By William C. Peters
The following quote was taken from the National Institute for Occupational Safety and Health (NIOSH) Web site and outlines its mission as it relates to firefighter safety: “The National Institute for Occupational Safety and Health (NIOSH) Fire Fighter Fatality Investigation and Prevention Program (FFFIPP) conducts investigations of fire fighter line-of-duty deaths to formulate recommendations for preventing future deaths and injuries. The program does not seek to determine fault or place blame on fire departments or individual fire fighters, but to learn from these tragic events and prevent future similar events.”
I was part of the NIOSH team investigating the accident described in this article. Hopefully, the fire service can learn that this has happened before and could happen again in almost any fire department in this country. Proper training, standard operating procedures, practice, and possibly some engineering changes on the apparatus could keep this from happening to you.
Although I was part of the NIOSH investigative team and my input will be part of the final report, the findings and recommendations in this article are mine alone and do not necessarily represent the views of NIOSH.
Visit the NIOSH Web site at www.cdc.gov/niosh/fire/ to see volumes of information on NIOSH firefighter programs and reports of firefighter fatalities that have been recorded. We can all learn from others’ past mistakes.
THE ACCIDENT
On April 8, 2008, a volunteer fire company responded to a working fire outside an industrial facility that was extending into the building. The deputy chief (incident commander, or IC) ordered a defensive attack with a two-inch handline followed by an aerial master stream.
The apparatus was positioned near a “yard hydrant” being fed by the facility’s fire pump at 150 psi. The truck was manufactured in 1994 and had a 75-foot, three-section aerial ladder with a “pinnable” waterway. A probationary firefighter with limited experience climbed the bedded ladder and moved the pin from the rescue mode (attached to the second ladder section) to the aerial master stream mode at the fly. Another firefighter raised and extended the aerial and noticed that the waterway stayed at the second section but was unaware of the probie’s previous actions.
When the aerial waterway was charged, witnesses reported hearing air exiting the nozzle followed by the monitor mount’s sliding toward the tip at a rapid pace and disconnecting from the fly section. The monitor/nozzle mount and the last section of the waterway pipe struck the deputy chief on the ground, injuring him fatally. The waterway pin was found on the ground in front of the truck after the accident.
APPARATUS AND COMPONENT CONFIGURATION
The unit involved is a 1994 custom fire apparatus with a rear-mounted aerial ladder with a 1,000-gpm waterway and 1,750-gpm single-stage fire pump.
Pump pressure is controlled by a hand throttle that adjusts the diesel engine rpm and a combination relief/dump valve. When the pump operator sets the desired pressure on the panel controller, the unit attempts to maintain the pressure first by recirculating water from the discharge side of the pump back to the suction side. If the pressure still exceeds the setting, a dump valve opens, relieving pressure to the atmosphere.
The six-inch pump intake on the right-side pump panel had a piston intake valve with a built-in relief valve installed. The valve opens by turning a crank wheel to introduce water into the fire pump. The relief valve is on the incoming side of the main valve and has a plunger that opens against spring pressure to relieve excess incoming water to the atmosphere. The valve setting could not be specifically determined, but it was between 100 and 150 psi (photo 1).
 (1) The piston intake valve on the right pump panel with the relief valve below. (Photos by author.) |
The single-stage centrifugal fire pump produced 45 psi at idle.
The aerial device is a 75-foot, three-section ladder constructed of welded steel components. The ladder is mounted to a turntable at the rear of the apparatus that allows it to rotate 360 degrees. All aerial ladder movements are performed hydraulically.
The aerial has a three-section, telescoping aluminum waterway mounted under the ladder. Several swivels at and through the turntable feed water to the waterway. Water can be introduced into the waterway system directly from a four-inch intake at the rear of the apparatus or from a discharge valve connected to the fire pump.
At the fire pump, an electrically controlled valve is plumbed into the waterway at the rear of the apparatus under the turntable. The operation of this valve was tested, with an average time of 7.45 seconds to move from fully closed to fully open. This valve can be “throttled” between open and closed, restricting the amount of flow to the waterway (photo 2).
 (2) The electric valve control at the pump panel directs water from the fire pump to the aerial waterway. |
In the waterway under the turntable, a pneumatically operated on/off valve controls the water to the waterway from either source (photo 3). This valve is controlled by a protected switch on the rear of the apparatus and is either on or off. Directly above the valve is a waterway relief valve, which relieves any excess pressure to protect the waterway seals when the system is charged.
 (3) The air-actuated water valve directly under the ladder turntable. A relief valve is located above the pneumatic valve to protect the waterway from overpressurization. |
At the rear step there is an aerial waterway flowmeter and pressure gauge. Another aerial flowmeter is located on the pump panel (photo 4).
 (4) The waterway pneumatic valve control switch, flowmeter, and pressure gauge. |
At the end of the waterway, a manufactured “slider” holds an electronically controlled monitor and electronically controlled 150- to 1,250-gpm automatic nozzle. The monitor allows the nozzle stream to be directed side to side and up and down. The nozzle is of the “automatic” type, which has a variable orifice controlled by spring pressure that maintains a 100-psi nozzle pressure over the rated flow of the nozzle. When the pressure is low, the orifice is near closed; as the pressure increases, it opens up. This maintains a workable fire stream for all conditions. The nozzle also has a motor-driven control to change the pattern from straight stream to a wider spray pattern (photo 5).
 (5) The 150- to 1,250-gpm electrically controlled automatic nozzle attached to the monitor. |
A spring-loaded wire reel is mounted to the right side of the aerial bed section with a captive four-roller guide mounted to the tip of the second section. A multiconductor electrical cable is deployed from the reel, through the guide, to the control box on the right side of the monitor assembly to provide remote control capabilities of the monitor position and the nozzle spray pattern.
The “slider assembly” is a heavy steel structure built by the aerial manufacturer to support the end of the third section of the waterwaythe monitor assembly and the nozzle. It is suspended under the ladder by four C-shaped hangers that capture the lower rail of the fly section of the ladder. Nylatron® pads are installed on the hangers to reduce friction and to allow the ladder to slide through the hangers (photo 6).
At the rear of the slider is a flat pin receiver plate with two reinforced holes in it (photo 7). When the ladder is bedded, these holes line up with corresponding holes in the fly section and the second section of the aerial ladder. If the fire department wants to keep the waterway at the second ladder section, to allow the fly section to remain clear for rescue purposes, a heavy steel pin with detent ball is inserted in the lower hole. As the ladder is extended, the fly section passes through the four hangers, leaving the monitor at the second section. If the intended purpose of the operation is to supply an aerial master stream from the tip of the fly section, the firefighter would remove the pin from the lower hole and insert it in the upper one (photo 8). The pin would capture the fly section, and the slider assembly and the aerial would move as one unit. The pin MUST be inserted in one hole or the other. The fire department in question routinely rode with it in the lower position.
 (7) The pin receiver attached to the rear of the slider (inverted). |
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NFPA STANDARD COMPLIANCE
The NFPA standard that governed the construction of aerial apparatus in 1994 was NFPA 1904 (1991), Standard for Aerial Ladder and Elevating Platform Apparatus. An examination of the apparatus indicated that the components of the aerial water delivery system were in compliance with the standard. The waterway requirements were as follows:
- 1,000-gpm monitor.
- 1,000-gpm nozzle.
- A relief valve in the waterway.
- A flowmeter.
- A 11⁄2-inch drain valve.
The pump section of the same standard required that any discharge outlet valve three inches or larger have an operating mechanism that will not permit changing the position of the flow-regulating element from full close to full open, or vice versa, in less than three seconds.
These items were all compliant on the apparatus involved.
CONDITIONS FOUND ON INSPECTION
After the accident, the apparatus was taken to an impound facility along with the waterway, which was transported on a trailer. It was secured and access was restricted only to personnel authorized by the district attorney.
An inspection of the apparatus components pertaining to the accident was as follows:
- A piston intake valve, with pressure relief, was located on the right-side steamer connection. The valve was in the closed position.
- The pump pressure control (relief valve) was set between 250 and 300 psi.
- The electrically controlled waterway supply valve on the pump panel was closed.
- The pneumatic waterway supply valve at the rear of the apparatus was open.
- The waterway drain valve was closed.
- The waterway (on the trailer) had the following characteristics:
- a. The nozzle at the tip was aimed to the right of center and up.
- b. The nozzle at the tip was broken. The orifice plunger was in pieces and held as evidence by the state police.
- c. The monitor housing was cracked (photo 9).
- d. The waterway pipe was curved to the right and up when the unit was placed in a normal position. It appears that this may have been caused when the monitor control cable reached the end of its travel and pulled the pipe up and to the right (photo 10).
 (10) From this view, the waterway is inverted. Notice that the end of the tube is bent up and to the right. |
- e. The waterway pin was secured by the state police and showed no evidence of damage or deformation (other than the pull ring, which several witnesses stated was always in that condition) (photo 11).
 (11) The waterway pin. |
- f. The holes in the slider assembly and in the two ladder sections showed no evidence of damage or deformation (photo 12).
 (12) The pin holes in the top of the slider receiver assembly show no evidence of damage or deformation. |
RECONSTRUCTING THE ACCIDENT
The following chain of events was based on several eyewitness accounts and the examination of the apparatus and equipment.
On the day of the fire, the unit initially responded with four firefighters. The deputy chief was the officer in charge, the engineer drove, and one veteran firefighter and one probationary firefighter rode in the crew cab. Plant personnel notified them en route that there was a working fire and not just an automatic sprinkler alarm.
When they arrived on the scene, the engineer was told to pull past a yard hydrant and set up for a defensive attack. The deputy chief assumed command of the fire. The firefighter in the crew cab pulled a length of four-inch hose from the hosebed and stretched to the hydrant. While she attempted to remove the four-inch cap, an on-scene firefighter working at the facility pulled a two-inch preconnected hoseline and called for it to be charged. The engineer did so using tank water.
The probationary firefighter asked the deputy chief if he should switch the pin on the waterway and was told to do so. He went up on the bedded aerial, removed the pin from the lower position, and placed it in the upper position to attach it to the tip of the fly. He then climbed down and assisted the firefighter on the handline.
At the hydrant, members were having great difficulty removing the four-inch cap. They used a mallet and a second hydrant wrench to try to loosen it. The firefighter and engineer were joined by a firefighter/EMT who was assisting. They decided to connect to the 21⁄2-inch hydrant discharge using an adapter. After they established the connection to the hydrant and the pump, the EMT opened the hydrant.
A chief officer arrived in his privately owned vehicle and spoke to the IC, asking what he needed. He responded that he needed the aerial up. The chief first connected the hydrant line to the piston intake valve and bled the air after the hydrant was charged. He then proceeded to set the ground pads and deploy the apparatus stabilizers with the assistance of one of the firefighters who arrived on the truck.
The engineer noticed when the hydrant was opened that he had 200 psi of pressure on the discharge side of the pump. The hydrant had a 150-psi residual pressure, and the pump added at least 45 psi. He returned the throttle to idle, gated down the handline that was operating on the fire to 80 to 100 psi, and opened his tank fill. He asked the firefighter who was assisting with the truck setup to partially close the intake relief valve, which she did. The pressure was still too high, so she closed it more. Then, on the engineer’s instruction, she turned it off completely, and he went back to using tank water. He then asked her to open it, which she did. The relief valve on the piston intake valve was reported to be discharging water the whole time.
The chief went to the turntable to operate the ladder. He raised it out of the bed to 60° elevation, rotated it to the right, and extended it to 67 feet (photo 13). Both the engineer and the firefighter on the ground questioned why the monitor was at the second section. The chief said it was “okay,” as he could still reach the fire with the stream. Since the apparatus was in pump mode, the aerial high-idle control was disabled. He felt that it would take too much time to take the aerial down to relocate the pin. He was unaware that the probationary firefighter attempted to relocate the pin earlier and thought that the monitor remained pinned in its normal travel position.
 (13) The truck is set up at 60° elevation and 67 feet of extension, as it was on the day of the accident. |
The chief called the IC and asked if he was ready for water. The initial response was to “wait,” and then he called for the ladder pipe to be charged. He adjusted the monitor nozzle position to the right and up in anticipation of an attack on the fire.
The engineer activated the waterway electric valve control on the pump panel but did not get a flow. He closed the valve and went to the rear of the truck, where he found the waterway pneumatic valve closed. He activated the switch to open it and returned to the pump panel. The second time he activated the waterway valve, witnesses reported hearing the rush of air and the sound of water rising in the pipe.
When the water column collided with the restriction in the monitor and the partially closed automatic nozzle, the waterway pipe became a large hydraulic piston. With nothing to contain the slider, it was propelled up the ladder rails at an estimated 30 mph toward the tip.
All accounts of the ladder pipe failure are consistent. As water started to discharge from the nozzle, the monitor traveled at a rapid pace toward the end of the ladder, where it separated from the aerial and was “launched” toward two members standing on the ground. The ladder pipe and monitor assembly, with an estimated weight of more than 200 pounds, struck the deputy chief fatally and knocked the other member to the ground. Lifesaving measures were attempted, without success.
A firefighter who arrived on another apparatus and did not witness the accident was walking toward the ladder truck and discovered the waterway pin on the ground approximately one to two feet in front of the truck. He picked it up and placed it on the bumper.
The state police were notified; opened an investigation; and impounded the truck, the waterway, and all evidence at a secure facility.
CAUSE OF THE ACCIDENT
Since the pin that was supposed to hold the monitor assembly to the ladder was found on the ground in front of the truck after the incident, the only conclusion that can be reasonably reached is that it was improperly installed.
Several members interviewed indicated that the pin was generally difficult to remove and replace in the holes because of the misalignment of the moving components. Some told of hitting the pin with the rubber mallet to seat it in, and others said that they were trained to take the “lady finger” bar up on the aerial. The flat end was used to pry the pin out of one hole and the pointed end of the bar was inserted into the other hole to align the ladder and slider holes, allowing the pin to be inserted through them. The probationary firefighter told interviewers that the pin came out and went in without a problem (photo 14).
 (14) The “lady finger” pry bar often used to pry out the pin with the flat end and align the holes with the pointed end to insert the pin. |
When this truck was built, most manufacturers secured their pinnable waterway by the same method with a single pin. Some have since gone to a lever-type device that secures the slider to plant personnel the fly or the second section. Although this appears to be a safer method of securing the device, it is not “fail-safe,” and there are many pin-style units in use today.
Considering that the single pin design could easily result in a failure because of human error, questions were asked as to why there were no stops at the end of the fly section to prevent the slider from coming off. Three aerial manufacturers contacted indicated that they felt that the waterway traveling at high speed up the aerial and striking a rigid stop might cause serious damage to the aerial device, possibly leading to ladder failure or knocking a firefighter off the tip.
Two manufacturers indicated that they do add stop blocks, but the result of hitting them with the slider under pressure is unknown.
POSSIBLE CONTRIBUTING FACTORS
The following conditions could possibly have been contributing factors to the accident:
- Initially, the deputy chief and the probationary firefighter were away from quarters on an unrelated detail. When the alarm was received, they had to return to the firehouse, park the original unit, and mount the apparatus that was responding to the call. The delay, combined with the knowledge that they were responding to a confirmed fire, may have increased the anticipation and stress factor.
- There was a delay getting water to the apparatus because of the “frozen” hydrant cap. This could have added to the stress of the members operating around the apparatus.
- Five different individuals took part in setting up and operating the apparatus for the defensive attack.
- A probationary firefighter with just three months of service with this fire department and limited experience assumed the critical task of pinning the waterway.
- The aerial ladder operator arrived on the scene later and was unaware that anyone had touched the pin, assuming that the monitor was secured in the travel mode at the second section.
- The motion of the aerial was slow because of the high-idle interlock (in pump), which discouraged the operator from returning the aerial to the bedded position to change the position of the pin.
- The yard hydrant delivered water at an unusually high pressure (150 psi). In addition to the 45 psi developed initially by the pump at idle, a pump pressure of nearly 200 psi was delivered to the waterway when the valve was opened.
- When the waterway was “launched” from the ladder, it appeared that the monitor control cable pulled it to the right and up, possibly redirecting it to where the victim was standing (photo 15).
HISTORY OF WATERWAY ACCIDENTS
In addition to the accident described in this article, research has revealed at least the following waterway accidents have occurred:
- New Jersey: A waterway dislodged; no injuries
- Michigan: A waterway locking lever was not fully engaged; the waterway pipe and monitor launched into the fire building.
- Ontario, Canada: The waterway locking lever was disengaged by a firefighter with the ladder up. When the waterway was charged, it caused damage to the pipe and monitor.
- Texas: Two incidents of waterway and monitor damage occurred after being charged without the pin properly installed.
Three different manufacturers were involved in these incidents.
PREVENTIVE MEASURES
The first preventive measure is to properly train and practice the correct method of pinning the waterway. I cannot overemphasize this. Be certain that any member who is involved in changing the configuration of the waterway understands the serious consequences of improper pin placement.
Fire trucks have many required warning labels applied at various locations. A warning label at the waterway activation control might remind the operator to check the pin before activating the pipe.
If the fire department has a single pin waterway, check with the original manufacturer to see if a safer, updated design is available and if it can be retrofitted on the aerial. There might be issues with clearances and equipment interference, making this impossible, but if it is available it would be well worth any costs involved.
A suggestion was made that the manufacturers might explore the addition of a limit switch interlock to prevent the aerial waterway from being charged without having the monitor properly secured. If not an interlock, perhaps a warning light at the waterway control valve (similar to the “Throttle Ready” light) indicating a properly secured monitor could help avoid another tragedy.
William C. Peters retired after 28 years with the Jersey City (NJ) Fire Department, having served the past 17 years as battalion chief/supervisor of apparatus. He served as a voting member of the NFPA 1901 apparatus committee for several years and is the author of the Fire Apparatus Purchasing Handbook, the apparatus chapters in The Fire Chief’s Handbook, and numerous apparatus-related articles. He is a member of the Fire Engineering editorial advisory board and of the FDIC executive advisory board.
