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

| BUILDING MARINE - _ ENGINES ON AS ~ QUANTITY: BAsIs By F B JACOBS. Fig. 14--Planing Twelve Link Blocks at One Operation--The Liberal Use of Jigs and Fixtures Enables This Plant to Turn Out Accurate Work at a 'Minimum , Labor Cost--This Practice Also Insures Duplication of All Units of a Given Kind NE of the most important units requires this step. This is easily done. while each one is adjusted .through of any marine engine is the The thrust bearing illustrated in the medium of nuts threaded over thrust bearing, often spoken Fig. 15 has a cast iron box-type base steel side rods. of as the thrust block or thrust. When designed to hold a supply of oil which The bearings for these ae rods one stops to consider that the force is cooled by copper coils through are fitted with cast-iron caps. to per- exerted on the water by the propeller which sea water circulates. The thrust mit easy removal. To prevent oil in driving the vessel either forward rings are cast iron, lined with bear-. from being thrown out, the thrust or astern comes directly on the thrust ing metal on both sides. The rings bearing is. provided. with sheet-metal bearing, it is readily appreciated that are cored. for water circulation guards. The end bearings for the this member must be properly de- signed and carefully made. Otherwise it is sure to heat and cause trouble. Thrust bearings are of two types called plain and horseshoe. This' unit is sometimes located at the stern end of the shaft tunnel, in close juxtapo- sition to the stern tube, but latter-day practice favors placing it directly abaft the éngine, in which case the thrust shaft is coupled directly to the engine crankshaft. With the type of engine built by the Hooven, Owens,, Rentschler Co., saheeien 0. the thrust bearing i f the horseshoe type installed direct- ty abaft the engine. This unit is illustrated in Fig. 15. In comparing the two types of thrust bearings, plain and horseshoe, many naval architects and marine engineers favor the latter type, due to the fact' that each thrust ring is a separate unit capable of independent adjustment or removal. Thus, if one ring runs. hot it is a comparatively simple matter. to adjust it or remove it entirely if necessity "I: 19 HORSESHOE TYPE ee sais BLOCK USED ON ENGINES FOR THE EMERGENCY HET CORPORATION 338