|Doubles hauling lumber|
|Use of Turkey rack to gain extra wheelbase|
|Dump Truck and Pup|
|Dump Truck and Pup (alternate)|
Shown here are a variety of different ways to build a truck combination that will allow extra weight in the Pacific Northwest. Oregon, Washington and a number of Rocky Mountain states follow similar rules for allowing trucks to exceed the national standards of 80,000 lbs on 5 axles. A number of these states will allow combinations to 105,500 lbs by special permit with enough axles. Usually 8 axles is the magic number although it can be done with 7, I think.
The first truck is a classic configuration for a flatbed. It is a very traditional flatbed semi with 5 axles (an 18 wheeler) fitted to pull a second trailer (a pup) In this configuration the first trailer is usually a classic 35-40 foot trailer, and the second trailer is a 20 foot trailer. Oregon and Washington (with a special permit) will allow the 2 trailers an the space between them to be 68 feet long without an over length issue. A variation is the "B-Train" which consists to 2 similar trailers, but the first trailer has 3 axles on the back and the front of second trailer rests on the back of the first trailer sharing the 3 axle combination. The "B train" is said to handle better than the classic doubles presumably the "A-Train" though they aren't called that. "B-trains" were popularized in Canada, but are now often seen in the NW as well.
The second truck is a classic Northwest log truck with 2 lift axles and a turkey rack. Log trailers have a telescoping reach and normally for shorter logs operators just shorted up the reach so they can bunk shorter logs. This, of course, compromises the ability to haul maximum weight because 'getting the weight' under the bridge formula requires certain wheelbase requirements. Here the operator installed a turkey rack with extra bunks on the combination allowing the long wheelbase even though the logs are relatively short. He is hauling Alder logs which are normally sold in 30 foot lengths which is too short to fit on a classic log truck lengthened to carry maximum weight.
The 3rd and 4th trucks are dumptrucks with pups. Both are 8 axle combinations, but one uses a 5-3 axle combination while the other has a 4-4 combination.
The 5th truck shown here is a special purpose truck for hauling trash and scrap metal. Here it was dumping a load of scrap metal, but it wouldn't surprise me if the combination is also used for transporting trash to distant landfills. Both boxes dump. The tongue extends to facilitate jackknifing the trailer allowing the truck to be dumped without disconnecting the trailer.