Team : Saravanan (Base Manager)
Saravanan Ven (Routine Engineer)
Capt. Edmund (HSSEQ MGR)
Muru (Sr. Elec. Engineer)
Current location : Labuan offshore anchorage
Scope : 1. General assessment on hazard
2. Explanation on cold lay up
3. Understanding the requirement from vessel operators
4. Propose system require
Observations
This AHTS has 4 deck of accommodation (including bridge) and 2 deck of engine room. The engine room are inter connected to the bow thruster room, cement room, main engine room, refer room, mud room and the steering room. Beside the entrance door to engine room, there has 3 hatches leading to this compartment direct from main deck. The emergency generator room located at port main deck. The shore power breaker rated 200 Amps. The emergency fire pump and the deck cranes are supplied from this emergency bus bar. The deck crane which located starboard side is rated SWL of 5 tonnes and the life raft hydraulic davit at port side rated SWL of 1.65 tonnes. The accommodation AHU located at starboard main deck.
Proposals
1. A 2000 cubic dehumidifier will be installing on aft loading deck. The ducting will run through the mid hatch at the port side in to the engine room. Then ducting will be distributed to both level of machineries spaces and extended to bow thruster room & steering room. The return air will be extract from the highest point of the machineries space or funnel stack.
2. If dehumidification to machineries spaces decided, then the vessel superintendent planning to run the main diesel engine to test the bollard winch unable to carry out. This will be affecting the efficiency of the dehumidification by removing compartment seal more frequently.
3. If above machineries routine is more essential, a high capacity layup generator leased to power directly. It is not so economical to lease higher capacity generator to run such only one machine. The idling consumptions normally are high for higher rating generator.
4. Other option is to lease a soft starter to step down the starting currently. Thus will reduce the requirement of bigger generator.
5. A 2000 cubic dehumidifier will be sufficient to dehumidify the whole accommodation. The supply ducting will be connected to the AHU and the return will extract from bridge.
6. Even for both machineries spaces and the accommodation a single 3500 cubic dehumidifier can be used to cut down the cost of diesel consumption. The ducting arrangement can be modifying such a way the whole ship is preserved.
7. A 250 kVa generator with 20 meter cable is sufficient for preservation and for normal routine. If the bollard winches included into the routine the 1000 kVa may required depending on the starting current of the biggest motor.
8. There no need any modification in emergency generator to run the windlass or the crane. Only the shore breaker needs to replace to 400 amps breaker.
9. Watchmen hut will be built at main deck far from the layup generator.
To dehumidify the whole AHTS just require only 2 medium sizes dehumidifiers or 1 bigger dehumidifier.
With 250 kVa generator can be expected 4000 liters diesel oil consumption at initial. Then it can be lowered haft during continues preservation. But if the bollard winches which required higher capacity generator will expected consume double of the above consumption.
Loading and offloading can be done at ASB berth or using ship crane at layup.
At least 6 float required for early notification of any water ingress.
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Prepared by,
Saravanan Ven
BP Shipcare
