8 Down Karachi Mail of North Western Railway leaving Lahore headed by an "eight-beat" XS2 class 4-6-2 Pacific No. 780 fitted with Lentz valve Gear. Vulcan Foundry supplied four experimental engines in 1930, two of XS1 class with Caprotti valve gear and two of XS2 class with Lentz valve gear. All four were 4-cylinder locomotives with 16-inch diameter and 26-inch stroke, 225psi boiler pressure exerting a tractive effort of 34,000lbs at 85% boiler pressure and weighed 108 tons without the tender. 760 and 780 had their inside cranks set at 135 degrees to the outside cylinders that gave a unique eight beats of exhaust for each revolution of the driving wheels while 761 and 781 had the cranks set at 180 degrees that provided the usual sound of four beats. These locomotives were often seen heading the Karachi Mails between Lahore and Samasatta and on the Punjab and Frontier Mails between Saharanpur and Lahore. All four locomotives remained in Pakistan after 1947. They were reputed to be the most powerful Express/Passenger locomotives in all Asia and did not have the stigma of rough riding at speed as their XC and XB cousins did. (Ken Staynor)

Date: 2014-12-22
Owner: Gallery Administrator
Full size: 470x480
NWR Class XS on Karachi Mail

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Date/Time 2014 Dec 22 12:43:28 +0000