1849.] 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



199 



SOLID WROUGHT-IRON RAILWAY WHEELS. 



(^Witlt Engravings, Plate XII.) 



On a Patent Solid Wrought-Iron Wheel. By Mr. Henry Smith, 

 of West Bromwich. — (Paper read at the Institution of Mechanical 

 Engineers.) 



The subject of the present communication is a new wrought- 

 iron railway wheel, which is forged solid in one piece, and is manu- 

 factured entirely by the forge liammer; the wheel is disc-shaped, 

 the disc portion being about g-inch thick, and gradually swelled 

 out to the thickness of the nave and the tyre. 



The following may be stated as tlie cliief desiderata in a railway 

 wheel: — 1st. The greatest possible strengtli with tlie least possible 

 weight. — 2nd. Durability, implying also facility of repair. — 3rd. 

 Economy in cost. 



On the first of these points it is conceived there will be no dif- 

 ference of opinion about the disc shape being the strongest possi- 

 ble; and also that when a wheel is made in one entii-e piece, it 

 must necessarily be less liable to the eifects of wear and tear than 

 one which is composed of a number of pieces. This will be made 

 more manifest by analysing the mode of manufacturing railway 

 wheels in the old or ordinary way. For this purpose, and for the 

 sake of drawing the fairest comparison between the wheel now 

 under consideration and the ordinary wheels, a wrought-iron wheel 

 is selected of the most improved make, liaving a wrouglit-iron 

 nave, with the spokes welded to the nave and to the inner tyre. 

 The following is the mode of manufacture of such a wheel: — 

 Pieces of iron with wedge-shaped ends, are brought together all 

 converging to a common centre. These are then welded toge- 

 ther to form the nave or boss, and the inner ends of the spokes, of 

 the intended wheel. Other pieces, T-shaped, are then welded to 

 the ends of these spokes and again to each other, foi-niing the 

 inner tyre of the wheel. This done, a rolled tyre-bar of a suitable 

 length, is bent into a circle of a proper diameter to go on the 

 inner tyre, and is welded to form a perfect circular hoop. This 

 hoop is then heated in a furnace and put upon the inner tyre, and 

 then the wheel is immersed in cold water to occasion such an 

 amount of contraction of the tyre as shall firmly fix it upon the 

 wlieel. Rivets or bolts are then passed through both to secure 

 them together. 



Now, it is submitted that the whole process of thus producing a 

 wheel is open to many well-founded objections — such as the fol- 

 lowing: — The possibility of a want of dexterity in the manipula- 

 tion of the different parts, in the making and bringing them toge- 

 ther. The chance of doing so when the iron is not in a proper 

 condition for welding; then, the uncertainty of the hoops or tyres 

 being exactly the same length, or the wheels with the inner tyre 

 of precisely the same diameter; and again, the amount of contrac- 

 tion of the outer tyre depending upon its slow or rapid cooling, 

 will be affected by any variation in the temperature of the wheel 

 itself and the water in the "bosh" or cooling cistern, and these of 

 course cannot be kept uniform. — All these circumstances are op- 

 posed to wheels being well made with loose tyres, whether with 

 wrouglit-iron naves and arms or with cast-iron naves. 



In reference to the second head, Durability, it is conceived from 

 the contingencies already alluded to, that it must be obvious, a 

 wheel made in one piece will be the more lasting; but on this point, 

 the wheel which forms the subject of the present inquiry has other 

 claims to prefer. In consequence of the iron in the wheel being 

 both granular and laminar, inasmuch as by the mode of manufac- 

 ture hereafter explained this result is ensured, and the grain of 

 the iron being brought to stand at right angles to the direction of 

 the wear, and the body of the iron being of a denser and more 

 compact character than rolled iron, it must doubtless be much 

 stronger and more durable than any rolled tyre-bar of piled iron, 

 which is liable to lamination, and altogether of a softer nature. 

 Again, the torsive and abrasive effects of the carriage-breaks will 

 not produce the same results on a solid disc wheel, as on one with 

 a loose hoop or tyre of rolled iron. Then as regards repairing, 

 wlien the tyre of the disc wheel is worn down so much as to re- 

 quire a renewal, the wheel can be put into the lathe and turned 

 cylindrical, to receive a tyre in the ordinary vvay, secured on by 

 bolts screwed into the tyre' from the inner side, or by countersunk 

 rivets through the tyre; and it must be then a better wheel than 

 any yet manufactured. 



On the subject of Cost, it can only be observed at present, that 

 as the first expense does not determine this point, it must be left 

 to be settled by the results of a sufficient exi)erience. 



The fcllowing is a description of the mode of manufacturing the 

 new solid disc irheels. In the first place, a stiv.ight bar of hammered 



or rolled iron is taken, of 4 or 1^ inches width or more if required, 

 and sufficiently long to form a hoop of such a diameter as is most 

 suitable to make the intended wheel. Other pieces of bar-iron are 

 then laid flat and close together, and cut in lengths to the same 

 circle as the hoop, to form the base of a "pile;" the hoop is then 

 placed upon this foundation, and filled with scrap-iron. The whole 

 IS then put into a reverberatory or heating furnace and when at 

 the proper heat, is hammered in the tools or dies shown by draw- 

 ing A, to form a "mould;" the face of the hammer is recessed in 

 such a shape as to form an approximation to the shape of one side 

 of the intended wheel, but only about two-thirds of the diameter; 

 and the anvil-face has a circular recess, flat-bottomed, into which 

 the hammer-face enters. Two of these "moulds" are then put to- 

 gether back to back, heated in a similar way and hammered be- 

 tween the tools or dies B, which are of the same sectional form 

 and nearly the full-size scale of the finished wheel; but these tools 

 embrace only a segment of about one-fifth part of the entire 

 wheel. The "mould" is turned round hoi-izontally during this 

 process, being turned a little between each blow of the hammer, 

 and it is tlius hammered out to the form and size of the required 

 wheel. The wheel is then put into an annealing furnace, and is 

 planished between tools similar to the last, which are of the form 

 and the full-size scale of the finished wheel, as shown by drawing 

 C, and the wheel then only requires the tyre and the nave turning 

 in a lathe, and the centre boring out. The finished wheel is shown 

 in drawing D. 



By this mode of manufacture it will be perceived that Low 

 Moor iron, or any other description of iron or steel, can be used if 

 required for the tyre of the wheel, and thus in all cases ensure n 

 clean wearing surface, and a compound character of fibrous and 

 granulated iron, which it is believed no other system of making 

 wheels affords. 



The centres for large spoke wheels are also manufactured in one 

 solid piece in a similar manner, by the tools or dies shown in draw- 

 ing E; the top and bottom tools are both alike, and are recessed in 

 the form of tlie nave of the intended wheel, with a short portion of 

 each of the spokes radiating from the nave. The centre of the 

 wheel is thus stamped out by the hammer with a portion of each 

 of the spokes al)out a foot long, ready for welding on to the T- 

 pieces to form the inner tyre and tlie remainining portion of the 

 spokes. A tliin web or fin is left in the centre between the spokes, 

 which is afterwards cut out by the smith. The object of this con- 

 struction is to surpass in certainty of soundness the precarious 

 method of making them at present in use. 



It is unnecessary to urge the importance of obviating, as far as 

 possible, the occurrence of such accidents as have too frequently 

 happened in consequence of defects of railway wheels; but a few 

 of these cases may be alluded to here, in illustration of the 

 subject. 



The accident on the Edinburgh and Northern Railway in Octo- 

 ber last, when the tyre of the leading wheel of the engine broke 

 and threw the train off the line. That on the East Lancashire Rail- 

 w,ay in November last, where the tyre of one of the carriage wheels 

 broke. That upon the Brighton Railway in September last, when 

 the tyre of one of the engine wheels broke, throwing the train off 

 the line. And that upon the Great Western Railway, about two 

 years ago, where the tyi-e of a carriage wheel broke, and a portion 

 of it fell through a carriage, causing a fatal accident. 



^V'ith the view of obtaining some practical information upon the 

 comparative resistance of tlie air to the revolution of the disc 

 wheels and of the ordinary spoke wheels, some experiments have 

 been tried at the Vulcan Iron Works, West Bi-oniwich, by JMr. 

 Henry Smith, with the assistance of Mr. Marshall, the Secretary 

 of the Institution; and the results of these experiments are ap- 

 pended in the following table. 



Experiments on the Resistance of the Air to the Spokes of Wheels, 



No. of Experiment 



Description of Wheel 



Weicht of Wheel, in lbs 



Weight suspended, in lbs 



Distance lolien by Weight, in feet... 



Time of revolution of Wheel, in 

 secnnds 



Total number of revolutions 



Average speed per hour of Wheel, 

 in miles 



l.e"gth of rope, in feet 



iTime before rope was detacbed, in 

 seconds 



Number of tevohuious before rope 



I wns dvtached 



iWeii ht wt toil rope, in lbs 



Disc 

 414 



279 



68 

 220 



21 

 355 



17 



50 



6 



Disc. 



414 



56 



279 



22 

 355 



Disc. 



414 

 71i 

 279 



75 

 267 



35S 

 12 

 50 



The.ie expeiimeiits were performed at an old mine shaft S7i< feet 



