sentences:  In September 1913 the first of the 2-6-0 K class locomotives entered traffic.These locomotives were intended to fulfill the need to accelerate the speed of goods traffic on the congested London suburban lines.They were fitted with parallel superheated boilers with Belpaire fireboxes (the first such on the LBSCR) and were capable of hauling 1,000 ton trains at an average speed of 30 to 35 mph.