Effect on Existing Marine Navigation for the Black Point Location

D1 Marine Navigation

D1.1 General

The principal hazards associated with a LNG carrier underway to and from a terminal within Hong Kong waters have been adopted as guiding criteria for site assessment. The following assessment parameters have been adopted to assess marine access for each layout option:

· Carrier Marine traffic (striking or being struck by any self propelled ship whilst underway to an LNG terminal within Hong Kong territorial waters, or at anchor);

· Grounding (when the carrier comes to a complete stop during transit to/from the terminal and is no longer able to manoeuvre); as a result of impacting the seabed or shoreline;

· The LNG carrier striking a navigation aid or the jetty; and,

· Striking moored LNG carrier by passing traffic.

Although no breach of containment has occurred from collision incidents in over three decades of LNG carrier operation, release of LNG is possible if there is sufficient penetration energy. That energy depends on the displacement, speed, design and angle of contact of the striking vessel

The probability of the occurrence of a collision between LNG carrier and other vessel is governed by:

· Mechanical failure (propulsion or steering gear);

· Non-compliance with the Collision Regulations;

· Density of traffic within navigable waterway restricting room to manoeuvre;

· Environmental factors (i.e., visibility, current velocity, wind speed / direction etc); and,

· Human error (pilot inexperience with carrier manoeuvrability, wrong helm instruction or incorrect application of helm command);.

Grounding refers to the incident of an LNG carrier coming to a complete stop and no longer able to manoeuvre as a result of impacting the seabed or shoreline. Although no breach of containment has occurred from grounding incidents in over three decades of LNG carrier operation, there is potential for release of cargo after grounding. A smooth seabed of sand or mud will apply a cushioning effect and penetration energy is usually spread over a large area of the carrier. Penetration through the double hull into the containment system is, therefore, less likely. Rocky seabed causes more jagged penetration with the impact being absorbed over a much smaller area and a greater risk for damage to the containment.

The probability of the occurrence of a powered grounding is governed by:

· Carrier draft versus projected water depth;

· Navigable channel dimensions;

· Navigation aids missing or not in charted position;

· Environmental factors (i.e., visibility, current velocity, wind speed / direction etc);

· Collision avoidance manoeuvre;

· Incomplete passage plan; and,

· Inexperience of pilot with carrier manoeuvrability.

Impact with structures refers to the LNG carrier making unplanned contact with the approach channel or turning circle navigation aids (allision) or with the jetty during the approach manoeuvre.

The potential for a breach of containment as a result of a LNG carrier striking a fixed object in the vicinity of the terminal would be dependent upon the speed and angle of impact. In order for such an incident to occur, there would have to be a failure in navigational procedures, tug control, mechanical failure, or excessive speed during the approach manoeuvre.

Grounding incidents are not a common occurrence in Hong Kong waters given the provision of delineated navigable fairways, deep water and traffic control. The consequence of grounding at slow speed during the carrier approach and departure is unlikely to include breach of containment but could cause operational limitations if the outer hull is penetrated.

When manoeuvring near the berth laden (arriving) LNG carriers should be moving at relatively low speeds and in the final approach to the jetty be under tug control, as such this hazard is of a lesser order than collision or grounding as significant damage to the LNG carrier hull is unlikely.

The probability of the occurrence for an LNG carrier striking the jetty structure during approach is governed by:

· Mechanical failure (carrier propulsion or steering gear);

· Environmental conditions (wind speed exceeds forecast, current velocity and direction not as predicted);

· Number and performance of assist tugs;

· Mechanical failure of tug(s);

· Human error (pilot inexperience in docking manoeuvre); and,

· Excessive approach speed without parallel landing on fenders.

Impact resulting from an LNG carrier being struck while moored at the jetty is also a potential hazard. The factors impacting the potential for impact while moored are similar to those presented above for ship collision. The probability of striking the LNG carrier at the jetty is governed by:

· Proximity to other traffic;

· Nature and volume of local traffic;

· Metocean conditions;

· Level of ship handling experience on passing traffic personnel;

· Mechanical failure, propulsion or steering gear; and,

· Passing traffic intruding into the prescribed safe distance.

D2 Marine Passage to Black Point

The marine transit route to Black Point (via East Lamma Channel, Western Fairway, Ma Wan and Urmston Road) passes through the centre of the Hong Kong harbour. Due to the water depth west of Lantau Island, safe transit of the LNG carrier to Black Point is restricted to the East Lamma Channel and Western Fairway.

In order to permit safe access for LNG carriers a dredged access and turning basin of sufficient depth will be required. The bathymetry contours after dredging the access and turning basin for Black Point are estimated to result in layers of sediment ranging in height from 50% to 60% of the water depth. These contours pose a potential grounding hazard to carriers arriving or departing, although it is recognised the soft marine sediments pose little risk to the hull integrity. Arrivals and departures may, however, have to be limited to certain states of the tide with the possible exception of a departure enforced by the proximity of a typhoon.

Although strong currents (over two knots) exist to the west of the area within the main channel the jetty is in a region of comparatively low current magnitude (less than 0.5 knots) due to the existing shallow water embayment. The tidal current gradients across the approach and turning area have to be compensated for on arrival and departure, while large eddies may be shed by the reclamation into the path of a carrier berthing, unberthing or moored in a flood tide.

Tidal current restrictions are already in place for transit around Ma Wan and it would be important to ensure that suitable tidal windows at Ma Wan and Black Point give the necessary flexibility to provide for a safe operation. This restriction is currently managed by large bulk carriers arriving at Tap Shek Kok, who “ride” the tidal high water from Ma Wan, ensuring that both passage at Ma Wan, and arrivals at the jetty can be conducted in the most optimal conditions.

Transit to Black Point is planned via the established route through East Lamma Channel, Ma Wan and Urmston Road. Based on the operational experience of LNG carriers, manoeuvrability is expected to be equal to or greater than the current Ocean-going vessel types that currently follow the same route.

The passage of an LNG carrier to the Black Point site can be summarised as follows:

(1) From the point where the carrier enters Hong Kong waters to the pilot boarding area near Round Island in the East Lamma Channel - Relatively protected waters from the south-east, in an open channel. The area is occupied by large vessels preparing to enter Hong Kong, along with some cross traffic consisting primarily of fishing vessels.

(2) From the point where the pilot is picked up through the East Lamma Channel to the Western Fairway at Green Island - This is an open run within the Traffic Separation Scheme (TSS) with little cross traffic, mostly consisting of small craft. The current plan is for 2 tug escorts to be picked south of Ap Lei Chau just after embarkation of the pilot. These will be retained for the entire transit to Black Point.

(3) From Green Island at the start of the Western Fairway, through the Western Fairway to its end at the Ma Wan Fairway - Heavy cross traffic of ocean going vessels coming in and out of Kwai Chung container terminal and anchorages, as well as a very high density of ferry traffic entering and departing Victoria Harbour.

(4) From the start of the Ma Wan Fairway, going through the Ma Wan Fairway between Tsing Yi and Ma Wan around turn to west up to location south of Brothers Point in Tai Lam Chung -This section crosses under the Tsing Ma Bridge from Tsing Yi to Ma Wan and turns west. Large vessel traffic in this area is under a one way control plan for ships greater than or equal to 170m or for drafts greater than or equal to 9.5m. Two additional tug escorts will be available south-west of Tsing Yi, with one tug being made fast to the LNG carrier prior to transiting the turn around Ma Wan Island.

(5) From the location south of Brothers Point up to Urmston Road south of Tuen Mun River Trade Terminal - There is an increased density of small vessels (river trade) and high crossing traffic of small craft of all types north of the route alignment which includes the passage between buoys “CP4” and “CP5”. This is the narrowest part (310m) of the whole approach and common practice by the Hong Kong Pilots is to operate the channel in a one-way manner for the passage of large ocean-going vessels. This transit sector is located a long distance from residential population, with most small craft traffic occurring north of the LNG carrier route, closer to the shoreline.

(6) From the start of Urmston Road south of the Tuen Mun River Trade Terminal through Urmston Road up to the turning basin at Black Point - There is heavy river trade vessel traffic in this area and Ocean-going vessel traffic from Shenzhen.

(7) Transit approach channel, with tug assistance turn 180deg and then berth carrier to jetty - The waters around this area are very shallow, with the primary traffic being small craft and shallow draft river trade vessels.

High density traffic passing the site predominantly comprises coastal river trade vessels transiting between Kwai Chung and the Western Harbour and ports on the Eastern side of the Pearl River Delta. However, the turning basin, set back as it is from the main channel area, is not subject to significant local traffic. While the jetty at Black Point is close to the Urmston Road fairway, the presence of the headland and shallow water protects the LNG carrier from the passing traffic.

The route for ocean-going vessels is delineated by traffic separation fairways and marked by navigation aids. Regulations have been established for control of traffic while transiting the Ma Wan Fairway.

The route to be followed by LNG carriers is identical to that of vessels (including the world’s largest container ships) that access the Mainland ports at Shekou & Chiwan, and experience with ocean-going CLP coal carriers has demonstrated that transit to Black Point can be done safely.

D3 Summary for Marine Navigation

A summary of the parameter values and relative scores derived from the engineering assessment for the construction of the approach channel and turning basin is given in Table D1 below.

Table D1 - Summary for Marine Navigation

Parameter	Option 1 (Base Case)	Option 2 (Full Reclamation)	Option 3 (Full Excavation)
Marine traffic	RS = 3	RS = 3	RS = 3
Grounding potential	RS = 3	RS = 3	RS = 3
LNG carrier striking jetty	RS = 3	RS = 3	RS = 3
Striking of the moored carrier by passing traffic	RS = 3	RS = 3	RS = 3

RS = Relative Score

D4 Scoring for Marine Navigation

Each of the parameters summarised above in Table D1 have also been scored in accordance with the procedure described in Section 2.1. The results are shown below in Table D2 for each of the layout options at Black Point. The table also shows the total score for each site derived using the weightings given in Table 2.6.

Table D2 – Scoring for Layout Options at Black Point for Marine Navigation

Parameter	Weight	Option 1 (Base Case)		Option 2 (Full Reclamation)		Option 3 (Full Excavation)
		Score	WS	Score	WS	Score	WS
Marine traffic	0.50	3	1.50	3	1.50	3	1.50
Grounding potential	0.10	3	0.30	3	0.30	3	0.30
LNG carrier striking jetty	0.10	3	0.30	3	0.30	3	0.30
Striking of the moored carrier by passing traffic	0.30	3	0.90	3	0.90	3	0.90
Total Weighted Score			3.00		3.00		3.00
Normalised Score		5.00		5.00		5.00

From the result of the assessment of all parameters for the marine navigation, all layout options have the same score.

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