The explosion of new technology has dramatically benefitted the fire service, in this article Daniel Mack explains how thermal imaging cameras, and electronic vehicle and pump controls, have enhanced our firefighting capabilities and our safety. Nevertheless, the most important resource we have for fighting fire is also the most low-tech: WATER. The saying “Put the wet stuff on the red stuff” still holds true. And, “Put the wet stuff where the red stuff wants to go” is equally true, as at times exposure protection is more important than trying to extinguish the fire itself. When it is not possible to extinguish the fire rapidly with initial resources, our water supply may be better used to protect threatened exposures such as tanks or expensive processing infrastructure. But, how do we get ENOUGH water to WHERE we need it most, and WHEN we need it most? Large Diameter Hose (LDH) is often the answer.
LDH and volume
There are many advantages to using LDH to move high volumes of water over a long distance. Obviously, the larger the diameter of hose, the greater the volume of water per foot or meter of hose. (In the right circumstances, 5-inch LDH can flow the equivalent of three 3-inch hoses.) Equally or more important is the dramatic reduction in friction loss as hose diameter increases. Less pressure is needed to move substantially more water. Five-inch LDH can deliver 1,000 GPM with only a 6-psi loss of pressure per 100 feet, or 1,500 GPM with only a 15-psi loss. The ability to deliver massive volumes of water with 6”, 8”, and 10” LDH is even more impressive.
Enhancing water supply and providing backup
In the industrial sector, we often have fixed fire protection and water delivery systems designed following strict engineering guidelines. But fire will often surprise us. Petrochemical fires are often accompanied by explosions that can destroy infrastructure, including water supply systems. LDH allows us to get water where we may not have it but need it, or where we need more than a fixed system can supply. Additionally, it provides a backup system to deliver high volumes of water when distribution systems are disrupted.
Deployment, retrieval, and storage
To benefit most from LDH (especially of very large diameter), we must be able to quickly place the hose where it is needed most, and be able to easily retrieve it after the fire (or even during the fire if it must be relocated to where it is needed more). Although smaller diameter LDH can be manually loaded back into vehicles, larger diameters require mechanical retrieval systems. We also must store the hose so that is quickly available when needed. Hose tenders (trucks, trailers, or both) with the ability to carry and efficiently deploy large amounts of LDH, and equipped with specialized loading equipment, are critical to success.
Final considerations
Implementing an LDH program can be expensive. But costs can be justified when we consider ways LDH can pay for itself. Having enough water available can be the key to saving very expensive infrastructure and product. It can dramatically reduce the impact an uncontrolled fire can have on plant operations and the environment (which may be more costly than the loss of infrastructure and product). LDH systems can be purchased in phases (spreading the total cost over several years) or can be joint purchased by various facilities within a region.
When purchasing an LDH System, consider: Where and what are our vulnerabilities? What are our needs (consider worst case scenarios)? What diameter hose best meets those needs? And, what water sources and equipment are available to supply our LDH? After answering these questions, we can select components for our ideal system. A final question to consider is: What companies can provide a “one-stop” solution (hose, deployment-retrieval-storage vehicles, and support)? Working with a single company reduces the risk that the components of our system will not work together and function properly in time of an emergency.
LDH will continue to have a positive impact on the fire service. Will we take advantage of this technology and be better prepared to respond to an alarm? Our answer can mean the difference between success and failure.
For more information, go to www.chief-fire.com
