That "oh no" moment

[frenchie477 2]

Anyone ever come across an outrigger that lifts off the ground during aerial operations? We have a 98 Pierce 100' rear mount tower ladder. The unit has 4 outriggers and the right rear stabilizer foot lifts up and disengages all aerial controls anytime the ladder is brought to the left. To re-engage controls you must switch back to stabilizer mode, drop the foot down to the ground again and then switch back to aerial mode.

The unit has been to our shop and been back to Pierce where the engineers deemed it "normal" based on the age and wear and tear of the vehicle and stated it was the suspension shifting. We have tried it in various situations and have jacked the truck up high enough to eliminate the suspension (in the rear) from the scenario completely. I can hardly believe this is normal.

ps - At 100 feet in the air it's scary moment when the ladder jerks to a stop and the truck teeters back and forth on 3 outriggers.

Edited April 19, 2012 by frenchie477

[PEMO3 523]

Since when is a malfunction normal. You should put the engineer who made that comment up there and have it happen. I am sure he will change his tune and his shorts.

[Alpinerunner 61]

My guess is something in the torque-box is snapped. It's caused by the chassis twisting. If it did it on both sides it could be that you're just overloading it based on weight/height, and the frame is just not stiff enough. It could also mean it's snapped in such a way that if affects both twisting directions equally.

What I'm trying to say is that overall frame stiffness should be largely symmetrical, if it's not, something in the torque-box probably snapped. I would take it to a shop other than Pierce.

[antiquefirelt 994]

Anyone ever come across an outrigger that lifts off the ground during aerial operations? We have a 98 Pierce 100' rear mount tower ladder. The unit has 4 outriggers and the right rear stabilizer foot lifts up and disengages all aerial controls anytime the ladder is brought to the left. To re-engage controls you must switch back to stabilizer mode, drop the foot down to the ground again and then switch back to aerial mode.

The unit has been to our shop and been back to Pierce where the engineers deemed it "normal" based on the age and wear and tear of the vehicle and stated it was the suspension shifting. We have tried it in various situations and have jacked the truck up high enough to eliminate the suspension (in the rear) from the scenario completely. I can hardly believe this is normal.

ps - At 100 feet in the air it's scary moment when the ladder jerks to a stop and the truck teeters back and forth on 3 outriggers.

Are you saying it retracts up or does moving the aerial around cause the sensor to lose down pressure forcing a "reset"? Our ALF will lose down pressure with enough movements, requiring an override once in a while. Thankfully I've seen this happen frequently in training and never on a job. I recall trailing a used Scope once and watching the outboard radial outrigger lift off the ground over 24" when the bucket was low and fully extended!

[IzzyEng4 427]

Depending on the operations of a specific aerial, under normal circumstances and outrigger that lifts off the ground on the opposite side of the truck where you are working off of is normal. Again depending on the manufacturer's operating specifications. For example, if you work off the right side and the left outrigger lifts off the ground (1 or both) that is normal. This should not cause the aerial from working properly.

The problem you are describing sounds like you have a serious micro switch problem and you'll need to override the controls or keep doing what you have been doing. For example, we have a 1995 LTI 102' rear mount at work. A few weeks ago doing out weekly inspection on it the right rear out rigger would not deploy down. It would engage to retract up, but no power going down. All the other outriggers deployed and retracted normally. Come to find out, the problem was a ground issue on the left side (the left rear outrigger spot light was out and the key to the problem). The ground contact was cleaned up and re-secured, the left spot light went back on and the right rear outrigger deployed normally again.

Get this problem checked out immediately if it hasn't been done already. Also make sure you follow what the specifications for setting up the tower is through the manual provided by Pierce. Some trucks you need only to take the bubble out of the tires, others you need to take the truck totally off the ground. It could be that the way everyone sets the truck up is totally wrong from what the original specifications outlined. Also make sure you utilize your jack pads!!! This could also cause a problem if they are not used.

I don't like the comment that the Pierce dealer / mechanic gave you. In the words of Col Potter "That's a load of horse manure!".

[frenchie477 2]

Everyone pretty much hit the nail on the head. I spoke to the Lt that has been dealing with the Pierce engineers on this. The torque box has been replaced once before and was checked this time and is working order. The outrigger picking up is normal for this apparatus but losing all aerial controls in the concerning part. We are working on figuring out exactly why the interlock is disengaging and why the micro switch isn't keeping things in check.

Thanks for the insights and I will check back when we get it figured out.

[frenchie477 2]

Just an update. The interlock sensors have been re-adjusted and we are keeping aerial controls. The foot opposite the side the ladder is on still picks up but we can still run the aerial thankfully. Thanks for all the responses. Also, as a side note... we just turned 100,000 miles on the old girl. Many many hard miles.