Drafting and Relay Pumping

Introduction

Drafting and relay pumping are essential techniques in fire fighting that allow firefighters to access water sources that are not directly connected to a fire hydrant. These techniques are particularly useful in rural areas or situations where the water supply is limited. In this topic, we will explore the basics of drafting and relay pumping, including the equipment involved, the drafting procedure, the need for relay pumping, and real-world applications.

Basics of Drafting

Drafting is the process of drawing water from a static water source, such as a pond, lake, or swimming pool, and supplying it to fire apparatus for firefighting operations. The purpose of drafting is to provide a continuous flow of water to the fire scene when a direct connection to a hydrant is not available.

There are several key pieces of equipment used in the drafting process:

1. Drafting Hose: A large-diameter hose that connects the drafting pump to the water source.
2. Strainer: A device that filters out debris and prevents it from entering the drafting pump.
3. Drafting Port: An opening on the drafting pump where the drafting hose is connected.
4. Drafting Pump: A specialized pump designed to draw water from a static water source.

Water Lift and Altitude

When drafting water, it is important to understand the concept of water lift and how altitude can affect the drafting process. Water lift refers to the vertical distance between the water source and the drafting pump. The greater the water lift, the more difficult it is for the drafting pump to draw water.

Altitude also plays a role in the drafting process. As altitude increases, the atmospheric pressure decreases, which can affect the performance of the drafting pump. Firefighters must take these factors into account when setting up a drafting operation.

Drafting Procedure

Setting up a drafting site involves several steps to ensure a smooth and efficient operation:

1. Selecting a Suitable Water Source: The water source should be large enough to provide an adequate water supply and free from contaminants.
2. Positioning the Drafting Pump: The drafting pump should be placed as close to the water source as possible to minimize the length of the drafting hose.
3. Installing the Drafting Hose and Strainer: The drafting hose is connected to the drafting port on the pump, and the strainer is attached to the other end of the hose to filter out debris.

Priming the Pump

Before starting the drafting process, the pump must be primed to remove any air and ensure a continuous flow of water:

1. Filling the Pump with Water: The pump is filled with water to create a seal and remove any air pockets.
2. Removing Air from the Pump: Air trapped in the pump is released through bleed valves or other air relief devices.

Starting the Drafting Process

Once the pump is primed, the drafting process can begin:

1. Activating the Pump: The pump is started, and water is drawn from the water source through the drafting hose.
2. Adjusting the Pump Speed: The pump speed is adjusted to maintain a steady flow of water.
3. Monitoring the Water Flow: Firefighters must monitor the water flow to ensure an adequate supply is being delivered to the fire scene.

Need for Relay Pumping

Relay pumping is a technique used when the distance between the water source and the fire scene is too great for a single drafting operation. In relay pumping, multiple pumpers are used to transport water from the water source to the fire scene.

Capacity of Pumpers

Determining the flow rate required for a fire operation and calculating the number of pumpers needed is crucial in relay pumping:

1. Determining the Flow Rate: The flow rate is determined based on the size and intensity of the fire.
2. Calculating the Required Pumpers: The number of pumpers needed is calculated based on the flow rate and the capacity of each pumper.

Relay pumping has several advantages, such as allowing for longer distances between the water source and the fire scene. However, it also has some disadvantages, including increased complexity and the need for additional resources.

Step-by-Step Walkthrough of Typical Problems and Solutions

In this section, we will explore common problems that can occur during drafting and relay pumping operations and their solutions:

Insufficient Water Supply

1. Identifying the Cause: Firefighters must determine the cause of the insufficient water supply, such as a clogged strainer or a low water source.
2. Solutions: Depending on the cause, solutions may include relocating the drafting site to a different water source or using multiple drafting pumps to increase the water supply.

Pump Failure

1. Troubleshooting the Pump: Firefighters must troubleshoot the pump to identify the cause of the failure, such as a mechanical issue or a lack of fuel.
2. Solutions: Depending on the problem, solutions may include repairing the pump on-site or replacing it with a backup pump.

Real-World Applications and Examples

Drafting and relay pumping techniques are used in various fire fighting scenarios:

Drafting and Relay Pumping in Rural Fire Fighting

In rural areas where fire hydrants are not readily available, drafting and relay pumping are essential techniques for accessing water sources and supplying water to fire apparatus.

Drafting and Relay Pumping in High-Rise Building Fire Fighting

In high-rise buildings, where the water pressure may not be sufficient to reach upper floors, drafting and relay pumping can be used to transport water to higher levels.

Conclusion

In conclusion, drafting and relay pumping are fundamental techniques in fire fighting that allow firefighters to access water sources that are not directly connected to a fire hydrant. Understanding the basics of drafting, the equipment involved, the drafting procedure, the need for relay pumping, and real-world applications is crucial for effective fire fighting operations.

Key Takeaways:

• Drafting is the process of drawing water from a static water source and supplying it to fire apparatus for firefighting operations.
• Drafting equipment includes a drafting hose, strainer, drafting port, and drafting pump.
• Water lift and altitude can affect the performance of the drafting pump.
• The drafting procedure involves setting up the drafting site, priming the pump, and starting the drafting process.
• Relay pumping is used when the distance between the water source and the fire scene is too great for a single drafting operation.
• The capacity of pumpers and the flow rate required for the fire operation must be calculated in relay pumping.
• Common problems during drafting and relay pumping include insufficient water supply and pump failure.
• Real-world applications of drafting and relay pumping include rural fire fighting and high-rise building fire fighting.

Summary

Drafting and relay pumping are essential techniques in fire fighting that allow firefighters to access water sources that are not directly connected to a fire hydrant. This topic explores the basics of drafting and relay pumping, including the equipment involved, the drafting procedure, the need for relay pumping, and real-world applications. Key takeaways include understanding the drafting process, the importance of water lift and altitude, the steps involved in setting up a drafting site, the priming of the pump, the starting of the drafting process, the need for relay pumping, and common problems and solutions in drafting and relay pumping operations.

Analogy

Imagine you are thirsty and there is no water tap nearby. You see a pond in the distance but it's too far to reach. What do you do? You use a long hose to draw water from the pond and bring it to where you are. This is similar to drafting and relay pumping in fire fighting. Firefighters use specialized equipment and techniques to draw water from static water sources and transport it to the fire scene when a direct connection to a hydrant is not available.