31. The class comprised six rebuilds, with superheater , of L & YR Class 3 locomotives. 32. A larger three-row superheater and header regulator were fitted into Swindon No . 1 boiler. 33. In an HRSG, water passes through an economizer, then a boiler and then a superheater . 34. Technological problems dogged the voyage, including the superheater of one of her boilers being burnt out. 35. Different railways had different ideas about the merits of drawing air through the superheater elements when coasting. 36. The remainder were converted by Richard Maunsell between 1925 and 1927 using his own design of superheater . 37. They also had slightly smaller firebox and superheater heating areas than the engines of the first batch. 38. Steel superheating, as short journeys allow little time for the superheater elements to reach working temperature. 39. In 1914, an experimental superheater was fitted to Dd 882 and was found to be very successful. 40. This causes air to be drawn through the superheater and heated so that it keeps the cylinders warm.
