41. These came with diameter drivers and boiler pressure , making these ATSF s the fastest and most modern of all. 42. The new firebox had a different shape and this reduced the boiler pressure from 245 psi to 215 psi. 43. During a General Repair at Eastleigh Works in November / December 1954, 34051 had its boiler pressure reduced from. 44. These, at a boiler pressure of, gave the locomotive a tractive effort of at 75 % of boiler pressure. 45. The S1 was similar to the NER Class S but had larger driving wheels and a higher boiler pressure . 46. From the second series, built in 1904, the boiler pressure of the S 3 / 5 was raised from. 47. Unlike the earlier version, these engines had a 2 bar higher boiler pressure and larger coupled wheel and cylinder diameters. 48. The upgraded engines were capable of producing more power : their boiler pressure was raised to and they could generate. 49. The boiler pressure was increased from 160 to 180 lbs per square inch but the cylinders reduced in diameter from. 50. The locomotive was rebuilt on 1878 with larger cylinders and an increased boiler pressure , which increased its tractive effort to.
