Saint Clair Tunnel Company 0-10-0 Locomotives in Canada

Class Details by Steve Llanso of Sweat House Media

Class 598 (Locobase 2850)

(Alexander, Iron Horse, pl 81). Data from "The St Clair Tunnel Locomotive" Railroad Gazette, Volume 23 (3 April 1891), p. 226. (Alexander gives boiler pressure of 210 psi.). (Thanks to Samuel Dickenson for his October 2014 email correction of the Michigan origin of the tunnel.) See also William E Miller's website dedicated to the history of the St Clair Tunnel -- [] (2 July 2003, last accessed 12 October 2014) and DeGolyer, Volume 16, p. 197. (Thanks to Chris Hohl for his 25 December 2019 email noting the correct weight and questioning the engine wheelbase.)

Works numbers were 11586, 11589, 11590 & 11595 in February 1891.

A double-ended camelback with small drivers, no guiding or trailing trucks, long water tanks and a center cab could only have one of a few purposes. This "Decapod Tank Freight"'s job was to haul 760 tons of freight trains through the tunnel that connects Port Huron, Michigan with Sarnia, Ontario on a ruling grade of 2%. Typical trains amounted to 25-33 loaded cars.

Although completed as camelback tank engines, they were later given tenders to increase capacity. The side tanks were removed in 1898 ( when the locomotives were renumbered 1301-1304). 1301 and 1304 later had conventional cabs fitted behind the firebox. This configuration's wheelbase measured 48 ft 2 in (14.68 m).

Miller adds that by 1908 they were relieved of tunnel duty (because of the suffocation hazard), but soldiered on for a few more years and one more renumbering (2650-2653 in 1910). 2652 was scrapped in 1916 and the others in 1920.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID2850
RailroadSaint Clair Tunnel Company
Number in Class4
Road Numbers598-601/1301-1304/2650-2653
Number Built4
BuilderBurnham, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)18.42 / 5.61
Engine Wheelbase (ft / m)18.42 / 5.61
Ratio of driving wheelbase to overall engine wheelbase1
Overall Wheelbase (engine & tender) (ft / m)39.87 / 12.15
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)195,000 / 88,451
Engine Weight (lbs / kg)180,000 / 81,647
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)180,000
Tender Water Capacity (gals / ML)2160 / 8.18
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)3 / 3
Minimum weight of rail (calculated) (lb/yd / kg/m)65 / 32.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)50 / 1270
Boiler Pressure (psi / kPa)160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)22" x 28" / 559x711
Tractive Effort (lbs / kg)36,861 / 16719.89
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.29
Heating Ability
Tubes (number - dia) (in / mm)281 - 2.25" / 57
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)13.50 / 4.11
Firebox Area (sq ft / m2)193 / 17.93
Grate Area (sq ft / m2)38.60 / 3.59
Evaporative Heating Surface (sq ft / m2)2448 / 227.42
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)2448 / 227.42
Evaporative Heating Surface/Cylinder Volume198.70
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation6176
Same as above plus superheater percentage6176
Same as above but substitute firebox area for grate area30,880
Power L13694
Power MT208.82

All material Copyright ©
Wes Barris