MORE ON TOWER LADDERS, PART 2
TOM BRENNAN
We continue our focus on this most important piece of firefighting apparatus. We are talking about some smart stuff that will make operations more efficient and successful and some dumb stuff that is a waste of time in the best case and that will put your apparatus out of service for up to one year in the worst case.
Some more dumb stuff is the practice of installing a globe or gate water shutoff valve for the large-caliber stream at the end of the telescoping water line–in the bucket. This gimmick is just a money-maker for those who sell it to you.
Let`s review some basics. Once you start a tower stream, you sure had better shift the strategy on the fireground (fire building) from offensive to defensive. Interior operations in that division, sector, exposure, or building itself have been halted, and a timely and orderly withdrawal of troops and equipment has progressed to a point where a tower stream will hurt no one and nothing but the home of the devil. Once water has started and has been augmented and is progressing in an orderly and objective manner across the face of the building on which it is located, there should never be a reason for an emergency shutdown at the nozzle location in the bucket. There should never be a need to shut down any large-caliber stream at the point of delivery. None. Tower streams, as well as any stream delivering more than 300 gallons per minute, should be shut down at the source of water supply, if possible. The emergency shutdown location for tower ladders is located at the gated inlets to the tower and are operated by the firefighter on the turntable.
Water is basically incompressible (those of you who remember hydraulic theory and calculations instead of digital numbers know what I am talking about). If you shut the tower stream by a gate valve in the bucket and you effectively create a solid pipe from the source of supply to the nozzle at a “fixed” length where the bucket is located at that precise point, and if you shut down slowly, you can argue that water hammer is not a problem and be correct. However, if you move the tower in any fashion that effectively reduces the length of the extended waterway, retract, that water has to go someplace. Where?
Correct! Out of the waterway. You rupture the hydraulic seals on the extending waterway or, worse, you rupture the conduit itself. Parts must be ordered, the truck must be transported, the aerial must be taken apart to get at the waterway, and more. You are out of service for at least six months.
Another reason for not even thinking of putting this valve in the specification is for my brothers in the North. Water not moving will freeze in winter. If it is a handline that you must leave at the scene, you will have a snickering reputation for the season. But if it is the tower ladder that must remain at the scene for thawing operations (hopefully, before the waterway splits), you will have a reputation for your entire career (build a thousand bridges … ), and the department will have an epic story to tell long after you are gone.
The answer is simple: Do not install a stream shutdown in the tower. Do not allow the decision to shut down this all-too-powerful stream to be made in the bucket!
More good stuff. Mount some tool holders inside the bucket`s railing, but keep them out of the operation arc. Actually, a four- to six-inch plastic conduit will do nicely. Mounts should be designed for the storage of short tools–axes, halligan tools, and the like.
Another good idea is to place a tested safety cable on which substantial objects with fastening devices attached can be stored across the rear of the bucket area. This is a great place for hooking onto and for storing the ladder belt or safety belt. It gets a little shaky up there at 100 feet, especially if your partner lowers the bucket without warning you or lets go of the controls while rotating.
It is also helpful to have a portable wooden work platform fit onto the rails in front of the bucket. It provides an excellent work station for removing façade on a structure or for any other task involving the use of heavy cutting and prying power tools. If you have found that you have no place to put your arms for a rest, you know what I mean.
Stupid stuff. Mounted stokes baskets located routinely in the bucket are a joke. But someone makes the hardware and will sell it to you. If you need the stokes, take it with you. No one needs a stretcher with the same speed that hoseline placement is needed.
More dumb stuff seen in my state is the installation of an electrical induction safety circuit–a wire held by insulators some great part of a 12-inch ruler out from the perimeter of the floor of the basket. It is then interfaced with the electrical controls for operating the bucket itself and shuts down any movement of the tower. It is there to pick up magnetic flux lines from current flow in high-voltage power lines. With that installed, the closest the base of the bucket can get to the building openings is in excess of one foot. This is a ridiculous restriction for our operations inside fire buildings, for our access to elevated exposed locations, and certainly for our ability to remove victims found in conscious panic or unconscious dead weight–not to mention an emergency exit for our firefighters when the “fan” gets hit.
When considering where to mount tools, equipment, storage boxes, and the like, remember that anything mounted on top of or out from the profile of the apparatus as it was delivered to you will compromise the ability to position the boom at optimum locations. Saw boxes and hose containers on top of the compartments under the boom or ladder assembly are just what I`m talking about. The top of the cab is another location that gets overloaded.
TOM BRENNAN has more than 35 years of fire service experience. His career spans more than 20 years with the Fire Department of New York as well as four years as chief of the Waterbury (CT) Fire Department. He was the editor of Fire Engineering for eight years and currently is a technical editor. He is co-editor of The Fire Chief`s Handbook, Fifth Edition (Fire Engineering Books, 1995). He is the recipient of the 1998 Fire Engineering Lifetime Achievement Award.
