Evolution 1.8 — Participate in Pumping a Hydrant as the Attack Pumper

• Water supply pumper — “Pumper that takes water from a hydrant or static source and pumps it under pressure to the next apparatus in the relay pumping operation. Water supply pumpers should be the apparatus with the largest pumping capacity. Some jurisdictions refer to water supply pumpers as source pumpers.” That is the other rig.
• 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 previous pumpers in the relay.
• Fire attack pumper — “Pumping apparatus located at the fire scene that receives water from the relay and is responsible for supplying the attack lines and appliances required for fire suppression.” That is your seat in this evolution.

The task book's own objective uses the manual's word for the rig feeding you — “being supplied by source pumper at a hydrant” — while its title and setup call the same rig the “supply pumper.” The Hydraulic Manual's “Key positions in a relay operation” names only Source Pumper, Relay Pumper/Pumpers and Attack Pumper.

Engine Company Operations 2023 V-1, p.110 (5-14) · OFD Hydraulic Manual, Key positions in a relay operation

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, from the receiving end
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)

Out-of-cab steps 1 through 5 on this sheet are a transition from tank water to an external supply. The task states the case exactly:

“Transition from the water tank to an external water supply source most commonly involves the use of a pressurized source. This will be a hose-line being supplied by another apparatus or from a fire hydrant.”

Its nine-step operating procedure, in order:

1. Position the apparatus in a safe positon, and immobilize it by setting the parking brake and chocking the wheels.
2. Engage the pump, and select the proper gear in the road transmission. Lock the gear into place.
3. Open the tank-to-pump valve (if necessary).
4. Set the transfer valve to the series (to PSI or RMP) positon depending on application.
5. Increase the throttle setting to obtain the desired pressure, priming (if necessary).
6. Set the relief valve or pressure governor.
7. Open the circulator valve or partially open the tank fill valve.
8. When an external supply becomes available, open the intake valve while closing the tank-to-pump valve (if necessary). As soon as an adequate supply of water is available, divert enough of it through the tank-fill line to replenish the supply in the tank.
9. Adjust the engine throttle to achieve the desired discharge pressure (if necessary).

Step 1 is where the chock step on this page comes from.

ADO Task #19 Basic Pump Skills-Changeover, Operating Procedure for Transition to an External Water Supply, Steps 1–9

Orem's documented multi-pumper method puts the variable pressure on your rig and holds everyone behind you steady:

• Step 1: Position Attack Pumper — “Placed at a forward 'Key' attack position.”
• Step 4: all pumpers except the source pumper open a discharge to exhaust air from the lines.
• Step 5–6: source pumper throttles up to 175 psi; relay pumpers do the same.
• Step 7: all Driver/Operators set their intake relief valves.
• Step 8: “Attack pumper adjusts PDP to supply attack lines” — “Attack Pumper - adjust PDP as needed making sure to dump excess pressure.”

“Orem Fire Department uses the Constant Pressure Relay method for establishing hydraulic pressures and distances during relay operations.”

OFD Hydraulic Manual, Constant Pressure Relay (Limited Max Volume), Steps 1–8 and “Key positions in a relay operation” · Engine Company Operations 2023 V-1, p.111 (5-15)

“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. Also known as Relay Pumping.”

“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.”

The drill on this sheet is that operation at its smallest — two rigs, no relay pumper in between. Add distance or a third pumper and the Hydraulic Manual spaces relay pumpers at 750-foot intervals.

Engine Company Operations 2023 V-1, p.110 (5-14) · OFD Hydraulic Manual, Implementing a constant pressure relay operation, Step 3

Printed setup 1 sets a floor of 100' of supply hose but says nothing about how many lines. The manual does:

“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.”

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

“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 paragraph is the manual's version of printed steps 4, 6, 7 and 8 on this sheet — constant radio traffic with the other engineer, and the master intake gauge as the instrument that answers “can I add another line?”

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

The manual assigns the supply, which decides who is being supplied:

“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.”

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

The Quick Reference Guide names the same pairing by building type:

• Residential & multi-family 1–3 floors, and Commercial — 2nd Engine Company: “Pump hydrant for 1st engine if needed” — so the 1st Engine is the attack pumper.
• 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”