Trencher Maintenance

[glsahl]

Anyone have any experience with trencher chain patterns?
I've got two Vermeer 955's,24" pads,setup to give a 27" cut.Dealer calls the patterns a "reverse chevron".My problem is the "alleged" 27" cut.Our 24" excavator buckets won't follow the trenchers after precutting.In house attempts to widen the trenchers' pattern,have poor wear charateristics.The pockets on the wider plates wear at an excessive rate.I have thought about increasing the plate width,but, that is a little pricy,at least intially.62 plates on each chain,$150.00 per plate,plus pockets,and weld time to install pockets.On top of that my dealer informs me that the steering pocket placment will have to change as well.The owner prefers "experiments" to be conducted "in-house",I would prefer more info than my dealer seems willing to give.
Any ideas?

 

[Dirtguru]

Not familiar with trenchers or what size excavators your following with or how deep your trench bottom has to be, what is the soil type? If it's glacial till or cobble you will never get clean trench sides. All that aside what about narrowing your excavator buckets 2 or 3 inches? Should be a lot cheaper. Would depend on the size and make of excavator. Worked for me a few years ago, did a bunch of fiber optic trenching, some areas required trenching through solid rock and we were lucky to get 300' a day with a excavator/hammer and backhoe. Brought in a huge rocksaw called a Tesmec to precut, 18" backhoe buckets had trouble following so I cut em down to 15", worked like a charm. We only had to be 4' deep. Got four custom 15" Cat backhoe buckets I will sell ya real cheap.
Have seen big trenchers used in California, looked like they were installing storm sewer, didn't pay any attention to size of excavator buckets but the soil looked like caliche and the excavators seemed to be keeping up.

A Chapman

 

[glsahl]

Narrowing excavator buckets is not an option. Our excavators,50K and up,come stock with their 24" buckets making a 27" cut,roughly,with new teeth. The more solid the ground conditions,the more noticable the problem we have.

 

[Dirtguru]

You have probably already thought of this. Call up your competitors and ask what there doing. If there not willing to help ask your dealer for a list of co's who have purchased simaler machines, maybe in SoCal or Salt Lake area. I understand oil and gas pipeline contractors use big chain trenchers quite a bit and they have become quite popular with water and sewer contractors in the southwest. What about contacting a factory engineer? I would think your dealer would be more helpful especially in a market as busy as yours.

A Chapman

 

[glsahl]

Most of our competitors aren't "pretrenching". Our contracts usually include wet and dry utilities. So while we have the trencher onsite for sewer and storm drain,we precut all possible utilities,back fill,then come back with an excavator. I was suprised at the actual savings.Both our trenchers are T955 Vermeers,our largest pieces,12' booms,27" cut,125K brutes. We've cut 1200 ft at 10',in a single day,with our first machine.The operator wasn't a "seasoned" trencher operator,and the ground was less than ideal,but the runs were long and straight.This was one of the few times we've had that kind of production,but man what a day.
We trying to ease the width out ,using the current 24" base plates,and a different style of pocket.Set at 27",it looks dubious,but will give us the width we reqire.I'm pushing for going to a 26" base plate at the next chain replacement.Expect to replace a chain at the end of this summer.Been averaging 2000 hrs on a chain,dealer advises replacement every 1500.Machines are averaging 2200 hrs a year.Both have just over 600 hrs since January.
Gary

 

[aebackhoe]

We use a t755 vermeer with a chain that cuts 33" doing the same technique that you are talking about, and ran into the same problems only real way to fix it is buy the hardest teeth and lots of hard facing on the widest plates. We do alot of pre trenching in solid rock and this seems to work very very well it takes time at first to build up the hard facing but it is worth the time because it will save you a ton of money in the long run in plates.

 

[glsahl]

Welcome To The Site

Are you using cap,or insert style teeth?
Caps are working best for us,hardfacing is a given,though I've changed to different style of pocket,ours has a thicker cross section at the tooth bore,hardfacing the pockets has proven to be a problem.The inner diameter tends to wear,almost as fast as the outer,leaving us with a problem of teeth walking in the pocket,and stripping the retainers off,causing a lose of teeth,as opposed to wearing the tooth out.
We have changed to a "C" clip retainer,instead of the snap ring,and that has helped.Using a grade 8 washer,the same diameter as the outside diameter of the tooth's shank,has extended the life of the pockets,as well.
I keep thinking that there should be an adjustment,to the pattern,that could help,more.Our oldest 955 goes from an "A" at centerline,to an "I" which is 27" tip to tip.We run a 12' boom,62 plates,"A"'s,and "D"'s have side cutters,I've removed all the blanks,which were every 4th plate,so the machine has 8 total chevrons,and tooth usage,considering the "cap" style tooth,has dropped almost 50%.
Our second machine,same boom setup,has a more aggressive pattern,and while it used fewer teeth,from the beginning,the pocket wore at a higher rate.We replace pockets more due to tooth loss,than breakage.Seems there has to be a "happier medium".
Teeth have gone to $13.00+ each,pockets are over $16.00 each,base plates have topped $200.00 each.I'm spending close to $5000.00 per month,just in wear items,per machine.