Weight and Balance - Trailmobile is a leading …

1 We covered this issue to some extent in our Apriledition (Careers, Axle Weights and StayingLegal ), but it seems I was a little of f the mark inmy theory for loading to legal maximums. RayCamball of Trailmobile Canada called me to saythat while I was on the right track, I was wrong insimply suggesting that drivers parcel out the loadand place so much here and so much there. Hekindly agreed to help out in providing a more pre-cise approach to the exercise. So, with Ray s help and perspective, we re going totake another look at axle weights here. And for clar-ity s sake, we ll be using American axle- Weight limitsin most of our examples. Some Canadian examplesappear in the chart on p34/35. Axle- Weight violations are costly, and they doaffect a carrier s safety ratings in many juris-dictions. But there are other aspects to theissue as well, like equipment spec ing and vehiclehandling characteristics, to name just a couple.

2 Trailer makers use Weight -distribution soft-ware to calculate axle weights under differentpayload and vehicle configuration conditionswhen engineering trailers. It s easy to load atruck right to the pound in a computer simula-tion, but it s a bit tougher to eyeball the load tothe legal maximum. With the help of TrailmobileCanada s Ray Camball s, we ll explain how to loadfor better axle- Weight distribution. Knowing howto load could save you a bit of dough on your nexttrip across a scale or when spec ing your nexttruck or trailer. In aviation, this exercise is called the weightand Balance calculation. It s the art and science ofproperly distributing the Weight of the passengersand their baggage on an aircraft. You can t, forexample, put all the passengers in the front of theplane because you d never get the nose to lift fortake-off.

3 Where Weight is placed on a trailer can alsomake an incredible difference, like 5000 to 10,000lb in lost payload capacity in a worst-case scenario,Camball says. You might think that distributing the weightevenly from front to back in the trailer will balancethe Weight borne by the drive and trailer axles, butthat s usually not the case. Placing the load on thetrailer in such a way as to split the Weight evenlyon either side of the trailer s mid-point will usuallyresult in a larger portion of the load s total weightbeing borne by the trailer axles. Knowing whereto center your load on the trailer can make all thedifference between a legal load, and an over- Weight AnalysisBefore we start mapping out load placement, itwould be worth looking at some of the factors thataffect payload capacity and Weight kingpin placement is one of the more sig-nificant ones.

4 You ll have probably noticed thatmulti-axle trailers have shallow pin placements, 2430highwaySTAR July 2003 Careers TRUCKING 202 Weight and BalanceLoading for maximum axle Weight is a science. But in the real world, there are just too many variables to nail every situation. By Jim ParkDespite your best efforts in getting legal beforeyou leave the dock, these folks keep a pretty closeeye on how well you do this part your is forearmed, and we re not talkingabout whether or not the lights are on. Learn toload the wagon properly. Reprinted with the permission of highwaySTAR 2003 highwaySTAR31in. or so, less in some cases, while the lead trailerof a set of B-trains tends to have a deeper kingpinsetting commonly around 42 in., with some asdeep as 60 in. or shallow setting causes more of the weightto ride on the trailer axles, which is desirable ina tri- or quad-axle application.

5 The deep settingon a B-train lead is designed to keep the weighton the tractor and off the center axle , the pup has a ver y shallow setting, intend-ed also to keep the Weight off the center axles byletting the pup tandem do most of the work. Thisis especially true in the case of a seven-axle train,while it s not so much of an issue with the eight-axle combinations. The 36-in. kingpin setting typical of 53-ft trail-ers is a compromise, and a throwback to the era of48-ft trailers. The 36-in. pin worked well with the48-footers, but the 53-footers really should have a42-in. pin setting, Camball says. When 53-ft trail-ers were introduced, a few jurisdictions had oldregulations on their books limiting the kingpin to36 in. and we pretty much decided to live with thatrather than go through a long and tedious processof convincing them to change their rules.

6 Now wehave to compromise by placing the center of thepayload [ Weight -wise] ahead of the center line ofthe trailer to overcome the effects of the wrong kingpin setting. By loading ahead of center, you removeweight from the trailer axle and place it towardthe front where, by sliding the fifth wheel for-ward, you can shift Weight off the drives andonto the steer axle. There are obvious limits to the Weight one canstuff onto a trailer; your payload will be dictatedby the gross combination Weight (GCW) limitminus the tare Weight of the truck and creates pressure to maximize payload byspec ing the absolute lightest unit possible using fewer crossmembers or vertical posts, forexample, or spec ing a lighter pick-up plate, by making better use of your existing carr y-ing capacity, Camball says you can often get awaywith spec ing a heavier and more durable tractor-trailer combination.

7 To gain a better understanding of how muchweight you re actually hauling, and how thatweight is distributed on the axles, ever y loadshould be weighed on an axle scale. You mightfind that you typically run light on the steer axle,light on the drives, but heavy on the trailer. Thiswould suggest the Weight is sitting too far backin the trailer. If you re heavy up front and light onthe back, the Weight might be too far for difference between the lightly loaded axleand its maximum carr ying capacity is lost pay-load potential that could be accommodated bysimply rearranging the freight. Being aware ofhow the Weight is distributed naturally is thefirst step toward learning how to position theweight where it should be to stay legal and tomaximize a few over Weight tickets may promptequipment buyers to lurch toward a lighter spec,simply learning to load the truck properly couldbe a wiser, less expensive alternative to thelighter spec.

8 Referring to the payload capacity chart on , the examples also illustrate how much pay-load capacity can be pulled out of two identicalunits just by loading them properly. As illustratedin example 13, switching from steel to aluminumwheels and hubs, going with low-profile tires, andskimping on the Weight of the structural parts,wouldn t make up one-quarter of the differencegained by just positoning the load for ward a cou-ple of same applies to over Weight fines: examinethe tickets to see where you re heavy, and adjustyour loading strategy to overcome the course, if you re over gross, there will need tobe some other adjustments made, which we can thelp you with. TRUCKING 202 Contact Recruiting or ext. 2293 Fax : carrier of Fleet Safety Award Grand Prize WinnerDO YOU CONSIDER YOURSELF TO BE ONE OF THE BEST VAN OWNER/OPERATORS IN THE INDUSTRY?

9 DO YOU CONSIDER YOURSELF TO BE ONE OF THE BEST VAN OWNER/OPERATORS IN THE INDUSTRY?We require the following Owner/Operators: Single Owner/Operators and Owner/Operators TeamsWe offer $ mile. Current fuel surcharge .0 6per Years in Business. Financial first 2000 litres of yard fuel FREEto all new first 2000 litres of yard fuel FREEto all new see us at the FERGUS TRUCK SHOWJuly 25th to 27thTRUCKING 202 CareersJuly 2003 highwaySTAR33 Ever ask yourself what you relooking for in a driving career?Think about it, then CALL US!Website: Email: 519-836-9396 NEWT rucksArriving!Expanding Our Fleet!We Need OTR Drivers, Teams & SinglesNOW HIRINGO wner/Operators andCompany Drivers Team or SingleVisit us at the FERGUS TRUCK SHOWThe Balancing ActWhen we talk about the center of the load, we re of course referring to the pointat which the load would Balance 23,000 lb at the front of the center point,and 23,000 lb to the rear of the center point.

10 Of course, the Weight center pointmight not be the actual middle of a row of pallets, especially if the load is mixedand of var ying weights. But here s where you earn your pay as a driver. You canmake your life less complicated by arranging the load prior to filling the trailerso as to keep it as evenly balanced as possible. If that s not an option, err on the side of caution by loading the heavier pal-lets first, but tr y to maintain a maximum floor loading of about 900 lb per footof trailer length. That would see two pallets loaded side by side, weighing atotal of 3600 lb. This approach isn t scientific, but it will give you a relativelyeven load from front to back. Centering the Load Centering the Weight -center of the load over the cen-ter line of the trailer may seem to be the obvious way to go, but it usuallyresults in overloaded trailer axles.