The global shipping industry has been thrown into “chaos”, reported The New York Times. Changes in consumer shopping habits and an increased demand for PPE, coupled with restrictions to dock personnel and truck drivers, have caused traffic jams at ports around the world. Container vessels are waiting sometimes as long as 90 days to secure a berth — a backlog that isn’t just expensive and inconvenient, but potentially dangerous.
Even before the pandemic, accidents at ports and harbors were a serious problem. Data from Allianz shows that foundering (e.g., shipwreck) was the most frequent cause of loss of all vessels in 2019, caused by bad weather, flooding and water ingress, engine trouble, and vessels capsizing. The increase in global shipping, as well as the growth of the size of ships, has contributed to higher safety risks at ports and harbors.
Ocean buoy data can play a role in increasing the safety at our harbors. This requires deploying compact ocean buoys close to ports to collect better information — here’s how ocean buoys can help improve harbor safety.
The risks at ports vary depending on the location, size, and function of the port or harbor. However, there are certain trends in marine shipping that impact safety at virtually every harbor.
First and foremost, vessel sizes have increased over the years to meet the demand of a globalized economy. Bigger ships are harder to maneuver, and harbor space often can’t accommodate the same number of ships at a larger scale. Safety margins, already complicated by weather conditions, are even tighter for these large vessels.
Simultaneously, fewer crew members are operating these bigger ships, as labor-saving technologies have been introduced to save money. Yet, ship captains are under increased pressure to meet deadlines imposed by shipping companies — and with fewer crew members to operate larger vessels, safety is easily compromised. Adhering to regulatory and environmental requirements while navigating, safely, on time without enough personnel, is a formidable challenge.
Even without these challenges, navigating in and out of harbors is a difficult task. A report to Congress explained:
“Most ship collisions, allisions, and groundings occur in harbors because that is where navigation becomes constricted by land, shallow water, other vessels, and man-made structures like jetties, bridges, and piers. Tide and river currents are also an important factor in harbors but not at sea. A ship’s response to the water displacement of a passing vessel, a channel’s bank, and minimal under-keel clearance are hydrodynamics peculiar to a harbor’s constricted waters. A fully loaded ship moving at typical harbor speed in a channel with a following tide may not be able to stop, even with engines in reverse and the assistance of tugs, for one or more miles.”
To pull off these maneuvers, captains and harbormasters require accurate information to schedule the movement of ships to and from the port. Real-time marine weather forecasts coupled with data from acoustic doppler current profilers (ADCPs), tide gauges, wind sensors (anemometers), and wave data help maintain the under-keel clearance (UKC) needed to prevent grounding or foundering.
Part of these calculations includes measuring the harbor seiche — defined by NOAA as a standing wave oscillating in a body of water. Harbor seiches can produce damaging surges of water in the form of infragravity waves or long-period waves that break mooring lines, impact entry/exit procedures, and can even harm moored vessels waiting to unload/reload.
Running a harbor is a complicated operation that can be made safer with the right data. And, ocean buoys play a critical role in providing that data.
Ports around the world have already started to deploy ocean buoys to help better manage harbor traffic.
The Port of Lyttelton in New Zealand started using Sofar’s Spotter buoys in 2019 to provide sea and swell spectral wave data, as well as inferred wind speed and direction information to inform piloting decisions. The size of the compact buoy was cited as a big benefit by the port company’s engineering advisor.
“The Spotter must be lightly moored to achieve its designed wave responsiveness, but this has significant upsides including reduced cost of providing the mooring components and the floating plant for servicing. Smaller and faster vessels can take the equipment to the site and to recover the buoy,” he said.
High-tech weather buoys are similarly providing key operational forecast information in the Port of Valdez, Alaska, a major oil terminal and the departure point of the Exxon Valdez. There, weather buoys provide data on the tidal currents, wind, air temperature, water temperature, and barometric pressure. These are reported in real-time to help guide port operations to make better, safer decisions; and ultimately help avoid another environmental disaster like the Exxon Valdez.
“This new system and others like them around the country reduce ship accidents by more than 50 percent, increase the size of ships that can get in and out of seaports, and reduce traffic delays,” reported Steven Thur, acting deputy director of NOAA’s National Ocean Service. “They also provide real-time, resilience-ready data as coastal conditions rapidly change, potentially threatening our coastal communities.”
And, in Stockholm’s Norvik Port, a “smart buoy” has been installed to improve the safety, situational awareness, and efficiency of the harbor’s busy shipping fairways. The sensor will report on currents and marine weather conditions and integrate into land-based navigational systems. The project also aims to collect long-term environmental data.
Ocean buoys equipped with underwater sensors can offer more accurate tidal predictions, operational forecasts, and wave forecasts. Sofar’s compact buoy, the Spotter, is roughly the size of a basketball — an unobtrusive source of data perfect for busy ports. The Spotter captures the complete wave spectrum with sea and swell data partitioning, as well as hourly updates. Wind measurements include wind speed and direction estimated from the equilibrium range of the wave spectrum.
Buoys can offer better data to help mitigate the risks of docking in and out of ports. Ocean buoy data can help harbormasters optimize vessel docking schedules. Some of the tools they utilize include using wind speed forecasts, wave forecasts, current forecasts, and tidal predictions to make sure ships of every size enter and exit safely.