Oshkosh P-4 Fire Crashtruck Preservation

[Another Ahab]

The Oshkosh is a beautiful beast, and I apologize for not knowing more about them:

Aviation fires are usually all suppressed with foam now, is that right? So was the Oshkosh originally designed to throw water, or has it always been foam, I'm wondering?

And just out of curiosity, what is the water tank volume/capacity in one of these things?

 

[tbar123]

From what I remember from watching the Air Guard Fire Team practice, they used water. But that was practice, m1010plowboy;I would check the air hoses that have been rubbing the paint off in picture 6.If they are anything like a Freightliner. Then that rubbing is the problem.

 

[steelypip]

The experts (and we do have some on here) can give more detail, but as I remember, the 'best' approach for dealing with an airframe fire has changed over the decades.

Back in the 1950s USAF SOP was to foam down the whole runway if the landing aircraft was afire or doing a gear-up landing and have the airplane skid to a stop on the foam. Not only was it hideously expensive, but it didn't really seem to help with anything, so they quit.

The goals are pretty straightforward:
1. rescue any surviving aircrew aboard
2. prevent avoidable damage/spreading to other aircraft/structures/the ramp, particularly if they're full of munitions or fuel
3. protect the equipment

What they figured out over the years was that if an aircraft was generally on fire, you weren't going to put it out. So they'd try to hit it hard with a huge amount of water to stop a nacelle fire from becoming general and getting into the wing, for instance. If that didn't work, they'd back the equipment away and concentrate on protecting things that weren't necessarily going to burn. Enough burning magnesium, aluminum, and jet fuel win every time over just about anything humans can do, even with a behemoth like a P-4. Once the airframe fire becomes general, the most you can hope for is to get the live people out before they suffocate and to minimize collateral damage.

What a big fire truck can do for you is do a great job of saving an airframe if a fire is localized. It can also keep something that isn't afire from getting too hot and catching. Pumping lots of water, or foam (to alter the albedo on vertical surfaces) onto nearby aircraft and structures can make a huge difference in the badness of the outcome when you've got a B-52 burning down on the ramp. For the record: they put out a huge amount of heat, take a long time to burn out, and when they're done, there's not much left than parts of eight engines in neat rows and a divot in the concrete where it was calcined back into quicklime and aggregate. I will admit to being struck speechless the one time I saw it.

 

[m1010plowboy]

P-4 info

Aviation fires are usually all suppressed with foam now, is that right? So was the Oshkosh originally designed to throw water, or has it always been foam, I'm wondering?

And just out of curiosity, what is the water tank volume/capacity in one of these things?

Pasted a couple of specs showing capacities. This beast could foam, spray water and excavate dirt. Tank capacity evades me right now but I fit in it so it'll hold more than a two six of Tangle Ridge.

I would check the air hoses that have been rubbing the paint off in picture 6.

Good eyes! It bounced a lot of miles to leave marks like that and since you noticed it, whatcha doin Saturday?

 

[m1010plowboy]

P-4 Capacities

Here they are.

 

[Another Ahab]

Pasted a couple of specs showing capacities. This beast could foam, spray water and excavate dirt. Tank capacity evades me right now but I fit in it so it'll hold more than a two six of Tangle Ridge.



Good eyes! It bounced a lot of miles to leave marks like that and since you noticed it, whatcha doin Saturday?

Here they are.


View attachment 488443View attachment 488444

If YOU fit in there (standing), then it's a swimming pool, no doubt about it.

Funny though, in the specs is gives 1) discharge capacity of the various pumps, 2) fuel tank capacity, 3) capacity of the primer tank (and I might have walked right past it), but didn't see the spec on capacity of the water tank.

I got a kick out of the spec on a climbing grade of 60%: wouldn't want to be the pilot flying out of any airfield like THAT.

 

[m1010plowboy]

P-4 Retirement

She won't climb for a while but now at least, we have a plan......and it's better than the last plan because this plan is flexible.

First lets have a toast to those guys that work on heavy trucks and love it!!!
You guys are nuts, plain nuts. 3 mechanics spent maybe a total of 4hrs on the truck to help me diagnose the health of the entire truck. Took me 2 hrs to drop 1/2 a drive-shaft because of those crazy safety tabs bent over the bolts, 5 ton jacks that still don't lift 33,000lbs, rolling the truck around to get access to the top nut....the top nut....on the drive-shaft only to find out I can barely bench press the thing to lower it to a third member...my head, which then gently set it on the ground. Everything needs to be planned out, lifted and moved around with heavy equipment, levers, long handles and a series of cables and pulleys......And to this, I salute you.

Patracy, we've gone through it and are putting it partially on the shelf for now, taking 12 months to evaluate further so I apologize that it'll be a while before I decide...........how many rear-end jokes can we come up with. I like these rear-ends because of the easy-off pull tab at the back.


We finally got air up, throttle working, one actuator leaking which is easy to get at




.... and cranked it over enough to know absolutely without a doubt, the head-gasket is bad. It was ready to start but to avoid potential damage the trying is over. The neighbour a 1/4 mile away thought I had it running because of the smoke that it was spitting out. It brings us to a point where I'm sure all addicts get to and that is the decision to put money into something where the Return On Investment ROI would never be seen. How do you guys decide which truck you should spend your kids inheritance on?

It won't cost anything to tear it apart and peak at the head and pistons, no crack we fix, we find crack, easier to decide if I'm hauling my rear-ends to America and going on a holiday...........besides the TM's make it look easy.

I've never done a head on anything before but how hard could it be. Ya open the bonnet, remove the hats, under the hats is the head, it probably sits on top of the neck and the little gasket between the neck and the head just needs to be slipped out and a new one back in. I'm sure there's a gasket between the head and hats but after the neck the hat'll be easy. After a quick glance at the manual I see someone has already gone in and removed most of the bolts so that'll speed things up.


Besides, if you can stand the excitement, there's always 1693TA tear down info on you tube
http://www.youtube.com/watch?v=lW_tiUirGPk

With the drive-shaft debacle I'll need to get it back together so I'm wondering on drive-shaft repair should we use 2 wraps of duct tape or will one be enough?,,,one looks better.

So for now Jelly Bean.............Oh ya, not much in-put from South of the border on a name for an American truck hiding in Canada.... so a young visitor to the farm, who knows nothing about American trucks......said "It looked like a big red Jellybean" ......so until I get some cool stories, names and ideas, we're going to call it Jellybean.

Had to get it out of the TEA and into a better spot to work on it ABSTWOI. The Duramax couldn't pull it, the skidsteers couldn't pull it, the hoe couldn't pull it.........so I had to grab an ol' beat up Deuce that nobody appreciated in the military and put the OshKosh in her place....but that's also another thread.

 

[jvandal]

P4 held 1500 gallons of water if my memory serves me right.... About 60 secs worth.... Really doesn't matter after that! If you don't have the aircraft suppressed in 60..... Probably ain't going to happen!

And yes, the most successful mechanics at working alone with p4 were not weaklings!

Side note.... Once you have it running... It will drag the deuce, skid steer and the duramax to **** and back.... All at once....

 

[m1010plowboy]

P-4 Parts

I may just sell it for scrap. the entire body is made of aluminum

We noticed the 2 nozzles on the top cannon of our P-4 were broken and it wasn't important at the time. Still not real important because the truck doesn't run yet but I thought I'd ask if you still had the P-4 around?
I know a guy that would like those diffs.



I wouldn't want to see someone go through all the trouble of removing it for me so if it's easier just to put it the whole thing a lowboy and haul it up, I'll cover the expense of removing them.

If it's gone it's gone just thought I'd ask.

jvandal

Side note.... Once you have it running... It will drag the deuce, skid steer and the duramax to **** and back.... All at once....

The vision of that happening just inspired me a little, thank you.

 

[DEMON]

I can probably round you up a start/heat switch. We still have a few machines around the mine that use the same style start switch.

 

[m1010plowboy]

I can probably round you up a start/heat switch. We still have a few machines around the mine that use the same style start switch.

I appreciate the thought but I bit the kitty and went to Cat. Fort Gary, Acklands, Greggs, Princess Auto and a few other little guys let me down. I got the "not in stock" line from nearly everybody.

Now I want to drive it to the mine and show you my new switches.

Have you ever pulled the head on a 1693?

 

[DEMON]

Unfortunately no. Not that engine. Can't imagine that it's much different than the 3406 though.

 

[jvandal]

Lol....use a hoist! But it isn't to terrible..... But .... I remember cylinder sleeves.... And some distant memory of them causing issues like yours.... But that is a distant memory, I need to review the T.O. .....

 

[jvandal]

Interesting how things just pop back in from the distant memory

 

[DEMON]

Counterbore is probably what your thinking of. If your block counter bore is rotted the sleeve will drop down and loose crush on your headgasket. Then combustion passes directly into the water jacket. You have to measure liner heights on an overhaul. If one is too low. You have to have the tooling to cut the counterbore then add shims to gain liner height. For proper headgasket crush for combustion seal on the headgasket. That's all very standard for a wet liner type engine. Regardless of brand.

 

[m1010plowboy]

1693 Cat Head

Interesting how things just pop back in from the distant memory

It is very interesting, after reading the info from Demon I remembered that I have removed a head off an engine before.

Hope all the skills I learned then pop back soon too.

 

[steelypip]

Ha! I recognize that engine. Anyway, yes, the whole sleeve/deck height/gasket crush thing is standard wet-sleeve engine stuff, even my Listeroid has the same arrangement, although the deck height adjustment is rather more casual than on a modern Cat. Are there in-the-frame counterbore cleanup tools for these? I'd guess so, given how traumatic pulling the block out is.

 

[jvandal]

Probably didn't need a hoist and 4 hands for that head! I never had to fix one of these problems as it was considered depot level repair and the P19's were coming online and replacing the 4's.

 

[m1010plowboy]

One man's junk

Remember all that lumber and metal everyone said you should get rid of?.........Well I picked it up and laid down a quick hockey rink platform for Jellybean and Dumbo. Hope to build a wee rolling roof for the P-4 engine area so we can remove the hood then slide a roof over when we're not working on it. With no budget for this Jellybean she's going to be roughing it for a while.

Keeping with the rules of our County they permit us to build without permit, a 10'x10' shed. They also like skid shacks so we're going to try for the best of both worlds. A rolling skid shed.

A few of the planks we laid down felt the crush in the soft ground but it's better than grass until someone builds a shop.


Good shot of the 13" frame on the P4.


For now, back to the GREEN.

 

[m1010plowboy]

Weed Treatment

I'm still trying to get the whole story on this but I think I blew it this time! When the big red thing, Jellybean the P4 showed up at the G749 farm we put it in it's own field so it wouldn't clash with the green iron.

We seeded and fertilized over the past weeks and a few other red things started to sprout. That was good for Jellybean because they are herd crops. Today, in the middle of the dandelions, a big green weed showed up amongst the red crop.

Not sure if we used the wrong fertilizer or too much seed but we need to spray it or move it to the green field.

This stuff just don't grow north of the border and I'll do a search but if anyone can ID it we can pick the right herbicide.

We're also trying to get some soft-wood cuttings to send to Svalbard. This thing wasn't there yesterday, now it's ten feet tall.

What is this thing......Do we use Glyphosate or 2,4-d?