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8 MARINE REVIEW. » Universal Roller Thrust Bearing. A patent universal roller thrust bearing, that has been given thorough trial on several lake vessels, is illustrated in the accompanying engravings which were made from working drawings. It is manufactured by the pat- entee, Michael Schmalty, of Bay City, Mich. The drawing shows the bearing as usually applied to marine engines, having the ordinary horse- shoe thrust and steady bearing combined; and the forward thrust from the roller bearing is taken by the steady bearing, the horseshoes being used for backing purposes -only. : J The bearing consists of a universal device, the steel rollers running between two disks and a device for taking up wear and tear. , The universal device consists of two steel rings tapered at slight angles towards two steel pins, which are placed at right angles against each other, thus permit- ting strain on the rollers to be equalized when shafting is slightly out of true line. These rings rest directly against steady bearing and are held stationary by steel dowse pins. The bearing proper consists of a number of conical steel rollers running between two'cast steel disks, the forward one being stationary against the universal device and the after one driven by a collar securely clamped to the shaft. The rollers are made of tempered tool steel and grooved, as shown in the drawing, so as to take the end thrust. Ends of the rollers are held in position by two steel rings united by radial arms, and fitted with bronze journals for rollers. In addition to the grooves, the outer ends of the rollers are designed to take part of the outward thrust by working against a bronze or copper washer, placed end- ways in the outer journals and supported by the outside ring. The after end of the steel disk is threaded for two steel adjusting rings, provided with slots or notches for spanner wrenches, so that any wear or tear can easily be adjusted by locking the rings against each other in the proper fore and aft position. This bearing has been in use for the last three years on several large raft-towing tugs owned in Bay City, and also on a high-speed triple ex- pansion engine making 400 revolutions per minute under 200 pounds steam, and has given excellent satisfaction wherever 'tried, © Having con- siderable less friction than the ordinary thrust bearing, the number of revolutions gained when tested in comparison with the horseshoe bearing has been from six to twelve per minute, all other conditions being equal. The patentee has received many unsolicited testimonials from owners and captains of crafts using this roller bearing, and recently it has been fitted aboard one of the largest tugs on the lakes, Capt. James Reid's Protector, which has a compound engine of 22 and 40 inches by 28 inches stroke, and which is reported to have gained by the use of it ten revolutions per min- ute. Further information regarding this device may be had from Mr, Sven Anderson, manager of F. W. Wheeler & Co.'s ship and engine building plant, West Bay City, Mich. Big Ships of Nickel Steel. Prof. J. H. Biles of Glasgow University says that if nickel steel were now the same price per ton as mild steel, there seems to be no reason why it should not be at once adopted for large vessels, either war or mercantile. But it is not produced at present for much less than three times the price of mild steel. Ina paper dealing with "Improved Materials of Construction and their Influence on Design," read before the British Institution of Civil Engineers, Prof. Biles writes very interestingly of questions of construction involved in the use of nickel steel as a material for ships. He concludes with a summary of the effect which the adoption of nickel steel would have upon the design of a 10,000-ton ship. "It may be assumed," says Prof. Biles, "that nickel steel, 50 per cent. stronger than mild steel, can be produced with certainty. The relative weight of parts subjected to longitudinal stress may be reduced 2&3 1-3 per cent. If we assume that to resist compressive strains we have to re- duce frame spacing, and can only take advantage of the increased strength of the material to the extent of one-half, we shall only gain 16 2-3 per cent. in transverse framing material. The total gain in a 10,000-ton ship will be 1,000 tons on a weight of 6,000 tons--this is 16 2-3 per cent. lt was found in passing from iron:to mild steel that from 1% to 3% per cent. was added by increased weight of butt straps, laps, ete., and though a small- er percentage would probably be added in this case, some allowance should be made. It seems as if from 14 per cent. to 15 per cent. of the weight of steel could be saved. This reduction in the weight. of hull can be used to increase weight of machinery and coal. The extra. speed. resulting therefrom in a 20-knot ship will be 14% knots with an extra total coal consumption of 13 per cent. To produce a mild steel vessel carrying the same dead weight of cargo and having 21%4 knots speed, the dimen- sions would have to be increased by 10 per cent., the horse power by 40 per cent., the first cost by 20 per cent., say $350,000 (supposing passenger accommodation to remain the same). Supposing the cost of workmanship is. the same in a nickel steel vessel of the same dimensions as in one of mild steel (it will probably be less), we should have as the only difference in first cost of the two vessels that between 6,000 tons of mild steel and 5,000 tons of nickel steel. The former might cost $200,000, but the latter could hardly cost $200,000 plus $350,000, which would be $550,000; and anything below this would be in favor of the nickel steel ship, both in "Ly economy of first cost and in economy of upkeep. The coal bill in the mild steel ship would be 19% per cent. more than in the nickel steel ship. The 5,000 tons of nickel steel could probably be bought at present. for $375,000, leaving a balance of $175,000 of saving. These figures are given to show the great value which increase of strength of material has upon the design of a ship and upon its first cost. In other types of ships savings in weight and engine power could be effected. In the low-powered ships the gain would be less. Take the case of a 14-knot Atlantic ship of about 7,000 tons in addition to coal to do her voyage. She could carry 10 per cent., 700 tons more cargo, if built of nickel steel. A mild steel vessel large enough to carry this extra cargo and maintain the same. speed would cost $50,000 more. This, added to the cost of the mild steel in the vessel carrying 7,000 tons, would give a sum which would enable the builder to pay $45 per ton for the nickel steel.. The extra cost at $75 per ton would be about 15 per cent. of the first cost of the vessel. As there would be only 5 per cent. less of coal and machinery expenses paid out to repay the extra first cost, it is doubtful whether, at $75 per ton in a vessel of this size, it would pay to build in nickel steel. It will be of interest to know what chance there is of this material being produced much more cheaply. No reference has been made to reductions in weight of machinery due to the adoption of nickel steel and their effect upon design. te