It does not take a rocket surgeon to realize a very hot exhaust manifold plus preheated oil equals a big concern. I have never had a machine burn down but will admit it scares me. We bought an older machine where replacing all the hoses is pretty cost prohibitive. I would hope that my daily inspections could catch a growing hose concern (bulging) but I realize some hoses do not give much warning. I am curious how common this really is and in the event of a broken hose, if it usually lights up? Also, I am curious if there are any extinguishers that are preferred to have in the cab since I could only assume that the best protection and chance of saving a machine is the operator hosing things within seconds.
Just a thought. How expensive would it be to re-hose just the engine compartment ..? Often there is a metal firewall between the engine and the hydraulic pumps that ought to prevent hot hydraulic oil getting on to the turbo/exhaust manifolds in the case of a hose failure. If you do nothing else I would replace all the fuel lines if you have no information regarding when they were last changed. Depends on the age of the machine of course.
https://www.ansul.com/en/Products/nonroad_sys/nonroad.asp We put these systems in many of our machines as an option if the buyer ordered it. The local distributer would come to our plant and do the installation. Took a couple of days as I recall. Regards D.D.
We use fire suppression systems also, but mostly on larger equipment. For example our 30-tonne excavators don't have a system, just a 5lb extinguisher in the cab and a 20lb one mounted on the machine somewhere.
Where I was going with this thread was to determine how often a blown hose occurs as long as someone is looking over the hoses daily or more to watch for changes in appearance. As well, in the event of a blown hose, is it VERY probable that a fire will occur? In the machine in question, regardless of how well I protect the exhaust, I would think getting some oil on it would be unavoidable with several kpsi. Probably a pretty good pop followed by smoke, mist, etc. As well, I am real curious to learn if an operator can usually curb major disaster with a good extinguisher or if that is just a spray and pray deal? I can only imagine that your best and only chance of saving a machine is stopping the flames within seconds of it happening. If a fire dept next door probably could not respond fast enough to curb disaster. Should a guy try and get a foam tank rather than dry?
To me the best method would be to create a database that carries the data of every hose and when/@ how many hours it was changed. Hoses coming up to end of life can be identified. A visual inspection of critical hoses (especially those that have been known to rub on structures) would always be good. Digital photos to accompany the inspection even better. For hydraulic oil fires dry powder would be my advice, fuel seems to respond better to foams. The only thing is that a system is a "one shot only" deal. You have to get all the equipment on the ground and the engine stopped before hitting the button, otherwise there's a distinct possibility of the fire being put out then reigniting due to the oil still being sprayed around.
Something else to look at besides just hydraulic lines, are the oil lines feeding the turbo. It seems that most fires we have on our hydraulic shovels come from a blown turbo oil line, or the turbo itself going out. We actually had a fire on one shovel the other day, that was pulled out through the rad by the fan, and actually burned the line off the turbo behind the one that the line broke on.....that doubled the fun! Had trucks calling about the flames shooting out the back of the shovel. It's actually pretty rare for us to have a fire due to a blown hydraulic line on any of our machines.
For those that have actually had one blow, how bad do they have to be to "really" get you in trouble? I know these hoses usually have several layers and have quite an engineered pressure margin. That being said, I have seen some VERY ragged hoses that run for years and years that way. Do they usually bulk or start cracking before they go? Also, is it a near guarantee that a blown hose around the engine area will start a fire or are they just as likely to create a huge plume of smoke and that is the end of it?
Bigger the machine the higher the pressure therefore the less tolerant to damage by wear, impact, deterioration, etc. A few months ago our outfit had a Liebherr 996 shovel burn completely to the ground because of a failed hydraulic hose and the resulting fire, even though it was equipped with a state of the art fire suppression system. Agree 100% with Alco, turbo oil feed hoses can definitely be a problem if they fail.
fire If you are interested check on converting your machine over to a "fire retardant" type hydraulic medium. You might even get a break on your insurance-another plus is that some are more "eco-friendly" than mineral oil. I've seen a couple 750 Komatsus equipped with a fire suppersion system burn-not a pretty sight. Good luck, Tom
We will be swapping the hydro oils out but due to a deal we cannot pass up on oil, it will probably get a standard ISO46 oil. Machine does not have a turbo so I guess that is a plus.. Machine will not be insured for some time. We are retiring it to farm service only. Might be able to get it on the farm policy later.
Generally hydraulic hoses are pretty stable for around 6,000 hours or seven years. The most common catastrophic failures I've seen are from where the fittings separating from the ends. The other usual failures involve rubbing on metal and wearing the covers and the wires underneath. Once those wires started breaking off, the hose should be replaced. I have seen pin hole leaks cause flash fires that run like a flame thrower. They mist up and any air flow can turn them into a fuel air bomb. Just cutting off the fuel to the engine is not usually enough. A boom in the air will feed the fire for quite awhile. Air pressure in the reservoir will also provide enough fuel to end the life of your machine. I've always used the dry chemical extinguishers. For awhile people were marketing the Halon systems but I've seen those do some bad things also. Get a fire in the engine compartment and blow the gas in and the fire will go right out. Fully open the hood and the fire erupts like a volcano blowing up. The fire suppression systems can be well worth the money but one has to remember to do the required maintenance to ensure the system will work. I did an investigation one year in Alaska. The operator swore he hit the firing pin and all he heard was a hiss and then nothing. When we cut open the powder cylinders we found they had used a plastic pickup tube. The cold weather and natural vibration of the machine caused the pickup tube to break off and fall into the canister. When the gas hit the canister it went right out top of the can and didn't blow any powder out at all. The fire was so hot it melted all the aluminum right off the sides of the engine. Hoses are expensive and generally fail over time. Most of the time even when they fail all that happens is you lose some oil and running time. Look them over carefully and don't hesitate to change them if you see something bad.
I'm just curious, you mention a pick up tube, but there should be no pickup tube in a system like that. Do you mean the pressure dispersal tube? That would be the tube that carries the pressure charge from the pressure cylinder to the bottom of the powder canister to fluidize the powder and carry it out through the discharge lines. I'm basically wondering if this is a type of system I have never seen before.
The tube screwed into the center of the cap on top of the dry powder can. The pressure cylinders were remote mounted and had two trigger mechanisms. The operator could fire the system from inside the cab or outside the machine. The gas entered the cans from the top and just pushed the powder down. The powder then was supposed to go up the tube to be dispersed out the nozzles mounted all over the machine. This machine as I recall was being operated outside of Copper Center which as I recall was a couple of hundred miles north of Valdez. They had just put some kind of arctic oil in the hydraulic system so it could work in the cold. I guess it worked fine. The operator said it smelled almost like lighter fluid when it started burning.
OK, that's what I thought. That's not a pick up tube, the purpose of that tube is to carry the pressure charge to the bottom of the powder canister to fluidize the powder and carry it out of the discharges. If that tube is not connected, or missing, the powder stays packed down and the gas charge simply blows out without carrying the powder with it. Typically, the discharge from the powder canister is not at the top. So the powder doesn't go up that tube, the pressure charge goes down it. The powder packs down with time and vibration, so the charge is required to fluidize it, in order to get it out of the canister. It's the same reason you should periodically take any fire extinguisher, turn it upside down, and bang on it with a rubber mallet. This breaks up the powder that has settled, and allows it to be carried out with the pressure charge.
That makes perfect sense to me. What I know is the engineer sent from the factory to view the tear down of the system when the components were shipped back to Seattle was embarrassed as all get out. With the top cap removed we couldn't see any tube at all. I went and got a band saw and we cut the top of the can and pulled it apart to see the plastic tube melted on top of the powder. That engineer described the operation to us when he pulled the top of the can off. The maintenance you describe is what typically never gets done. Even today I see tags with initials on them and the cans still have unbroken paint on the mounting hardware. There is no way they have ever been removed let alone turned over. I'll check and see if I still have the photos somewhere.
funnily enought i almost had my kobelco burn down on me, wires shorted out and started smoking, luckily it stopped. after we got everything sorted i put an extinguisher in the digger, i put the fire extinguisher under the seat.. (idiot) i was working on a hill and it rolled under the left track lever, almost took me over the bank
There have been quite a few harvester fires here over the last few years and some of the farmers here have been fitting Fire Knockout cannisters in the engine bays of their harvesters. I would think they would work equally as well in the engine bay of an excavator or anywhere else where there might be a risk of fire. The cannisters were selling here for around $200 and they can be mounted any where, using a bracket that comes with them. As the fire comes in contact with the cannister, it ignites a fuse, the cannister splits open and smothers the fire with a water based retardant. http://www.fireknockout.com/index2.asp?p=3 RnR.
I've had a brief fire when a radiator hose blew and somehow ignited oil seeping from the turbo (couldn't believe it, must've been a live wire somewhere). Heard of a few fires in forestry excavs engine bays due to couplings letting go, probably from all the impacts with stumps and logs? Most scary thing I've seen is birds building a nest on the manifold while I ate lunch. Bird nests are a major cause of tractor fires here. I check the oil, water and debris before I start up, every time, and keep two extinguishers in the cab.
speaking of which ^ i had rats or mice living in the engine bay and body of my excavator lol
What about a halon style fire extinguisher? It seems to be a large problem with expensive equipment burning up, a relatively cheap fire extinguisher would work well. Halon is used in marine and military vehicles etc.
Hi i stumbled across this thread today, has anyone heard of Ardent Ltd, we fit fire suppression systems to plant machinery world wide to liebherrs, Bomag, Cats, etc and are actually the UK leading Ansul distributor. Iv heard of some really bad cases where millions of pounds have gone up in flames, we get sent quite a few pictures for marketing purposes but i dont think i should publish these.. i think using a fire suppression system can dramatically reduce your mobile plant insurance as well. In most cases its probably worth doing.
www.ardent-uk.com www.ardent-uk.com check it out!
You may not be aware of this but Halon extinguishers are now illegal, and have been for close on 20 years in certain applications, including marine. I prefer AFEX systems thanks.
Just out of curiosity, can i ask why? Its always useful to know how the products are percieved. Thanks
Personal experience of all the major makes over about a 20-year period - Wormald, Ansul, & AFEX. Of the 3 makes I much prefer AFEX.