Safety and pucker phenomena

[davesisk]

My old PT1418 can lift around 600-700 lbs with the bucket. I found out when moving gravel, sand, blocks, and pavers that it can lift this much weight without tipping forward if it's on level ground AND the steering isn't turned. I discovered, however, that when I attempted to turn a corner, the articulated steering essentially shortens the machine, moving it's center of gravity forward enough to now allow the machine to tip forward with the bucket loaded.

From reading I did before buying anything, I learned that you should always carry loads as low as possible (and even sometimes back downhill with a load in the bucket). With the load low, the machine can only tip a few inches forward before the bucket hits the ground. If I had been carrying these loads up high, I could certainly see how it would have been possible for the machine to tumble forward, and then very likely fall to the side (given the heavy backend would be up in the air). All this, even giving the stability and low COG of these machines. I'm glad I took the advice I read! With the load low, it was an "oh sh*t" feeling, but a non-issue. With the load high and a potential tumble forward or to the side, it could have become more than a non-issue pretty quick!

I guess one of the few disadvantages of the articulated steering is that it does indeed "shorten" the length of the machine when you make a sharp turn, thus changing it's balance with a load in the bucket.

Mine doesn't have a ROPS, and based on what I've read, my opinion is that it's probably safer for me to not wear the seatbelt given that there's no ROPS. If mine did have a ROPS, then I'd wear the seatbelt. (Btw, I'm not one of those folks who never wears seatbelts. I always bucket up in a vehicle, so this is a conscious decision rather than a habit.) What do you think?

One thing I could do, of course, is to add some ballast weight to the back (maybe a bar or two to hang gym-type weights on?). This would allow me to lift more weight on the front, but I'm wondering if I might overload the hydraulics by doing so. I believe I've seen that there's some relief valves that open to prevent overloads, but I'm not even certain if my 12-year old machine has these, at least for the lift cylinders, etc.

Opinions or thoughts?

Dave

 

[deadstick]

Yes I have noticed this when I was lifting some heavy limestone rocks (don't know how heavy they were). If I kept the machine straight everything was fine but the minute I turned too sharply one side of the backend would rise...

I have to admit I have not felt a "normal" style tractor lifting so have nothing to compare but when the PT does it for me, it isn't that alarming. It starts to feel like you are riding on a cushion of air and it happens fairly slow that I have time to straighten up. I have gotten used to when Im lifting something real heavy to make those turns as shallow as possible and to keep the bucket low....

I haven't thought about putting more weights on the back. My thinking is if the machine can't lift it as designed then I shouldn't be lifting it...

 

[Charlie_Iliff]

Dave:
Articulating it with a load in the bucket does a little more than shortening the wheelbase. It also sets the machine with the rear angled off to the side relative to the front, so the effect is actually the front weight tending not just to lift the rear but to tilt it forward over the inside rear wheel. Since the front and rear can also twist relative to each other, it's hard to understand everything that happens without building a model. I haven't done that, but I have picked up a rear wheel. In fact, while digging, I do it often and merely straighten the steering to put it back down. Sedgewood reported doing the same thing with his 1845, and MossRoad reported essentially the same with his 425. Although it is startling, I agree with you that it doesn't pose a hazard unless you have your bucket high. In that event, I think it could roll to the inside until the bucket hits, which could definitely ruin your afternoon.

 

[MossRoad]

I wouldn't add more weight to the rear, just because you would then push the limits of the machine to that weight, then add some more, then push it some more, etc...

If you really need to lift something more than it is rated for, rent another machine, or better yet, find another great deal like you did on your 1418 on a bigger machine. Then you could have two, one for each occasion. /w3tcompact/icons/smile.gif

As for the seat belt, you and I are probably thinking alike. I always wear mine, because I have a ROPS and I want to stay inside the unit if it should roll and let the ROPS do its job. With no ROPS, if you were seat belted in, you would be the pivot point for the roll and probably get squished. Have you investigated the possibility of getting a ROPS for the 1418? A few hundred bucks would be well spent insurance money.

 

[Bird]

Dave, you're absolutely right about the seat belt. It's best to have both a seat belt (and wear it) and a ROPS, but if there's no ROPS, no seat belt is the safest way.

 

[davesisk]

<font color=red> I have to admit I have not felt a "normal" style tractor lifting ... </font color=red>

Neither have I, as this PT is my first tractor. But, I think I'd rather have this tipping-forward experience with a PT, given it's front-end is the same width as it's back-end and it's low COG. I can imagine that a similar tip forward on a traditional CUT (given it's higher COG and usually narrower front) would have a quite higher pucker factor! Plus, from what I've read, it's particularly scary going downhill with too much load in a FEL on a 2WD CUT, as tipping forward takes weight off the rear wheels where the brakes are! I think tipping forward and rolling uncontrollably downhill on a CUT is an experience I can live without. /w3tcompact/icons/smile.gif

Dave

 

[ernemats]

Dave , I agree with you on the seat belt issue, I have a pt422 without the rops and I never wear my seat belt, if I had the rops I would definately wear the seat belt all the time. Also on the pucker factor I have had mine on 3 wheels many times going downhill with loaded bucket and making a slight turn. It is hard to tell when you are 3 wheeling without looking back as you are seated on the front portion of the tractor and you cannot tell what the back is doing due to the articulating. my worst experience was when I was hauling firewood down a steep hill with a small trailer behind filled with oak logs and the bucket full of logs, I had the bucket several inches off the ground and going very slow. I was turning the steering wheel slightly to correct what seemed to an odd feeling that I was not going straight, the steering did not seem to have any effect on the direction of the tractor. I stopped and turned around in the seat to see that the trailer had jackknifed and was pushing the rear of the tractor sideways, the one rear wheel was about 8 inches off the ground and this was on a hill of about 20 degrees slope. I put the bucket down and the rear wheel came down, raise the bucket the rear wheel would go back up, I could not get the tractor to straighten out no matter what I did. I ended up having to unload the trailer and disconnect it from the tractor to get straightened out, I then dumped the bucket of logs , hooked up the trailer and loaded it up and then proceeded down the hill (with empty bucket). From my experience there I learned a lot about what not to try. I still have a hard time believing the tractor did not roll over in this situation.

 

[davesisk]

Ernemats:

Wow! Sounds like a pretty hairy situation. Would backing down the hill make the difference in a case like this?

Also, I'm just curious, was this the little trailer that Power-trac sells (or a similar "lawn trailer" type deal), or a larger automotive type utility trailer?

Dave

 

[ernemats]

Dave:
Yes backing down the hill with a full bucket is definately the way to go, but with the trailer it is a little hard to do. The trailer was a homemade one 3 foot wide 4 foot long and wood was stacked on it over 2 foot high, probably total weight of trailer and load was about 800 lbs, that all would have been fine if I did not have the bucket loaded so full.