The wheels of such little locomotives, since speed is no object, should be kept as small as possible, and the stroke should be of the greatest length. The nearer the stroke can be extended to half the diameter of the wheel, the more successful will the engine prove on steep inclines. Good sand-boxes, front and back, of ample capacity are essential, but it is not advisable to fit any steam sanding apparatus, for, owing to the low position of the motion, a good deal of the sand will rebound into the joints and bearings, as I found by experiment.
Cabs on such small engines are to be avoided as unbearably hot in summer, dangerous in case of emergency, and inconvenient at all times on account of the contracted dimensions. A stout mackintosh is cheaper and far better for the driver.
A steam water-lifter is a convenience in frosty weather when the water supply above ground may be frozen up, but in summer the engine tanks get so hot from their proximity to the boiler that the water, which becomes lukewarm in the process of being raised by the lifter, is then very soon at a temperature which makes the action of the injectors precarious.
I may say that in all my locomotives I use Holden and Brooke’s restarting injector, which, after experiment with many types, I find takes the hottest water and is in all ways most reliable. I place brass wire strainers in both steam and water-supply pipes close to the injector, which is invaribly fixed below the tanks, so that when the injector is overheated the water will run through by gravity and cool it; a most important advantage.
NUMBER, DATE OF COMPLETION, No. 1. 1875. No. 2. 1881. No. 3. 1894. No. 4. 1896. No. 5. AND NAME OF ENGINE. “EFFIE.” “ELLA.” “MURIEL.” “KATIE.” Diameter of cylinders 4 in. 4⅞ in. 6¼ in. 4⅝ in. 5½ in. Length of stroke 6 in. 7 in. 8 in. 7 in. 8 in. Diameter of wheels 1 ft 3½ in 1 ft 1½ in 1 ft. 6 in. 1 ft. 3 in. 1 ft. 4 in. Length of wheel-base 2 ft. 6 in. 4 ft. 6 in. 6 ft. 3 ft. 5 ft. Number of wheels (all 4 6 8 4 6 coupled) Length over framing 7 ft. 8 ft. 8 in. 10 ft. 9 in. 8 ft. 10 ft. Overhang at each end 2 ft. 3 in. 2 ft. 1 in. 2 ft. 4½ in. 2 ft. 6 in. 2 ft. 6 in. Width over framing 2 ft. 3 in. 3 ft. 10 in. 3 ft. 10 in. 3 ft. 10 in. 3 ft. 10 in. Length of boiler 4 ft. 6 in. 6 ft. 6 in. 8 ft. 3 in. 5 ft. 8 in. 7 ft. 8 in. Diameter of boiler 1 ft. 10 in. 2 ft. 1 in. 2 ft. 1 in. 2 ft. 1 in. 2 ft. 1 in. Length of firebox (flue) 1 ft. 9 in. 2 ft. 3 in. 3 ft. 2 ft. 3 in. 3 ft. Diameter of firebox 11 in. 1 ft. 3¼ in. 1 ft. 3¼ in. 1 ft. 3¼ in. 1 ft. 3¼ in. Number of tubes (brass, 1⅜ 23 57 57 57 57 in.) Heating surface 23 sq. ft. 70 sq. ft. 91 sq. ft. 53 sq. ft. 80 sq. ft. Grate area 1.25 sq. ft. 2.12 sq. ft. 3 sq. ft. 2.12 sq. ft. 3 sq. ft. Capacity of tanks 18 gals. 50 gals. 84 gals. 49 gals. 77 gals. Working steam pressure per 125 lb. 160 lb. 160 lb. 160 lb. 160 lb. sq. in Weight in working order 1 ton 3 cwt. 3 tons 15 5 tons 3 tons 5 4 tons 5 cwt. cwt. cwt. (?) Co-efficient of adhesion at 3.6 4.7 4.5 4.9 lb 4.3 (?) 145 lb. mean pressure Tractive power per lb. 6.2 lb. 12.3 lb. 17.3 lb. 9.9 lb. 15.1 lb. pressure in cylinders If diameter cylinder2 = 1, 207 425 336 356 381 ratio heating surface = If diameter cylinder2= 1, 11.2 12.8 11.0 14.2 14.3 ratio grate area = Load (exclusive of engine) 15 tons. 35 tons. 49 tons. 28 tons. 44 tons. on level. (These are up 1 in 100 9 tons. 21 tons. 30 tons. 17 tons. 27 tons. average working loads which can be considerably exceeded on the easier gradients.) up 1 in 50 6.4 tons. 14.6 tons. 21 tons. 11 tons. 18 tons. up 1 in 25 3.8 tons. 8.3 tons. 12 tons. 6.5 tons. 11 tons. up 1 in 12 1.8 tons. 3.4 tons. 4.9 tons. 2.5 tons. 4.4 tons.