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Getting used to sustainable system design - the case of ship and ocean 2 BY OLADOKUN SULAIMAN
6.2 Policies and procedures build-up - collision preventions and control -Although ships may spend 90 – 98 percent of their operational lives underway at sea speed in deep water, it is during the mandatory beginning and end of every voyage when the risk of collisions, and groundings are highest. Ensuring the ability to maintain complete and positive control of a ship’s movement during these segments of a voyage is absolutely vital if that risk of navigation safety and protection of the marine environment is to be reduced. According to INTERTANKO’s 1996 Port and putting bigger and bigger ships (and more of them) into the same old channel:
· The design limit for trim by the stern for a tanker is 0.015L in accordance with Regulation 13 of MARPOL 73/78, Annex I. This information, which is based on tests conducted in deepwater, includes a turning circle diagram as well as tables showing time and distance to stop the vessel from full and half-speed.
· IMO Resolution A601 (15), which was adopted in 1987, contains recommendations for ensuring maneuvering information is available on board ship.
· The 1995 Seafarers’ Training, Certification and Watch keeping Code, Section A-VIII/2 part 3-1, and article 49 require the master and pilot to “exchange information regarding navigation procedures, local conditions and the ship’s characteristics.”
· A Marine Board study assessed the use of numerical simulation technology to train mariners and concluded that while modeling accuracy is sufficient for deep-water operations; modeling requires refinement to provide the accuracy needed for shallow and restricted water operations.
6.3 Ship design policy build-up -In 1971, IMO adopted Resolution A.209 (VII) establishing recommendations regarding posting maneuvering 9 Regulation II-1/29.3.2 of SOLAS requires rudder movement from 35 degree on either side to 30o on the other to occur in 28 seconds or less.
IMO approved circular MSC/Circ.389 in 1985 establish interim guidelines for estimating the maneuverability -Rudder size and effectiveness, Ability to transit at slow forward speed, Propulsion and propeller characteristics, Number of available engine reversals, Adequate horsepower for control, Extra reserve rudder angle needed to allow for ship crabbing from wind forces or moored ship suction, Visibility from bridge and bridge arrangement, Hull form squat (trim and sink age) characteristics and effect of bank forces on moorings and passing ships, Air draft, Emergency anchoring ability, Amount of tow line leads and line access.
7.0 Current Ship design practice
Existing design tools cannot, at least with any degree of reliability, be used to design a vessel and ensure it will ensure environmental reliability and adequate maneuverability in shallow or restricted waters neither can it be use to satisfy demand need by clean ships . In part this is because of the extreme on-linearity of hull and propulsion characteristics under these conditions. In general, naval architects and marine engineers are educated and equipped with knowledge, skills, and design processes that permit continuous checking and balancing of constraints and design tradeoffs of vessel capabilities as the design progresses.
The intended result of the process is the best design given the basic requirements of speed, payload, and endurance nor where the waste is going. Focus is not placed on how the channels and waterways are designed. Perhaps even more importantly, there is a general lack of understanding of the operational scenario regarding piloting of vessels in constrained waterways. Only recently has there been a real attempt to fully integrate human operational practices with vessel design. The involvement of human beings onboard vessels both extends and restricts the inherent vessel maneuvering capabilities vastly complicating the necessary methodology for assuring safe and efficient operations. Taking waste issue and restricted waterway maneuverability as an important part of ship design spiral would seem a necessary step to enabling proper tradeoffs in vessel design. The reality is that maneuverability and pollution protection is still not an important consideration in ship design of many merchant ships. The result is that design decisions that can compromise environment and collision are decided in favor of other factors. Only with consideration of the full range of ship and channel design and human factors relationships affecting maneuverability will we be able to produce an efficient and safe environmental friendly marine transportation system. Now that the new issue of environment is around, then we have to squeeze in more stuff in the spiral.
Table 1 – parameters s demand and impact
Environmental parameters
Environmental Demand
Impact areas
Ship design,
Need for longer safe life cycle
New limit definition, Correct material selection, Material technology, Quality control of safety and environment
Construction
High worker safety standards, Low energy input
Improved hull hydrodynamic,
Emission
Minimum pollution and emission, Minimum Sox, Nox and green house gas-Zero discharge
Advance Close loop process on board,Waste recycling equipment, Improve training
Scrapping
Zero harmful emission
Beneficial disposal
Operations waste,
Efficient maneuverability
Improve maneuverability
Energy
Maximum fuel efficiency
Engine design, use of alternative energy
Antifouling
Harmless
Biocide free technology
Ballast water
Zero biological invasion or transfer of alien species
Segregated ballast tanks, Improved ballast water tank design, Ballast water treatment, Ballast water data base
Sea mammal
Interaction
Maneuverability capability
Safer ship structure design, Improve maneuvering capability, Navigation AID, misinformation, Exchange, Reeducation
Accident
Able officer, Ship structure, Integrity
New monitoring through port sate control
Fire
Harmless
Halon phase out
Wave wash of High speed
Marine craft
Zero inundation and spray ashore
Moderation of hydrodynamic force
8.0 Mitigation
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