QuAD

nice !!
does anyone has a picture or movie that shows the operator seat and controls and can explane how this machine makes a turn , is it braking one side on the front machine to make a turn when going forward ?? and going backward is it the machine in the back that slows down one side to make a turn???

Hi, Marcoten.
I have never run one but, as I understand it, the controls are set up so that it acually cross steers as you are starting a turn. Whichever one is leading - forward or reverse - de-clutches and brakes the inside track to start the turn and the trailing one de-clutches and brakes the outside track. This has the effect of throwing the middle of the unit away from the centre of the turn and both ends toward the centre of the turn - - - - and round she goes. Exiting a turn is as simple as letting the leading machine - front for forward or rear in reverse - run straight or you can let the leading machine go slightly beyond the line you want and then straighten them both up on line. The attached Service Bulletin explains it pretty well.

They tell me it is a bit of an art form and that you should have slightly more 'loud pedal' on whichever machine is leading in the turn or the trailing one may push the leading one sideways at the connection ball.

[attachment=16163]Cat DD9 Service bulletin 1965_02_Acmoc.jpg[/attachment]

Just my 0.02.

I have a copy of the operator's handbook .
The Netherlands , Johan7

Sorry only in French

[img]http://imageshack.us/a/img41/3092/quadmk.jpg[/img]

thanks to all!! this explains how it works!!

the first ones the opt seat was stright and it killed your back and a lot of those scraper opt were worthless you never chase the scraper you pull right in front or the push cat opt did not push scrapers much i owned 20 scrapers and a set of quads and a set of quad 10 working in the mines and the cat opt never chased the scraper you pulled in front of the cat single or quad the last big cat we got was a D11 with a pushing cushion and we allways pushed the scrapers coupled up so you had 6 engs working😖mokin: but thats just my 2 bits

yancy44mag.

2bits is right on, the quads I was around back in the day only backed about the length of the scraper and they pulled in front of the push cats. A good pull skinner could whip right in front and straight out about the same time the push cat hooked up. Depending where, or who you were working for it was called, chain or link loading. There seemed to be always at least one if not more than one right along the side of the quad idling along waiting to get in, sometimes very unbalanced. But the quad only backed up a short length. The quad PKS had on I-70 in Colorado had a wireless busser that the quad operator could signal the pull skinner when he was loaded, some paid attraction and some never. LOL!

About the only time the quads had to backup any distance and get over and behind a scraper that was waiting for a push was when they were loading in short areas like hauling out a top soil pile, where the piles were short in length and the spread was unbalanced (short haul, more scrapers than the push cat could handle) and the scrapers had to be the ones that set back at the end of the stack and start over, there waiting for the push the cat.

Kelly

we had 1 guy that you could not get it through his thick head easy then hammer down he would hit you some times in 2 gear about half speed and man that hurt sounds like you know what we are talking about well i kept watching i let it go 2 days i talked to him the first day after work and he still did not get it so i told of the scraper hands to go take a dump opr a leak and i would run the scraper they were 657s well i left the can just touching the ground and here he come just about the time he got to the stinger i had it in revrce and i hammered both engs he did not have his seat belt tigh enough to do much good but he came out of that seat and was hugging the muffler he never ran in to anybody any more and he kept that seat belt tight and the thing was the quads had a pushin cushin so talk about easy if you can do it on a reg rig the pushin cushin simple we worked that job for 4 yrs 24/7 and he never ran in to anybody 👍

Thanks for chimeing in with some real life stories on these dozers. I think in the video example she is not a full blown production show like back in the day, just a company making an honest living with the gear they got, mind you pretty impressive as it does the business in 2nd gear.