Section
5 Bulwarks, guard rails and other means for the protection of crew
5.1 General requirements
5.1.1 Bulwarks
or guard rails are to be provided around all exposed decks. Bulwarks
or guard rails are to be not less than 1,0 m in height measured above
sheathing, and are to be constructed as required by this Section.
Consideration will be given to cases where this height would interfere
with the normal operation of the ship.
5.1.3 Guard
rails fitted on superstructure and freeboards decks are to have at
least three courses. The opening below the lowest course of guard
rails is not to exceed 230 mm. The other courses are to be spaced
not more than 380 mm apart. In the case of ships with rounded gunwales,
the guard rail supports are to be placed on the flat of the deck.
In other locations, guard rails with at least two courses are to be
fitted.
5.1.4 Guard
rails are to be fitted with fixed, removable or hinged stanchions
fitted no more than 1,5 m apart. Removable or hinged stanchions shall
be capable of being locked in the upright position.
5.1.5 At least
every third stanchion is to be supported by a stay. In lieu of this,
flat steel stanchions shall be of increased breadth as given in Figure 8.5.1 Support of stanchions, and aligned with a member
below deck unless the deck plating thickness exceeds 20 mm. Guard
rail stanchions of increased breadth are to be welded to the deck
with double continuous fillet weld with a minimum leg size of 7 mm
or in compliance with a standard recognised by LR.
Figure 8.5.1 Support of stanchions
5.1.6 Where
necessary for the normal operation of the ship, steel wire ropes may
be accepted in lieu of guard rails. Wires are to be made taut by means
of turnbuckles. Chains are only permitted in short lengths in way
of access openings.
5.1.7 Satisfactory
means, in the form of guard rails, life-lines, handrails, gangways,
underdeck passageways or other equivalent arrangements, are to be
provided for the protection of the crew in getting to and from their
quarters, the machinery space and all other parts used in the necessary
work of the ship in accordance with Table 8.5.1 Protection of crew .
5.1.8 Where
gangways on a trunk are provided by means of a stringer plate fitted
outboard of the trunk side bulkheads (port and starboard), each gangway
is to be a solid plate, effectively stayed and supported, with a clear
walkway at least 450 mm wide, at or near the top of the coaming, with
guard rails complying with Pt 3, Ch 8, 5.1 General requirements 5.1.3 and
hatch cover securing appliances accessible from the gangway.
5.1.9 Where
permitted by the National Authority, gangways or walkways may be omitted
on ships engaged on protected or extended protected water service.
However, life-lines are to be provided on tankers and flush deck ships,
or where the cargo hatch coamings are less than 600 mm high.
5.1.10 For
a Type 'A' ship with freeboards assigned greater than, or equal to,
Type 'B', a life−line may be provided in lieu of a walkway.
5.2 Bulwark construction
5.2.1 Plate
bulwarks are to be stiffened by a strong rail section and supported
by stays from the deck. The spacing of these stays forward of 0,07L from the forward perpendicular is to be not more than 1,2
m on Type `A', Type `B-60' and Type `B-100' ships (as defined in Pt 3, Ch 11, 1.1 Application), and not more than 1,83
m on other Types. Elsewhere, bulwark stays are to be not more then
1,83 m apart. Where bulwarks are cut to form a gangway or other opening,
stays of increased strength are to be fitted at the ends of the openings.
Bulwarks are to be adequately strengthened in way of eyeplates for
cargo gear, and in way of mooring pipes the plating is to be doubled
or increased in thickness and adequately stiffened.
5.2.2 Bulwarks
should not be cut for gangway or other openings near the breaks of
superstructures, and are also to be arranged to ensure their freedom
from main structural stresses. See shell plating in appropriate
Chapters.
5.2.3 The
section modulus, Z, at the bottom of the bulwark stay
is to be not less than:
|
Z
|
= |
(33,0
+ 0,44L) h
2
s cm3
|
5.2.4 In the
calculation of the section modulus, only the material connected to
the deck is to be included. The bulb or flange of the stay may be
taken into account where connected to the deck, and where, at the
ends of the ship, the bulwark plating is connected to the sheerstrake,
a width of plating not exceeding 600 mm may also be included. The
free edge of the stay is to be stiffened.
5.2.5 Bulwark
stays are to be supported by, or to be in line with, suitable underdeck
stiffening, which is to be connected by double continuous fillet welds
in way of the bulwark stay connection.
5.2.6 It should
be noted that the above requirements do not allow for any loading
from deck cargoes.
5.3 Freeing arrangements
5.3.1 The
requirements of Pt 3, Ch 8, 5.3 Freeing arrangements 5.3.2 to Pt 3, Ch 8, 5.3 Freeing arrangements 5.3.11 apply to ships of Type `B'.
Additional requirements applicable to ships of Type `A', Type `B-100'
and Type `B-60' are indicated in Pt 3, Ch 8, 5.3 Freeing arrangements 5.3.18 and Pt 3, Ch 8, 5.3 Freeing arrangements 5.3.20. The ship
Types are as defined in Pt 3, Ch 11, 1.1 Application.
5.3.2 Where
bulwarks on the weather portions of freeboard or superstructure decks
form wells, ample provision is to be made for rapidly freeing the
decks of large quantities of water by means of freeing ports, and
also for draining them.
5.3.3 The
minimum freeing area on each side of the ship, for each well on the
freeboard deck or raised quarterdeck, where the sheer in the well
is not less than the standard sheer required by the
Load Lines, 1966/1988 - International Convention on Load Lines, 1966, as Amended by the Protocol of 1988
, is to be
derived from the following formulæ:
-
where the length,  , of the bulwark in the well is 20 m or less:
area required = 0,7 + 0,035 m2
-
where the length,
, exceeds 20 m:
area required = 0,07 m2
 need not be taken greater than 0,7L
L,
where L
L is the length of the ship as defined
in Pt 3, Ch 1, 6.1 Principal particulars.
5.3.4 If the
average height of the bulwark exceeds 1,2 m or is less than 0,9 m,
the freeing area is to be increased or decreased, respectively, by
0,004 m2 per metre of length of well for each 0,1 m increase
or decrease in height respectively.
5.3.6 Two-thirds
of the freeing port area required is to be provided in the half of
the well nearest to the lowest point of the sheer curve.
5.3.7 When
the deck has little or no sheer, the freeing area is to be spread
along the length of the well.
Table 8.5.1 Protection of crew
| Ship
type
|
Location
in ship
|
Assigned
Summer Freeboard, in mm
|
Acceptable arrangements according to type of
freeboard assigned
|
Type
A
|
Type
(B-100)
|
Type
(B-60)
|
Type
(B
& B +)
|
| Oil tankers, chemical tankers and gas
carriers (see
Pt 3, Ch 8, 1.1 Application 1.1.5)
|
1.1 Access to bow
1.1.1 Between poop and bow or
1.1.2 Between a deckhouse containing living accommodation or
navigation equipment, or both, and bow, or
1.1.3 In the case of a flush deck vessel, between crew
accommodation and the forward ends of ship
|
≤
(A
f + H
s)
|
a
e
f(1)
f(5)
|
a
e
f(1)
f(5)
|
a
e
f(1)
f(5)
|
a
e
f(1)
f(5)
|
|
|
>
(A
f + H
s)
|
a
e
f(1)
f(2)
|
|
|
1.2 Access to after end
In the case of a flush deck vessel, between crew
accommodation and the after end of ship
|
As required in item 2.2.4 in Table 8.5.1 Protection of crew for
other types of ships
|
| Other ship type
|
2.1 Access to midship quarters
2.1.1 Between poop and
bridge, or
|
≤ 3000 mm
|
a
b
e
|
a
b
e
|
a
b
c(1)
e
f(1)
|
a
b
c(1)
c(2)
c(4)
d(1)
d(2)
d(3)
e
f(1)
f(2)
f(4)
|
| 2.1.2 Between poop and deckhouse containing living
accommodation or navigation equipment, or both
|
> 3000
mm
|
a
b
e
|
a
b
e
|
a
b
c(1)
c(2)
e
f(1)
f(2)
|
|
|
2.2 Access to ends
2.2.1 Between poop and bow (if there is
no bridge),
2.2.2 Between bridge and bow, or
|
≤ 3000 mm
|
a
b
c(1)
e
f(1)
|
a
b
c(1)
c(2)
e
f(1)
f(2)
|
a
b
c(1)
c(2)
e
f(1)
f(2)
|
|
|
2.2.3 Between a deckhouse containing living
accommodation or navigation equipment, or both, and bow, or
2.2.4 In the
case of a flush deck vessel, between crew
accommodation
and the forward and after ends of ship
|
> 3000
mm
|
a
b
c(1)
d(1)
e
f(1)
|
a
b
c(1)
c(2)
d(1)
d(2)
e
f(1)
f(2)
|
a
b
c(1)
c(2)
c(4)
d(1)
d(2)
d(3)
e
f(1)
f(2)
f(4)
|
| Symbols
|
|
Af
|
= |
the minimum summer freeboard calculated as Type A ship
regardless of the type of freeboard actually assigned |
|
Hs
|
= |
the standard height of superstructure as defined in
International Convention on Load Lines, Regulation 33 |
|
Acceptable
arrangements:
Acceptable arrangements referred to in the
Table are defined as follows:
|
| a: A well-lighted and
ventilated underdeck passageway (clear opening 0,8 m wide, 2 m high) as
close as practicable to the freeboard deck, connecting and providing access
to the locations in question.
|
| b: A permanent and efficiently
constructed gangway fitted at or above the level of the superstructure deck
on or as near as practicable to the centreline of the ship, providing a
continuous platform at least 0,6 m in width and a non-slip surface, with
guard rails extending on each side throughout its length. Guard rails shall
be at least 1 m high with courses as required in Pt 3, Ch 8, 5.1 General requirements, and a foot-stop shall be provided.
|
| c: A permanent walkway at least
0,6 m in width fitted at freeboard deck level consisting of two rows of
guard rails with stanchions spaced not more than 3 m. The number of courses
of rails and their spacing are to be as required by Pt 3, Ch 8, 5.1 General requirements. On Type B ships, hatchway coamings not less than 0,6
m in height may be regarded as forming one side of the walkway, provided
that between the hatchways two rows of guard rails are fitted.
|
| d: A wire rope life-line not
less than 10 mm in diameter, supported by stanchions not more than 10 m
apart, or a single hand rail or wire rope attached to hatch coamings,
continued and adequately supported between hatchways.
|
e: A permanent and efficiently
constructed gangway fitted at or above the level of the superstructure deck
on or as near as practicable to the centreline of the ship:
- located so as not to hinder easy access across the
working areas of the deck;
- providing a continuous platform at least 1,0 m in width
(may be reduced to 0,6 m for tankers less than 100 m in length);
- constructed of fire-resistant and non-slip
material;
- fitted with guard rails extending on each side
throughout its length; guard rails should be at least 1,0 m high with
courses as required by Regulation 25(3) and supported by stanchions
spaced not more than 1,5 m;
- provided with a foot stop on each side;
- having openings, with ladders where appropriate, to and
from the deck. Openings should not be more than 40 m apart;
- having shelters of substantial construction set in way
of the gangway at intervals not exceeding 45 m if the length of the
exposed deck to be traversed exceeds 70 m. Every such shelter should
be capable of accommodating at least one person and be so constructed
as to afford weather protection on the forward port and starboard
sides.
|
| f: A permanent and efficiently
constructed walkway fitted at freeboard deck level on or as near as
practicable to the centreline of the ship having the same specifications as
those for a permanent gangway listed in (e) except for foot-stops. On Type B
ships (certified for the carriage of liquids in bulk), with a combined
height of hatch coaming and fitted hatch cover of together not less than 1 m
in height, the hatchway coamings may be regarded as forming one side of the
walkway, provided that between the hatchways two rows of guard rails are
fitted.
|
| Alternative transverse locations for c, d and f:
(1) At or near centreline of ship; or
fitted
on hatchways at or near centreline of ship.
(2) Fitted
on each side of the ship.
(3) Fitted on one side of the
ship, provision being made for fitting on either side.
(4) Fitted on one side of the ship only.
(5) Fitted
on each side of hatchways as near to the centreline as practicable.
|
NOTES
Note
1. In all cases where wire ropes are
fitted, adequate devices (for examples turnbuckles) are to be provided
to ensure their tautness.
|
Note
2. Wire ropes may only be accepted in
lieu of guard rails in special circumstances and then only in limited
lengths.
|
Note
3. Lengths of chain may only be accepted
in lieu of guard rails if fitted between two fixed stanchions.
|
Note
4. Where stanchions are fitted, every
third stanchion is to be supported by a bracket or stay.
|
Note
5. Removable or hinged stanchions shall
be capable of being locked in the upright position.
|
Note
6. A means of passage over obstructions,
if any, such as pipes or other fittings of a permanent nature, should
be provided.
|
Note
7. Generally, the width of the gangway or
deck-level walkway should not exceed 1,5 m.
|
5.3.8 In ships
with no sheer the freeing area as calculated from Pt 3, Ch 8, 5.3 Freeing arrangements 5.3.3 is to be increased by 50 per
cent. Where the sheer is less than the standard, the percentage is
to be obtained by linear interpolation.
5.3.9 Where
the length of the well is less than 10 m, or where a deckhouse occupies
most of the length, the freeing port area will be specially considered
but in general need not exceed 10 per cent of the bulwark area.
5.3.10 Where
it is not practical to provide sufficient freeing port area in the
bulwark, particularly in small ships, credit can be given for bollard
and fairlead openings where these extend to the deck.
5.3.11 Where
a ship fitted with bulwarks has a continuous trunk, or hatch side
coamings that are continuous, or substantially continuous, the minimum
freeing area is to be not less than 20 per cent of the total bulwark
area where the width of trunk or hatchway is 0,4B or
less, and not less than 10 per cent of the total bulwark area when
the width of the trunk or hatch is 0,75B or greater.
The freeing area required for an intermediate width of trunk or hatch
is to be obtained by linear interpolation.
5.3.12 Where
the trunk referred to in Pt 3, Ch 8, 5.3 Freeing arrangements 5.3.11 or
its equivalent is included in the calculation of freeboard, open rails
are to be fitted for at least 50 per cent of the length of the exposed
part of the weather deck. Alternatively, if a continuous bulwark is
fitted, the minimum freeing area is to be at least 33 per cent of
the bulwark area. The freeing area is to be placed in the lower part
of the bulwark.
5.3.13 Where
a deckhouse has a breadth less than 80 per cent of the beam of the
ship, or the width of the side passageways exceeds 1,5 m, the arrangement
is considered as one well. Where a deckhouse has a breadth equal to
or more than 80 per cent of the beam of the ship, or the width of
the side passageways does not exceed 1,5 m, or when a screen bulkhead
is fitted across the full breadth of the ship, this arrangement is
considered as two wells, before and abaft the deckhouse.
5.3.14 Suitable
provision is also to be made for the rapid freeing of water from recesses
formed by superstructures, deckhouses and deck cargo arrangements,
etc. in which water may be shipped and trapped. Deck gear, particularly
on fishing vessels, is not to be stowed in such a manner as to obstruct
unduly the flow of water to freeing ports.
5.3.15 The
lower edges of freeing ports are to be as near to the deck as practicable,
and should not be more than 100 mm above the deck.
5.3.16 Where
freeing ports are more than 230 mm high, vertical bars spaced 230
mm apart may be accepted as an alternative to a horizontal rail to
limit the height of the freeing port.
5.3.17 Where
shutters are fitted, the pins or bearings are to be of a non−corrodible
material, with ample clearance to prevent jamming. The hinges are
to be within the upper third of the port. Shutters are not to be fitted
with securing appliances.
5.3.18 Ships
of Type `A' and Type `B-100' are to have open rails for at least half
the length of the exposed part of the weather deck. Alternatively,
if a continuous bulwark is fitted, the minimum freeing area is to
be at least 33 per cent of the total area of the bulwark. The freeing
area is to be placed in the lower part of the bulwark.
5.3.19 Where
superstructures are connected by trunks, open rails are to be fitted
for the whole length of the exposed part of the freeboard deck.
5.3.20 Ships
of Type `B-60' are to have a minimum freeing area of at least 25 per
cent of the total area of the bulwark. The freeing area is to be placed
in the lower part of the bulwark.
5.3.21 Gutter
bars greater than 300 mm in height fitted on the weather decks of
tankers are to be treated as bulwarks and freeing ports arranged as
required by this Section. Closures for use during loading and discharge
operations are to be arranged in such a way that jamming cannot occur
while at sea.
5.3.22 In
ships having superstructures which are open at either or both ends
to wells formed by bulwarks on the open deck, adequate provision for
freeing the open spaces are to be provided as follows:
The freeing port area, A
w for the open
well:
The freeing port area, A
s for
the open superstructure:
where
 w
|
= |
the length of the open deck enclosed by bulwarks, in metres |
 s
|
= |
the
length of the common space within the open superstructure, in metres |
 t
|
= |
 w +  s but if 20 m or less then the freeing
area is to be calculated in accordance with Pt 3, Ch 8, 5.3 Freeing arrangements 5.3.3
|
|
S
c
|
= |
sheer correction factor, maximum 1,5 as defined in Pt 3, Ch 8, 5.3 Freeing arrangements 5.3.8
|
|
b
o
|
= |
breadth of openings in the end bulkhead of the enclosed superstructure,
in metres |
|
h
w
|
= |
distance of the well deck above the freeboard deck, in metres |
|
h
s
|
= |
one standard superstructure height, see
Pt 3, Ch 8, 1.3 Definition of tiers 1.3.2
|
|
h
b
|
= |
actual height of the bulwark, in metres |
|
A
c
|
= |
bulwark height correction factor taken as; |
| = |
0 for bulwarks between 0,9 and 1,2 m in height |
| = |
 for bulwarks of height greater than 1,2 m, and |
| = |
 for bulwarks of height less than 0,9 m. |
To adjust the freeing port area for the distance of the well deck above the freeboard
deck, for decks located more than 0,5h
s above the freeboard deck, multiply by the factor 0,5 (h
s/h
w).
5.4 Free flow area
5.4.1 The
effectiveness of the freeing port area in bulwarks of vessels not
fitted with a continuous deck obstruction, depends on the free flow
across the deck.
5.4.2 The
free flow area is the net total longitudinal area of the transverse
passageways or gaps between hatchways and superstructures or deckhouses,
due account being made for any obstructions such as equipment or other
fittings. The height of passageways or gaps used in the calculation
of the area is the height of the bulwark.
5.4.3 The
provision of freeing area in bulwarks should be related to the net
free flow area as follows:
-
If the free flow
area is equal to, or greater than the freeing port area calculated
from Pt 3, Ch 8, 5.3 Freeing arrangements 5.3.11 when the hatchway
coamings are continuous, then the minimum freeing area calculated
from Pt 3, Ch 8, 5.3 Freeing arrangements 5.3.3 is sufficient.
-
If the free flow
area is less than the freeing port area calculated from Pt 3, Ch 8, 5.3 Freeing arrangements 5.3.3, then the minimum freeing
area is to be that calculated from Pt 3, Ch 8, 5.3 Freeing arrangements 5.3.11.
-
If the free flow
area is less than the freeing port area derived from (a) but greater
than that derived from Pt 3, Ch 8, 5.4 Free flow area 5.4.3.(b),
the minimum freeing area, F, in the bulwark is to be
obtained from the following formula:
5.5 Special requirements for tugs and offshore supply ships
5.5.1 In tugs
and offshore supply ships where there is a recess at the after end
of the forecastle for the towing winch, the freeing port area in way
of the recess is to be calculated as follows:
|
= |
mean length of recess |
|
a
|
= |
freeing
area for well length L
|
Freeing port area in way of recess:
Reduction due to breadth of recess:
Reduce A
1 by 25 per cent
for winch area:
|
|
= |
required freeing
port area each side in way of the recess |
Where the winch is enclosed in a non-weathertight
compartment freeing ports are not required but adequate drainage by
means of scuppers is to be provided.
|