31. This was a result of two features : firstly the low mass of metal in the heating surface rose quickly to temperature. 32. In order to increase the heating surface the boilers were made longer than previous types, and were fitted with raised fireboxes. 33. These locomotives represented a further advance on earlier 6th Class locomotives, with a greater heating surface and a larger firegrate area. 34. The differences between the A1 and A2 classes were minor : in particular, the A2 class had a larger heating surface . 35. On March 24, 2015, NASA reported the first detection of nitrogen released after heating surface sediments on the planet Mars. 36. To provide enough heating surface to generate sufficient steam through its projected use the firebox was made wider for greater burning capacity. 37. She had 56 corrugated furnaces heating six double-ended and two single-ended boilers that had a combined heating surface of. 38. She had nine corrugated furnaces with a combined grate area of heating three single-ended boilers with a combined heating surface of. 39. These engines were slightly longer with larger water tanks and had larger firebox and boiler heating surfaces , with an increased boiler pressure. 40. Each had 18 corrugated furnaces with a combined grate area of that heated six single-ended boilers with a combined heating surface of.
