Several factors go into spec’ing the most effective, productive, durable and versatile flatbed trailers to meet a fleet’s operational needs. Great Dane Trailers supplied the following to provide fleet managers with some important information about flatbed ratings:
The foundation of a platform trailer –– its main load-carrying component –– is its beams. Most models are built using I-beams, which consist of top and bottom flanges connected to a thin web. In use, beams convert the vertical loads of the cargo into tensile forces on the bottom flanges and compressive forces on the top flanges. For a higher strength platform trailer beam, the usual method is to increase the thickness of the flanges, although that comes at the cost of increased weight.
One of the ways flatbed manufacturers refer to the strength of their trailers is in beam ratings. A beam rating is a theoretical calculation of the structural capability of the platform trailer’s beams. Beam ratings are a function of trailer length, kingpin and suspension locations, beam design, flange and web strength, flange thickness, and type of loading (evenly distributed or concentrated).
Manufacturers can determine beam ratings in different ways. For example, an OEM may choose to calculate a beam rating based on static loading. While this will result in a very high rating, it has no relationship to the trailer’s actual load-carrying capability. Similarly, the rating for a beam used on a 45-ft. trailer can be vastly different than the rating when that same beam is used on a 53-ft. model. And a large beam rating is not an indication that the load can be carried legally or without overloading axles or suspension components.
A more realistic way to evaluate a trailer’s carrying ability is to use gross vehicle weight rating (GVWR) and gross axle weight rating (GAWR). GVWR is the maximum rated combined weight of a trailer and its payload based on its structural capabilities. GAWR is the rated load-carrying capacity of an individual axle and wheel assembly restricted to the lowest working rating of any component in the system.
Great Dane calculates each platform trailers’ GVWR using methods approved by the Truck Trailer Manufacturers Association. This methodology takes into account the limitations of the GAWR to avoid misleading customers into loading a vehicle in a manner that would cause components to be overloaded.
Great Dane Trailers
(www.greatdanetrailers.com ) platform trailer offerings include the manufacturer’s FREEDOM Flatbed, part of an “in stock” program that produces multiple units with standard specs. The design and engineering of the line of straight frame and drop-deck platforms, according to the OEM, includes models with 12-in. crossmember spacing for extra strength in forklift operations and with 16-in. spacing for heavy-load hauling. The trailers also feature a rear crossmember constructed of extruded aluminum and doubler plates to provide reinforcement of crossmember punches and transition areas.
Another key feature of the FREEDOM line are the trailers’ standard extruded aluminum side rails designed to provide an almost infinite number of cargo restraint locations. The built-in tracks use industry-standard “Double-L” winches, which can be installed at any location on either or both sides of the trailers, and always provide an anchor point for flat hooks to secure loads. The built-in winch track was thoroughly tested, the OEM notes, and meets or exceeds U.S. and Canadian requirements.
Great Dane also offers a line of Combo flatbeds. The lightweight steel-aluminum combination GPL models feature Huckbolt construction in place of welding to eliminate the possibility of cracks. GPL models are offered with standard specifications that can be customized to meet the needs of specific operations. For example, basic add-ons include toolboxes, tire carriers, bulkheads, winches and straps, and other modifications on request.
Utility Trailer Manufacturing Co.
(www.utilitytrailer.com ) recently introduced its new 4000A flatbed. Based on the company’s 2000A model, the 4000A offers equal beam strength, including an 80,000 lb. distributed load beam rating, while featuring an aluminum-steel composite that reduces tare weight by 400 lbs. The 4000A features Hendrickson Narrow Hanger AANT 23K spread axle-air ride suspension, an 80,000 PSI steel main beam top flange, 6,500-lb. working load pipe spools, and aluminum side rails with an integral sliding winch track.
Utility also offers its center-frame 2000S steel flatbed model with a beam capacity rating of 80,000 lbs. evenly distributed, up to 60,000 lbs. concentrated over ten feet, and as much as 57,000 lbs. single coil capacity in the center, based on the trailer’s wheelbase. Options on the 2000S include factory-installed bulkheads, extra floor nailing strips, a coil steel reinforcement package, sliding suspensions, tri-axle suspensions and goosenecks in various extensions.
Utility also manufactures a line of flatbed doubles available in both center and wide-frame models. Both feature a beam rating of 30,000 lbs. distributed load capacity. In addition, the OEM offers a dual-axle; drop frame flatbed in both aluminum-steel and all-steel designs.
(www.eastmfg.com ) offers a number of flatbed trailers, including the MMX Flatbed, rated up to 72,000 lbs. (concentrated in 4 ft. on a 48-ft. spread-axle trailer), and up to 145,000 lbs. distributed (multi-axle), and the Beast (BST) flatbed, rated up to 50,000 lbs. (concentrated) and up to 80,000 lbs. distributed (tandem axle). Additional styles include drop platforms and aluminum B-trains.
A unique optional offering for East platform trailers is a built-in stairway. When open, the aluminum integrated stairway’s deck lid locks securely in the upright position via double rods that slide into two specially designed receivers. The first of two handrails is located under the lid, providing a 45° vertical handhold that’s above deck height.The second handrail is built next to the steps, which are made of punched aluminum for both drainage as well as skid-resistance. In the down position, the deck lid latches to prevent bouncing during transit and lights that comply with DOT requirements are built into the lower step as well.
(www.transcraft.com ) a wholly owned subsidiary of Wabash National Corp., offers several flatbed models, including standard-duty, heavy-duty and extreme-duty versions of its Eagle, Eagle II and all-steel TL-2000 models. Offered are 42-, 45-, 48- and 53-ft. lengths and 96- or 102-in. widths. Lightweight features on some models include tandem, various axle spacings, and aluminum floors, front and rear plates, side rails and floor sills.
Recently, Transcraft announced that it has increased the legal payload capacity of its standard duty flatbed models by approximately 8,000 lbs. to allow fleets to haul more freight. The company’s standard-duty flatbed trailers, which were formerly designated as “normal” duty with a 65,000-lb. GVWR, now carry a GVWR of 73,000 lbs. The added capacity, which was achieved through engineering and the use of higher-strength materials, is effective on 2008 model year flatbeds.