Adapted from Coyle, J.J., E.J. Bardi and R.A. Novack (1994) Transportation,
Fourth Edition, St. Paul/Minneapolis: West Publishing Company, p. 262.
Piggyback and Doublestack Train Cars
One of the first attempts at piggybacking dates back to 1872 when
the Barnum & Bailey Circus used its own special train of flat railroad
cars to tour cities in the United States. It took 3 to 5 hours and considerable
effort to unload and load trailers, but the concept remained and piggybacking
started to be adopted by railroad operators. By the 1950s piggybacking
became increasingly used and a good source of income for rail companies,
with the common piggyback load being two 40 foot trailers.
By the 1980s, containerization however changed from piggybacking to stacking and then
to doublestacking where possible. Piggybacking became a marginal
activity. Doublestacking of containers (Container
on Flat Car; COFC) saves much more convoy space than the piggyback method
(Trailer on Flat Car; TOFC) with the added advantage of not to have
to carry a trailer. However, several rail routes are not compatible with
doublestacking because of the required height clearance for bridges
and tunnels (5.5 meters). Converting a rail line to doublestacking can
be a costly undertaking, especially on the much older European rail
system where bridge clearances tend to be lower. In North America, such
investments are done over high priority corridors. Additionally, the
standard trailer size in North America grew to 48 foot and then
53 foot, changing the
dynamics and the economics of piggybacking.