Siegl used a power plane to remove the plywood down to the last, thin ply. Shells constructed with wooden ply usually produce lower tones. The ribs were made of birch ply and spruce. A few Japanese long liners still ply the waters. They were called cross ply or bias ply tires. They travel through boats that ply on the river. This is vital for insulating such small bodies against the chilly waters they ply. Buses ply frequently on the circular road surrounding the city center. Every man who could ply an oar pulled up to give Mr Gladstone a cheer. Frequent buses and dolmuses ply these highways. Fast craft ferry services ply Surigao-Cebu everyday. Night super buses ply between Guwahti to Majuli via Lakhimpur. MEMUs and one or two regular passenger trains ply on this route. There are numerous buses which ply around the city to the stadium. From Borongan City, buses ply to Manila.