There's little information about the history of these locomotives in the diagram, but it does have one typo (or "printo" since the annotation is handwritten) that results in amusing overstatement. The Loughridge Belpaire firebox's area on these little Eight-wheelers was in fact a bit bigger than the average, but to call coal's landing place "great area" perhaps preens a bit. See Locobase 7848 for the P-4s, which had not so greats but more firebox area.
Four years after the P-3s arrived from Brooks (Locobase 7847), that builder rounded out the decade with four more. These had slightly less "great" area in their narrower Loughridge Belpaire fireboxes but more heating surface, and six fewer boiler tubes. Otherwise they were quite similar.
Locobase enjoys the little mysteries unearthed while compiling a database of the world's steam locomotives. For example, the editor often notes that a successor class often connotes merely removing a few tubes from the boiler. Such happened on the HV from 1900's P-3 ((Locobase 7847) to 1904's P-4 (Locobase 7848). But why take out 54 more in the next year's delivery, as happened in the current entry? The Loughridge Belpaire firebox remains and the power dimensions are identical. Was the original boiler too big?
At this point, one should note, the grate area is no longer "great" - the "printo" has been corrected.
Let's press on; see Locobase 7850.
See Locobases 7847-7849 for the first three HV classes of Eight-wheelers in this series. All had the Loughridge Belpaire firebox, the same power dimensions and wheelbases. Compared to the others, this final pair of 4-4-0s had a boiler whose size put it in the middle. Unlike the others, however, the P6 threw over the Stephenson link motion and slide valve in favor of Walschaert radial gear and 10 1/4" piston valves.
|Principal Dimensions by Steve Llanso of Sweat House Media|
|Railroad||Hocking Valley (C&O)||Hocking Valley (C&O)||Hocking Valley (C&O)||Hocking Valley (C&O)|
|Number in Class||6||4||3||2|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)||8.75 / 2.67||8.75 / 2.67||8.75 / 2.67||8.75 / 2.67|
|Engine Wheelbase (ft / m)||24 / 7.32||24 / 7.32||24 / 7.32||24 / 7.32|
|Ratio of driving wheelbase to overall engine wheebase||0.36||0.36||0.36||0.36|
|Overall Wheelbase (engine & tender) (ft / m)||47.25 / 14.40||47.25 / 14.40||47.25 / 14.40||44.50 / 13.56|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)|
|Weight on Drivers (lbs / kg)||90,000 / 40,823||90,000 / 40,823||89,200 / 40,460||91,400 / 41,458|
|Engine Weight (lbs / kg)||135,550 / 61,485||135,700 / 61,553||135,200 / 61,326||141,400 / 64,138|
|Tender Loaded Weight (lbs / kg)||103,200 / 46,811||104,100 / 47,219||103,200 / 46,811||109,400 / 49,623|
|Total Engine and Tender Weight (lbs / kg)||238,750 / 108,296||239,800 / 108,772||238,400 / 108,137||250,800 / 113,761|
|Tender Water Capacity (gals / ML)||5000 / 18.94||5000 / 18.94||5000 / 18.94||5000 / 18.94|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)||10 / 9.10||10 / 9.10||10 / 9.10||10 / 9.10|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||75 / 37.50||75 / 37.50||74 / 37||76 / 38|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||66 / 1676||66 / 1676||66 / 1676||66 / 1676|
|Boiler Pressure (psi / kPa)||180 / 12.40||180 / 12.40||180 / 12.40||180 / 12.40|
|High Pressure Cylinders (dia x stroke) (in / mm)||18" x 26" / 457x660||18" x 26" / 457x660||18" x 26" / 457x660||18" x 26" / 457x660|
|Tractive Effort (lbs / kg)||19,528 / 8857.76||19,528 / 8857.76||19,528 / 8857.76||19,528 / 8857.76|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.61||4.61||4.57||4.68|
|Firebox Area (sq ft / m2)||161.90 / 15.05||166.54 / 15.48||167.71 / 15.59||167.71 / 15.59|
|Grate Area (sq ft / m2)||30.81 / 2.86||28.82 / 2.68||28.82 / 2.68||28.82 / 2.68|
|Evaporative Heating Surface (sq ft / m2)||1973 / 183.36||1941 / 180.39||1619 / 150.46||1793 / 166.64|
|Superheating Surface (sq ft / m2)|
|Combined Heating Surface (sq ft / m2)||1973 / 183.36||1941 / 180.39||1619 / 150.46||1793 / 166.64|
|Evaporative Heating Surface/Cylinder Volume||257.65||253.47||211.42||234.15|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||5546||5188||5188||5188|
|Same as above plus superheater percentage||5546||5188||5188||5188|
|Same as above but substitute firebox area for grate area||29,142||29,977||30,188||30,188|