SOCIETY OFAUTOMOTIVE ENGINEERS, INC. TwoPennsylvania Plaza,NewYork,N.Y.10001 50YEARS OF MARINE GEAREVOLUTION ByRichardC.McRoberts, P.E. Development Engineer-MarineProducts TwinDisc,Incorporated, Racine,Wisconsin Automotive Engineering Congress Detroit,Mich. January10-14,1972720280 Downloaded from SAE International by University of Birmingham, Sunday, August 19, 2018Downloaded from SAE International by University of Birmingham, Sunday, August 19, 2018720280 FIFTY YEARS OF MARINE GEAREVOLUTION RICHARD C.McROBERTS DEVELOPMENT ENGINEER MARINE PRODUCTS TWINDISC, INCORPORATED Theobjective inpreparing thisreviewofmarinegeardevelopment istopro videapermanent recordofthisinteresting history. Without exception, eachoftheeightcontributing manufacturers encouraged thework.Fortunately, thosewhosemarinegearmanufacturing datedbackintothefirstquarterofthe centurysuccessfully searched througharchives withsomesurprising results. Thenatureofthesubjectdictated theneedforapictorial presentation using 35m.m.colorslidestakenof150pertinent marinegearreferences actually spanning 66years,1906to1972.Thesereferences wereearlydrawings, photo graphs,illustrations fromservice literature andsalesbrochures. This includes 1910periodinternal combustion marineengines andracingcraftwhich areshownwithexcellent clarity. Asexplained intheabstract below,the entireslidepresentation isavailable oncolorstripfilmwithwritten commentary included. Itishopedthefilmwillbeausefulsupplement forschoolandcollegecourses inmachine design. Alsonavalarchitects, usersofboatsandcommercial craft mayenjoythisevidence ofthetrialsandsuccesses whichpreceded development oftoday's veryexcellent marinegears. ABSTRACT Acolorful seriesof150slideswaspresented tracing 5HPto1200HPmarine geardesignevolution beginning in1906,followed bypre-WWI developments, LibertyAircraft engineusageanda1924to1972seriesofpleasure boatand workboatmarinegearphotographs. Theentireslidepresentation isavailable in35m.m.filmstripandmaybe ordered (atcost)fromtheauthor, R. C.McRoberts, TwinDisc,Incorporated, Racine, Wisconsin, 53403,U.S.A. Forshorttimeusage,aloanfilmisavail able. Thishistory ofU.S.marinegeardevelopment includes information contributed bytheSnow-Nabstedt GearCorp.,Capitol Gears,Inc.,Paragon Gears,Inc.,The Walter Machine Co.,Inc.,Detroit DieselAllison Div.ofGeneral MotorsCorp., Caterpillar Tractor Co.,WarnerGearDiv.Borg-Warner Corp.andTwinDisc, Incorporated. Downloaded from SAE International by University of Birmingham, Sunday, August 19, 20182 Bychoice,thishistoryislimited to1000HPandsmaller marinegears. An apologyisextended toanydomestic marinegearmanufacturer whoisnot included. However, theauthorwillwelcome supplementary information from thosewhohaveitorknowwhereitmaybeobtained. Thefollowing textisintended tosupplement theslidepresentation fromwhich 16photographs areincluded attheendofthispaper. Itemsin( )refertonumbered illustrations intheslidepresentation and filmstrip. MARINE GEAREVOLUTION OF THESNOW-NABSTEDT GEARCORP., HAMDEN, CONNECTICUT TheSnow-Nabstedt GearCorporation storybeginswithLeviT.Snow.(1)anative sonofMaineandamanofgreatinventiveness andmechanical ability. Hecame toNewHavenasayoungmanandmanufactured severalofhisowninventions until 1906,whenheorganized TheSnowandPetrelli Mfg.Co.andstarted toproduce thelineof"Joe'sFamousReversing Gears". Photo(1)showsMr.Snow,Mr.A.T.Nabstedt anda1910published statement that"Joe'sMarineReversing Gearscameintogeneral usein1906"--which is thebeginning forthishistory ofmarinegearevolution. Alsoshownaretwo viewsoftheveryearlyJOESmarinereversing drive. Theattached photo(4)showsaninstallation of"Joe'sRearStarter forMarine Engines" soldasanaccessory withthebandbrake,planetary reversing hand leveroperated (notenclosed) marinegear. Theirsalesbrochure oftheearly1920'scarriedthisremarkable recitation: JOESDUPLEX DRIVE RACING MODEL NO.143 "JoesDuplexDriveGearshavetransmitted thepowerinpractically allthevictorious boatsinthebigspeedcontests formorethan tenyears. "MissMinneap