Came across this old photo taken 5/24/50 not far from my shop when the Penn Lincoln Parkway (I-279) was built through Pittsburgh,PA.

I remember years ago there were a few D9s made up like that and we had one come into the dealer that one was hooked behind the other one too for scraper pushing I believe they used it for. The ball on the hitch on the front one must have been 10" in diameter. The rear one was controlled (operated) from the front one.

Like this PK had a few of them they still have this one at Brooks OR.

An article from Caterpillar News and Views, 4-5/65

Here some pics that I've saved from the BB over the years

Look familiar in your lower left photo Mike?

A buddy and his family own a machine shop and farm. Have farmed for many generations. The had two propane Allis Chalmers that they connected one in front of the other back in the sixties. Used them up through the early 90's. Not sure what happened to them...

They called it "the four wheel drive" tractor...those guys can do just about anything. That is just the tip of the iceberg for them.

bernie

cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&i...s=tab%3DWatching

photo's of there large two cylinder tractors hooked together "Pusher/Puller" style by removing the front axle on both, then attaching them, one to the rear of the other and articulating it.

"drujinin" wrote:

photo's of there large two cylinder tractors hooked together "Pusher/Puller" style by removing the front axle on both, then attaching them, one to the rear of the other and articulating it.

I used to have a pic of a set of Double D's...and I'm not talkin' about THAT kind of "double D's"-you can find them all over the Net...

A few years ago I went to a farm tractor and equip. show near Danville In. and they had some Farmall tractors there that two were put together side by side and also one with three tractors together. I have pictures of them I took but have no way to post them to see.They sure were an odd looking tractor all of them.I can,t remember for sure but I think they were F-20 Farmall tractors I don,t think they were F-12s or F14s.I went twice to shows out there while visiting my son & family out in Avon In.

I guess it says something of the strength in CAT's design in that by marrying the two D8's together all the engine power and torque would be going through one steering clutch and track.
Amazing!