Small, light passenger locomotives originally delivered with 64" drivers and developing 26,121 lb TE. Firebox heating surface included 28 sq ft of arch tubes. Later fitted with 67" drivers. 550 dismantled in June 1942, 551 in August 1944. (One supposes demand for passenger service along the southern shore of Lake Superior must not have very high in wartime to allow these two relatively young locomotives to be scrapped.)
(http:/fp-www.wwnet.net/`dulong/dssa/locomot.thm)
The largest passenger locomotives delivered to the Duluth, South Shore, and Atlantic. Served until 1951. Two more Pacifics (555-556) were delivered after 1922. One irony about wheel arrangements: this railroad, which so optimistically carried the Atlantic as its ultimate destination, never had a 4-4-2 in its stud.
(http:/fp-www.wwnet.net/`dulong/dssa/locomot.thm)
This pair followed the first two batches (Locobase 1330, 1331) from Brooks by 9 years. Although the new locomotives maintained much of the original light Pacific design, they traded heating tubes for a substantial amount of superheat. Firebox heating surface included 28 sq ft of arch tubes. The radial valve gear worked 12" piston valves.
| Specifications | |||
|---|---|---|---|
| Class | H | H-1 | H-2 |
| Locobase ID | 1330 | 1331 | 6667 |
| Railroad | Duluth, South Shore, & Atlantic | Duluth, South Shore, & Atlantic | Duluth, South Shore, & Atlantic |
| Whyte | 4-6-2 | 4-6-2 | 4-6-2 |
| Road Numbers | 550-551 | 552-554 | 555-556 |
| Gauge | Std | Std | Std |
| Builder | Alco | Alco-Brooks | Alco-Brooks |
| Year | 1912 | 1913 | 1924 |
| Valve Gear | Walschaert | Walschaert | Walschaert |
| Locomotive Length and Weight | |||
| Driver Wheelbase | 12' | 12' | 12' |
| Engine Wheelbase | 32.42' | 32.42' | 32.42' |
| Ratio of driving wheelbase to overall engine wheebase | 0.37 | 0.37 | 0.37 |
| Overall Wheelbase (engine & tender) | 57.92' | 55.17' | 58.48' |
| Axle Loading (Maximum Weight per Axle) | |||
| Weight on Drivers | 115000 lbs | 124450 lbs | 129000 lbs |
| Engine Weight | 185000 lbs | 196850 lbs | 203000 lbs |
| Tender Light Weight | 113033 lbs | 113033 lbs | 123000 lbs |
| Total Engine and Tender Weight | 298033 lbs | 309883 lbs | 326000 lbs |
| Tender Water Capacity | 5800 gals | 6000 gals | |
| Tender Fuel Capacity (oil/coal) | 9 tons | 10 tons | |
| Minimum weight per yard of rail on which locomotive could run | 63.89 lb rail | 69.14 lb rail | 71.67 lb rail |
| Geometry Relating to Tractive Effort | |||
| Driver Diameter | 67" | 67" | 67" |
| Boiler Pressure | 180 psi | 180 psi | 200 psi |
| Cylinders (dia x stroke) | 20.5" x 26" | 21" x 26" | 21" x 26" |
| Tractive Effort | 24952 lbs | 26184 lbs | 29093 lbs |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.61 | 4.75 | 4.43 |
| Heating Ability | |||
| Firebox Area | 188 sq. ft | 188 sq. ft | 190 sq. ft |
| Grate Area | 46.30 sq. ft | 46.30 sq. ft | 46.30 sq. ft |
| Evaporative Heating Surface | 1643 | 1643 | 1540 |
| Superheating Surface | 363 | 363 | 415 |
| Combined Heating Surface | 2006 | 2006 | 1955 |
| Evaporative Heating Surface/Cylinder Volume | 165.42 | 157.63 | 147.75 |
| Computations Relating to Power Output (More Information) | |||
| Robert LeMassena's Power Computation | 8334 | 8334 | 9260 |
| Same as above plus superheater percentage | 9842.10 | 9842.10 | 11225.68 |
| Same as above but substitute firebox area for grate area | 39963.59 | 39963.59 | 46066.50 |
| Power L1 | 11838.45 | 11281.42 | 13338.43 |
| Power MT | 680.85 | 599.55 | 683.86 |
| This page last modified: . | [Contact] | All material © 1999-2008 SteamLocomotive.com |