Trailer Talk

Wabash Shows What a 33-Foot Pup Would Look Like

Stretching a 28-foot pup trailer to 33 feet would not be difficult, and Wabash National already has a procedure ready to go.

March 31, 2014

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What would a 28-foot pup trailer look like if it were stretched to 33 feet? The photo of a Wabash National van at the Technology & Maintenance Council’s annual meeting and expo a few weeks ago in Nashville gives us an idea, but here are some details.

In the name of productivity and for the sake of cutting traffic congestion, the less-than-truckload segment of the industry has asked Congress to approve the idea. It would require altering a federal law limiting pups to 28 feet in length.

A pair of 33-foot pups would offer 18% more volume than the current federally approved double-trailer combination, and would require fewer trucks to move the same amount of freight over the highways. As the economy recovers and the country continues to grow, more and more freight will have to be hauled, and the industry doesn’t see how it can do it with the current restrictions and a worsening driver shortage.

Significantly, the proposal does not ask for an increase to the federally imposed weight limit of 80,000 pounds for a set of doubles (or any other five-axle rig) – a sticking point for previous ideas because more weight per axle will put more wear and tear on pavement and bridges. And it has nothing to do with long combination vehicles operating in certain states and on some toll roads.

Staying with 80,000 pounds would work for LTL carriers because their rigs usually “cube out” before they “weigh out,” meaning the trailers are filled with relatively light commodities before reaching the weight limit.

Members of Congress concerned with highway legislation are reportedly inclined to OK the idea, and passage has a good chance, observers say. If it happens, we’ll soon see a rapid conversion of 28s to 33s, and of course the building of new 33-footers.

We old-timers recall similar expansion of the nation’s fleet of 40-foot trailers to 45 feet, then 45 to 48 feet, and finally to the current 53-foot standard.

Thousands of van trailers were stretched from 45 to 48 feet in the early to mid-1980s. It was a relatively simple procedure where mechanics inserted additional wall, floor and roof material somewhere along a 45-footer’s body. Usually it was at the tail, just ahead of the doors and behind the tandem, so the stretched frame wasn’t stressed much where it was grafted on.

So it would mostly go with a 5-foot stretch needed for a 28-to-33-foot conversion, according to Mark Ehrlich, Wabash’s business development manager. “It would not be difficult. We have a procedure all ready,” he said, but declined to describe it for competitive reasons.

The 33-footer shown at the TMC expo was built from scratch, and carried graphics describing where its end would be if it were a common 28. Its construction is like a 28, with composite walls and other details from Wabash’s line of van trailers.

Its rear axle is close the trailer’s rear end, as with a 28. That's where it would likely stay in a stretch,  to preserve the dynamics between a lead trailer and a converter dollie’s tongue, and therefore the second trailer, while going through turns. This would require moving the axle rearward after adding 5 feet of body -- nothing too complicated. 

Anyway, take a look, for this could be the future.


  1. 1. Big Yellower [ April 01, 2014 @ 07:03PM ]

    The ironic thing is they run double 32',35', and varies of combinations all over western US for past 20+ or so years..

  2. 2. roger [ April 06, 2014 @ 09:00AM ]

    no way how about 18 %more pay I am tired of longer trailers but no more pay just like pulling triples our company gives a penny more what a joke maybe its time for the whole ltl industry to tell them no way we wont do it all this is is corporate grreed

  3. 3. Michael Gully [ April 06, 2014 @ 11:25AM ]

    Stretching trailers not a new concept. In the late 70's a lot of 45 footers were stretched to 48 foot before 102 wide became law in 1983. Also in past Fruehauf stretched a lot of rail trailers from 40 to 45 foot. Great benefit to LTL carriers using doubles or package carriers such as UPS / Fed Ex. As an industry LTL carriers highest paid aside Wal Mart. Also in the changing economic conditions of the USA the LTL business has shrunk and is immensely competitive. The larger pup will not create a safety risk and help keep some LTL carriers alive and preserve the jobs of many good people that wish for their company to survive. Triva point, when my dad and uncles started driving in the early 40's a 28 foot single axle was the standard while being considered a BIG truck. The 32 foot tandem came about in the Midwest around 1944. It was a big deal and considered a really BIG TRAILER then!

  4. 4. Ping Pong [ April 09, 2014 @ 11:29PM ]

    Bigger, more available cubic inches and 11 different carriers driving 500 mile turns wit 3 to five pallets where 14 or 16 could ride. Wave as your empty truck going that way passes mine going this way. Half the fun was waiting for a new widget. The money in Fast Freight lures carriers to concentrate on zipping all over to get the need it now dollars and fail to focus on consolidation that ought to be first and foremost to stretch our natural resources.

  5. 5. Micbael Cummings [ May 28, 2014 @ 09:01AM ]

    So of our yards are very tight. Parking would become a big problem.

  6. 6. Patrick [ September 03, 2015 @ 07:46PM ]

    I wonder how you would park ALL these doubles in a truck stop overnight. They may make changes to the trailers, but what about the "actual" operation "day to day" activities? Staying overnight at a truck stop because you're out of time. Backing into a spot? Are you going to disassemble your double, back it all in, then reassemble it? "That" would be the question I would want answered.

  7. 7. Fred Bezemer [ December 04, 2015 @ 03:49PM ]

    if they do pass these 33 ' doubles perhaps they could recommend "B" train configurations like we have in Canada at least then you could back them up to all the haters of this proposal especially people who have never even drove doubles. turning is easier due to the extra articulating point, I have never seen a set of doubles drive over curbs,signs cause property damage now when you look at some of the steering wheel holders nowadays look at all the damage they cause trying to maneuver a 53'one would have to wonder how do these people get their CDL so if safety is the concern here rather than efficiency perhaps lawmakers should stick their nose into the training these new drivers are getting from these puppy mill driving school


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Author Bio

Tom Berg

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Senior Contributing Editor

Journalist since 1965, truck writer and editor since 1978. CDL-qualified; conducts road tests on new heavy-, medium- and light-duty tractors and trucks. Specializes in vocational and hybrid vehicles.


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