Data from table entitled"Motive Power Boston & Providence Railroad Company-November 1856" in Railway and Locomotive Engineering, Volume 12, No 10 (October 1899), page 443, prepared by George S Griggs, then Superintendent of Motive Power at the B&P's Roxbury, Mass Machine Shop. NB: Boiler pressure is an estimate.
This Bury design was one of only three locomotives on the 1856 roster to operate a single set of drivers. The other two (built by Roxbury) were smaller; see Locobase 9523.
Data from table entitled "Table of Dimensions of the Locomotives" in New England Association of Railway Superintendents, Report of the Trials of Locomotive Engines Made Upon 1st and 2nd October, 1851 (Boston: B J Yerrinton, Printers, 1852), p. 16.
NB: Boiler pressure is an estimate.
It's not clear if Roxbury was a tank engine (the entry is shown in Locobase 9523). But the Dedham, also designed by George S Griggs and delivered in May 1851, is so described. These were small engines with V-hook motion and lap valves. The number of tubes is surprisingly large, but each tube had a relatively small diameter. Smaller than the other engines in the trial, the Dedham made its own 9-mile run trailing 2 passenger cars carrying 81 passengers for a total load of 18 tons.
The engine was scrapped in 1888.
Data from table entitled"Motive Power Boston & Providence Railroad Company-November 1856" in Railway and Locomotive Engineering, Volume 12, No 10 (October 1899), page 443, prepared by George S Griggs, then Superintendent of Motive Power at the B&P's Roxbury, Mass Machine Shop. See also Charles E Fisher, A Little Story of the Boston & Providence Railroad (self-published, 1917).
These were small engines with V-hook motion and lap valves. The number of tubes is surprisingly large, but each tube had a relatively small diameter. Roxbury was delivered in April 1851. It was scrapped in 1888.
Dedham, which is described as tank engine, was delivered in May and is described in Locobase 13546.
NB: Boiler pressure is an estimate.
| Principal Dimensions by Steve Llanso of Middle Run Media | |||
|---|---|---|---|
| Class | Boston | Dedham | Roxbury |
| Locobase ID | 9522 | 13546 | 9523 |
| Railroad | Boston & Providence | Boston & Providence | Boston & Providence |
| Country | USA | USA | USA |
| Whyte | 4-2-0 | 4-2-0T | 4-2-0 |
| Number in Class | 1 | 2 | 2 |
| Road Numbers | |||
| Gauge | Std | Std | Std |
| Number Built | 1 | 2 | 2 |
| Builder | Edward Bury | B&P Roxbury | B&P Roxbury |
| Year | 1845 | 1851 | 1851 |
| Valve Gear | Link | V-hook | V-hook |
| Locomotive Length and Weight | |||
| Driver Wheelbase (ft / m) | |||
| Engine Wheelbase (ft / m) | |||
| Ratio of driving wheelbase to overall engine wheelbase | |||
| Overall Wheelbase (engine & tender) (ft / m) | |||
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |||
| Weight on Drivers (lbs / kg) | |||
| Engine Weight (lbs / kg) | 25,350 / 11,499 | ||
| Tender Loaded Weight (lbs / kg) | |||
| Total Engine and Tender Weight (lbs / kg) | 25,350 | ||
| Tender Water Capacity (gals / ML) | 780 / 2.95 | 300 / 1.14 | 300 / 1.14 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |||
| Minimum weight of rail (calculated) (lb/yd / kg/m) | |||
| Geometry Relating to Tractive Effort | |||
| Driver Diameter (in / mm) | 60 / 1524 | 54 / 1372 | 54 / 1372 |
| Boiler Pressure (psi / kPa) | 75 / 520 | 75 / 520 | 75 / 520 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 12" x 18" / 305x457 | 9" x 16" / 229x406 | 9" x 16" / 229x406 |
| Tractive Effort (lbs / kg) | 2754 / 1249.19 | 1530 / 694.00 | 1530 / 694.00 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | |||
| Heating Ability | |||
| Tubes (number - dia) (in / mm) | 76 - 2.25" / 57 | 115 - 1.5" / 38 | 113 - 1.5" / 38 |
| Flues (number - dia) (in / mm) | |||
| Flue/Tube length (ft / m) | 7.67 / 2.34 | 8 / 2.44 | 8 / 2.44 |
| Firebox Area (sq ft / m2) | 40.20 / 3.73 | 22 / 2.04 | 29.30 / 2.72 |
| Grate Area (sq ft / m2) | 9.20 / 0.85 | 4.50 / 0.42 | 4.60 / 0.43 |
| Evaporative Heating Surface (sq ft / m2) | 383 / 35.58 | 383 / 35.58 | 387 / 35.95 |
| Superheating Surface (sq ft / m2) | |||
| Combined Heating Surface (sq ft / m2) | 383 / 35.58 | 383 / 35.58 | 387 / 35.95 |
| Evaporative Heating Surface/Cylinder Volume | 162.29 | 324.58 | 327.97 |
| Computations Relating to Power Output (More Information) | |||
| Robert LeMassena's Power Computation | 690 | 338 | 345 |
| Same as above plus superheater percentage | 690 | 338 | 345 |
| Same as above but substitute firebox area for grate area | 3015 | 1650 | 2198 |
| Power L1 | 1856 | 2820 | 3052 |
| Power MT | |||