Please let me introduce the drop deck tank container chassis. I’m sure I’ve written on the subject before, but there are always folks who are just getting into the industry, or possibly coming from a very different industry where they are exploring potentials of design. The unit pictures above was a very popular design through the late 1980’s well into the late 1990’s. These were originally designed to haul the ISO Tank Container (pictured below), which is built upon the 20 ft. ISO frame that standard shipping containers use with a steel barrel inside used mostly for hauling bulk liquids or gases. These are built with the same corner castings as boxes and can be quickly locked into the twist locks welded to the end of each tank chassis bolster. Together they make a very effective bulk liquid trailer. The drop deck tank chassis is named that because the “goose neck” portion is significantly lowered to give the chassis a 40″ or 41″ rear deck height. This lower center of gravity is best for transporting bulk liquids as it reduces the risk of roll overs.
The tandem axle 90 degree neck design has mainly been replaced today in 2016 because it is heavier than the newer “s-shaped” neck design that is prevalent today. That being said, this chassis type is still in high demand mainly for re-purposing projects. The solid neck and deep webbing of the I-beam frame provide a very robust frame for extending the bolsters and adding additional ones to be utilized for logging trailers, crane counter weights, custom tank for sealants and other construction or farm trailer uses. Their heavy duty frames can easily tolerate heavy loads of equipment and the tandem configuration usually wears evenly on the tires. These typically tare around 8,500 lbs.
The newest design on chassis is the 109″ spread axle tank chassis. This design has been around since the early 1990’s so it’s been well tested. The earliest designs had some neck failures due to the weight along the new tapered neck, but adding beam reinforcements in subsequent designs helped to mitigate that problem. With the 109″ spread, in most states, you can load up the rear axles to 40,000 lbs – 42,000 lbs of weight. You’ll note, this design still maintains its very deep webbing/main rail I-beam. Then you see another taper towards the rear again. With some less steel in the design, most units come in around 7,690 lbs. with those manufactured in the last 5 years or so coming in closer to 7,400 lbs.
These units are also available in a tri-axle configuration as pictured below. These configurations are much less frequently available on the used market. The tri-axle configuration allows up to 42,000 lbs. of weight on rear axle configuration and is useful in places with poor infrastructure.
Generally most used tank chassis or used drop deck tank chassis come with spring supsension, 255/70R 22.5 Low profile radial tires, and hubb piloted wheels. Very few come with stud piloted wheels, and many tandems come with spoke wheels.
These tank chassis have been in use effectively for a few decades now and can have a long healthy life with proper preventative maintenance and restoration. Their relative low cost compared to platform trailers make them ideal candidates for re-purposing as well. If you’re interested in further information, please contact our office at 832-433-7114 or email [email protected].
