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[[File:Alexandra Bridge v1.png|thumb|Alexandra/Chenab Bridge]][[File:Alexandra Bridge Site 1876.png|thumb| Chenab River in vicinity of the Alexandra/Chenab Bridge, 1876]]The ‘Alexandra Bridge’ ,constructed near the town of [[Wazirabad]] , carried the [[Punjab Northern State Railway]](PNSR) over the River Chenab. The bridge was 9,300 feet(2830mtr) long and 100 feet (30mtr) deep. The first brick was laid on the 1st of November 1871; and the structure was formally opened by his Royal Highness the Prince of Wales on 27 Jan 1876, and the first section, viz., from [[Lahore]] to [[Jhelum]], 103 miles(165km), was opened for traffic <ref>[http://www.icevirtuallibrary.com/doi/abs/10.1680/imotp.1878.22417 Lambert "Minutes of the Proceedings of the Institution of Civil Engineers"; Volume 54 Issue 1878, 1878, pp. 71 ]; Retrieved on 8 May 2018</ref>. The ‘Alexandra Bridge’ was designed to the metre gauge([[Rail_gauge_#Metre_Gauge|MG]]) and the first train metre gauge train passed over the bridge on the 23 Dec 1875 and ran to [[Gujrat|Gujrat(''Goojrat'')]] on the new line just constructed <ref> Lambert "The Alexandra Bridge, Punjab Northern State Railway" by Henry Lambert; page 91</ref>

The ‘Alexandra Bridge’ ==Gauge Question==In January 1871 the orders of the [[Government of India]] were issued was designed to adopt the metre or 3 feet 3⅜ inches gauge([[Rail_gauge_#Metre_Gauge|MG]]) and the first train metre gauge train passed over the bridge on the 23 Dec 1875 and ran to [[Gujrat|Gujrat(''Goojrat'')]] on the all new line just constructed railway constructions <ref>[http:IOR/V/www.icevirtuallibrary.com24/doi/abs/10.1680/imotp.3590 ; 'Public Works Department: Railways, 1876-79' - "Punjab Northern State Railway - 1878.22417 "Minutes -79 Administration Report on the Construction of the Proceedings of PNSR from its Commencement to the 31 March 1879" Para 7</ref>. The girders for the Institution of Civil Engineersbridges were ordered for metre-gauge weights only <ref> Lambert "; Volume 54 Issue 1878The Alexandra Bridge, 1878, pp. 91]Punjab Northern State Railway" by Henry Lambert; Retrieved on 8 May 2018page 78</ref>

==Gauge Question==In January 1871 the orders of the [[Government of India]] were issued to adopt the metre or 3 feet 3⅜ inches gauge ([[Rail_gauge_#Metre_Gauge|MG]]) on all new railway constructions. <br>The background to this decision, and the later decision in 1877-78 to revert to the 5 feet 6 inches broad gauge([[Rail_gauge#Broad_Gauge|BG]]) , is fully detailed in a separate page [[Rail gauge#Gauge Question| ‘The Gauge Question’]].

'''Location and Practical Considerations:''' “The Chenab rises in the Himalayas and reaches Wuzerabad after a course of about 700 miles (1100km), its course for the greater part is through a plain, composed mainly of silt carried down from the high lands of fine sand, and the banks are mostly undefined. During the winter the river is contained in a main channel about 500 yards wide and 10 to 15 feet deep., By the middle of April, floods from the melting of the snow on the Himalayas set in, and increase in volume up to the middle of June, when the monsoon commences and lasts until the middle of September. Vast floods during this time pour down into the plains, sweeping away the river banks, destroying villages, and scouring out the shifting sand of the bed of the river to a great depth. In floods, the Chenab rises 11 feet above low-water mark, and its width at Wuzerabad is 3½ miles. The mass of the water does not flow rapidly, but the main stream, corresponding to the fluctuating deep channel, rushes through with great velocity, in a serpentine direction. This is often nearly at right angles to the general course of the river when obstacles occur. Under these circumstances the bed is driven before it, and the depth of the main current of water is more than 50 feet, moving at a rate exceeding 10 miles an hour. The ground for about half the space of miles between the banks is composed of river deposit there being a depth of 2 feet of light soil over fine sand.” <ref >Lambert "The Alexandra Bridge, Punjab Northern State Railway" by Henry Lambert, I.C.E. Institution of Civil Engineers, 1878; pages 71-72</ref>:-

'''River Training Bunds:''' Details see Lambert’ Technical details are given in Lambert’s Report pages 73-77 <ref>Lambert pages 73-77</ref>

'''Wells and Well-sinkingand Pier Construction:''' Details see Lambert’ Technical details are given in Lambert’s Report pages 82-87<ref>Lambert pages 82-8788</ref>

*1873-74: Chenab, 195 wells, forming 65 pier foundations, were completed, as well as the north and south abutments; and the superstructure of all but 15 piers was built. The girders were being delivered at site. <ref>IOR/V/24/3590 Para 13</ref> *1874-75: Chenab, the floods in the summer of 1874 caused new foundations to be sunk to three of the piers <ref>IOR/V/24/3590 Para 16</ref>*1874-75: Chenab, the 15 spans remaining installed and bridge completed, the first metre gauge train passed over the bridge on the 23 Dec 1875 <ref> Lambert "The Alexandra Bridge, Punjab Northern State Railway" by Henry Lambert; page 91</ref>

'''Girders:''' Details see Lambert’ This decision required the engineers to re-specify the bridge structure to take the wider and heavier locomotive and train weights. Lambert’s Report pages 87-88<ref>Lambert pages 87-88</ref>records as follows :-<br> “The girders had been designed to take metre gauge by [[Alexander Meadows Rendel]], M. Inst. C.E., Consulting Engineer to the Home Government, in accordance with instructions furnished to him, and were constructed by Messrs. Westwood, Baillie, and Co. The reversal of policy finally resulted in a return to the broad gauge (BG) of 5 feet 6 inches. In order to make the bridge suitable for greater rolling loads, it was thought expedient to abolish the buckled plates and asphalt for the Trunk Road traffic, and to lay the rails only on the cross girders, together with planked footpaths for platelayers. The main girders were also set 1 foot farther apart, to admit of BG rolling stock passing freely, and the cross girders were lengthened accordingly. This made the bridge suitable for light BG engines , but whether it is to be strengthened for the ordinary engines, or whether higher strains are to be adopted to suit them, has not yet been decided.”

'''Roadway:''' Details see Lambert’ Report The [[Lahore]] to [[Jhelum]], 103 miles(165km) section, pages 79which included the ‘[[Ravi Bridge]]’ and the ‘Alexandra Bridge’, was converted to broad gauge and re-opened on 6 Oct 1878 <ref>Lambert pages 79IOR/V/24/3590 Para 35</ref>

The following are recorded as No records have been found for the PWD staff being responsible during the construction <ref>ibid ==Later Change of Gauge==The decision in 1877-78 to revert to the 5 feet 6 inches broad gauge([[Rail_gauge#Broad_Gauge|BG]]) is fully detailed in a separate page [Rail gauge#Gauge Question ‘The Gauge Question’]]. The [[Lahore]] to [[Jhelum]], 103 miles(165km), section was converted to broad gauge and re-opened on 6 Oct 1878 <ref>1918 page 106 pdf 115 ‘Alexandra Bridge’