The Pressure Governor Broke…Now What???

[E229Lt]

Staying off the Truckie path...(which I walked for 15 years) ...

You have three lines off your engine and the electronic pressure governor shuts down, the engine goes to idle and the three line are getting nothing but hydrant pressure and the boost of the pump at idle. The fire is far from under control and you are hit with three radio messages for... "WATER"

The rig is state of the art electronic, no relief valves, dump valves or screw throttles. You tell the poor boys inside, "we lost pressure, better back it up 'til I get it figured out". The reply is, "Give me pressure now or we're toast!"

What to do? Technology has failed us again! Give me your 60 second fix, that's all the time they have in there.

[FlyingKiwi]

Grab a spare FF or yourself, get in the cab and place boot firmly on accelerator?

[dfdex1]

Write a grant and get some new equipment!

Well I belive its NFPA somthing or other that states that you have to have a manual relief valve on the pump panel even with a automatic one. I would have someone else put there foot on the gas pedal and have you still as the pump operator.

[slackjawedyokel]

Ive always said--Them electronics and water dont
mix. And most time a fire truck has water around
it. Id try tromping the gas also--- electronics
might let her rev up--- might not.
That failing -If another engine was close-id pull
a 2-1/2 discharge off the good engine-tie it to the
pony on the bad engine-then stretch a discharge off
the bad engine and tie it to the intake on the good
engine. Ought to work--ill think about it more when im
not so tired.

[ADSNWFLD]

switch to RPM mode (the back up for most electronics) if it doesn't work many rigs can be run up with the gas pedal.

Good question, Find out now and not on the scene.

[Engine5FF]

On our rigs the gas pedal is inoperable when it is in pump gear so tromping on it won't work with us. I have never run across a pump with no manual throtle control before. That just sounds too stupid to me. Puts too much faith in technology. Don't get me wrong, I'm a former electrical engineer, it's just bad practice not to have mechanical back-ups on something that important.

[Halligan84]

The throttle seems to be an either/or proposition. We have found that if the rig goes into pump and has no throttle control the accelerator pedal works, if it swaps over properly to the pump panel, the pedal is dead. My 60 second fix is this, if im getting fed from an engine on the hydrant I ask him to max it out and pump through me, might not be all the water, but it might be enough. My second choice would be to shut down the rig and restart it. We have had alot of electronics problems cured that way. One other note on a "screw" throttle, talked to manufacturer of governors and throttle controls and they were making an electronic replica of the old vernier throttle, seemed guys were more comfortable seeing that even though it works the same as all the new ones.

[E229Lt]

I ran this scenario with some of my ECCs back in ’97 when we received our ’97 Seagrave with a Pro II Pressure Governor. Like many of you said, we found by going in the cab and stepping on the throttle, we could maintain pressure so the lines could safely withdraw.
I notified our shops of the results and was told, “that won’t work” because, indeed, the throttle pedal is disabled when switched from road to pump. A mechanic was quickly dispatched and the problem “fixed”. NO MORE THROTTLE PEDAL.

When I requested a manual throttle on the panel, I got, “no can do”. There is no mechanical connection to the electronic throttle body.

How about an override? “That could work, but if the failure is in the throttle receiver, it would do nothing” And it would be too expensive.

Could I have my old rig back?

My second choice would be to shut down the rig and restart it.

Reboot the rig, yup, this is the common answer we get for electronic failures. What if it doesn't start again, I still have three lines in the fire?

[Rescue101]

229,We've got the sister to this bi**h.Will never fail on a pi** fire but has done EXACTLY what you described on five working fires.In each case it was put a FF in the cab.Yes the foot throttle still works in ours.For the not knowing,anything late model(within 5-8 yrs)is drive by wire,no mechanical connection between throttle pedal/pump panel and fuel rail.If FRED (fabulous rediculous electronic device)says it's a no throttle day,then guess what? IT'S A NO THROTTLE DAY!On some units you can set the cruise control,the truck doesn't know if you're driving or pumping.Either way it's a bad situation.T.C.

[N2DFire]

O.K. - In an "Ideal World" (which we all know don't always exist):

1)Call an All-Out
2)Activate / Upgrade RIT to cover the evacuating hose team(s) with their hose lines (We all know that RIT always has their own hose line(s) off of a separate pumper with a separate water supply - right?)
3)Try romping the pedal in the cab also.
4)If only one of the hose teams was giving the "Water vs. Toast" message - I'd shut down the other 2 discharges in an attempt to give that team all of whatever pressure I was supplying (and direct the RIT to cover them first).
5)Call for a pumper in staging to jack a 3" line to the Aux intake and pump to me off their booster tank.
6)Shut down the hydrant, remove my supply line and stretch it to the pumper supplying me (unless also in our perfect world the hydrant was properly dressed and they could take a supply w/o shutting down - or another hydrant was nearby & reachable)
7)Request an additional alarm because a failure like this will normally send things into the crapper fast till we regroup - might be nice to have fresh troops on the way in when we regroup.

Oh - almost forgot - I would also be doing a lot of swearing & praying

Originally posted by Halligan84
One other note on a "screw" throttle, talked to manufacturer of governors and throttle controls and they were making an electronic replica of the old vernier throttle, seemed guys were more comfortable seeing that even though it works the same as all the new ones.

BINGO !!! - You would be surprised at how many "Rank & File" FF's see that same old screw handle and think it's the same old mechanical linkage. I had one guy swear up & down it was a mechanical linkage even after I showed him that the in cab throttle pedal was electronic (I was then going to open the pump panel and show him the back of the knob but realized that in the words of the Captain in Cool Hand Luke - "Some men you just can't reach")

Good Post Lt. - Make us think about stuff we take for granted.

[RyanEMVFD]

was it not Y2K compliant?

[MalahatTwo7]

First thought I had was "Hey Johnny ya wanna sit in the cab for a while, and put your foot 'right here'...."

After reading through, it came to me that ok, if the pedal is disabled when in "pump" mode, and this one would be a real bugger to make happen and again require a second pair of hands, but you could go right to the throttle box under the hood, (not sure of exact terminalogy) where the regular linkage would connect to the motor and work it by hand; assumming of course that at least that part of the truck is "normal". Of course if its all electronic fuel injection, with no "moving parts" then that wont work.

I dont know if I would have ever thought of "rebooting" the truck though, but that is a good piece of information for future reference. So it can be said "I learned something new today."

[firemanpat29]

I will check and refresh my memory but on our trucks
there is a manual lever, you can put the pump half in
gear pull the OH SH** lever and control the throttle in the
cab "Rebooting" the truck works most of the time for us.
Is your parking brake "wired" into your pump? if ours is not set
the pump will not engage. We had an air brake valve hang up
and would not let pressure build up and then pump would not
engage.

[blancety]

27,

The trucks with this electronic throttle, don't have no stinkin linkage. Everything is "by wire", no moving parts. we have been told that this is due to the changes with the motors, and the Fire Service has been forced to adapt to it. Still would rather use my 1970 Mack CF......pumps all day, pumps all night...

Dave

[Rescue101]

Malahat,buddy,yer SOL!Drive by wire is just that,WIRE,No linkage no acess no override.N2 has it pretty close,get a backup feed from another unit and push.If it ain't happenin'get ready for the attack team roaches,that is the "heated" team will do what happens when you show a roach the light.They build buildings every day,if you can't keep a firestream you won't be staying long.Modern stuff is why you should always have a staging pool nearby so you can get needed stuff quick.Another reason not to accept low bid on control components.T.C.

[FFFRED]

Although It might take a little more than 60 seconds...You could use your second or third or whatever Engine Co. that has secured its own water supply to augment the original Engine via relay pumping. Thus the POS Engine that craped out would just then be one large manifold.

All of this takes the right amount of men in the right place at the right time...and for most Depts 3 and 4 man rigs wouldn't be able to pull this off in the time frame presented.

I've also used pumps that had the so called "manual back-up" relief valve and throttle...it however was connected to the same electronics as the digital govenor relay. There for if the electronics craped out(the reason for having a backup) you would be SOL.

How come NFPA doesn't have standards against this type of spec???? How come Depts. spec this???

FTM-PTB

[HFDCLanger]

Spec'ing a manual override/throttle/relief valve could just save your butt in this case. Many departments are spec'ing these already.


Figure the standard department runs two engines and a ladder on the first alarm. One attack engine, supplying handlines (craps the bed) and one engine at the hydrant. Where does your "relay engine" come in? Is that on the second alarm from your neighbors 10 miles away? Hmmm, sounds like a good argument for a QUINT. HAHAHAHAHAHAHAHAHAHAHA.

What's that? Not worth the extra money? Never use it? How about if it saved a firefighter's LIFE? ONCE? Perhaps this is just one example of why so many departments use the "just in case" phrase when they decide to put pumps on their aerials.

Nobody needs to comment on this post. I just needed to strike while the iron was hot.

[blancety]

...and everything was going along so nicely.....

[Rescue101]

Well I'll comment.Just how exactly do you think you're going to install an override?If your problem is the ECM going to idle there is no "override"unless you want to install another complete wiring harness and ECM(Engine control module).There is no way to do this unless perhaps you could tap into the field service mode which would give you a fixed idle of say 1000-1100 rpm.When the module throws a head fit you have NO throttle control,nix nada,zippo!I know of no way currently available to overcome this problem.If the problem is the relief valve/govenor yeah maybe,if it's the module it ain't gonna happen.T.C.

[ullrichk]

Assuming for the moment that the pressure governor went south and it wasn't the ECM/throttle body, could you hit the high idle switch?

Granted high idle switches are supposed to be "locked out" when the pump is engaged, but when electronics get screwed up all bets are off. (And is the lockout still effective when the pump is manually engaged?)

It wouldn't be pretty, but you might get enough flow for the hose teams to bail out.