USE OF PNEUMATIC CAPSULE PIPELINE FOR UNDERGROUND TUNNELING Paper presented at the 12th International Symposium on Freight Pipelines,
Prague, Czech Republic, September 20-24, 2004

USE OF PNEUMATIC CAPSULE PIPELINE FOR UNDERGROUND TUNNELING

Henry Liu

Freight Pipeline Company, 2681 Maguire Blvd., Columbia, Missouri, U.S.A.; E-mail: fpc_liuh@yahoo.com

Sanai Kosugi

Pipeline Engineering , Sumitomo Metal Industries, Ltd., 1-8-11, Harumi, Chuo City, Tokyo 104-6111, Japan;
E-mail: kosugi-sni@sumitomometals.co.jp


Pneumatic capsule pipeline (PCP) has been used successfully in Japan to construct the Akima tunnel, which is a cross-mountain
rail tunnel 8 km long. A similar system has been considered recently for possible use in New York City for constructing deep
underground tunnels. This paper presents the result of the New York study, which is one of several potential applications of PCP
to New York City considered and analyzed in a recently completed research project. Although this study was conducted with
application to New York City in mind, it is rather general in scope and hence is believed to be applicable to also many other
major cities around the world that need to build deep underground tunnels. The study found that with the use of a PCP system
similar to the one used for the Akima tunnel, and with the use of a vertical lift system for transporting capsules from underground
tunnels to aboveground streets, the PCP technology can be used for deep underground tunneling not only to enhance construction
safety and reduce air pollution generated by trucks but also to reduce the tunnel construction cost.

KEY WORDS: capsule pipeline, pneumatic capsule pipeline, tunneling, tunnels, underground



1. INTRODUCTION

Pneumatic capsule pipeline (PCP) is the modern version of the tube transport system used throughout the
world for over a century as discussed in Liu (2003) and many other publications such as Zandi (1976), ASCE
(1998), and Cohen (1999). In contrast to the tube transport technology which uses small-diameter pipe (usually less
than 200mm) and non-wheeled capsules each of which carrying less than 10 kg of materials (usually less than 1 kg),
the newer technology of PCP uses larger pipes of the order of 1m, and uses wheeled capsules each of which carrying
more than one tonne (1000 kg) of cargo. Such PCPs have been used successfully in both the Former Soviet Union
(FSU) for transporting rocks (Jvarsheishvili, 1981), and in Japan for transporting: limestone to a large cement plant
(Kosugi, 1992), excavated materials for disposal in a tunnel construction project (Kosugi 1999), vertical transport of
soil in underground excavation (ASCE 2002), and other applications (Yanida, 1982).
In 2003, the New York State Energy Research and Development Authority (NYSERDA) awarded a contract to
the Freight Pipeline Company to investigate the feasibility of using PCP for underground freight transport in New
York City. The project, completed in June 2004, explored various potential applications of PCP to New York City.
Six different potential applications were studied in detail. They are: (1) tunnel construction, (2) solid waste transport,
(3) mail and parcel transport, (4) transporting goods on pallets and in boxes, crates and bags, (5) container dispatch
from ports, and (6) transporting entire trucks.
The first of the six applications mentioned above, tunnel construction, is the focus of this paper and will be
discussed in detail in the next section. The other five applications will be described only briefly here. In the
application to solid waste transport, a PCP was designed to transport 18000 short tons (16400 tonnes) of solid waste
per day to a common large landfill at a distance 55 miles (89 km) away. This PCP would use steel pipe of 40-inch (1
m) diameter, and would use blowers to drive the air and capsules through the pipeline. In the application to mail and
parcel transport, a 1m diameter steel pipe would be used to transport mail and parcels from New York City to
Washington D.C. over a distance of 210 miles (338 km). This system, driven by linear induction motor (LIM)
pumps instead of blowers, would operate at a linefill rate of 10% and a cargo throughput of 31030 short tons ( 28210
tonnes). Note that linefill is the portion of the pipeline occupied by capsules divided by the total length of the
pipeline. The system would have five inlet/outlet stations in New York City, one in Washington D.C., and one in
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each of the four major cities en route: Newark, Trenton, Philadelphia and Baltimore. In the application to
transporting pallet goods, a network of PCPs consisting of circular tunnels of 7 ft (2.13 m) diameter would be used.
These tunnels would be constructed by using modern tunnel boring machines (TBM) through the bedrock under
New York City, at a depth between 50 m and 100 m underground. The network would have multiple cells; each cell
would contain an underground inlet/outlet station similar to that of ordinary subway stations, with vertical
connection to the streets through elevators. Most of the freight that needs to be transported in New York City,
whether on pallets or in boxes, crates and bags, can be transported by this system between underground stations.
Once a cargo has reached its destination, it would be unloaded from the capsule and transferred to one or more
battery-powered vehicles, which would then be transported by elevators to streets above for local delivery. The
system has a capacity of transporting 205000 short tons (186000 tonnes) of freight in each direction, more than
enough to handle most of the freight that need to be transported at present.
In another application, a large pipe has been considered for transporting standard size containers between four
ports in New York City and a container inspection/intermodal-transfer station located in an inland rural location 24
miles (39 km) away from the City. This PCP would use a combination of circular tunnels (for the portion under
urban areas and the bays where construction is by boring tunnels through bedrock) and rectangular conduit (for the
portion in rural areas where construction can be done by open-cut). The PCP would be driven by LIM pumps, and
would have a capacity of transporting 30200 TEUs (twenty-foot-equivalent units) of containers per day in each
direction, which is more than adequate for handling the large number of containers currently arriving at the ports of
New York City each day. Finally, a PCP system of large rectangular cross-section and 1.8 km length has been
considered for ferrying trucks through a special region of New York City the Hunts Point. The system is similar to
the Euro Tunnel between England and France, except that it would be much shorter, be on land instead of undersea,
would use PCP capsules instead of electric trains to ferry trucks, and would cost much less than the Euro Tunnel.
More about each of these applications can be found in the final report of the project written by Liu (2004). The
project concluded that all the six potential applications can be justified on combined merits of cost-effectiveness,
environmental values and social values. Five of the six applications, except for the truck ferrying system in Hunts
Point, are cost effective. Benefits that can be derived from implementing these applications in New York City would
include the following:
Drastic reduction in the need for trucks and the number of trucks that clog the Citys streets.
Drastic reduction in air pollution, noise and accidents generated by trucks. Since PCP uses electricity
instead of diesel fuel, it causes much less air pollution in New York City.
More rapid delivery of goods than currently possible by trucks on congested streets.
Greater reliability in freight deliverybecause PCPs are unaffected by inclement weather, traffic jam and
road/street repairs.
Conservation of energyPCP uses much less energy than truck uses in congested cities where trucks
cannot operate efficiently due to traffic jam.
Reduced reliance on foreign oilwhile trucks uses diesel fuel, PCP uses electricity, which can be supplied
by U.S. domestic energy sources, including renewable sources.
Increased securityGoods to be delivered by PCPs cannot be stolen as easily as those transported by
trucks. Terrorists cannot hijack the vehicles (capsules enclosed in an underground pipeline) and use them as
car bombs or truck bombs. Also, it is far more difficult for terrorists to attack an underground pipeline and
inflict catastrophic damage to it than to an aboveground structure such as a building or a bridge. Unlike
aboveground structures, which are readily accessible by terrorists and difficult to guard against their
attacks, underground pipelines are inaccessible to people except at the inlet and outlet and hence can be
more easily guarded against any attack or sabotage. Even though the routes of certain PCPs would be under
major structures of the New York City, they dont pose serious security threats because they are deeply
underground inside bedrocks. Even if a terrorist could sneak a bomb into the pipe and cause an explosion, it
would not damage the building aboveground during to the containment of the explosion by the thick layer
of hard bedrock above the pipeline. Besides, due to security protection at the inlet and outlet of the
pipeline, it would be very difficult for any terrorist to sneak a bomb into the pipeline. It would be much
easier and