Richfield Reaper | 1918-10-12 | Page 3 | Force of Compressed Air

force of comar Compressed sed air Alp the ne effects of air resistance ara ar well known in the twelve and one half mile simplon tunnel where ar an exceptionally high amount of 0 energy Is required for running the electra elec clec tri trains the tunnel which Is fifteen feet wide and eighteen elgh teea feet high with a sectional area of two hundred and fifty square feet has a vent ventilating current of cubic feet of nil it per second maintained by two larg blast fans at the brig end exhaust fans at eiselle iselle trains going with avith vils mils current encounter less resistance si than in open air up to fifteen and a half miles an hour but at al higher speeds or in the opposite direction the resistance is rauch much greatel lhnn than outside coasting by gravity down the seven per one thousand maxim maximum irm gradient a train even going in 9 with tho the current cannot exceed thirty five alve miles per hour on account of the braking by tho the air