The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

62 A QUICK METHOD OF REPAIR- ING A BROKEN SHAFT. BY UO. 5.0. MEIGS, The writer recently, almost by acci- dent, hit on a method of repairing a broken shaft, so cheap, so quick, and so surprisingly strong that he thinks it may be of service to your readers., The use of the method would often ob- viate a long and expensive delay and loss of work, for the shaft gives nearly as good service as before it was broken. The writer has under his charge a hydraulic dredge used on the Missis-, sippi river improvements in the vicin- ity of Keokuk, Iowa. This dredge is driven by a compound high-pressure engine, with cylinders 14 and 24 in. in diameter by 15-in. stroke, running 220 R. P. M. and developing about 250 H. P. The steel shaft of this engine, 6 in. in diameter, broke about 10 in. from one of the cranks. The cranks are quartering, and the shaft is a highly finished one that takes. a long time to build, even under the best of circumstances. It was, as you can see, a difficult task to weld this' shaft so as to repair it, as the stub-end was.so close to the crank that to heat it sufficiently was likely to warp the latter out of shape and spoil the whole shaft. The attempt was made, however, and the shaft promptly broke again at the Same place, although a whole week and a large expense had attended the effort to put the shaft in working con- dition. At the suggestion of a traveling en- gineer, we simply squared the two broken ends and screwed them to- gether with a stud that went half into each piece of shaft. Squaring the ends shortened «the shaft some . 6 in,, but this could be remedied by moving in the outboard pillow block. A chunk of soft and tough steel, that had once done duty jas a wristpin for a large en- gine, was selected from the scrap pile. . This was cut off 10 in. long and turned} to 4 in. in diameter; it was then thread- ed the whole length with a screw of four threads to the inch; each piece of shaft was then bored and threaded to fit this screw, and when finished the stud was screwed into one piece of shaft, and the other piece screwed home. To make the job a little more solid, the stud was dipped into salt and water to make a rust joint of it, and keep it from coming unscrewed by any chance. It took an afternoon and part of the night to complete this job, and the next morning the shaft was replaced in the engine and put to work. It has never; shown the least indication of weakness so far, and is still, after 18 months, ap- parently as good as ever. The new strain THE Marine REVIEW shaft, ordered as a hurry job, was re- ceived in two months, but is still kept in reserve. The joint between the two pieces of shaft was fortunately an inch or so inside of the pillow block, and is now undistinguishable from the rest of the shaft. The work of the engine, of course, always tends to screw the pieces tighter together; but it seems a little surprising that the threads do not strip off ard let the two pieces separate. Probably the friction between the out- er parts of the shaft takes up most of the torsional strain. The 4-in. stub would not last a minute by itself.-- Scientific American. FERRO-CONCRETE FOR SHIP- | BUILDING. An article in the engineering sup- plement: of the London Times de- scribes the use of ferro-concrete for ship building purposes. It describes several 'barges built for the Italian navy of this material, the thickness of the skin being but little more than an inch, for barges of several hun- dred tons burden. The metallic frame- work, or skeleton of reinforcing iron is arranged in accordance with the actual distribution of stresses, and this frame is covered with expanded metal, which supplements the pro- tective action by the distribution of the armoring over a large area, while it unites the various portions of the mass in such an effective manner as to preclude any risk of fracture. This process dispenses with 'the provision of molds and renders it permissible to employ extremely thin walls to serve as the outer skin. Owing to the metallic reinforcement, the con- . crete mass, instead of being fractured by sudden shocks, undergoes an elas- tic deformation, but immediately re- sumes its previous shape when the is removed. The first ferro-concrete boat to be constructed on this system was. built in 1897 and was about 18 feet long by 5 feet wide. The thickness of the sides was only about % inch. ~The first canal barge to be built on this system was constructed in 1902 for a burden of 50 tons, and has since been in continuous use in connection with engineering work on the river Tiber. The Italian navy ordered the first 'boat in 1906. These have a bur- den of about 100 tons each, and have double skins and water-tight com- partments. The first cost of these ferro-concrete boats is less than that of iron vessels of equal tonnage, and the expense for upkeep is practically nil. : NEW HUDSON RIVER STEAM- BOAT. An addition to the fleet of fine pas- senger steamboats plying the Hudson river was made Oct. 26, when the Tro- jan, building for the Hudson Naviga- tion Co., was launched at the yard of the T. S. Marvel Ship Building Co., at Newburgh. It is expected that the Tro- jan will be completed and in commis- sion next season. She is to run to Troy. A sister ship of the Trojan, also for the Troy service, is under construc- tion at the same yard as is the Prince- ton, building for the company's Albany service. The Trojan is 330. ft. Jong, 76. ft. beam. over guards, 42 ft. beam of hull and 13 ft. 9 in. deep. She will draw 8 ft. 6 in: of .watet. Uheré are. more than 250 staterooms, some of them with private bath. The staterooms will be carried in three tiers above the main deck, with a central grand saloon and wide staircases communicating with the various tiers. Her steam will be gen- erated in four boilers and delivered to a surface condensing beam engine of similar type to those which drive the two latest Night Line steamboats. The engine will be of 70 in. diameter of cylinder, with 12-ft. stroke, developing 4,000 horsepower,. and producing a speed of 18 knots an hour through feathering paddle wheels. The Trojan will be equipped with powerful searchlights, and will have a wireless telegraph outfit. TWO CAPTAINS SUSPENDED. The New "York board of steamboat inspectors has announced the suspension of two skippers of large passenger-car- rying craft because they allowed per- sons in the pilot house while navigating the bay with passengers on board. The convictions were for violation of sec- tion 19 of rule 5 of the Rules and Reg- ulations, a section which has been looked upon by many skippers as a dead letter. During the summer one craft came to grief on the Hell Gate rocks, and it was then reported that the skipper had been entertaining a party of friends in the pilot house when the boat struck. Such reports became rather numerous, and inspectors were detailed to keep an eye open for violators of the law. Capt. 1. Hubbs, of the Patten liner Elberon and Capt. Henry B. Edward, of the steamer Little Silver of the same line, running from the Battery to Long Branch, were tried for having persons accompanying them in the wheel house. Both men were tried by the board of inspectors. Yesterday it was announced that they had been suspended for 10 days and fined in addition.