70 EEPORT— 1876. 



On the Investigation of the Steering Qualities of Ships. 

 By Prof, Osborne Reynolds. 



[A communication ordered by the General Committee to be printed in exicnso.] 



The primary object of using steam power in ships is to enable them to pass 

 quickly over long distances. Under normal circumstances rapidity aud cer- 

 tainty iu manoeuvring are matters of secondary importance ; but circum- 

 stances do arise under -which these powers are of vital importance. Experi- 

 ence has taught those who go down to the sea in steam-ships that their 

 greatest danger is that of collision ; and fogs are feared much more than 

 storms. That there must always be danger when long ships are driven at 

 full speed through crowded seas iu a dense fog caimot be doubted ; but this 

 ' lugcr is obviously increased manyfold when those iu command of the ships 

 are under the impression that a certain motion of the helm will turn the 

 ship in the opposite direction to that in which it does turn. 



The uncertainty which at present exists iu the manoeuvring of large ships 

 is amply proved by the numerous collisions which have occirrred between the 

 ships of our own navy while endeavouring to execute ordinary movements 

 under the most favourable circumstances, aud M'ith no enemy before them, 

 •xhcse accidents may be, and have been, looked upon as indicating imperfec- 

 tions iu the ships or the manner in which they were handled ; but it must 

 be admitted that the ships are the best and best found iu the world, aud 

 that they are commanded by the most skilful and highly trained seamen 

 alive. And if peaceable ships fail in their manoeuvres when simply trying 

 not to hurt each other, what will be the case of iighting ships when trying 

 to do all thoy can to destroy each other ? If the general impression as to 

 the important part which the ram is to play in the naval combats of the 

 fature is ever reahzed, then certainty iu manoeuvring must not ouly be of 

 very great importance (this it has always been in sea fights), but it must 

 occupy the very first place in the fighting qualities of the ship. 



Now the results of the investigation of the effect of reversing the j^ro- 

 pellers on the action of the rudder appear to show that, however capricious 

 the behaviour of ships has hitherto seemed, it is in reahty subject to laws ; 

 and that by a series of careful trials the commander of a ship may inform 

 himself how his ship will behave iindcr all circumstances. 



The experiments of the Committee on largo ships have completely esta- 

 blished the fact to which it was my principal object last year to direct atten- 

 tion, namely, that the reversing of the screw of a vessel with full way on 

 very much diminishes her steering-power, and reverses what little it leaves ; 

 so that where a collision is imminent, to reverse the screw and use the rudder 

 as if the ship would answer to it in the usual manner is a certain way of 

 bringing about the collision. Aud to judge from the accounts of collisions, 

 this is precisely what is done in nine cases out of ten. In the paper of 

 to-day I find the following (August 22, 1876) : — 



"The Fatal CoUision off Ailsa Craig.— The Board of Trade inquiry into 

 the collision between the steamer ' Owl ' and the schooner-yacht ' Madcap ' 

 was continued at Liverpool j^esterday. Two passengers by the ' Owl ' were 

 recalled, and spoke to some of the facts of the collision. The night was not 

 misty, though some rain had fallen. They saw the green light of the yacht 

 shiniug brightly after the collision. "VVilham Maher, third officer of the 

 ' Owl,' said it was the chief officer's watch at the time of the collision. 

 There were five able seamen in the watch. Witness and the chief officer 



