Semi-trailers and freight cars are two very different pieces of equipment that perform the same task. One hauls cargo by road while the other hauls cargo by rail. But what if you could have both at the same time? That was the concept of the Triple Crown RoadRailer, a special semi-trailer that ran on both road and rail. These innovative trailers hauled auto parts and other goods for nearly 40 years, but now they’re dead and the reason why is kind of silly.

Triple Crown, a subsidiary of Norfolk Southern Railway, has long found a niche in the logistics business. There are customers who want the convenience of highway service, that is, door-to-door delivery of goods by truck, but are willing to accept the size and expense of long-distance delivery by rail. In general, it is cheaper to transport a ton of material a long distance by train than to transport a ton of material the same distance by truck. However, trucks can provide a fast door-to-door service that trains cannot.

What if you want both?You want to save costs by transporting goods by rail, but still want to have your goods delivered directly from the supplier to your doorstep with as little disruption as possible? Triple Crown found that niche, and for nearly four decades, auto parts suppliers and auto factories have used it to keep operations running smoothly. Fortunately, that niche is here to stay, but the equipment that made it possible is not.

How it works

Triple Crown was an alternative to traditional intermodal transportation. In intermodal freight transportation, trucks pull standardized containers mounted on a chassis to an intermodal facility. These containers are then lifted off the chassis and lowered onto a rail car chassis. The train then takes its load to another facility where the containers can be removed from the train and loaded onto another truck or perhaps a ship.

Much of the world’s logistics depends on intermodal transportation. In many situations, this is more cost-effective and better for the environment than simply sending a series of trucks to move the load. Union Pacific further explains:

Intermodal shipments typically fall into one of two categories: international intermodal or domestic intermodal. International intermodal shipments are transported in 20- or 40-foot containers. Because international intermodal shipments travel between ocean carriers, trucks, and trains, the product stays in the same container throughout the entire trip. Domestic intermodal shipments are transported in 53-foot containers. Although these shipments are called “domestic intermodal,” the products may still arrive from overseas. The main difference is that after the products arrive in 20- or 40-foot international containers, they are transferred to 53-foot containers for domestic delivery at a port, be it a cross-dock facility, transshipment facility, or distribution center. From there, they are transported to destinations within the country (hence “inland”).

What’s unique about Triple Crown Services is that it takes the chassis out of the equation. Triple Crown’s trailers traveled throughout the Midwest and Eastern United States. They didn’t need to be loaded onto ships or anything like that. So a truck with a Triple Crown trailer would drop it off at an origin facility, and the trailers would be joined together into a train and transported to a destination. Different trucks would pick up the trailers to take them to their final destinations. This type of configuration is called bimodal transportation.

Triple Crown advertised this as a “highway-like” service because while the trailers still traveled huge distances as if they were traveling on a highway, it took dozens of trucks out of service for some locomotives. The origin and destination facilities also didn’t require the kind of equipment needed for typical intermodal freight, like cranes or side loaders, because again, these were literally just truck trailers tied together into a train, not containerized freight.

As Trains Magazine As Norfolk Southern writes, it was not the first to come up with this idea. One of the first examples of this concept was the Chesapeake & Ohio Railway (see above). In the 1950s, this railroad offered what was known as the trailer service. Loaded truck trailers were loaded directly onto flat cars and pulled behind passenger trains. The railroad only offered this service for a few years.

The official name for these was “trailers-on-flat-cars,” but they were also called “piggybacks,” and one of Norfolk Southern’s predecessor railroads, the Norfolk and Western Railway, also offered a similar service:

In 1986, Norfolk Southern attempted to solve the problem of delivering auto parts from suppliers to plants and factories in the Midwest in a way that combined the advantages of rail and truck transportation.

This is what Triple Crown’s current network looks like (note the thicker line between Kansas City and Detroit, that’s the RoadRailer line that was just discontinued on Sunday):

Triple Crown Services was launched that year to transport auto parts between suppliers in St. Louis and auto plants in Detroit. The service was so popular that two years later Triple Crown Services was expanded to include a route between Chicago and Atlanta. In 1993, Conrail partnered with Triple Crown and opened the RoadRailer network to the east of America. RoadRailer later expanded to Minneapolis in the west, Fort Worth in the south and Toronto in the north.

I grew up watching Triple Crown RoadRailers haul freight around North Chicago, and I’ve always wondered how it works. How do truck trailers ride on rails? I mean, semi-trailers aren’t really designed to be lashed together in trains with 150 trailers. That’s right, a lot of those RoadRailers were really long trains made up of just semi-trailers.

Accordingly Trains Magazine and Triple Crown, a RoadRailer trailer has a reinforced frame. These heavy-duty frames are designed to withstand 400,000 pounds of towing and pulling forces, much more force than they would endure when pulled by a semi-trailer truck. They are additionally reinforced at the front and rear points where they attach to a coupler and the rail bogie.

This rail chassis is another specialized piece of equipment. Triple Crown says the trailer is pulled onto a track and an air suspension system lifts the trailer over the chassis. Then the trailer is backed onto the chassis and tied down. After that, the air suspension pulls the trailer’s wheels up so it no longer directly touches the ground. The chassis carries additional equipment as well as a braking system. The trailers have their own railroad brake line. Overall, the curb weight of a RoadRailer trailer is 800 to 1,000 pounds more than a typical semi-trailer of the same size.

Trains Magazine notes that RoadRailer trains between Detroit and St. Louis were often near or at the legal limit of 150 trailers. These trains were about 8,500 feet long, but only hauled 4,000 tons of freight. Much of this was auto parts, but also other general cargo that was transported in dry vans. A 4,000-ton load is not a heavy haul for a locomotive, so Norfolk Southern pulled these trains with just a single six-axle locomotive.

The RoadRailer system had other advantages too. The trailers weighed less than comparable rail vehicles and were only a foot apart, making them surprisingly aerodynamic for rail transport. The RoadRailers were also quite difficult to steal, as a foot of space is not really enough to break into a trailer and steal goods.

Wabash National was the manufacturer of the highly specialized RoadRailer trailers and both the trailers and the bogies went through several generations over the decades.

As silly as all this may sound, Triple Crown Services was considered so innovative that Amtrak, BNSF, Canadian National, CSX and Union Pacific all tried their hand at the RoadRailer thing, as did railroads in other countries as far away as Australia and India. Unfortunately for the U.S. railroads, RoadRailer service, while popular, was still niche and Norfolk Southern’s Triple Crown was king. So when other attempts failed, Triple Crown continued to thrive.

The end of an era

You may be wondering what happened. If the Triple Crown was so popular, why didn’t the last RoadRailer train run until last Sunday?

Accordingly Trains Magazineit’s about money. As you read above, Triple Crown Services used highly specialized equipment and that only made sense for the niche of customers Norfolk Southern found for the service. Over time, the RoadRailer equipment got old and as the equipment aged, the railroad company decided it would be too expensive to modernize the fleet. And since Norfolk Southern wouldn’t repair the aging fleet, the RoadRailers would no longer be able to do their job reliably. Trains can’t sit around waiting for repairs, so Norfolk Southern decided to scale back Triple Crown operations.

First, most RoadRailer routes were discontinued. In 2015, the Triple Crown’s operations were reduced from 13 terminals to just two, the lucrative auto parts route from Kansas City to Detroit. Then came the announcement that the RoadRailers as we know them would be discontinued on August 25. As if to bolster Norfolk Southern’s argument about lower reliability, the last train was delayed by over four hours due to equipment failures. Still, railfans in the Midwest chased the train to get the last shots of the last train using this strange concept.

In an interesting twist, Norfolk Southern says this is not the end of Triple Crown or the RoadRailers. The company wants to expand the Triple Crown network again, but the trains will not carry modified truck trailers, but typical standardized intermodal containers, from Trains Magazine:

“With great appreciation for the historic role RoadRailers has played in expanding our network, Norfolk Southern plans to retire the equipment and launch a new service product with greater value that will enable growth for our railroad and our customers,” said spokeswoman Katie Byrd. “We will move the Triple Crown business to its TCZU 53-foot container fleet, freeing up capacity on existing trains and paving the way to expand Crown services across North America.”

So that’s the end. For nearly 39 years, Norfolk Southern pulled trains across the American East that were essentially just truck trailers tied together. It sounded silly, but it made sense, as it combined trains and trucks into a single service. Now the rails in the Midwest are getting a little duller.