Evolution 1.7 — Pumping a Hydrant as the Supply Pumper

When more water is needed than a single supply line delivers, the manual ranks the options from least to best preferred:

1. Multiple supply lines from a single hydrant (least preferred)
2. Pumping the hydrant with the 2nd or 3rd due engine supplying the attack pumper — this evolution
3. Multiple supply lines from different hydrants sharing the same water main
4. Multiple supply lines from different hydrants NOT sharing the same water main (best preferred)

Engine Company Operations 2023 V-1, p.109 (5-13)

• Water supply pumper (source pumper) — takes water from a hydrant or static source and pumps it under pressure to the next apparatus. Should be the apparatus with the largest pumping capacity. That is your seat in this evolution.
• Relay pumper — receives water from the source pumper or another relay pumper, raises the pressure, and supplies the next apparatus. May be of smaller capacity, because it uses the acquired energy of the previous pumpers.
• Fire attack pumper — at the fire scene; receives water from the relay and supplies the attack lines and appliances required for suppression.

Engine Company Operations 2023 V-1, p.110 (5-14)

Forward lay (Lay-In) — hydrant to fire. The engine stops at the hydrant, "lassoes" the LDH around it, and proceeds to the fire. On a wet lead a firefighter remains at the hydrant and charges the line when the command is received; on a dry lead the hose is anchored, the hydrant bucket is left, and the crew proceeds to the fire — other personnel are assigned to charge the hydrant.

Reverse lay (Lay-Out) — fire to hydrant. The engine arrives at the fire building first, then proceeds to the hydrant. Its advantage is the reason this evolution exists: it places the engine at the source of the water, so the engine can supplement the pressure from the hydrant to the engine parked in front of the fire. In the supply evolution, the LDH is connected between the suction (intake) side of the pump and the hydrant.

Engine Company Operations 2023 V-1, pp.103–106 (5-7 to 5-10)

Orem's primary hydrant type is dry-barrel. The standard hydrant carries one 4½" (steamer) outlet and two 2½" outlets.

• Double 2½" hydrant — two 2½" outlets, fed by a 4" main. Expected flows are less than 600 gpm. Recognize this low-flow hydrant on sight before you commit the supply operation to it. p.100 (5-4)
• Once a dry-barrel hydrant is charged, no additional lines may be added to the other outlets unless the hydrant is shut down, or a shut-off valve was added prior to charging — opening the stem valve supplies all outlets at once. p.98 (5-2)
• Multi-outlet dry-barrel hydrants must have a 2½" hydrant gate valve attached to an unused outlet at the onset of ANY hydrant operation — before you charge, not after you need it. p.98 (5-2)
• Stem valves open counter-clockwise — "Open-Left." p.101 (5-5)

Engine Company Operations 2023 V-1, pp.98–101 (5-2 to 5-5)

"A single 5-inch line may not flow all of the available water from a hydrant and/or water main. Provide one 5-inch hose line for every 1000 gpm to be delivered."

Two more of the manual's basic hydrant flows bear on which outlet you take:

• "A 2.5″ hydrant outlet will delivers approximately 80% of the flow of a 4.5″ outlet."
• "A 4.5″ hydrant outlet with a flow pressure of 15 psi = 2100 gpm"

Engine Company Operations 2023 V-1, p.101 (5-5)

The decision first, then the seat:

"The first arriving Engine Company Officer will make the determination for the need for water supply or communicate that responsibility to the second arriving Engine Company. In either case that information is transmitted from the first arriving to the second arriving Engine Company."

"The Engineer of the second arriving engine is assigned to supply the first engine, this should be accomplished without placing their apparatus at the front of the fire scene. This is best accomplished by laying a supply line away from the first engine, spotting the second engine at the hydrant, connecting to that hydrant, and supplying the first arriving engine."

Engine Company Operations 2023 V-1, Ch.1 (1-10 to 1-11)

The Quick Reference Guide assigns it the same way, and names the engine by building type:

• Residential & multi-family 1–3 floors, and Commercial — 2nd Engine Company: "Complete water supply, Pump hydrant for 1st engine if needed."
• Mid rise, 4 floors and above — 3rd Engine Company: "Pump hydrant for 2nd engine."
• Mid rise and Commercial — 5th Engine Company: "Complete water supply, pump hydrant for 4th engine if needed."

OFD Quick Reference Guide for Initial Company Operations, May 2024 — which states it "is a quick reference document and is not designed to override or replace understanding of the full applicable Manuals"

"The Engineer must recognize the need for and initiate supply line operations when required. When arriving other than first due, the Engineer must remain aware of water supply needs of units already on the scene."

Engine Company Operations 2023 V-1, Ch.1 (1-9)

"In order to establish and maintain proper pumping pressures, all Engineers must know how many hoselines, the size and length of the hoseline, the type of nozzles being used, and their flow. It is imperative that the Engineer listen closely to the radio at all times for traffic concerning charging, shutting down or adjusting hose line pressures on hose lines. They should also monitor the residual pressure of the pump master intake gauge to determine the capability of supplying additional volumes when available or as needed."

That is the manual's version of printed steps 2, 5 and 6 on this sheet — constant radio traffic between the two engineers, and the intake gauge as the thing you read to answer "can I give them more?"

Engine Company Operations 2023 V-1, Ch.1 (1-11)

"Using two or more pumpers to move water over a long distance by operating them in series; water discharged from one pumper flows through hoses to the inlet of the next pumper, and so on."

Two rigs 100′ apart is the smallest case of it. Add distance or another pumper and the same drill becomes a relay:

"A relay pumping operation consists of a pumper positioned at the water supply source that is used to pump water under pressure through one or more supply lines to another pumper connected further down the supply line(s). This pumper boosts the pressure to supply the next pumper and so on until water reaches the attack pumper. In order to be effective, relay operations require pre-planning, training, and coordinating of all participants."

Engine Company Operations 2023 V-1, p.110 (5-14)

"Orem Fire Department uses the Constant Pressure Relay method for establishing hydraulic pressures and distances during relay operations. For more specific information see the current APPARATUS DRIVER / OPERATOR HYDRAULIC CALCULATION STANDARDS in Target Solutions."

Engine Company Operations 2023 V-1, p.111 (5-15)