GAUGE CONUNDRUM
by
RAJIV KUMAR TYAGI
1.0 Selection of Track Gauge is even now as empirical and questionable as it was at the
starting of Railway System. In UK, Wagon ways were precursor to Rail Transport.
There was no standardization of gauge of these Wagon ways but gauge of 4 feet 8
inch was common. George Stephenson used this gauge for his steam traction from
Stockton to Darlington. Available horse driven wagons were used. The gauge was
widened to 4 feet 8½ inch for section from Liverpool to Manchester commissioned
in September 1930. The additional ½ inch was to prevent binding of wheels on
curves. Stephenson then went on to build several railway lines with this gauge. This
seems to be the main reason for 4 feet 8½ inch becoming the standard.
2.0 Obviously there was no rational merit to the gauge of 4 feet 8½ inch except that it
allowed use of available horse drawn vehicles. That was at the most a short term
advantage. It was left to the ingenuity and boldness of legendry British Engineer IK
Brunel to make radical departure from the practice of providing standard gauge.
Gauge selected by Brunel for Great Western Railway (GWR) founded in 1833 was 7
feet. This was probably also not based on any engineering studies or methods. The
primary purpose of wider gauge was to have wider carriages and wagons. Great
Western Railway earned the reputation of providing luxurious coach services. It was
variously named as “Gods Wonderful Railway” and “Great Way Round”. Brunel also
toyed with the idea of providing larger wheels outside the bodies of the rolling stock,
so that riding at high speeds is smoother.
It is possible that change of gauge by Brunel was also dictated on grounds of
monopolizing the territories. In any case it led to Gauge Wars and breaking of gauge
at multiple locations in the system. A Royal Gauge Commission was set up in 1845
followed by Railway Regulation Gauge Act of 1846. Standard Gauge was legally
prescribed and gauge of GWR was converted to Standard Gauge in 1892.
3.0 Barring few exceptions, Standard Gauge became norm in most of the countries due
to pre-eminent position of UK in Rail Industry. Russia, Finland and iberian countries
i.e. Portugal and Spain adopted wider gauges on military considerations. Japan
adopted cape gauge (1067 mm).
High speed in JAPAN
was developed on
Standard Gauge on considerations of stability and marketing of the technology to
other countries.
4.0 Evolution of track gauge in India
4.1
In India, Lord Dalhousie displayed remarkable clarity on the issue. In a Minute
dated 4th July, 1850, written in response to the Court of Directors of the East
India Company forwarding the Report of FW Sims, Consultant Engineer of the
Company, for his views, he expressed as under:
a. Uniformity of gauge is all important in railway development. India should
avoid the mistake made by the United Kingdom where two gauges exist
and where ultimately a Royal Commission had to enquire and the
Parliament to legislate on the issue.
b. 4 feet 8½ inch fixed by Stephenson is a measurement that is haphazard
and an accident of local circumstances.
c. The gauge recommended by the Court of Directors – 4 feet 8½in is not
acceptable. It should be 6 feet .
4.2
The Court of Directors ultimately passed a resolution adopting a gauge of 5
feet 6 inch for India. Lord Dalhousie mockingly remarked that perhaps the
figure of 5 feet 6 inch was arrived at by averaging 4 feet 8½ inch and 6 feet
suggested by him!
4.3
Meter gauge was introduced during the Viceroyality of Lord Mayo.
The
reasons were lower capital costs and easier and faster construction. The first
meter gauge line to be laid was from Delhi to Rewari. The meter gauge
system then expanded rapidly; most of such lines were in Rajasthan, Gujarat,
Bihar, north of Ganges in UP and Sourthern States; the then East Bengal –
now Bangladesh – also laid lines to this gauge. In fact, after independence,
the separate meter gauge systems of the north and the south were
interconnected by building the Khandwa Hingoli railway line.
4.4
The next to come were the 2ft 6 in narrow gauge lines, build mostly by the
princely states and private companies. The then princely states of Vadodara
and Gwalioer were most active. Some were by the Government to connect
hill stations – Shimla, Darjeeling and Matheran. And two of them – the railway
lines to Darjeeling and the Matheran were to a narrow gauge of 2 ft.
5.0 Bay Area Rapid Transit System (BART) was commissioned in 1972 in San
Francisoo (USA). Area falls under intense seismic zone. Indian Gauge of 1676 was
adopted after ab initio study on consideration of better lateral stability .
6.0 India along with erstwhile part of British India i.e. Burma, Pakistan and Bangladesh
has the widest gauge in the World. Honours are shared with Argentina. Other
countries in the descending order are Spain and Portugal (1668 mm), Ireland (1600
mm) and Russia and Finland (1520 mm).
7.0 Standard Gauge (1435 mm) is most widely used in the World. All high speed lines
operate on Standard Gauge except in Finland and Russia.
8.0 Indian Railways took a uni gauge policy decision in 1990. This policy has been in
implementation since then. Some quantum would be left over as some of the lines
are in the ‘heritage category’ (example the Darjeeling Railway Line) and some
cannot be converted due to the very nature of topography in which they traverse.
9.0 On Indian Railways, maximum permissible curvature is as under:
Gauge in mm
In Degree
Curvature
In Meter
1676 (BG)
10
175
1000 (MG)
16
109
762 (NG)
40
44
9.1 Maximum curvature is related to maximum length of rigid wheel base
Gauge
Curvature
BG
Upto 10
Maximum
length
Rigid Wheel Base
metres
6.1
MG
Upto 10
4.875
> 10
3.660
Upto 10
3.660
> 10 < 16
3.050
>16 < 30.17 m
2.440
> 30.17 m
1.905
NG
10.0 Following general observations can be made:
of
in
(i)
Haulage capacity, Lateral stability and Pay load to Tare weight improves with
increasing gauge.
(ii)
Larger the gauge, higher is the Capital cost.
(iii)
Technologies related to propulsion, braking, coupling, communications, train
control, signaling are gauge neutral.
(iv)
Axle and Bogie design is solely gauge dependent.
(v)
On curves, speed and Kinematic envelope of the coaches are gauge neutral.
(vi)
Lengths of Turnouts reduce with reduction in gauge.
Bibliography
1.0 Report of Expert Committee for Selection/Choice of Gauge.
2.0 Schedule of Dimensions in 762 mm Gauges 1963
3.0
Schedule of Dimensions in 1000 mm Gauges
4.0 Schedule of Dimensions in 1676 mm Gauges 2004.