The Rastrick Notebook

[Page 16] 5 Octr. 1829. Mr. Timoy. Hackworths Engine Green & Yellow. Boiler 4’.. 2” diamr. 7/16 In thick and 6 feet long Fire Tubes ½ In thick at top, & 7/16 thick at Bottom. Haunch Ring 11/16 In thick “Fire Bars 5 ft long “2 Steam Cylinders each In dir. 18 Inch Stroke “4 Wheels each 4 ½ feet diamr. soul 3 ¾ wide by 1 1/8 thick – Haunch Inclusive 7/8 thick. “ Feed Pump 2 ½ In dr. 4 Inch Stroke. “ Safety Valve 1 ¾ Dr. Held down by Springs “ Lock up Valve Same Dr. Do Do “ Ball Valve ¾ Dr. _ _ _ _ _ _ _ _ _ _ _ _ 2.4 Sqr. In area of 1.78 In Valve 50 lbs 4√120 Pounds Load [illegible] Valve 30 Pounds Power of Spring at end of Leaver 6 Novr. 1829 880 ft pr. Mt. a3 10 Miles per Hour A Wheel 4 ½ ft Dr. will be 14.13 feet Circumference 880/14.13 = 62.278 Strokes per Mt. _ will be 10 Miles per Hour Single Stroke 1 ½ ft double stroke 3 ft = & 62.278 x 3 = 186.834 feet Velocity of Piston per Mt. [Page 17] 7 In Dr. of Cylinder 38.48 sqr. In Area & 38.48 x 25 lbs. effective Pressure per Square Inch = 962 Pounds load upon the Piston. 186.834 x 962 = 179,734 Pound raised one foot high per Mt Power of Engine 179,734/33,000 = 5.446 Horse Power of One cylinder & 5.446 x 2 = 10.892 Horse Power of the Engine at 10 Miles per Hour supposing the Steam kept Constantly up to 50 Pounds per Sqr. Inch on the Safety Valve & supposing the effective pressure on the Piston 25 lbs per sqr. in. But if the Effective Pressure per sqr. Inch on the Piston can only be maintained at 20 Pounds per Sqr. Inch then the Power of the Engine would be only 8.7 Horse Power.