Parking a Machine

[Steve Frazier]

I've noticed in my area here that when a telehandler is parked on a job overnight that it is almost always parked with the boom fully raised. I've been taught since I can first remember being around machines that you park any machine with the hydraulics at rest in the event of a failure that there is little possibility for injury or property damage that way. This flies in the face of that.

Do these machines have safety locks on them? What is the purpose of parking with the platform in the air?

 

[Ross]

Aye well they Have load check Valves on the Main Hoist/Tilt Circuit's.

Allways common Practice to Have the equipment down, You can gauge the Hydraulic level for safe cold start etc ....

Rental places around here Have the Booms at full lift but I thought that was an advertising thing.

P.S Havent been on in a while .. Like the new Site layout ..

 

[D5G]

I always thought it was a space thing, if the boom is down it takes up more space. Every single man lift that is parked around here has the boom raised. Most telehandlers on the other hand if there is plenty of room, the boom is down while the machine is parked. During the day, I see most forklift operators keep the boom up when parking the machine for a few minutes, this I know for a fact is becuase they figure there is less chance of a failure than chance of someone getting pronged or hooking the forklift with their truck, machine...etc.

 

[Steve Frazier]

After I posted this thread I got thinking and had a brain fart this morning when I typed it up. I did mean man lift, the type on 4 wheels and a boom similar to the telehandlers. Almost without fail they are parked with the platform up in the air.

 

[Tigerotor77W]

I've seen the same thing and was wondering likewise. I wonder if they keep it up so that kids (and other trouble makers) don't climb in the basket and hurt themselves.

 

[willie59]

I've seen the same thing and was wondering likewise. I wonder if they keep it up so that kids (and other trouble makers) don't climb in the basket and hurt themselves.

That would be the most likely reason, but not to prevent the punks from hurting themselves...they can do that anywhere on the site. They probably do this to protect those very expensive controllers at the platform controls. And a number of manlift type machines simply have latches that hold the upper control box shut. Pop the latches, open her up, and there's wiring and components out the wazoo. A prankster could make a helluva expensive mess in there.

 

[lynger]

That would be the most likely reason, but not to prevent the punks from hurting themselves...they can do that anywhere on the site. They probably do this to protect those very expensive controllers at the platform controls. And a number of manlift type machines simply have latches that hold the upper control box shut. Pop the latches, open her up, and there's wiring and components out the wazoo. A prankster could make a helluva expensive mess in there.

That and we park our lifts up just to save space. Each cylinder has a releif valve right on it, but I dont think they have check valves...will have to ask the lift tech tommorow.

 

[willie59]

Each cylinder has a releif valve right on it, but I dont think they have check valves...will have to ask the lift tech tommorow.

That would be an "oh yes". Every brand manlift, telehandler, and crane has internal pilot operated holding valves on the lift cylinders, which are basically check valves. They lock the oil inside the cylinder preventing it from drifting. To make a boom cylinder come down, you have to apply hyd pressure to the side of the cylinder that retracts the cylinder, and that pressure goes through internal porting that unlocks the holding valve on the other line of the cylinder.

 

[lynger]

That would be an "oh yes". Every brand manlift, telehandler, and crane has internal pilot operated holding valves on the lift cylinders, which are basically check valves. They lock the oil inside the cylinder preventing it from drifting. To make a boom cylinder come down, you have to apply hyd pressure to the side of the cylinder that retracts the cylinder, and that pressure goes through internal porting that unlocks the holding valve on the other line of the cylinder.

I was kinda leaning towards yes..just for safety reasons, a hose blows and without them youd be in a whole lot of trouble quick. Thanks for the info Atco!

 

[willie59]

I was kinda leaning towards yes..just for safety reasons, a hose blows and without them youd be in a whole lot of trouble quick. Thanks for the info Atco!

Your quick thinking lynger, to protect from hose failure is probably the main reason for holding valves. And it's also why they are located on the cylinder and not connected by a hose between holding valves and cylinder. There are a few out there that do that, but not much anymore. On a P&H T-300 hydro crane and a Bucyrus 45C hydro, they both have the holding valve manifold mounted on the turntable base with a hose connecting to the cylinder. In the case this hose blew, they install a velocity fuse on the outlet port of the cylinder. It allows oil to flow freely in normal working. But if it blew the hose and oil rushed out rapidly, the velocity fuse senses this high oil flow, and it closes internally allowing oil to escape slowly, controlling the descent of the cylinder.

 

[OCR]

Parking a Machine:

velocity fuse

Amazing, I've actually learned something from ATCO!! ... lol (just kidding, of course)

I'd never heard the term before, but don't they put thoes devices on fuel storage tanks and bulk haulers... In case of a bad leak some where, they shut off the flow???

"Velocity fuse"... good term... makes sense... :thumbsup


OCR...

 

[willie59]

I'd never heard the term before, but don't they put thoes devices on fuel storage tanks and bulk haulers... In case of a bad leak some where, they shut off the flow??

Hmmm, don't know. But I can see where that would be appropriate. Yep, a velocity fuse is used in a number of hyd applications. One would be the lift cylinder of industrial type forklifts. You know, straight mast, propane engine, solid tire warehouse lifts. These machines don't have holding valves on the lift cylinder. With the engine not running, you can push the lift down lever and the forks will come down, hence, no holding valve. But if the hose that goes to the lift cylinder were to fail, they install a velocity fuse to control the descent of the load.

 

[TSK415]

Around here, man lifts up for space and vandalism. I agree with Atco and lynger about a hose blowing and the check valve holding. I operated a GCI crane and the check valve on the upper "leaked off" when dirt or particles got in the way of the spring loaded ball bearing. Not a good thing.

 

[pittedmess]

My insurance guy said raise the arms, legs, buckets and whatever as high as it will go and park everything up tight...Suppose to stop theft..seems kind of dangerous to me..

 

[Dualie]

we do it to discourage vandalism and joyriders. we have been known to store some things in the basket overnight and outta sight. propane cans and cheaper things of that nature.

 

[ScottAR]

I figured there was a valve like that in the warehouse lift I used to
run. I know the lift circuit was a LOT faster than the lower circuit.
Pretty new Cat lift with only 200 hrs on it when I started. Pretty
sweet it was.

 

[willie59]

I figured there was a valve like that in the warehouse lift I used to
run. I know the lift circuit was a LOT faster than the lower circuit.
Pretty new Cat lift with only 200 hrs on it when I started. Pretty
sweet it was.

Your spot on ScottAR. On a warehouse forklift, you could ease into the down lever and it would begin to descend. If you slowly ease the lever more, the speed will increase until something makes a notciable "change" in the descent, that's when the velocity fuse has kicked in, and now the forks descend at the same slow speed no matter where you have the lever. That's what prevents you from dropping a load. It makes the descent more controlled. Same applies if the lift cylinder hose blew.

 

[ScottAR]

I remember finding it annoying even though I knew why it was slower... Seems like I was always waiting for it to come down when it would seemingly leap up. 'Course I was always in a hurry stacking or unstacking "stuff."

Gaylords stacked four high made for some interesting driving.

 

[Colorado Digger]

we had a few new holland 885 skid steer that we used for snow removal. they were always parked with the booms up, there was a boom lock. but they were near ti impossible to work on or get going w/o the booms up. espescially with 2 foot of snow and below zero.

 

[willie59]

we had a few new holland 885 skid steer that we used for snow removal. they were always parked with the booms up, there was a boom lock. but they were near ti impossible to work on or get going w/o the booms up. espescially with 2 foot of snow and below zero.

Amen brother, I wish everyone with a NH skid would do that. I've had to repair failed starters on NH skids before...with the boom down. PITA! :Banghead