It is correct to have a single axle tractor pulling tandem axle trailer. Back in the 50's to 70's when I was driving truck, it was common to see single axle trctors with tandem axle trailers. The reason you would use a tandem axle tractor or trailer is to carry more weight. In wisconsin in the 60's, we could carry 19500 lbs on a single axle. We could carry 32,000 lbs on tandem axles. At that time, Wisconsin had a bridge law, which meant you had to have length to carry more weight. Example, in order to carry 19,500 on two axles, you had to have about 14' between the axles. With a semi, in order to carry a gross weight of 64,000 lbs, we had to have 22' between the tractor axle and center of the trailer axle. To carry 72,000 lbs, we had to have 30' between the tractor and trailer. To carry 72,000, we would have to have a tandem tractor and trailer. The truck I drove for many years was a dump trailer with a single axle tractor and tandem axle trailer. In the state of Illinois at this time, they did not have a bridge law so you could carry 72,000 lbs in a 20' dump trailer. So, trailer length plays a part in what and where you are modeling. If you are pulling double bottoms, you only need a single axle tractor because you don't have that much weight on the tractor axle. The weight is spread out between the trailer and dolly axles. The only time you would see a tandem axle tractor pull a single axle trailer is it the trucking comnpany didn't have a single axle tractor on hand. Sorry I got carried away with my answer.
Roy J Meissner ----- Original Message ----- From: Bob Werre To: [email protected] Sent: Monday, April 30, 2012 9:24 AM Subject: Re: {S-Scale List} trucks Roy, I've got a question for a 'truck' guy. In a truck/trailer situation, if the tractor only has one rear axle are they ever seen pulling double axle trailers? And of course, what about the opposite situation. Bob Werre cows got off of the tracks. We all thought that would be some "lean beef". Roy J Meissner __________ Information from ESET NOD32 Antivirus, version of virus signature database 7096 (20120429) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 7096 (20120429) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com
