CANTON, Ohio, Dec. 1, 2010 /PRNewswire/ -- (NYSE: TKR): On
Oct. 15, 2010, Switzerland's Gotthard base tunnel became a
reality. At 2:17 p.m. Geneva Time
that day, a boring machine in the east tunnel located 6 km (3.7 mi)
south of Sedrun broke through the last meter of rock deep inside
the Alpine range. The colossal 57-km (35.4-mi) Gotthard
railway tunnel is the world's longest, most deeply set passage of
its kind. It took 15 years, 3,000 workers, euro 9.1 billion (US$12.7
billion) - and thousands of bearings made by The Timken
Company - to complete.
(Photo: http://photos.prnewswire.com/prnh/20101201/CL10166
)
(Logo:
http://photos.prnewswire.com/prnh/20100210/TIMKENLOGO )
Four Herrenknecht Gripper tunnel boring machines completed the
work, which excavated and secured two parallel, main-tunnel tubes
of more than 85 km (52.8 mi), for a combined expanse of 114 km
(70.8 mi). Since 2003, the cutter assemblies in these
machines required thousands of Timken® standard and P900 tapered
roller bearings. Frequent bearing replacement helped the machinery
manage grueling loads and difficult conditions while making the
passageway through the mountains.
Timken's P900 bearings feature surface modifications to help
address performance concerns associated with the mountain
conditions such as marginal lubrication, a maintenance constraint
caused by an overburden of rock of 2,500 m (8,202 ft).
Additionally, special race profiles in the P900 bearings help
manage the higher loads and misalignment conditions, which pose
particular engineering challenges for deep tunneling applications.
"This is perhaps one of the most challenging applications for
cutter-specified tapered roller bearings," said Steve Boyd, Timken principal application
engineer, who assisted the cutter design. "The rugged terrain
required a cutting action that subjected the bearings to highly
variable loads. Leading up to the start of this massive
project, our customer engineering group provided detailed modeling
of the bearing loads to assist in optimizing the bearing
design."
Supplying such a large quantity of bearings through the duration
of the project was a challenge. "During the actual tunneling phase,
our customer service and supply chain teams had to maintain
delivery and service levels to avoid any work stoppage over the
eight-year work period," said John O'Hearn, specialist, Timken
Tunnel Boring Sales.
Herrenknecht's best boring machine performance on this project
was a record-breaking 56 m (184 ft) – at a 9.5 m (31 ft) diameter –
in a 24-hour period. The top monthly tunneling performance
for Herrenknecht's boring machines was 711 m (2,333 ft). As
they cut deep inside the mountain, grippers at the rear of the
boring machines braced themselves with two gripper plates against
the rock. From there, hydraulic cylinders pushed the cutter
heads into the tunnel face. Rock chips that broke out between
the 75 mm to 90 mm spaced concentric cutter tracks at the face were
removed from the tunnel to the surface on a conveyor belt.
David Krauter, Herrenknecht
cutter product manager based in Sumner,
Wash., said, "The cutters are rated for a load capacity of
267 kilonewtons (approximately 60,000 lbs.). Because of the
severe and challenging environment, bearing reliability was of
great importance."
The Gotthard base tunnel in Switzerland connects the north portal in
Erstfeld (Canton Uri) with the south portal in Bodio (Canton
Ticino) and consists of two side-by-side, single-track tubes that
are connected every 325 m (1,066 ft) with 40 m (131 ft) galleries.
Projected to be operational by the end of 2017, officials
expect the tunnel to markedly improve high-speed passenger and
heavy-freight transport in Europe.
Travel time between Zurich
and Milan, for example, would be
reduced nearly an hour – from 3 hours and 40 minutes to 2 hours and
50 minutes.
About The Timken Company
The Timken Company (NYSE: TKR, http://www.timken.com) keeps the
world turning with innovative friction management and power
transmission products and services, enabling its customers'
machinery to perform more efficiently and reliably. With sales of
$3.1 billion in 2009, operations in
27 countries/territories and approximately 17,000 employees, Timken
is Where You Turn® for better performance.
About Herrenknecht Group
Herrenknecht AG is a technology and market leader in the area of
mechanized tunneling systems. It achieved sales of
euro 866 million in the year 2009 and
has more than 3,100 employees around the world. With 65
subsidiaries and associated companies working in related fields in
Germany and abroad, Herrenknecht
is able to quickly provide, in a targeted way, a comprehensive
range of services in close proximity to project sites and
customers.
Media Contacts:
The Timken Company
Lorrie Paul Crum, Manager
– Global Media Relations & Strategic Communications, Office:
+1.330.471.3514, Mobile: +1.330.224.5021,
lorrie.crum@timken.com
Herrenknecht Group
Achim Kuhn, Head of
Corporate Communications, Branding and Public Affairs, Tel.: +49
(0) 7824 302-540, Fax: +49 (0) 7824 302-473,
pr@herrenknecht.com
SOURCE The Timken Company