Emergency Cargo and Machinery Cooling Water Supply To Cofferdam Eductor To Cofferdam Eductor To Cofferdam Eductor To Cofferdam Eductor From Emergency Fire Pump AI/015VF AI/014VF AI/052VF Spill Tray Filling Line Spill Tray Filling Line
5.1.2 Firemain System
The firemain system is supplied from the engine room, by two, two speed centrifugal pumps XA/405 A and B 160m3/h at 2.3 bars or 90m3/h at 12.8bar.
The emergency fire pump YA/480 is mounted forward in the emergency fire pump room.
Isolating valves mounted on the cargo deck, allow isolation of the forward or poop decks. 3 further isolating valves are situated at regular intervals along up the deck, to allow any part of the system to be supplied from either end of the ship.
The cofferdam eductors are driven from this system, as is the manifold water curtain for ship side wetting during loading and discharge.
There are 12 fire hydrants situated along the cargo deck, each with its fire hose mounted adjacent. The firemain also supplies anchor washing water.
The emergency fire pump can be started locally, from the bridge or the fire station.
Under normal operating conditions the firemain will be under pressure during port time, supplying the manifold sprays and with hoses run out as a fire precaution.
5.1.3 Air locks
The motor room is fitted with a double door air lock, to ensure that any hydrocarbon vapour which may be present on deck cannot enter the room. The doors are fitted with micro switches connected to an alarm which will sound if both doors are open together.
The motor room and air lock are maintained above atmospheric pressure by a supply fan. The motor room is vented by a natural exhaust trunk.
5.1.4 Dry Powder System
The system is supplied by Silvani Antimcendi S.P.A and
consists of: (A) 2 x 1550kg units mounted forward of the
accommodation block on ‘A’ deck. (B) a 1000kg unit
mounted in the cross alleyway between the accommodation and engine casing.
Each unit consists of:-
A powder container holding 1550kg ‘winnex’ powder. 5 x 50 ltr at 200 bar nitrogen cylinders to expel the powder. Pneumatic/manual actuator 5pc
Pressure reducing valve 200-15bar Pressurisation valve for container Safety valve set at 12bar
Pressure reducer 15 to 10bar Tank depressurisation valve Lever safety valve set at 16bar 0 - 25bar pressure gauge 2 distribution valves
Pneumatic control powder on/off valves
Pneumatic control station contains 1 x 4 ltr 200bar pilot nitrogen cylinder, for opening of associated distribution valve.
Each of these 1550kg units supply 2 x 10kg/s monitors mounted forward and aft above each manifold. Each monitor has a 10m throw. The 1550kg units also supply 8
hose stations. Each hose has a 3.5kg/s nozzle and is 30 metres long.
The manifold monitors have a control station port and starboard outboard and aft on No. 3 cargo tank liquid dome. Each dry powder hose unit has a remotely operated powder valve.
(B) 1000kg unit mounted in the X-alleyway between accommodation and engine casing. This unit supplies a
10kg/s monitor with a 10 metre throw mounted above the
poop deck and positioned to protect the jettison line and nozzle.
A portable hose unit is mounted on the poop deck with 20 metre hose and 3.5 kg/s nozzle.
The pneumatic actuator for this unit is mounted aft end, port side of ‘A’ deck. All equipment is similar to the 1550kg units except that there are only 4 x nitrogen cylinders.
5.1.5 Ship Side Water Curtain Spray
This system is used when loading and discharging and is fitted to both manifolds to protect the deck, deck edge, shearstrake and vertical ship’s side from the effects of cold embrittlement in the event on liquid leakage at the
manifold. The nozzles are spaced 600mm apart and at
500mm from the vertical shipside inboard.
The water for these sprays is taken from the firemain/ wash down system pipeline. There are 30 GAW2761
nozzles at each manifold delivering 136.8m3/h. at 3 bar.
5.1.6 CO2Protection in Cargo and Motor
Compressor Rooms
The compressor room and motor room are protected by a
self contained CO2system housed in its own CO2room on
the starboard aft corner of the motor room.
The system consists of 2 packs of 60 Ltr cylinders. Pack 1 of 14 cylinders. Pack 2 of 4 cylinders. The system is so arranged that all 18 cylinders are available for discharge to the compressor room and 9 to the motor room.
The volume of the spaces protected are:
Compressor room 870m3and motor room 401m3
Each space has a pneumatic control station which can be operated manually locally or electrically via an intrinsically safe circuit and barriers from the fire station on the upper deck.
Each release control station has a 4ltr nitrogen cylinder which releases into the actuator pipework for the cylinders selected.
Both protected spaces are fitted with a pre-release alarm
siren, to warn personnel of impending CO2release.
The action of opening the pneumatic control station operates the pre-release alarm, the main discharge is delayed by a mechanical device, actuated by hand for up to 30 seconds before release.
The ball valve to the required space is also operated
remotely and CO2 flooding takes place through nozzles
mounted below the deckheads in both or either space. The system is fitted with a pre-alarm test connection and a flushing connection to be used to flush out any
remaining CO2after a release.
In the case of inadvertent release, the system is fitted with a relief valve which discharges to atmosphere.
5.1.7 Vent Mast Extinguishing
No. 2 vent mast riser is fitted with a fixed nitrogen smothering system. Activation is carried out from the main
console in the wheel house, or from the main console in
the cargo control room. The gas heater regulating valve and snuffer valves in the vent mast are shut, before injection of nitrogen takes place.
5.1 Deck Salt Water Systems - Page 2 Issue: 1
5.2.1a Emergency Shutdown System Issue: 1
Pvh < Patm + 3mbar EMERGENCY SHUT DOWN SYSTEM
MANUAL RELEASE - Cargo control room. - Wheel House.
- Manifolds - port and starboard sides - Compressor room
- Fore main deck
- After deck - port and starboard sides
FUSIBLE PLUGS - Each tank liquid dome (4 units) - Port and starboard manifold platforms (3 units).
Cargo compressor room (2 units).
SHORE LINKS FROM SHORE TO SHORE
HEADERS PRESSURE Pvh : vapour header pressure Pph : primary space header pressure Patm : atmospheric pressure Pvh = Pph
OR
TANKS PRESSURE (on each tank)
Ptk < Pps + 5mbar Ptk : tank pressure
Pps : primary space pressure Ptk = Pps
OR
TANKS LEVEL
(2 independent sensors per tank) VERY HIGH LEVEL 99%
OVERRIDING AT SEA
AND
OR OR
STOP MAIN CARGO PUMPS AND EMERGENCY PUMP
STOP STRIPPING PUMPS STOP HIGH DUTY COMPRESSORS
CLOSING MANIFOLD VALVES
STOP LOW DUTY COMPRESSORS
CLOSING MANIFOLD VALVES