GAUGE CONUNDRUM

by

RAJIV KUMAR TYAGI

1.0Selection of Track Gauge is even now as empirical and questionable as it was at the starting of Railway System. In UK, Wagonways were precursor to Rail Transport. There was no standardization of gauge of these Wagonways but gauge of 4feet 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.

2.0Obviously 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 7feet. 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.

3.0Barring 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.

4.0Evolution of track gauge in India

4.1In 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:

  1. 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.
  2. 4 feet 8½ inch fixed by Stephenson is a measurement that is haphazard and an accident of local circumstances.
  3. The gauge recommended by the Court of Directors – 4 feet 8½in is not acceptable. It should be 6 feet .
  4. The Court of Directors ultimately passed a resolution adopting a gauge of 5 feet 6inch 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!
  5. 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.
  6. 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.

5.0Bay 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 .

6.0India 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).

7.0Standard Gauge (1435 mm) is most widely used in the World. All high speed lines operate on Standard Gauge except in Finland and Russia.

8.0Indian Railways took a unigauge 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 / Curvature
In Degree / In Meter
1676 (BG) / 10 / 175
1000 (MG) / 16 / 109
762 (NG) / 40 / 44

9.1Maximum curvature is related to maximum length of rigid wheel base

Gauge / Curvature / Maximum length of Rigid Wheel Base in metres
BG / Upto 10 / 6.1
MG / Upto 10 / 4.875
> 10 / 3.660
NG / Upto 10 / 3.660
> 10 < 16 / 3.050
>16 < 30.17 m / 2.440
> 30.17 m / 1.905

10.0Following general observations can be made:

(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

1.0Report of Expert Committee for Selection/Choice of Gauge.

2.0Schedule of Dimensions in 762 mm Gauges 1963

3.0Schedule of Dimensions in 1000 mm Gauges

4.0Schedule of Dimensions in 1676 mm Gauges 2004.