The establishment of Cause and Effect (C&E) for an airport terminal building is more than just fire safety and building system integration. It is an opportunity to establish a solution that can offer many benefits to the airport operator’s emergency management and business continuity strategies.
Achieving success with C&E starts with the alignment of evacuation zones that use the natural features of a terminal and its operational spaces. This simple arrangement will help to create C&E rules that align with terminal operation protocols. It will help synergize the emergency management of an event with business continuity strategies, to retain an appropriate level of operational continuity of the terminal.
What is Cause and Effect?
Cause and Effect (C&E) can be applied to a variety of conditions and systems. Broken down this phrase has two meanings:
- Cause – A person or thing that gives rise to an action, phenomenon, or condition
- Effect – A change which is a result or consequence of an action or other cause
Ultimately C&E describes a principle, where a single action has a single or multiple ranges of consequences. Apply this principle to a system and it then defines what happens as a result of a specific action occurring upon it. Therefore, in very simple terms the C&E principle can be applied to a house lighting circuit. Press the light switch (cause) and it will turn a light off/on (effect) subject to the switch position.
In the context of fire safety engineering, C&E helps to bring alive the intent of a building’s fire safety strategy and sets out how a building reacts in an emergency. It does this by setting out a sequence of actions between systems, based on predefined scenarios. This information is expressed in a matrix detailing cause on the left column and effect across the top row. Based on the method of detecting fire or smoke, the C&E matrices define the required actions of other fire & life safety systems as well as other general building systems or equipment. It is important to note that the Effect or subsequent actions of the systems also involve communication of information. This communication provides necessary information to building maintenance and emergency response teams, for them to initiate a level of response commensurate to the cause of the system activation.
To generate the C&E matrices that inform the programming of the system, C&E rules need to be established. These rules set the method in which all matrices are created and programmed into the fire alarm system. How complex these rules are is intrinsically link to the level of risk associated with a buildings operation, and its sensitivity on evacuation of occupants.
Simple buildings with low risk occupancies may have only a few systems such as fire detection and fire sprinkler. The C&E for such a property would be very simplistic. However, an airport terminal building and the complexities of security, large open spaces, performance based fire strategies and many variations of systems create conditions that would require a complex C&E.
Typically C&E is addressed at the latter stages of a project. It usually starts towards the end of construction phase just before testing and commissioning (T&C) begins. Its long term association with T&C means that any changes or gaps that are identified in the C&E rules, can create significant impact and delay on project completion. The reviewing team must match the C&E data with approved shop drawings to align programming with site conditions. This must all be done in conjunction with the approved fire safety strategy. During these reviews, items such as fire alarm interfaces with access controlled doors may be missing. If such gaps are not resolved in the project delivery phase, this would only pass the issue down the line to the Client. This would likely result in further financial investment to correct the system arrangements, or modify operational processes to mitigate system design failures.
Figure 1 provides an insight into aspects of the C&E that would need to be considered for an airport terminal project. This example is broken into three key areas: INPUT, Monitoring and OUTPUT.
INPUT – The automated and manual means to raise an alarm through C&E rules is shown here. These alarms generally come in the form of fire, supervisory and fault.
Monitoring – Panels and computer displays are used by teams to monitor system operations. These teams initiate a range of responses commensurate to the nature of the signal received in the system. Example being the activation of a supervisory signal received for a valve that has been closed, which would require a maintenance team to attend the location, investigate and take the necessary action.
OUTPUT – These systems listed show example automated actions that would be performed on their components, based on the approved C&E rules.
When to begin to think about C&E for a project?
The journey of developing C&E rules and matrices, should start early in the project delivery timeline. At the inception of building layout and design, the evacuation zones and operational philosophy need to be agreed. These two aspects then serve as key ingredients in the development of the fire safety strategy and influence the direction of C&E throughout the project life cycle. Another key ingredient to prepare would be the naming conventions to be applied across the building and its systems. Early agreement of the naming rules for operational areas, evacuation zones, floor references etc, provide the basis for all future development of the project.
Working with an airports fire safety team can offer an insight into the operational protocols for evacuation and incident management. The establishment of smaller evacuation zones that align with the architectural layout or operational zones for instance, would meet primary life safety goals. In turn this would support business continuity objectives to help reduce the scale of impact that an evacuation can create. The objective here is to establish a method that can implement an emergency response that is commensurate to the scale and nature of an emergency. As airports are at risk of acts of aggression as well as fire, the zone arrangements will need to consider how these emergencies would be managed. In doing this it helps to reduce impact on airport operations whilst maintaining priority on life safety. For example, adopting a progressive horizontal evacuation philosophy in a terminal with the use of such C&E arrangements provides a staged response. The initial automated sequence under C&E helps to move people away from an effected area of the terminal, whilst the emergency management team attends to the fire. Instances where the fire condition spreads, the C&E rules of the system can automatically detect the spread and cascading rules in the C&E would apply evacuating further zones. Alternatively the emergency management team initiates a manual activation to evacuate zones as they feel is required. Such an approach must be considered with the airport fire safety and emergency planning teams. This approach provides great opportunities in the fire system design and C&E rules, synergizing systems, people and processes.
What to consider in C&E for an airport terminal?
The progressive development of C&E starts in the preparation of the fire strategy for the terminal. The establishment of evacuation zones and operational processes need to accommodate the operational nature of a terminal. Historically terminals have been aligned with Shopping malls. In essence they share similar assembly and retail characteristics. However, they are not susceptible to the risk associated with security and operational continuity like an airport terminal.
Security – During the evolution of air transportation over the last few decades, security management of airports has dramatically improved and is constantly evolving to maintain control of terminals. The requirements intensified during this period, to mitigate and prevent the risks that now threaten the safety of air travel. This creates a significant influence to design of evacuation zones, escape routes for the fire service to gain entry within the building.
Operational Continuity – The development of hub airport operations and general aviation industry is sensitive to any impact on time. Any time lost at an airport will impact the airlines schedules and subsequently their customers. Evacuating large areas of a terminal will create delays to airport operations. The processes that need to be completed for repopulation of the terminal, can lead to several hours of effort and delays to the flight schedule. Such a scenario creates a range of impacts to a multitude of stakeholders at the airport. A few hours delay at an airport terminal could result in having to re-arrange flight schedules, arrange replacement crews, place passengers into hotels until they can be accommodated onto the next flights. The list goes on.
Ultimately a shopping mall can be evacuated free from such onerous security management, whilst creating no significant impact on operational continuity that can be experienced at an airport. Therefore, it is important when working on a terminal project that one understands such information for the benefit of the fire strategy, evacuation, and system zones. Aspects to be considered would include but is not limited to the following:
Operation of access control doors and associated security implications;
- Positive alarm sequence;
- Operation of lifts and escalators;
- Shutdown of critical equipment, plant and baggage systems;
- Operation of specialist systems such as gas suppression, in context of the evacuation zone;
- Operation of smoke management system, including dampers fans, curtains.
The below diagram sets out four key areas of focus on C&E, which would need to be given attention from the start of a terminal project. These aspects are then further developed along the project timeline to deliver a workable solution for the Client.
Information and Communication
As an end user of systems, the information programmed into a system needs to align with the language used by a Client. Experience of projects across the world has seen Contractors moving ahead with construction using their language of gridlines and construction sectors, which means nothing to a Client. When a terminal becomes operational the Client uses gate and stand numbers in every day operation. Utilising these references can help link a device to a zone, which provides an efficient way to locate an activated device within the terminal during an emergency.
Understanding naming conventions and zone labels for evacuation and system zones helps all project stakeholders from Designer, Contractor through to the Client. It will eliminate lost time and costs for re-programming, changing of labels, data and asset tags. All of this data becomes part of the programming of fire systems and is captured in C&E development. The end product provides clear locations for maintenance, fire wardens, emergency management and response teams to locate devices or zones that are communicated under C&E rules.
As most airports have on site emergency services, it is important to capture the best way in which they are alerted and guided to reach a fire location in the terminal. It is important to remember the responding emergency services entering the terminal to tackle a developing fire. Terminals can contain a maze of routes to reach zones within the building. These routes are typically influenced by the airside / landside boundary that segregates the security zones of the terminal. Using external beacons within the design of the fire alarm system can provide an opportunity in C&E, to direct fire services to the best access points to reach a zone that has activated. The structure of the text shown in fire alarm panel and graphical displays can be arranged in a manner that is informative to the end user. This structure would help a person understand the location of the device in terms of horizontal and vertical position within the building.
Establishment of an emergency response protocol that can adapt to the scale and nature of a fire in a terminal is a key objective. This would involve the link between the positive alarm sequence (PAS) of a fire alarm system and on airport emergency services. The time delay associated with PAS, provides sufficient time for teams to investigate alarm conditions that occur on the system. The period of time for the response does however need to accommodate the response time needed to reach the most remote areas of the terminal. The time delay options that are available in the system can be modified to suit the operational protocols. In doing this it will help prevent false alarms occurring in the terminal which would otherwise create an evacuation and subsequent disruption. This aspect of C&E can provide a robust mitigation tool that reduces the likelihood of false alarms creating an impact on airport operations. The manner in which evacuation zones are arranged and then operate together under C&E rules can aid emergency management. A hierarchy of evacuation zones can be created in the terminal, to scale the automated response by the systems under C&E in line with the emergency management strategy for the terminal.
The way in which terminal based fire wardens and general occupants behave under an alarm condition must be considered. Most passengers will require some form of direction from staff before they begin to move, as they will not wish to leave a queue for example at Check-In. C&E rules and content for evacuation messages announced over the PA system within the zone of activation, can help initiate Fire Warden teams to commence an evacuation. Other displays in the terminal such as the flight information boards can be activated to provide additional alerts to occupants to evacuate an area.
Working in parallel to the emergency management response, operational teams can be supported through C&E. Graphical displays of evacuation zones impacted by the fire can presented in the command centre of the terminal, linking the emergency condition with the critical activities associated with that zone. This helps teams to quickly identify the strategies that would need to be applied to sustain terminal operations, whilst the fire service tends to the fire. Smoke management systems are not always a requirement under code; however they can provide added benefit in terms of operational continuity of a terminal. Removing smoke post fire can be a time consuming task, which only increases the period of recovery for a terminal. Providing adequate means during a fire to deal with smoke will help reduce the level of impact it creates in the terminal. This arrangement supports a more efficient recovery process from a fire to allow terminal operations to resume normal operating capacity, supporting the recovery time objectives (RTO). Such an arrangement would be controlled through the C&E rules from the initial device under alarm.
Most terminals utilize access control systems to secure their facility. During evacuation the management of access to and from a terminal creates risk to the security control of the terminal. This is a key challenge when arranging C&E rules for a terminal, to link security sensitive doors to an evacuation zone. If a zone is under evacuation, all signed routes from that location must be made free access to allow occupants to escape.
Performing regular testing of each zone on an annual basis is a challenge for busy international airports that operate 24/7. The regular changes that occur in concessionaire areas, means C&E labels and programming is going to be modified on a regular basis. Providing the data in an agreeable format with the Clients maintenance team, will help complete the transition of information at the end of the project.
What does this all mean?
The information presented in this article has been focused around airport terminals, their complex operational conditions and low risk appetite for impact to their operation. If you are working on a project or preparing to deliver a project involving C&E, think about the end operation and benefits it could bring your client. C&E development should be an integral part of the design process growing with detail as the project develops from design to construction. Think about the technology options available for the project through graphical displays. Look at how these systems can provide intuitive displays that support the end users of the systems. It is important to always remember that C&E arrangements are for the life of the building and its operator. Therefore always seek to include the Clients Fire Safety and Maintenance teams in the planning and development of C&E.
For more information, email [email protected]