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Journalism of Courage
It8217;s not propped up by mythology or weighed down by myths, but has mystically survived. It8217;s not quite Rama Sethu, but is strung out across the sea and spans a vision that has straddled a century and braved the elements. It8217;s the Pamban rail bridge in the Palk Straits that connects the mainland at Mandapam to Rameswaram island in Tamil Nadu.
Divinity may have intervened in ensuring its survival, but design has played an important role. When German engineer, Scherzer, built it 93 years ago, it was considered an engineering marvel8212;in two years, with 600 workers and Rs 20 lakh, he built the 2.06-km-long bridge without any loss of life8212;and made news. It still does. Only, this time it8217;s for other reasons.
For the first time ever, the metre gauge rail track has been converted to broad gauge. After being shut down on July 15 last year for modification, the bridge will soon be opened by President A.P.J. Abdul Kalam, who also hails from Rameswaram.
However, J.P. Batra, Chairman, Railway Board, says it is yet to be ascertained if the bridge is indeed the only one of its kind in the world so that the application for making it a World Heritage Site can be forwarded to UNESCO.
The bridge runs almost straight from east to west, the depth of water varies from 2-10 ft and around this area and its foundation rests on sandstone reef. And as Sinha found in his quest, the stones used in the bridge were brought by rail from a quarry about 270 km away, while the sand came from a site 100 km away. Old railway records showed that nearly 5,000 tonnes of cement, 18,000 cu ft of crushed metal, 2,600 tonnes of steel and 80,000 cu ft of boulders were used in the construction that began in June 1911, was completed in June 1913 and commissioned on February 24, 1914.
Till December 23, 1964, the bridge stood strong against the vagaries of weather. Then a cyclonic storm swept through the Palk Straits and the Gulf of Mannar, lashing against the bridge and washing away most of its sections. But under the stewardship of E. Sreedharan, the current chief of the Delhi Metro Rail Corporation, but then a 31-year-old executive engineer in the Railway Board, it was reopened in a record time of 46 days. Sreedhran even won the Railway Minister8217;s award for his accomplishment.
Meanwhile, on October 2, 1988, a 2.34 km-long Pamban road bridge with a clearance of 24.4 m and supported by 79 pillars, 64 of which are in the sea, was also opened. 8220;The Palk Strait is subjected to frequent cyclonic weather conditions and high waves and periodic change in direction of flow of water. The project is one of the most difficult bridge construction jobs undertaken in the country. This is also the biggest bridge built across the open seas in India,8221; said S.A. Reddi, who was then chief engineer project, Gammon India Ltd, in a report.
Hemant Kumar, Divisional Railway Manager, Madurai, would agree on the complexity of undertaking such a project. Referring to the recent gauge conversion project, he says, 8220;We used 450 workers and 35,000 rivets fasteners. It was a very difficult terrain as people had to work at a height of 50 ft above sea level 40 ft from the bridge at the highest point and about 12 ft sea depth in conditions where winds blow at 55 km per hour.8221;
8220;It was a massive task in difficult conditions, but we completed it in time,8221; says Sinha, who closely supervised the project.
The Pamban rail bridge has 145 fixed spans and one navigation span which opens for ships. The draw bridge at the centre comprises two leaves or sections of the navigation span, also called the Scherzer span, weighing 415 tonnes each and requiring six persons on either side to manually operate and lift them for ships to pass. Normally, the navigation span needs to be lifted about four times a month. The total length of the navigation span is 225 ft and could probably be the longest in the world, according to Railway officials.
During the 1964 storm, several girders of the bridge were washed away, but the navigation span remained intact. The girders were replaced and after the storm, engineers installed an anemometer, which is a safety parameter against high wind speeds. When the wind speed crosses 55 km per hour, signals on the bridge send out a warning to the approaching trains. The trains normally slow down with a squeal of brakes before entering the Pamban bridge.
It was the navigation span that proved the biggest hindrance during the gauge conversion. The metre gauge coaches were lighter and a study was conducted to check if the dimensions of the navigation span could be altered to accommodate the broad gauge trains. 8220;A lot of calculations and redesigning were required as when a train is on the navigation span, there is an upward thrust in the rear and when a heavier broad gauge train is on it, the thrust is more. Ultimately 150-odd steel structural members were strengthened, replaced or modified,8221; says Hemant Kumar. Finally, the bridge8217;s foundation was tested for integrity and stress and the calculations showed it could take the weight of the broad gauge coaches as well.
Much before the cyclone, it was corrosion which proved to be the bridge8217;s biggest problem. The life of the girders provided in 1914 was short as they were of the BG deck type and also because of the corrosive atmosphere. These were later changed to PSC girders and also metalled with aluminium before insertion. 8220;However, further regirdering was stopped because of apprehension that tensile steel wires might get corroded, which could go unnoticed. Accordingly, it was felt that it would be prudent to replace the girders with steel girders, duly metalling them to enhance their life,8221; says Sinha.
Before the cyclone, the railway line continued to Dhanushkodi located on the southernmost tip of Rameswaram, while the rail terminus for Sri Lanka was at Thalaimannar. Passengers at the time used the steamer service across the sea to go to either side. But after the cyclone, portions of railway tracks at Dhanushkodi were swept away. The survivors also deserted Dhanushkodi, and the village now sports a ghostly appearance with only portions of the railway track and dilapidated structures remaining.
Meanwhile, the Commissioner for Railway Safety opened the bridge for traffic last month and the IIT, Chennai, and the Structural Engineering Research Centre, also based in Chennai, the technical consultants, have certified the foundation as being in 8220;good condition without any defects.8221;
For the first time after the gauge conversion project, a ship was allowed to pass under it on June 21. The IIT Chennai is now working on a design to motorise the spans so that they need not be manually operated.
The tourists, meanwhile, are not bothered by the technicality or the operational intricacies of the Pamban bridge. If they are lucky, they catch a glimpse of the navigation span opening up to allow passing ships. For most days, they8217;d much rather view the bridge in all its aesthetic glory as it spans the sea, connecting eras and endeavours that have made it a unique creation.
