Handbook of Railroad Construction; For the use of American engineers. / Containing the necessary rules, tables, and formulæ for the location, construction, equipment, and management of railroads, as built in the United States. - George L. Vose

Example.

Let stroke be twenty inches, and diameter of wheel five feet, the ratio will be

40
188.4 = 0.2122.

369. Table of decimals, which, multiplied by the total piston pressures (table 5) will give the traction in pounds, or ratio between double stroke and wheel circumference. Table 4.

Wheel.	STROKE IN INCHES.										Wheel.
Wheel.	18	20	22	24	26	28	30	32	34	36	Wheel.
3½	2728	3031	3334	3638							3½
3¾	2553	2837	3120	3404	3688						3¾
4	2386	2652	2918	3182	3444	3708					4
4¼	2250	2500	2750	3000	3250	3500	3750				4¼
4½	2151	2390	2593	2830	3071	3294	3529	3764			4½
4¾	2012	2235	2459	2682	2905	3129	3352	3575	3800		4¾
5	1910	2122	2334	2546	2766	2979	3192	3405	3617	3830	5
5½	1736	1929	2122	2315	2500	2692	2885	3077	3273	3473	5½
6	1591	1768	1945	2122	2321	2500	2678	2857	3036	3215	6
6½	1468	1632	1796	1958	2131	2295	2459	2623	2790	2951	6½
7	1364	1516	1667	1819	1970	2121	2273	2424	2576	2727	7
7½	1272	1414	1556	1691	1831	1972	2114	2254	2394	2535	7½
8	1194	1326	1417	1592	1688	1818	1948	2078	2208	2337	8
Wheel.	18	20	22	24	26	28	30	32	34	36	Wheel.
Wheel.	STROKE IN INCHES.										Wheel.

FORMULA.

2(d² .7854 × p) = P.

Where d = diameter.

p = pressure per inch.

Example.