Data from James Dredge (ed.), "Section V Historical Locomotives and Rolling Stock -- No 95, 'The Comet", in A Record of the Transportation Exhibits at the World's Columbian Exposition (New York: John Wiley & Sons, 1894), p. 343. See also "Links in the History of the Locomotive-No.XVIII", The Engineer, Volume LVIII [58] (19 December 1884), pp. 468-469. Works number was 4 in 1832.
A debate erupted in the pages of The Engineer in 1884 when some correspondents claimed that the "Comet" was a somewhat reworked Rocket of the previous year that was renamed after its initial run on the L&S. Others contested that opinion, describing the Comet as the result of 11 months of hard work at the Stephenson Works. Clement Stretton presented the strongest case for the latter with considerable detail. Basing much of his analysis on a sketch of the 1830 "Rocket" (the second locomotive to bear that name) by James Nasmyth and a later one of the Rocket/Comet by W Stenson on 12 March 1832, Stretton cites an "Old West Bridge Man" for much of his commentary.
The argument offers some convincing reasons for arguing that this locomotive was the one that left the Stephenson Works in February 1832 for Hull, transferred to a canal boat for the leg to Leicester and began work as a ballasting engine in March. It seems certain, for example, that it is this engine that opened L&S's rail traffic from West Bridge Station to Bagworth Station on 17 July 1832. Stenson's sketch shows a locomotive with coupled axles (the original Rocket drove a front set of wheels only) and cylinders raised from their original mounting at the base of the firebox to its shoulders.
The question of one-Rocket-or-two seems to have been laid to rest.
The name "Comet" allegedly was suggested by Robert Stephenson as a way of avoiding confusion. Another reason for regarding this as an upgraded design from the Rainhill Trials winner was the presence of George Stephenson and his son Robert on the Comet's footplate on that inaugural day. (Robert Weatherburn, the usual engineer, also rode along.)
On the other hand, Dredge's 1894 diagram of the Comet shows a Planet-type locomotive with low-mounted cylinders inside the frame (and drivers) with valves on top.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Comet |
| Locobase ID | 20327 |
| Railroad | Leicester & Swannington |
| Country | Great Britain |
| Whyte | 0-4-0 |
| Number in Class | 1 |
| Road Numbers | 1 |
| Gauge | Std |
| Number Built | 1 |
| Builder | Robert Stephenson & Co |
| Year | 1832 |
| Valve Gear | |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 5.25 / 1.60 |
| Engine Wheelbase (ft / m) | 5.25 / 1.60 |
| Ratio of driving wheelbase to overall engine wheelbase | 1 |
| Overall Wheelbase (engine & tender) (ft / m) | |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 21,224 / 9627 |
| Engine Weight (lbs / kg) | 21,224 / 9627 |
| Tender Loaded Weight (lbs / kg) | 7840 / 3556 |
| Total Engine and Tender Weight (lbs / kg) | 29,064 / 13,183 |
| Tender Water Capacity (gals / ML) | |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 18 / 9 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 60 / 1524 |
| Boiler Pressure (psi / kPa) | 50 / 340 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 12" x 18" / 305x457 |
| Tractive Effort (lbs / kg) | 1836 / 832.80 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 11.56 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 97 - 1.75" / 44 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 7.62 / 2.32 |
| Firebox Area (sq ft / m2) | 37.30 / 3.47 |
| Grate Area (sq ft / m2) | 6.80 / 0.63 |
| Evaporative Heating Surface (sq ft / m2) | 340 / 31.59 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 340 / 31.59 |
| Evaporative Heating Surface/Cylinder Volume | 144.30 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 340 |
| Same as above plus superheater percentage | 340 |
| Same as above but substitute firebox area for grate area | 1865 |
| Power L1 | 1117 |
| Power MT | 232.05 |