Evolution 1.4 — Place the deck gun in service while flowing additional hand lines

The majority of structure fires an engine company meets can be handled with hand lines. On some occasions there is a fire that cannot be controlled by hand lines and requires the engine company to deliver large quantities of water from a great distance.

By most definitions, any stream greater than 350 gpm that requires mechanical assistance for handling is a “master” stream — also called large-caliber streams (LCS). They may be portable (“ground-based”), elevated (ladder pipes and nozzles on elevating platforms), or mounted atop the engine apparatus itself — which is what the deck gun is. They are deployed in situations, usually defensive, where the fire is beyond the ability of hand lines to control, or where a fire stream is needed in a location no longer safe for department members.

Engine Company Operations 2023 V-1, p.133 (7-1)

Master stream operations require a coordinated effort from the companies operating on scene, one of which is ensuring that all department members have been backed out of the building prior to flowing any master stream or elevated ladder pipe. That is the STOP above, and it is not specific to the ladder pipe — the deck gun is covered by the same sentence.

Engine Company Operations 2023 V-1, p.133 (7-1)

• There is an increased likelihood that the higher flows will knock debris loose from the building, sending it through the air to strike people or apparatus.
• Operating in the portable mode, the master stream has a limited side-to-side range. Turning the nozzle too far left or right may cause the base to become unstable and tip over.

Engine Company Operations 2023 V-1, p.133 (7-1)

When master streams are placed into service it generally means interior offensive operations have been abandoned and a defensive posture is being employed. The device must be properly positioned to provide an effective stream: once the line is in operation, it must be shut down to be repositioned.

The safest exterior positions are at the corners of the building. Setting a master stream up in front of the building — whether operated from the top of the engine or from the ground — is a dangerous and ineffective tactic: the firefighters operating the stream are in the collapse zone and may not have enough time to react to a sudden collapse of an exterior wall.

Should a master stream have to operate from the front, it should be set back far enough that it will not be struck by falling walls or debris. The widely accepted figure is a collapse zone of one and one-half times the height of the tallest exterior wall — a store front with a 20-foot wall gets a 30-foot collapse safety zone, and the further the better.

Engine Company Operations 2023 V-1, pp.133–134 (7-1–7-2)

A drawback with deck gun nozzles that sit as much as nine to ten feet above the ground is a dramatic loss of effectiveness at low-angle operations. Take the positioning limits imposed by a narrow street, combine them with the height of the deck gun above the ground, and most of the water is wasted — the stream hits the floor only 25 to 30 feet inside the structure.

A limiter pin prevents the nozzle from being rotated too low.

Engine Company Operations 2023 V-1, p.134 (7-2)

The most effective operation in the use of the pre-connected deck gun is to direct a quick application of high-pressure water through the window to knock down the heavy fire while other members get a hand line into position by whatever means available. Faster fire control means increased life safety for civilians and firefighters. That is the objective of this evolution, in the manual’s own words.

At upper-floor operations the stream angle reduces the chance of “pushing” the fire through the compartment and out into the hallway: most of the water strikes the ceiling of the fire compartment and coarse droplets rain down on the burning contents. The penetration of deck gun streams decreases as the stream angle increases.

Employing a smaller tip than normally used with a deck gun, and limiting the application of water, further reduces the danger of forcing fire out of the compartment of origin. A 1½-inch tip is used to generate the high-velocity pressure necessary for reach and to conserve water.

Engine Company Operations 2023 V-1, p.135 (7-3)

The Stinger is a dual-purpose break-apart monitor that can be used as a deck gun or as a portable monitor. It is mounted to a plumbed outlet on top of the engine with the nozzle assembly attached; because it is plumbed it can be placed into operation rapidly without having to run a supply line to it. Based on the tip in use, the Stinger can deliver up to 1,250 gallons per minute.

A disadvantage of using the Stinger in the deck-gun configuration: it may require the engine to be parked in close proximity to ensure proper reach, placing the apparatus in a potentially dangerous position.

Engine Company Operations 2023 V-1, p.136 (7-4)

The two components that make up the monitor are the nozzle and the base. The nozzle is typically a combination fog nozzle, or a stacked set of smooth bore tips varying in size and gpm delivery — which is what the drill setup means by “utilize different smooth bore tip sizes.”

The nozzle assembly is the upper portion of the deck gun. Either a combination nozzle or a stacked tip set attaches to the nozzle assembly pipe. The assembly also carries a hand wheel for adjusting the angle of the tip and an in-line pressure gauge, and it can be affixed to either the engine or the portable base.

The base is a lightweight portable stand with folding legs for stability and a single 5” LDH inlet. Normally stored in the rear compartment, it can be set up at any desired location, removing the dangers of the fire from the apparatus and from firefighters working nearby. To use it: set up the base, remove the Stinger from the engine, and stretch the LDH supply line.

Engine Company Operations 2023 V-1, pp.136–137 (7-4–7-5)

This evolution asks the hydrant to carry the deck gun and then a 2½” hand line as well. Two operative water-supply figures:

• A double 2½” hydrant — two 2½” outlets on a 4” main with no steamer — should be expected to give less than 600 gpm.
• Provide one 5” supply line per 1,000 gpm to be delivered.

The manual’s own reason for reaching for a smaller deck gun tip is reach and conserving water (p.135 / 7-3), not a supply calculation — but a Stinger that can take up to 1,250 gpm and a hydrant expected to give less than 600 are numbers worth having in your head before you open the discharge.

Double 2½” hydrant flow: Engine Company Operations 2023 V-1, p.100 (5-4). The one-5”-line-per-1,000-gpm figure is published per the 2026-08-29 ruling on chapter 5’s flow list; the remaining bullets in that p.101 (5-5) list are a known error in the manual and are not published here.

Transition from the water tank to an external supply most commonly involves a pressurized source: a hose line supplied by another apparatus, or a fire hydrant.

• Purge the air first. Air in the empty supply hose causes problems if it enters the pump while the pump is supplying attack lines under pressure. Open the bleeder valve on the gated intake so air escapes as the line fills; close it when all the air is out. The water is then at the pump and ready for the transition.
• Open slowly, watching both gauges. Open the intake valve from the supply line very slowly while observing intake and discharge pressure, adjusting discharge pressure as you go until the intake is completely open. It may be necessary to adjust the engine throttle to get the desired discharge pressure.
• Then close tank-to-pump. After the intake valve is open, the tank-to-pump valve can be closed — but the tank-fill valve should be left partially open until the tank has refilled. A full tank is a limited reserve if the external supply is lost unexpectedly.

ADO Task #19, Basic Pump Skills — Changeover (Transition to an External Water Supply)