Lots of things have changed in more than 150 years of US railroading, but until now one rule has never varied: You couldn't run a railroad without railroad cars.
Today you can, say Connecticut-based promotor Robert Reebie and his backers at the giant Chicago-based North American Car Corporation.
Mr. Reebie and a growing number of fans in the railroad industry insist the American railroads now can haul high-revenue merchandise shipments in highway semi-trailers fitted with a special set of retractable steel wheels that allow the trailer to be run on rails behind a locomotive.
The RoadRailer, as Reebie calls his trainlike truck, has already been tested in revenue service on five US railroads. Despite some initial skepticism from traditional railroad operating officials, it seems to be winning more than grudging approval, particularly from railroad marketing executives who are eager to lure lucrative merchandise traffic off the highway and back to the newly deregulated rails.
One of those executives is Peter Novas, vice-president for intermodal (piggyback and container) traffic at the Illinois Central Gulf Railroad (ICG), the first carrier to lease a set of RoadRailers and place them in nightly scheduled service.
A maverick marketing specialist and engineer, Mr. Novas agreed to test a special train of 50 RoadRailer trailers last spring between Memphis and Louisville because the new technology promised to solve a pesky operational problem that has kept the ICG from developing the route's potential as a ''corridor.''
''We identified a lot of overnight truck traffic between those two points that should have been on a piggyback train,'' Novas said.
''But our track between Memphis and Louisville has so many curves and hills, especially on the east end between Louisville and Paducah, that there's no way a conventional train can make the same schedule as a truck on the Interstate.
''Regular piggyback flatcars are 89 feet long, so you can't go around tight curves very fast with them,'' Novas explained, ''and the weight of the cars means it takes a long time to get up to speed when you reach a straight stretch and a long time to slow down when you come to a curve.''
The RoadRailer solves that problem by dispensing with the flatcars entirely, using the trailers alone as a train.
Since each 45-foot trailer is half the length of a piggyback car, it does a better job of tracking through curves. And because RoadRailers alone weigh 178 per cent less than a piggyback train of the same capacity, fewer locomotives are needed, trains accelerate to top speed sooner, and only half the usual distance is needed to make a complete stop.
Result: ICG's experimental RoadRailer train made the tough Louisville-Memphis run four times on a truck-competitive schedule of about 16 hours, resulting in ICG's decision to lease a fleet of trailers and begin service Sept. 28. Planned track and handling improvements could slice another two or three hours off the train's time.
''We are meeting the test of the marketplace with flying colors,'' Mr.Novas said.
''This train brought us brand-new business - not business that used to be in boxcars or on somebody else's piggyback train, but highway business that had never been on a train before. There's a good chance we could be the first railroad to sign a lease for a set of RoadRailer equipment.''
Earlier, the RoadRailer train made demonstration revenue runs from Washington , D.C., to Jacksonville, Fla., over the Richmond, Fredericksburg & Potomac and the Seaboard Coast Line railroads; between Chicago and Los Angeles via the Chicago & North Western and the Union Pacific; and between Chicago and Seattle on the Burlington Northern.
Two of the trailers, carrying simulated loads, survived a grueling winter-test program in a Montreal-Toronto shuttle on the Canadian National, and the Federal Railroad Administration (FRA) tried to punish the equipment at its test-track facility near Pueblo, Colo. The FRA tests showed RoadRailers can operate safety at 105 miles an hour forward and 65 m.p.h. backward.
From a commercial standpoint, however, the ICG's nightly runs are probably the most critical for the future of the RoadRailer because only the Louisville-Memphis route involves substantial stretches of difficult track paralleling a federally subsidized motorway carrying freight that so far has been invulnerable to railroad competition.
The feeling at the back of the railroad industry's mind seems to be that if ICG can successfully divert truck traffic to its crooked, hilly line between Louisville and Paducah, no highway in the country is safe from rail competition.
To make sure its backers understand precisely just what RoadRailer can and cannot do, every demonstration trip proceeds under the scrutiny of a team of engineers, technicians, and officials of the host railroad riding in a laboratory car sandwiched between the locomotive and the RoadRailers.
So far, Reebie says, RoadRailers have cut the use of diesel fuel by about 44 percent compared with conventional TOFC (trailer on flatcar) trains - no mean achievement considering that TOFC itself is usually two to three times more fuel-efficient that highway trucking.
The RoadRailer does have its drawbacks, however. While considerably lighter than an equivalent TOFC train, the trailers are heavier on an individual basis than conventional highway trailers not equipped with railroad wheels. Also, RoadRailers cannot be mixed in the same train with conventional rolling stock.
But since RoadRailers do not have to be hoisted aboard flatcars, the railroad saves not only the cost of the flatcar but also the cost of the cranes used to hoist trailers aboard trains at special piggyback yards.
When it's all together the RoadRailer train looks a little strange to veteran railroaders - almost like an aluminum snake.
Typical TOFC trailers stand two to four feet apart on flatcars which themeselves are separated by gaps of four or five feet. But RoadRailers, because of their simpler hitches, show only about a foot of daylight at their junction points.
''This train is theft-proof when it's standing in a yard,'' says a North American spokesman. ''The cars are so close together you can't get the doors open.''