The mainline railway networks
making up the TAR network incorporate five different track
gauges, i.e. 1,676 mm, 1,520 mm, 1,435 mm, 1,067 mm and
1,000 mm (Map).
It must be noted that other gauges are also found in some
countries (e.g. 762 mm in India) but these line are not
part of the Trans-Asian Railway network. (Track
gauges and overall route length by country along the TAR
network).
Break-of-gauge points
on the Trans-Asian Railway network
On the Trans-Asian Railway network,
rail border crossings at which a break-of-gauge occur are
between the following countries:
|
| (i) |
China
(1,435 mm) and Viet Nam (1,000 mm), |
(ii)
|
China
(1,435 mm) and the Russian Federation (1,520 mm), |
(iii) |
China
(1,435 mm) and Mongolia (1,520 mm), |
(iv) |
China
(1,435 mm) and Kazakhstan (1,520 mm), |
|
(v)
|
Democratic
People's Republic of Korea (1,435 mm) and
the Russian Federation (1,520 mm), |
|
(vi)
|
Islamic
Republic of Iran (1,435 mm) and Turkmenistan (1,520
mm), |
(vii)
|
Islamic Republic of Iran (1,435 mm) and Azerbaijan
(1,520 mm), |
(viii)
|
Turkey
(1,435 mm) and Armenia (1,520 mm). |
When the construction of the rail
link between Kerman and Zahedan in the Islamic Republic
of Iran is completed, another break-of-gauge will occur
between this country and Pakistan.
In addition, discontinuity of track gauge also occurs within
the individual domestic railway networks of Bangladesh and
India.
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Overcoming the
break-of-gauge
A break-of-gauge is often seen as
an obstacle to the smooth flow of traffic. However, a number
of technical solutions exist to reduce its effect on the
efficiency of rail services. These solutions include transhipment,
bogie changing and the use of wagons with ‘variable-gauge’
bogies.
(i) Transhipment is the transfer of freight
by manual or mechanical means from wagons of one gauge to
wagons of another gauge.
(ii) Bogie changing is the operation by
which wagons are lifted on a set of jacks, bogies of one
gauge rolled out and bogies of the other gauge rolled in.
(iii) The Use of wagons with ‘variable-gauge’
bogies enables wagons to be pulled along a special
transition track at reduced speed. During the process, the
distance between wheels is adjusted from one track gauge
to another.
(iv) Two other solutions exist. One involves the provision
of dual gauge, i.e. the provision of two different track
gauges on a single track foundation through the insertion
of a third rail (or sometimes a fourth rail to obtain the
so-called ‘composite gauge’). The other option
is to convert tracks of different gauges to a single gauge
standard. However, these two solutions are viable only when
different standards are applied within the same country
or for cross-border movements over a very short distance
to fit specific requirements such as extending a line section
of one country onto the territory of another country to
gain access to specific installations or sites, e.g. ports
or mining sites.
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Break-of-gauge:
is the obstacle real?
While continuity of gauge along all
routes of the Trans-Asian Railway would be ideal, a break-of-gauge
does not constitute a major problem to efficient services.
With limited exception, break-of-gauges occur mostly at
border points where a range of operations already require
trains to stop. These operations are generated by railway
needs (e.g. change of locomotives, change of crew) or the
requirements of other administrations (e.g. Customs, border
police). Well-designed and well-organized facilities allow
for transhipment to take place within the time allocated
for these other operations, the disappearance of which cannot
yet be realistically envisaged.
In addition, the bulk of time-sensitive traffic is containerized
cargo which, by nature, lend itself well to fast and efficient
transhipment.
Finally, efficient transhipment often takes place within
a few hours representing a fraction of the overall transit
time over distances of 3,000 km or more.
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