The increase in speeds of trains and safely operating higher axle loads on existing networks are the major challenges facing railway engineers, Minister of State for Railways Manoj Kumar Sinha said on Friday."There are areas where we need to improve. The increase in speeds of trains and operation of higher axle loads on existing network in safe and efficient manner are major challenges before P-Way engineers," he said at an event here organised by the Institution of Permanent Way (P-Way) Engineers."Proper inspection and maintenance of track including station yards are very important as many derailments happen in station yards," Sinha said.Of about the 13 lakh staff of the Indian Railways, about 2.75 lakh are from the engineering department responsible for construction, maintenance and upkeep of fixed assets like railway tracks and bridges, a railway ministry statement said."The capacity constraint on Indian Railways has to be overcome, if it wants to meet the ever growing traffic demands," Sinha said.He said that towards enhancing railway capacity, construction of new lines, doubling of existing ones and third line projects are being planned.