Hawaii Holomua, Volume I, Number 21, 11 ʻOkakopa 1893 — THE “THUNDERBOLT." [ARTICLE]

THE “THUNDERBOLT."

Two Hundred Mi!es *n Bour. I Aay object p*>&iag throagh the air meets «ith a m proportion to its T«locity. E. Henn Kelley in the Roehe*ter Erpre*t. The resistanco % motI ing object eneounieni is giren by standanl aathority at so many ponnds pressnre for evory s«{U»re foot of surf«ce oxposod. At a I speed of ton milos an bonr air rosistance i« ono ba)f poand foi eaeh s*]irfare foot oxj>o«rd, twonty miles hcnr, air rosistance is two jiouuds for ea« h foot; forty miles. eigbt jK>uuds: si\tv milee, eightooo jK>ands; eighty milo*. thirty-iiro jH>nnils: ono hundrod miie*. fiffty jK>unds; one hundre<i and twelTO milea. Emj*iro Stato e\presii tirao, sixtv jh>uu<1s for every foot of snrfaco, and ono hundrod and tweuty miloa an honr, soveotv-two jK>onds, An object passing throogh the air at a given rato of sj>eod hu also a vacnum or suctiou rosistanco to overeome at its rear end. whieh is fijual to iU forwartl or displacemeut rosistance. JIo* ing botlies aiso drag along thtdr j*ath tbe >urr<*uudiug air iu j*roj>ortion to their sj*eed aud £oru>. At a sj>ood of a mile a minute the buik >>f «ir drawn by an object is etjual t<> its own bulk. At ouo balf-mile a m nuto the air dra > n along is one-foorth tho bulk of the object; at one-fonrth mile a mi.uie. one-si\teeuth bnlk of tiie object. Could we Iay asido the air resistaoce an objo.‘t eouKl bo m«<lo to traTel at a veiocitv of a mile a secoiui. Heaven!v bctlies in spaeo, lH»ing free from i<tmospheric pressure. have mainta:ued thn>ng!» coanfcless agcs a velocity of u thousm<i iuiles a miniUe. Then to athiin a great »peed for railroad travel, tbe great aim to cent r on meehanieul abi!ity at present should be ihe constrnction of a train that will ot!er tho least jx>ssiblo nurfaco e\j>osed to tbe air. The train illustrated as tbe | “Thooderboli” consists of engme, tender and tive earu. Tbe ’ j*rinc-ij>*i improvement c>Ter standard cars is in ihe shaj>e of Uie train. whieh ai end vu*w is ' j the sbaj*e of a borscshoe. The entire train is made of boi)er iron rivete<l together. being trne, evcn an t .-mootn, withont eveu a ’ . bolt head projecting to catcb tho | air from nose of pilol to e\haust I port at extreme rear of last car, sinootb iU cntire Iength like a ( snake. Cars ūt tight togethcr with f i telescoj>e joint. dust tight. Xo s}ej«s or platfonns are nsPnl as the doors are st tbe suie witb the fioor only eigbt inehea froin the t track. The conpliog is fnii with car base. therefore tbere is eo , sw«ying or iockicg monmone so eommon in other eam* Tbev are the mme size inside measnre. as , tbe old cars. bot run four iuehea alnne tbe tr*ck to bottom of sili. Qld care are 46 inehea to

bottom of sill. The center of gravity is !ower tban oKl cars an«i also below tbe axel-bearmg. Con.seqoent!v it is almost impossibIe to overturn, & thing of erery div occarrence on the oniinary railroai. The tracks rnn lengthwise of the train insteail of cross\*ise the ears. allo\ving the door to be drop|)etl to eieht inehee of the track. Eaeh ami erery wheel has an imiividnal airbrake. whieh works aione and indepeudently of all others. One brake to a car is the eommon wray. In a traiu of five standard cars there is by actual measnrement 1,43ti square feet of 3arface e\posed to the resistance of tbe air. whiie in tne “Thunderbolt there is but 140 sqnare feet esposeil, or less than one-tenth as mueh surface oxposed to air resistance. The side friction of bota trains is considoreil in this calculation. Bv the forgoing data of wiud preasure we find tbat the Empire State e\press ou its famous run of 112 miles an hour had a direct air resistance of tiO pounds a foot ag.»iust 1.436 square feet of surface. eqnal to 86.160 pounds or 43 tons, without counting about 40 tons power lost dragging tho surrounding air along its path. “Thuuderbolt” has si\ty pounds pressure times 140 sqnare feet of surface e\pose<l to air, cr 8,460 pouuds ouly. equal to one-tenth of Erapire State resistnuce. Engiue? In the eommon loeomotive the boiler nsediso6 inches iu diaraetor by 27 inehea over all, having 230 two-inch flaes 12 inches long. supplying the cylinders with wet steam taken directly from top of water. Steam travels 24 inches through pipe to cylinder heail, tbns wasting 40 per cent of pressure in pipe friction aud tarning five corners. The boiler iu ‘Thunderbolf ’ is the same leugth, ellipiie instead of circular in form; has 502 tiues insteadof 231. ! It bas a borizonUl partition with super-heating steam chambor, larger than a epmmon boiler; the steani travels only fonr inches to g«t from boiler to cyliud- r iusteadof 24 inche<. thnss.»ving tha eutire 40 per cent lost by tlie old boiler. All steam is super- j hcat d a!so a great advautage. A eomiuon eugine exbausts per|»endicular up against the air at its gravity weigbt of 15 ponnds jwr sqnare ineh. whieh is equal to a downward slroke of 3,800 ponnd hammer ou top of the engine every limo the engiue putTs at the open throttlo. In the new engine the e\haust is directly back, sending the siuoke »r»l cindei> ont of the rear cnd of the train and thus 1 forciug the tr»in fcrward by a . preas«re of 3,800 pounds. a clcar saviug of nearlv two tocs of j power. ■■■ 1 "