I: Emergency Situations - Response - Equipment

Question 1

What general action should be taken in the event of an emergency?

Answer 1

1) Assess:
OIL SPILL Y/N (follow SOPEP)/(Monitor for development of pollution)
REQUIRE EXTERNAL ASSISTANCE Y/N (Call for assistance Securite, pan pan, mayday)/(Notify nearby vessels, vts etc)

2) Act: Follow Emergency Procedures, Monitor situation / adjust emergency response
3) Notify / Alert: Nearby Vessels, VTS, Port State, Flag State, DPA - Company, Class, P&I, H&M Insurance
4) Record and Follow Reporting Requirements

Question 2

Which laws and conventions stipulate a masters obligation to render assistance?

Answer 2

Navigation act 2012
International Maritime Search and Rescue Convention
SOLAS Ch V/ 33: Distress Situations: Obligations and Procedures

Question 3

What is a masters obligation to render assistance?

Answer 3

Common:
Obligation to render assistance to any person / person’s (vessel) in distress.
Must proceed as fast as practicable.
Must inform person(s) that he is proceeding.

He may not if he is unable to do so, it is unreasonable, persons no longer require assistance, another vessel has been requisitioned. It must be entered into the official log book.

International Search and Rescue Convention & SOLAS:
Must provide initial medical needs and deliver persons to place of safety, treat them with humanity.
Must notify SAR Services
Vessel may be requisitioned by vessel in distress, SAR authorities or OSC.

Question 4

How would you use Buys Ballot’s Law to determine the centre of TRS?

Answer 4

Face True Wind Direction and Center of storm will be on LHS (SH) / RHS (NH)
If Fall of 5 HPA – 12 points to R (NH) / L(SH) Outer Edge
If fall of 10 HPA – 10 points
If fall of 20 HPA - 8 Points (90˚) Near the Eye

Question 5

In what Latitudes can a TRS Form and why?

Answer 5

TRS can only occur between 5-20˚ Latitude

1. Need Coriolis Force, which does not happen at the equator >5˚
2. Need warm water – not warm enough at latitudes higher than 20˚
   • Heat / Energy provided by the condensation of water vapour.
   This occurs in late summer (when declination of sun has passed the equator and ITCZ has moved north or south of equator.

Question 6

What are the 6 preconditions for a TRS?

Answer 6

1. Pre-existing surface disturbance
   Troughs of Low Pressure aprox 990hpa (to create uplift)
   Rising air (convergence below – rising air – divergence aloft)
2. Moist atmosphere in the mid troposphere
3. Sea temperature of >27˚
   This means saturated air will ascend and condense (adiabatic cooling)
4. Light winds aloft steady in speed and direction. Low vertical wind shear between surface and upper troposphere. So the eye and its convective column is not displaced vertically. Maintains the eyes vertical structure.
   Not under influence of the jet stream
5. Whirling motion caused by Coriolis Force (must be greater than 5˚ of latitude for required Coriolis force.
   Usually develops where trade winds meet.
6. Divergence aloft.
   Horizontal convergence at sea level (net inflow of air) – increase in mass of air – air flows upwards. (A)
   The tropopause is statically stable and prevents air from continuing to flow upwards, instead it spreads horizontally (divergence)
   Here there is divergence aloft (in the upper troposphere) (net horizontal outflow of air). (X)
   If X is greater than A, then we have a negative pressure gradient where air is sucked into the surface area and then taken upwards.

Question 7

What are the warning of a TRS?

Answer 7

Mainly an increasing trend in the fall of pressure (below the expected average) and an increase in wind strength and change of direction.

Pressure:
Cessation of semi-diurnal pressure (two highs and two lows a day). Daily amplitudes of pressure level off.
If pressure is remarkably lower than mean sea level pressure for time of year possible TRS (3hpa possible – 5hpa trs may be in vicinity)

Wind:
Change in wind strength and direction

Squalls and Lightning
Heavy Swell and high seas
Swells coming from an unexpected direction (from the centre of the low)
High Humidity (>75%)
Clouds Cirrius – Radiate in one direction

Question 8

Draw a TRS?

Answer 8

Rotation Rolls against the curvature
Eye: Centre area, may be calm, surrounded by Force 12 or greater
Track: Where TRS has already passed
Path: Anticipated movement (NW in NH, SE in SH) Down to east coast and then goes offshore.
Trough: Line of lowest barometric pressure to a stationary observer
Wind: Small indraught in outer circle, tangent at eye.
Dangerous Semi Circle: Where a vessel should not run before the wind
Dangerous Quadrant: Advanced quadrant of dangerous semi circle, TRS may recurve over vessel
Navigable semi circle: Where a vessel may run before the wind
Vertex: Point at which curvature is greatest. Western most point of the path/track.

Question 9

Evasive Action for a TRS?

Answer 9

Keep ship well away from the eye
Avoid the Dangerous Quadrant – Cross well ahead of the path to get into navigable semi circle. The TRS may recurve over a vessel if it is in the dangerous quadrant.

In RH Semicircle (both NH / SH) Wind Veers
In LH Semicircle (both NH / SH) Wind Backs.

IN SH:
Dangerous Semi Circle: Wind 1-4pts port bow – A/C to port at wind backs
Punching into wind and weather
Navigable Semi Circle or TRS Path: Wind 4 pts Port Qtr – A/C Stbd as wind veers
Following wind and seas

IN NH:
Dangerous Semi Circle: Wind 1-4 pts stbd bow – A/C to stbd as wind veers
Punching into wind and weather
Navigable Semi Circle: or TRS Path: Wind 4 points Stbd Qtr – A/C Port as wind Backs
Following wind and seas