, a test should be carried out with the brake
wetted, but in this case the stopping distance may be exceeded. The various tests
must achieve a cumulative lowering distance of at least 150m.
3.3
Recovery
It should be demonstrated that the inflated boat with a launching crew of at least
two persons, its engine and full equipment can be hoisted by means of hand gear.
Where a powered winch is fitted it should also be demonstrated that the boat,
launching crew, engine and full equipment, or an equivalent mass, can be hoisted
at a rate not less than 0.05 metre per second.
Section 2
Production tests
1
Launching appliance tests
Each launching appliance is to be static load tested in accordance with Schedule 6,
Part 4, paragraph 4 of MSN 1676 (M).
2
Winch tests
Each winch is to be statically and dynamically load tested and the boat lowering
speed determined in accordance with Schedule 6, Part 1, paragraphs 5.2, 5.3 and
5.4 of MSN 1676 (M).
3
The Nominated or Notified Body will make random inspections of
manufacturers' premises to ensure that the quality of the materials and associated
equipment used in the fully completed launching appliance comply with the
specification of the approved prototype item.
4
Manufacturers are required to institute a quality control procedure to
ensure that the launching appliance or equipment are produced to the same
standard as the prototype approved by the Nominated or Notified Body and to
keep records of any production tests carried out in accordance with the Nominated
or Notified Body.
5
As part of the monitoring process of Nominated or Notified Bodies,
appointed by the MCA, a MCA surveyor may make random inspections of the
manufacturers premises to ensure that the appointed bodies are carrying out their
duties in accordance with the bodies instructions.
Section 3
Installation tests
1
General
The mechanically controlled single arm davit arrangements should be inspected to
ensure that they have been installed in accordance with the approved drawings.
2
Operational
Tests should be made to ensure that any boat served by any single arm davit when
loaded with its full equipment can be lowered by gravity into the water.
3
Loaded lowering
The boat loaded with its normal equipment or an equivalent mass and a distribution
mass equal to two persons, each weighing 75kg, plus 10% of the working load
should be released by the operation of the launching controls on deck. When the
boat has reached its maximum lowering speed, the brake should be abruptly
applied to demonstrate that the attachments of the davits and winches to the ship's
structure are satisfactory. The lowering speed should be within limits as stated in
paragraphs 5.3 and 5.4 of Part 1 of Schedule 6 of MSN 1676 (M).
4
Remote control lowering
If the lowering of the boat is controlled from within the boat by means of a control
wire paid off from an auxiliary drum on the winch, the items listed in Schedule 6,
Part 1, paragraph 5.8 of MSN 1676 (M) should be checked to ensure that they have
been complied with.
PART V
FREE-FALL LIFEBOAT LAUNCHING APPLIANCES
Section 1
Prototype
1
General
1.1
Free-fall lifeboat launching appliances should comply with the
requirements contained in Schedule 6, Part 1, paragraph 7 of MSN 1676 (M).
1.2
The surveyor should be satisfied with the designed stability and strength of
the structure ensuring that the statutory factors of safety are achieved. Where the
structures are of welded steel construction, the thickness of the plates and steel
sections should not be less than 6 mm and should be fabricated under suitable
conditions using electrodes suitable for the type of steel used. The launching
appliances should be efficiently protected against corrosion and be so constructed
as to prevent incendive friction or impact sparking during the launch of the lifeboat.
1.3
A standby or auxiliary davit, generally complying with the requirements of
Schedule 6 Part I of the MSN 1676 (M), should be installed in order to retrieve the
free-fall lifeboat or to launch it when free-fall launching is impossible because of
shallow water or rocks. The exact requirements for this are still evolving, however,
the auxiliary launching devices of a free-fall boat differs from a conventional boat as
below:
.1 The launching should be accomplished with a maximum list of 5° and trim
of 2° either way.
.2 Remote launching from inside the boat is not compulsory, but where this
facility is fitted, see Part V, Section 3, paragraph 3.
.3 Provision only of power hoisting of the boat may be adequate although the
boat should be able to be launched without power. If launching is not
provided by gravity, stored mechanical energy or manual means, the launching
power required must be supplied by both the normal and the emergency
power source of the ship.
.4 A single suspension release and hoisting arrangement may be accepted
with a purely off-load type of release hook.
.5 The lowering and hoisting speeds should be reasonable and satisfactory.
2
Launching appliance tests
2.1
Proof load
2.1.1
The structure of the launching appliance should be tested with a static load
of 2.2 times the working load in any position which gives a maximum stress
concentration. The structure or frame must not be deformed or damaged by this test
and any cast components in the structure should be hammer tested to determine
that they are sound and without flaw.
2.1.2
The anchorage attachment, and any other parts from which the boat is
suspended, should be proof load tested with a static load of 2.2 times the working
load on the attachment or other part in the direction of the free-fall lifeboat position
allowing for the 10° trim of the ship.
2.2
Adjustable ramps
When provision is made for the ramp of the free-fall launching appliance structure
to be adjustable, it should be demonstrated that those ramps may be satisfactorily
adjusted with the free-fall lifeboat loaded to 1.2 times its related load.
2.3
Standby or auxiliary davits
2.3.1
Launching appliances for lowering a free-fall lifeboat by falls, except the
winch brakes, should be subjected to a static proof load of 2.2 times the maximum
working load at the full outboard position. There must be no evidence of significant
deformation or other damage as a result of this test.
2.3.2
A mass equal to 1.1 times the maximum working load should be
suspended from the lifting points. The load should be moved from the full inboard
to the full outboard position using the means of operation that is to be used on the
ship. The test should be repeated with a mass equal to the fully-equipped lifeboat,
without persons to ensure the satisfactory functioning of the appliance under light
load conditions. The appliance should successfully lower the load under both
conditions and there must be no evidence of significant deformation or other
damage as a result of the tests.
2.3.3
Where the standby or auxiliary davit is turned out by means of a
hydraulically operated luffing system, the pressure parts of the system should be
hydrostatically tested to 1.5 times the design pressure.
3
Standby or auxiliary davit winch tests
3.1
Overload lowering
Winch drums should be wound to the maximum number of turns permitted and a
static test load of 1.5 times the maximum designed pull exerted on the winch
should be applied and held by the brake or equivalent device. This load should
then be lowered for at least one complete revolution of the winch barrel (drum)
shaft and held.
3.2
Winchfall end fastenings
The method of attaching the wire rope falls to the wind drums should be acceptable
to the MCA, and samples of the arrangement should be subjected to a proof load
test of 2.2 times the working load on the drum. Where the design allows for a
minimum number of turns to remain on the drum, the test may simulate such a
condition. Where identical end fastenings are incorporated in winches approved
for the same working load, this test need only be carried out on the prototype
winch.
3.3
Brake
A test load of 1.1 times the maximum designed pull should then be lowered at the
maximum speed in accordance with Schedule 6, Part 1, paragraphs 5.2 and 5.4 of
MSN 1676 (M) through at least 3 metres and stopped by applying the hand brake,
or braking device, sharply. The test load must drop no more than 1 metre when the
brake is applied. If the winch design incorporates an exposed brake, a test should
be carried out with the brake wetted but, in this case, the stopping distance may be
exceeded. The various tests must achieve a cumulative lowering distance of at least
150m.
3.4
Recovery
Where a powered winch is installed on a set of standby or auxiliary davits to which
a free-fall lifeboat may be attached, it should be demonstrated that the lifeboat with
its launching crew of at least two persons and its full equipment, or a mass
equivalent to that weight, can be hoisted at a rate of not less than 0.05 metre per
second.
Section 2
Production tests
1
Free-fall launching appliance tests
1.1
Each launching appliance after production is to be load tested in
accordance with paragraphs 2.1 and 2.2 of Section 1 above.
1.2
Each standby or auxiliary davit after production is to be static load tested as
prescribed in paragraph 2.3.1 of Section 1 above.
2
Winch tests
Each winch for the standby or auxiliary davit is to be satirically and dynamically
load tested in accordance with Schedule 6, Part 1, paragraph 5.2, of MSN 1676
(M).
3
The Nominated or Notified Body will make random inspections of
manufacturers' premises to ensure that the quality of the materials and associated
equipment used in the fully completed winch comply with the specification of the
approved prototype item.
4
Manufacturers are required to institute a quality control procedure to
ensure that the winch or equipment are produced to the same standard as the
prototype approved by the Nominated or Notified Body and to keep records of any
production tests carried out in accordance with the Nominated or Notified Body.
5
As part of the monitoring process of Nominated or Notified Bodies,
appointed by the MCA, a MCA surveyor may make random inspections of the
manufacturers premises to ensure that the appointed bodies are carrying out their
duties in accordance with the bodies instructions.
Section 3
Installation tests
1
General
The free-fall launching appliance arrangements, together with its standby or
auxiliary davit should be inspected by the surveyor to ensure that they have been
installed in accordance with the approved drawings and the manufacturer's
instructions and that the attachment to the ship's structure is satisfactory.
2
Loaded lowering
2.1
Each new free-fall lifeboat should be loaded to 1.1 times its related load
and launched by free-fall with the ship on even keel and in its lightest seagoing
condition.
2.2
Using the standby or auxiliary davit the free-fall lifeboat should be loaded
to 1.1 times its related load and released by the operation of the launching controls
on deck. When the lifeboat has reached its maximum lowering speed, the brake
should be abruptly applied to demonstrate that the attachments of the davit and
winch to the ship's structure are satisfactory. The minimum lowering speed need
not be as high as in Schedule 6, Part 1, paragraph 5.3 of MSN 1676 (M), but should
be reasonable and satisfactory considering the auxiliary requirement of launching.
3
Remote controlled lowering (where fitted)
Where remote controlled lowering is fitted for free-fall lifeboats surveyors should
check the items listed in Schedule 6, Part 1, paragraph 5.9 of MSN 1676 (M) to
ensure that they are complied with. (See also Part V, Section 1, paragraph 1.3.2.)
4
Recovery
4.1.1
It should be demonstrated that the lifeboat can be recovered to its stowage
position and can be safely and properly secured.
4.1.2
Where a standby or auxiliary davit has been installed and the davit is
recovered by power, it should be demonstrated that the power is automatically cut
off before the davit arms come against the stops.
Adjustable ramp
4.1.3
It should be demonstrated that adjustable ramps for free-fall launching may
be adjusted satisfactorily with the free-fall lifeboat loaded to 1.2 times its related
load.