There are many types of maritime incident that may require a quick response in order to save life, prevent pollution or prevent the loss of assets. These range from a man overboard incident (from a vessel or offshore fixed asset) to the loss of a vessel or an offshore platform and major pollution incidents. In many cases, the most important issue is speed of response and therefore it is vital that Emergency Response Plans are in place so that there is no indecision delays when an Emergency incident occurs.
Emergency Response Plans should consider all probable types of incident and then determine how the organisation will respond in each case and whether the assistance of others will be required. The preparation of such plans is therefore essential and, in many countries, a legal requirement.
The role of VTS in Emergency Response
VTS technology (whether used for Port Vessel Traffic Services, Coastal Surveillance or Offshore Sea Surveillance) is able to provide a real time image of the current operational situation. Therefore, if an object (e.g., container or vessel) is drifting within the VTS area and a hazard to other shipping, the VTS can detect and continuously track the object using its non-cooperative (radar) sensors. Note, a ship that is adrift is likely to be without electrical power and therefore AIS transponders are unlikely to be operational. Using environmental prediction models for the area, it may also be possible to use the real time information from the VTS as an input to prediction models for tidal activity and wind effects to determine the likely impact or risks from the drifting object.
Oil Spill Response
An Oil Spill can cause significant environmental damage as well as causing a variety of economic problems. Minimising the damage and its potential consequences should therefore be a priority for any maritime authority and for the offshore oil & gas industry. However, when a spill occurs there are three key steps in the management process. These are:
- Clean up
The key issue in managing any oil spill is early detection. There are many ways to detect an oil spill using sensor systems and there are positive and negative factors associated with each one. the most common means of Oil Spill Detection is by satellite remote sensing. Synthetic Aperture Radar Satellite imagery can be very effective at detecting oil on the surface of the water and systems such as Radarsat are widely used by maritime authorities. Satellite imagery is very good for providing large area coverage but as the satellite orbit typically only passes over any specific area, once per day, it could be nearly 24 hours after a spill has occurred that it is seen via satellite imagery.
Local area, real time, Oil Spill Detection can be provided by radar. The satellite imagery detects oil spills by the smoothing effect the oil has on the small waves that create radar clutter. In the same way, shore or ship based radars could detect oil spills through the suppressing effect the oil has on the normal sea clutter conditions. A radar system provides continuous 360 degree surveillance and therefore can provide real time alarms when a spill is detected. Whether the radar is on board a patrol vessel, a coastal or offshore site, radar based Oil Spill Detection provides an effective means of detection. This technology will provide a day and night Oil Spill Detection capability. Depending on the frequency band of the radar, rain may have a degrading effect on performance, but overall,this technology is able to provide continuous 360 degree oil spill monitoring and alarms.
Thermal camera systems will also detect oil spills. The spill will be clearly seen on the Thermal image and can be used to confirm the presence of a spill following initial detection by a radar based system. Cameras do not normally provide 360 degree surveillance and therefore will only detect a spill if the camera is on the correct bearing. However, radar based oil spill detection could produce some false alarms (depending on the set up of the system) as features such as the wake of a ship or calmer water that is sheltered by a ship or other object, can produce a similar effect on the sea clutter as an oil spill. Therefore initial detection by radar and confirmation by Thermal camera can provide an effective solution.
Search & Rescue
Search & Rescue (SAR) operations are normally carried out by a specially trained unit of the national Emergency Services capability. It is not normally carried out by a VTS Authority but the VTS system can be a useful tool to aid Search & Rescue planning and in the monitoring of operations as they progress. For any SAR incident, early notification is vital, particularly if the incident relates to a person in the water. The recovery operation will involve SAR Assets such as Helicopters and Fast Rescue Craft as well as planning tools to determine the most likely location of the SAR incident when allowing for the effect of tide and wind since the first, or most recent, sighting.
Following notification of a SAR Incident, it will be necessary to determine the effect of wind and tide on the object or person in the water over the elapsed time. It will also be necessary to determine how long it will take to deploy SAR Assets to the scene.