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me DEVOTED.TO COMME pa FD, ~_ eee RCE, ENGINEERING VOL. V. NO 9. CLEVELAND, O., MAR. 3 4883. ENGINES OF THE ROBERT WAL-| 1881, while they are actualy 129,500 tons in * LACK, Last year we presented our readers with a supplement containing the following de- scription of the engines of the s. s. Robert “Wallace. We have received a large number of cards and letters from our new subscrib- ers, who had not received a copy of the sup- plement, but wished « paper contain- ing the engraving of the engines. We .. feel theretore compelled to reprint the — article with the engraving, for the benefit of the large number of new subscribers. which we have received since the supplemen twas issued : F These engines were designed by Mt. J. F. Pankhurst of the Globe Co., for a line of steamers that needed a Y light, simple, compound engine. that ound be coail handled: and , without the complication ot the. larger com- fMj\ pounds, ue ¥) ’ How this has béen accomplished by \ the designer may be seen by the en- gravings. ‘The engines are ot the fore and att type, with 27 high pressure . oylinder and 50 low pressure cylinder, /\ with a stroke of 36. ° ‘The cylindere~ a ; simple castings, with the exhaust pis from the high pressure cylinder connected direct to the steam chest of the low pressure cylinder. ‘his pipe are Jason thre back-of the, engines and-ont~” ofthe way. ‘Ihe cranks are. diamet- Tically opposits, necessitated by this arrangement of connecting the cylin- ders. all The engines ure reversed by steam, [= as will be seen from the engravings. This gear has been well worked out. It is positive in its motion, and so powerful that the engine’ can? be stopped and reversed under full steam | if necessary. 2 . The crank shaft is built up, with forged cranks and steel pins, fitted to- gether with keys, so that it can be taken apart in case of a broken pin. ‘The columns and framing of these en- gines are of the well Known type “adopted by this company, and are well connected together, and have a light but rigid framing. Both cylin- ders are fitted with cut-off valves working on the backs of the main valves, and are adjusted to any point of the cut-off by a sword arm. These engines have been favorably ‘ cri:icised by engineers on the lakes, and have given good satisfaction since they have ben put to work on board the s.8. Robert Wallace. ‘The com- pany have lately contracted to puta pairof these engines in a vessel now building at Garden Island, Canada, for Messrs. Calvin & Son, which obliges these parties to pay a duty of 25 per cent. over and above the contract price. ~q <> THE SCOTCH SHIP BUILDING TRADE IN 1882. A few weeks since we had occasion to briefly refer to the shipbuilding trade of Scotland during the year 1882 and more particularly during the month of November, and though our remarks at that time were well calcu- lated to give a tair idea of the pros- perity of the industry considered, the following interesting supplement will undoubtedly’ .mevt with favor. As stated by the Glasgow Herald the returns, submitted below, of. the number of vessels and the aggregaet amount of tonnage launched by the various firms on the River Clyde reveal an exceedingly healthy state of matters. ‘The - builders are said to-have surpaased all their . previous efforts, and having turned out an amount of new tonnage greatly in excess of the figures for, 1881, which were con- sidered at.the time to be unusually large. The returnsare 60,912 tons above those for ¢ excess of the returns for 1874, the year which was for some time : considered as the greatest in the history of the trade, returns for the past two years: have given proof that the. depression which prevailed a few years ago was not due to lack of enter- prise or falling off in: technical ‘skill on the part of the Clyde builders, but was caused by inactivity among the ocean-carrying com- \ HANGIN ALG WiC YN ae) ne I \ ( N\ ) aK We A, NIN VAN AND SCIENCE. The $2.00 Per ANNUM SINGLE COPIES 6 CENTS with well-filled stocks in every shipyard-| The use of steel in the construction of There were launched during the year by | vessels has been steadily on the increase, the various firms engaged in shipbuilding | and it is gratifying to see the ideas of naval on the Clyde 260 vessels, of an aggregate| architects so generally adopted by ship- tonnage of 391,934 tons, as against 261 ves-jowners. At first the new material was re- sels and 341,022 tons during 1881. The| ceived with vaution, exact bearing of the returns will however, be seen by reference to the following. table, Clyde it had a very favorable reception, and which gives the amount of tonnage launched | the tonnage of ateel-built vessels has been during each year since 1870: but now: the majority of large steamers are built of it. On the going up by leaps and bounds. In 1879 the steel-built vessels amounted to 18,000 tons, in 1880 they rose to 42,000 - tons, and in 1881 to 66,609 tons. ‘The latter figures have been far surpassed during the past year, the steel vessels numbering 60 of an aggregate tonnage Wil of 108 264 tons, While the use of a . steel is on the increase, wood has been \MAVWIH Steadily declining, and in the returns A NK which have been received only two ‘ small vessels are marked as having f been built of wood. : While the Clyde builders are chiefly NN} occupied in the construction of high- \\ class. vessels, their work is of a very varied character, and embraces. every i i f\ torm of floating’ craft, from a simple ) LiVAl\ ee lighter toa complex, highly-finished ( Atlantic passenger steamer. The re- turns show the wide variety of work accomplished on the river. The 291 vessels Jaunched by all the firms on di. ; + me the Clyde were made up as ‘follows: * 172 serew steamers, 37 sailing ships, 14 paddle steumere, 8 yachts, 21 barges, | ,5 barke,2 war ships, 2 hopper barges -- ql - 6 screw tugs, 10 steam launches, 4 7 lighters, 8 dredgers and 3 cargo flats. Hn, The River8 Tyne, it appears, has a | monopoly of tugs, and the East Coast j lite] of England devotes its energies to cargu-carrying boats, but on the Clyde every form of vessel is construct-. ed. From a general abstract of the | trade on the Clyde for the year 1882 || We find that the total number of ves- | | sels constructed was 291, while. the amount of tonnage, as indicated in the table given above, was 391,934 tons. It will be seen that a notable increase I has taken place with almost every uf succeeding year, and the future, it is thought, will yield still more gratify- ENGINES OF S. 8. ROBERT WALLACE. panies of the world. Notwithstanding the immense quantity of new tonnage put into the water during the year, the amount of work on hand is very substantial, Many of the firms have more tonnage on hand than they launched during 1882, and consequently diel prospects are.good, while, in the great majority of the cases, the new year opened t ing results. =p A NEW METHOD OF PROPELL- ING BOATS. The inventor of a new system of propelling, or rather towing, boats upon the canals exhibited his inven- tion to the New York state engineer and surveyor a few days agé. In this system the boats are moved by an endless wire cable, operated by Stationary engines located at different points along the canal. This cable is above the banks and within easy reach when the boats are steared near the UU side of the canal, the boatman by a q simple device attaches a selt-recover- ing towline to the cable. ‘This line is i : ] controlled by a friction brake which \ eases off the line until the boat attains the same speed as the cable, thus pre- venting jerks and strains before {the boat gets under way. Careful H} diisj estimates by practical engineers show a 2 the system can be applied and operat- = ed in towing boats for less than the cheapest method now in use. It is likely that a section of a mile or more will be tried during the goming Pear upon some portion of tte Erie canal. ' —0— ‘The Court of Chancery and the Supreme ; | Court of Canada have decided, after an ex- ” 202,480 | haustive investigation, that the Mississi pi 232,926 | was not flontable prior to McLaren’s im- 196,299 | Provements. The Whig maintains that it : 180,401] Was. The Judges will feel like hanging themselves when they learn this. TONNAGE FOR THE LAST 13 YEARS. i