For even larger spills, the above technique may begin to falter because we can only push the foam so far. The nozzle team can then employ the Bank-down Method. Such a technique uses obstacles farther from the nozzle team. Let’s say a tanker has overturned and there is product between the nozzle team and the overturned tanker. Too great of a distance between the two won’t allow for the Roll-on Method to effectively cover the entire area, so the nozzle team can resort to the Bank-down Method. This entails the foam stream striking the tanker and allowing the finished foam to cascade downward onto the spill and spread out. This is an effective technique and can be used with vehicles, buildings, or any other solid object that won’t fail after being struck. Be wary of electrical components. Foam is mainly water and the nozzle team can be subjected to the danger of electrocution if they’re not careful!
The Rain-down Method is the final of the three techniques for foam application. Like the name implies, a stream is projected high into the air and the finished foam product falls down on top of the product. Moving the nozzle rapidly from side to side will prevent a stream from impacting into the spill.
Regardless of the technique used, remember not to disturb the fuel as best as possible. When the foam blanket is applied it is also important not to disturb the foam blanket as well. The use of a water stream near the foam stream can also have a damaging effect. Plain water will dilute the foam blanket and create an unsafe situation as well as waste the foam that was just applied.
The application of foam requires training and practice. Even just setting up a foam delivery system without using expensive concentrate can offer valuable lessons for firefighters. Concentrate is expensive and slightly corrosive to equipment (requiring five minutes of flushing with fresh water after each use), so it isn’t a drill that we do every day. Nevertheless, we are expected to be proficient in all facets of foam delivery and application.
Putting It All Together
Up to this point, we have covered a lot of material. Now we’ll take a look at how we can apply foam at the site of a spill or fire involving Class B fuels. Everything we do should always be based on safety. The safety of our firefighters, of the civilians we are tasked with safeguarding, as well as other emergency responders on scene all fall within our realm of responsibility.
Our response to an incident requiring foam application requires each responder to conduct his or her own size-up. Size-up is a term that translates into the gathering of clues and vital intelligence that helps orient us towards a safe strategy. Our size-ups are never completed. A size-up is an ever-evolving process on the part of each member. The fireground is a dynamic and ever-changing place. What was appropriate initially may no longer be relevant or even safe! Obviously, the concept of size-up differs significantly depending on the role of the department member.
For example, the newest member of the team, the probationary firefighter, will perform a size-up that might include some of the points that were covered in basic training, such as the class of fire the company will be dealing with, the need to keep a safe distance, and the need for full personal protective equipment (PPE) and self-contained breathing apparatus (SCBA). This size-up differs significantly from that of the first-due company officer. Our company officer has a myriad of tasks going through his mind from the time the call is received to the arrival of the company to the transfer of command to a more experienced officer.
Upon arrival at the scene, some requirements (in addition to the foam operation) also include the need to set up a cohesive command structure. The use of an incident command system (ICS) enhances organizational efficiency and reduces confusion. Our first-due company officer will establish command, break the incident down into manageable bite-size pieces, and establish a staging area to corral the additional units that are arriving. The initial overwhelming burden of so many tasks can be eased by assigning specific objectives to firefighters or assigning tasks to the next-arriving company for example.
As part of the initial size-up, our company officer has to call for the additional resources based on what “could be.” This is proactive thinking and looks at the situation not so much from what is, but what it could be. It is far better to start out additional resources when you think there may be a need than to have to wait for them later. As a company officer, always get into the habit of playing the “what if?” scenario.