Sobre los Desvios

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Revision: March-09

© 2009

This document has copyright, which is owned by Sonneville International Corporation (SIC) and may not be reproduced, in

whole, in part, or in any form whatsoever without prior written authority from SIC. This document has been submitted on the

understanding that it will not be used in any way against the interest of SIC.

LOW VIBRATION TRACK (LVT)

Special trackwork

SONNEVILLE INTERNATIONAL CORPORATION

8109 Tis Well Drive, Suite 513

Alexandria, VA 22306, USA

Tel. +1 703 619 1530

Fax +1 703 619 1534

E-mail [email protected]

www.sonneville.com

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Introduction

Turnouts supported by independent concrete blocks bearing on resilient block pads encased in

rubber boots and embedded in concrete were installed in the Swiss Heitersberg tunnel in

1975 as shown below.

While these turnouts have performed satisfactorily over a period of more than 30 years and

supported in excess of 700 million gross tons of traffic with 22.5 metric ton axle loads and a

train speed up to 140 kilometres per hour, their development has been limited by the

complexity and cost associated with the large number of different concrete block, block pad

and rubber boot sizes involved.

Standardization

After the successful development of the Low Vibration Track (LVT) system for plain line

applications, Sonneville International Corporation has collaborated with turnout

manufacturers to extend the use of that system to special trackwork.

As a result of that collaboration, which focused on coordinating baseplate and LVT support

sizes as well as hold-down bolt and insert locations, it became possible to accommodate any

turnout or crossing geometry with only four special LVT support sizes.

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Typical configuration

A typical LVT turnout configuration is shown below.

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LVT support details

In addition to the type 2 plain line LVT supports, three longer types 3, 4 and 5 supports having an overall length of up to 1,200 mm are equipped with baseplates while smaller non-

baseplated type 1 supports are used in single rail locations where space limitations do not

permit the installation of type 2 supports.

The fact that all concrete blocks have the same width opens the possibility for these blocks as

well as the corresponding block pads and rubber boots to be economically produced with

universal moulds in which the addition or removal of partitions permits to switch from one

length to another.

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Once baseplates are installed on the shallower types 3, 4, and 5 concrete blocks, their height

becomes the same as that of the non-baseplated types 1 and 2 blocks, thus allowing for easy

assembly of the steel work while the LVT supports are bearing on the base slab prior to final

adjustment and concreting.

With their 153 mm deep rubber boots, the special trackwork LVT supports maintain the same

embedment depth as the plain line ones and confer the turnouts and crossings a substantially

greater stability than the system installed in the Heitersberg tunnel, where the rubber boots

were only 100 mm deep.

Main advantages

From an economic point of view, the aforementioned standardization has resulted in very

competitive component prices.

The fact that LVT turnouts can be fully assembled on the base slab below their final level and

used for work train traffic prior to final adjustment and concreting in the same manner as

plain line LVT, the absence of general reinforcement of the track concrete and the high speed

and low cost of installation inherent to the top-down construction method further contribute

to the economic attractiveness of LVT for special trackwork.

In terms of performance, special trackwork LVT maintains all the advantages of plain line LVT,

including effective vibration attenuation, exceptional lateral stability, highly accurate track

geometry, vertical adjustability, maintenance free operation and easy access to all components

in case of accidental damage.

While the block pads supporting the types 2 and 3 blocks are manufactured according to the

same specification as for the plain line LVT, a stiffer material is installed under the type 1 blocks and a softer one under the types 4 and 5 blocks, thus providing a consistent track

modulus throughout the entire system.

The independent LVT supports furthermore simplify surface drainage as illustrated on the

following pages.

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Top-down installation illustrations

A turnout being adjusted prior to concreting is shown below.

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Particular turnout locations

Various LVT turnout locations are shown below.

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