Couple rules I keep posted in the job office on my sites, and reiterate with all my scraper hands about once a month, or anytime we get a new guy.
1.) Do NOT pass on haul roads
2.) Do NOT pass on haul roads
3.) Do NOT spin tires
4.) Loaded scraper has right of way over all other machines on site. Unloaded scraper is second.
5.) Left-hand traffic for everyone on site at all times
6.) Keep your right hand on the can lever at all times
7.) Keep your apron closed on the haul road
8.) Make sure your apron is closed before leaving the cut (don’t be dribbling material on the haul road)
9.) Keep your can close to the ground
10.) Do not follow the scraper in front of you too close on haul roads/fill
11.) Split your tracks on the fill
12.) Go faster
Regarding the rule about passing on haul roads: On my sites, if the haul roads are wide, than each morning at the toolbox talk, the foreman will tell his scraper hands that they can pass the blade on the wide haul roads if they follow the right safety procedure: radio the blade hand that you’re about to pass passing on his left or right side. The operator will confirm with coordinating right/left hand signal, then pass. If he doesn’t wave: Do not pass
As when mentioned by Joe and Gavin; “IF IN DOUBT – CAN OUT”
Hand signals are important if you don’t have a radio, or it’s a big job and there’s no sense in getting on the radio and having to fight the chatty pipe trash to fit a word in edgewise. Thumbs down means for the other partner to pass you and load first. Arms held up so forearms cross, creating an X means to load singly (often used when you need to bring in the edges on a cut/stockpile or clean up your windrows to put your cut to bed at night). Opening your door signals to your partner that you are about to come to a stop. Lead scraper raising his right hand when entering the fill signals the rear scraper to start a new line of dumps, not hook onto the end of the lead scraper’s.
When turning, stay off that back throttle. Use that front engine to pull you through turns. You’ll learn by feel at what point of a turn you can get back on that rear throttle to start pushing yourself. As soon as you’re straight enough, hammer both throttles to the floor and go.
When running twins, the hook-up and unhooking is important. It should be smooth and seamless. No slamming, no hard engagements, no scraper dragging the other out of the cut for a hundred feet. Probably the most difficult part to get smooth is when the rear scraper should set in and begin cutting, and when the front should then shift up and grab gears. Caterpillar’s literature/trainers teach that as soon as the rear scraper’s bail clears the tail-hook to immediately turn to the left to signal the lead machine. I don’t like that for one very simple reason: when you’ve got green hands, the rear scraper cab turning increases the propensity for someone to speed up or slow down and put a stinger into a battery box, up under the cab, or just generally smash fenders and damage scrapers. I prefer to use hand signals because it keeps everyone in a straight line eliminating the propensity for damage to the machines. As soon as the lead scraper sees his hand signal (just a raised hand), he shifts to 8th and takes off. After a pair of operators gets good, they can do how they want, but while learning, I like to keep everyone in a straight line.
I’ve got four scraper hands who have been working for me for five years now, all running twins. When they hired on, I told them to learn using hand signals to signal load/unhook. To this day, two of them still use it, like second nature. The other two dropped it after about 4 months. All four are excellent hands, all running GPS equipped scrapers. So it’s a lot of personal preference for how you and your partner like to run. Make sure you communicate with your partner about how you’re going to run things. More than anything, you need to have a partner you like to work with.
In the cut, make sure that the rear scraper sets in and starts cutting right where the front scraper lifted out. If there’s a noticeable transition where each machine started cutting, you need to talk to your partner to work on improving the second scraper’s set-in. That transition should be seamless. Keep the cut as smooth as possible.
The smoother, more level the cut, the faster the cycle times and the bigger the loads the scrapers will get. Twin engine scrapers should work together to chain load the cut. The smaller the number of scrapers working the cut, the easier it is to properly execute this. Cut like a typewriter. If you’ve got a lot of twins diving in/out of one cut, just plan on having a blade/beegee spend a lot of time maintaining that cut. Even with excellent scraper hands running as leaders, and radios to communicate, a bunch of scrapers will still get their typewriter cut a little off after a while. Just make sure there’s some communication and all lead hands are on the same page as to how to actually run the cut.
Make sure the haul road blade hand knows that while the scrapers are running, it’s his job to make the cut, haul roads and fill as smooth as the Autobahn. He shouldn’t be off making love to the fill trying to become a finish hand. That’s what finish blade operators are for. He should be constantly blading everything the scrapers are running on so that their ride is smooth and comfortable. The more comfortable the scraper hands, the more loads they’ll haul. If the scrapers are getting to beat to hell on their haul roads, send the blade hand down the road. The smoother and nicer the roads are for the scrapers, the better the scraper hands you can keep around. It’s the good hands who can truly harness the scraper’s potential as the most versatile earthmoving machine that’s been built. So take care of them.
Go fast and have fun.
