Liebherr dozer and strange attachment

Ran across this in Iceland today, any ideas what the
rear attachment is for? Looks like boat rudder on
back of the dozer.

Cable plow that vibrates as you move forward, makes pulling it very easy, Plows down some kind of wire cable like phone or fiber optics. They like that dozer because it is one of the larger hydrostatic machines.

Plowing underground phone and electric lines

The other posters have it correct in that it is a vibrating wire plow. The unit on top is the hydraulic powered vibrator. They used a smaller version to put in phone line here a few years ago. It shook the entire house. The wife ran to the kitchen to hold dishes in the cabinets. That unit was just a little bigger than one you walk behind. I can imagine this one really shakes.

On the ground in front of the machine, you can see the mounting bracket that holds the spool of whatever is being put in the ground.

Thanks for all the replies, looks like heavy/duty application as Icelandic rocks very unforgiving. I know Liebherr is a name companies buy for big jobs and extreme conditions. See a lot of CATS here, too.

Vibratory plow for laying pipe or cable. When I was in high school my uncle had a Ditch Witch dealer and did trenching work. I with him one summer pulling wires for streetlamps on tree lawns. Tamp the sod back down and you're done.

My neighbor was a foreman for an electrical utility contractor. I remember him telling about a frantic housewife running up to get the dozer operator's attention. They had hooked the vib plow on the lady's gas service line, and the gas meter was coming across the yard behind them. Lots of damage on the inside too.

Sounds like bad day for the contractor, needed another set of eyes on the job.

Last fall a contractor for the phone co. plowed in fiber optic lines in our rural area.

The first photo is of the plow.

In the second photo they used a backhoe to dig from my shop to where they had to cross a 15KV underground 3-phase line, then hand-dug over the line, and are getting ready to drop in the plow on the other side of the line.

In the third photo, they are plowing in a road ditch in water and cattails.

A few hundred beyond there they cut a single-phase line branching off from the 3-phase line, tripping out the 3-phase line, cutting off power to our grain subterminal about 5 miles away. The original plan was to plow the wire in on the south side of the road, and the line was marked there, but at the last minute they chose to plow on the north side, instead. There were a LOT of unhappy folks that day! A couple of friends that work for the power co-op said there were never so glad to have a crew get done and pack up and leave, think they cut 4 or 5 more power lines!

Fourth photo is of the facility that lost power.

<img src = "http://i167.photobucket.com/albums/u125/27Grainfield/Stuff/Fiber1_zpsaz8mgczg.jpg">

<img src = "http://i167.photobucket.com/albums/u125/27Grainfield/Stuff/Fiber2_zpsyrvnwjtw.jpg">

<img src = "http://i167.photobucket.com/albums/u125/27Grainfield/Stuff/Fiber3_zpsr6ntbevu.jpg">

<img src = "http://www.ncgrain.com/images/E0246301/spring_elevator1.jpg">

Back in 1968/69, the local telephone coop bought an industrial IH 706 with a vibrating cable plow. First time I seen it they were plowing the phone cable up the driveway to the rural school house. It rattled the windows so bad and because of the noise, the teacher let us watch the plow.

Sounds like good teacher, knew she couldn't do anything about the noise and everyone learned about something new