Victorian Government Rlys 4-8-4 Locomotives in Australia

Class H (Locobase 7687)

Many thanks to Graeme Reid, who contacted Wes Barris about the H class in July 2006 and prompted Locobase's research.

Data assembled 14 July 2006 from:

[], a website offering a model of this unusual locomotive and offering the original locomotive diagram in support.

[], Peter Ormsby's site of drawings with a summary of Heavy Harry's career, and

ttp://www.vicsig.net/index.php?page=locomotives&class=H&

orgstate=V&type=Steam, which supplies the valve diameter, travel, lap, and lead info.

See also "H220", an entry last updated 31 March 2017 on the Australian Railway Historical Society Victorian Division Inc at [], last accessed 14 April 2017.

"Heavy Harry" was to be the first of three large mixed-traffic locomotives designed to handle the heavyweight Overland express to Adelaide. Chief Mechanical Engineer A C Ahlston assembled all the elements of prevailing practice in the prototype, which rolled out 7 February 1941. A large Belpaire firebox with combustion chamber and thermic syphons provided plenty of direct heating surface for the boiler; it was fed by an automatic stoker. No other Australian locomotive had so much combined heating surface or so large a grate. (The nearest competitors in both areas were the SAR's 500-class 4-8-4s, which were supplied by Armstrong-Whitworth; see Locobase 2419.) In terms of superheater area as a percentage of overall heating surface area, however, the H class ran a little lower than most main-line locomotives delivered in the same period.

Three 11"(279-mm)-piston valves fed the three cylinders, the middle one of which was actuated by a conjugation lever. The valves had 6 1/2" (165 mm) travel, 1 1/2 (38 mm) lap, and 1/4" (6.35 mm) lead. Exhaust poured out of a double blastpipe in a smokebox that was flanked by "elephant ear" smoke lifters.

From its initial run date of 7 February 1941 to its final run in May 1956, H220 traveled 821,860 miles (1,323,195 km). Its most intensive use came during a 2.7 year interval between 18 March 1949 and 23 November 1951 when it averaged almost 6,500 miles (10,465 km) per month.