For those interested in the performance/power output of the four operating R class locomotives, I have calculated the following Rail Horsepower (RHP) figures for R711's recent re-launch tour to Bendigo and made some comparisons to the other three R's over the same climbs. The results are as follows, the columns represent the date, loco, load (including loco), speed held/attained at top of bank, the rail horsepower that equates to, and (when noted) the cut-off used;-

SUNBURY BANK

Dec 1984 R761 522 tons 16mph 1070 rhp

Jul 1985 R707 526 tons 21mph 1597 rhp

Sep 1985 R766 440 tons 19mph 1180 rhp

Oct 1986 R761 403 tons 26mph 1580 rhp

Oct 2012 R711 530 tons 24 mph 1763 rhp

MACEDON BANK

Dec 1984 R761 522t 29mph 2046rhp -cut-off 15”

July 1985 R707 526t 25mph 1750rhp 12”

Sep 1985 R766 415t 34mph 1990rhp

Oct 1986 R761 403t 41mph 2216rhp 18”

1999 R711 518t 29mph 1953rhp 21”

Oct 2012 R711 530t 17mph 1177rhp

ELPHINSTONE TUNNEL

Nov 85 R766 518t 32mph 2205rhp

Mar 86 R761 545t 20mph 1500rhp

Apr 89 R761 540t 27mph 2030rhp

Oct 86 R761 403t 39mph 2263rhp 15” (D.Colin Holl)

1999 R711 518t 27mph 1943rhp

2002 R761,707 877t 28mph 1770rhp

2012 R711 530t 22mph 1598rhp

One can draw their own conclusions from the above figures but there is no reason not to conclude that any of the R's are capable of readily achieving their VR rated 1800 HP and, given a good crew and pushed a little, can achieve around the 2200 RHP when required. It is of interest that Sunbury Bank does not normally provide a great power output despite line speed being able to be regained between Sunbury Station and the foot of the grade. The climb to Elphinstone Tunnel (10kms) on the Up often produces a good performance and has the added advantages that long climbs produce, a test of the loco's steaming ability and stabilised speed. It should also be remembered that a locos optimum power output is produced between 150-200 RPM (ie. between 33 - 43 MPH for an R class) therefore, if the load is heavy that speed range can never be achieved at the top of a long 1/50 climb. This is evident in the figures taken at Elphinstone Tunnel with R761 hauling gross load of 545 ton in March 1986 and 7 months later with 403 tons (this load was made up specifically for HP calculations and included the Dynamometer Car) where at the top of the climb almost double the speed (39mph) was achieved.