Engine Idling and Noise Pollution in Port Cities: An Overview

Maggie Wang
What is the real impact of noise pollution in ports? Is there anything we can do about it? Many attempts to tackle port noise to date have involved the construction or improvement of physical infrastructure, such as walls and ramps. However, port noise could be more easily mitigated at the source—by using best practices for running engines on ships and vehicles.

Ports have long acted as beacons of globalization and connectivity by exchanging goods between states throughout history. They are part and parcel of why we see mass development, economic expansion, and sprawling urban populations living coastally today. However, a by-product of this modern modus vivendi is the prevalence of noise-creating pollution fueling adverse impacts, especially due to the proximity of high traffic ports to thriving marine ecosystems and high density human settlements. Solutions for the future may look to new hardware and inventions to reduce pollution, but what can cities do today?


What does noise pollution look like in port cities?

For competitive economic reasons, ocean-going vessels typically use the least expensive - and often the dirtiest - fuels available. Large diesel engines propel these vessels, while auxiliary engines provide electric power for domestic electrical needs, cargo operations and other vessel maintenance uses. Diesel-driven hauling equipment, trucks, and locomotives unload cargo and then ferry it to faraway inland destinations. Port cranes add to the noise by handleling bulk cargo and containers, meaning optimal crane power is an important issue for many ports. To compound noise pollution, cruise ships that function like mini-cities line up in port in vast numbers to ferry passengers and collect cargo from trucks delivering provisions for customers. To recap: Multiple ships the size of a small city idle for days collecting cargo from trucks and creating noise and pollution at a rapid rate.

Noise is produced by diesel-run auxiliary engines as ships approach ports and idle at the dock. In close proximity to auxiliary engines, noise levels can reach 80-120 decibels - in comparison, a chainsaw averages 110 decibels! During the last three decades of the 20th century, ambient noise levels in a frequency band consistent with sounds produced by large vessels increased at a rate of about 3 decibels per decade at a single location off of Southern California.

A high level of low-frequency sounds are produced by vessels while cruising in the sea. At this frequency, sound can travel long distances and may change local acoustic environments, impacting marine animals that use sound in reproductive interactions and interference with predator or prey detection. In extreme cases, noise pollution may even cause these animals to avoid their habitats. Noise pollution has even been blamed as a potential reason for whales beaching. Sharma 2006

What are the problems surrounding noise pollution in ports?

The port environment is highly heterogeneous in terms of both usage and intensity of the activities at different times. Due to a wide range of noise sources such as trains, heavy vehicles, ships, and industrial machines operating simultaneously, the port area is more complex to study than other noise sources. Additionally, ports are usually surrounded by other large transportation infrastructures and by urban areas that are widely affected by the noise, even at long distances due to the low-frequency noise produced from the ships’ internal power generator. Noise as an environmental challenge for ports (2013)

Besides annoyance, long-term noise exposure has several negative health effects. Noise exposure is related at least to cardiovascular diseases, sleep disturbance, and cognitive impairment in children. Hearing is the one sense that is always open for sensations; it is not “switched off” even during sleep. This is due to the hearing’s role as an important warning system. Hearing sensations have effects both on the autonomous nervous system and on the hormonal system. Exposure to a high level of noise triggers a stress reaction that can be measured in high levels of stress hormones. Long-time noise exposure can lead to a more permanent imbalance in the stress regulating system of the body. These physiological effects can be measured regardless of the experienced annoyance or sleep disturbance.


Sources of noise in ports:

  1. Working machines. Cargo handling equipment is a significant noise source in ports
  2. In and out truck and car traffic
  3. Railway
  4. Vessel-quay interface: ramps
  5. Cargo handling: containers, bulk cargo
  6. Vessels

Challenges to reducing noise in ports:

  1. Outdoors environment
  2. Acoustically hard materials
  3. Closeness to water
  4. Several different noise sources
  5. Scattered noise sources on different heights
  6. Low-frequent, tonal, and impulse noise

What solutions exist to address pollution in ports?

  1. Port layout
  2. Traffic arrangements
  3. Ramp design
  4. More silent cargo handling methods. Noise from the cargo handling operations can be reduced by “soft” driving. A lower driving speed gives lower engine and tire noise from the cargo handling equipment and can also help to reduce fuel consumption
  5. More silent machine fleet
  6. Onshore Power Supply (OPS) - a method by which ships can turn off their engines and connect to the electricity grid to power ships, reducing air emissions from idling and ship noise
  7. Speed limits
  8. Differentiated port fees

Bailey et al. 2004

Photo by Joseph Chan.

How do solutions for noise pollution reduction work in reality?

Case study: The Port of Los Angeles (PoLA) has implemented a noise mitigation plan including two key measures: construction of 12- and 24-foot sound walls, and the implementation of construction noise measures - including clear rules about construction hours and days, temporary noise barriers, equipment regulations, idling prohibitions, noise complaint management, and a monitoring and management plan. These mitigation efforts were predicted to be especially significant for nighttime operations. The PoLA hired a third party to test the effectiveness of the noise mitigation plan, and the results revealed that the noise mitigation measures do help control noise impacts. Even with increased capacity to 1.7 million TEUs, the operational noise still meets the requirements of the City of Los Angeles. Gonzalez-Aregall et al. 2019

Case study: In Hamburg, to solve the increasing conflict between urban life and port usage in this transitional port-city interface, the port authority installed specially-designed soundproof windows in all the residential and commercial buildings to keep the noise low even when the windows are not completely shut. This type of passive noise protection does not strengthen the city-port tie, but rather separates them functionally by adding a physical barrier between separate spheres of functions, therefore, reducing the potential interactions between the two. At the same time, the port official also divided Hafen City, a residential area near the port, into different districts with different noise amplification limits based on the usage and location of the district. In contrast to the implementation of one consistent noise cap for all districts, this flexible noise cap system respects both urban and maritime interests at the transitioning port-city interface. Such a system promotes the co-existence and reconnection of the port and the city. Li 2018

Focus on Southeast Asia

Approximately 70% of South East Asia’s population live in coastal areas. Intensive farming practices, rapid urbanization, industrialization, greater shipping traffic & over-fishing, widespread deforestation, and nearshore development are contributing to the pollution problem. As SE Asia encompasses approximately 34% of the world’s reefs and between a quarter and a third of the world’s mangroves, as well as the global biodiversity triangle formed by the Malay Peninsular, the Philippines, and New Guinea, the need to reduce the impacts of marine noise pollution in this region is all the more critical. Todd et al. 2010

In 2016, Rob Williams, co-founder of the ocean-conservation group Oceans Initiative, learned about a Hindu tradition called Nyepi, a day of silence in Bali in early March. It is rigorously observed: all shops, airports, and shipping and fishing shut down, and tourists are gently led off the beach back into their hotel rooms. Williams saw this as a unique opportunity: “No one in the world shuts up for a day,” he says. In 2017, he went to Bali and put six hydrophones in the water to measure the effect of the silence. “The drop was in the order of 6–9 dB. About the same [as] New York and Boston after 9/11,” he says. “This was extraordinary.” The next step, says Williams, is to investigate what the corals and fishes do in response to the silence, although he has no specific plans or funding to go back. Ocean uproar: saving marine life from a barrage of noise (2019)


How can Signol influence engine idling at ports?

Many attempts to tackle port noise to date have involved the construction or improvement of physical infrastructure, such as walls and ramps. However, port noise could be more easily mitigated at the source—by using best practices for running engines on ships and vehicles. Ships idling in ports produce distressing quantities of noise for port workers and nearby residents as well as releasing large quantities of pollutants into the air. Likewise, ports rely on the support of trucks, cranes, and other machinery which also run engines with low-frequency sound. Such idling increases operating costs for companies, first, because of excess fuel burn and, second, because some ports have begun to charge fees for pollution.

Signol’s platform, which is designed to cut harmful behaviors such as idling, is well suited to tackling the two-fold pollution and operating cost problem. By encouraging crews to use onshore power instead of burning fuel or encouraging onshore staff to cut engines when not in use. Signol could help save money and emissions in ports while leaving positive health and wellbeing impacts on surrounding communities.

About Signol

Signol is a software platform that draws on insights from behavioral economics to encourage employees to make more efficient decisions. Signol provides personalized feedback through multiple communication channels, as well as data analysis for managers. In aviation, Signol aims to use behavioral "nudges" and incentives to reduce pollution and fuel waste and cut operating costs.

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