THE EFFECT OF PROPELLERS ON THE STEERING OF TESSELS. 427 



did the ship's head swing to port of her course, but invariably to star- 

 board. I would have preferred to wait until these differences had been 

 either accounted for or explained by further experiments before placing 

 the facts before your readers ; but an imperfect account of the trials having 

 appeared in the local newspapers, it was thought desirable to publish the 

 facts just as they were obtained, and to reserve for a future letter further 

 remarks, and a description of a series of similar experiments made by 

 direction of the Local Marine Board on board the Gervin steamer, off 

 the Tyne in August last year. 



"While the inquiry in reference to the Tabor collision was pending, 

 Captain Henderson, the Secretary to the British Shipmasters' and Officers' 

 Protection Society, suggested to the owner of that ship the importance of 

 trying some experiments on the effect of the rudder and screw when 

 reversed. Mr. Westall, the owner, immediately gave instructions to his 

 manager to place the ship, which was then in the Tyne, at the disposal of 

 of Mr. Torke. That gentleman, thinking that it was a point of some 

 interest to mercantile and nautical men to have the matter settled by 

 actual trial, requested Messrs. Gillie and Tate, the Examiners to the Tyne 

 and Wear Local Marine Boards, to accompany the ship to sea, and have 

 the experiments carried out under their inspection. 



On the 19th inst. the Tabor was unmoored from Shields Harbour, 

 and at 2 p.m. proceeded to sea in charge of a pilot and Captain Mankin. 

 There were also on board Rear- Admiral Powell and Captain Nicholas, the 

 Nautical Assessors ; Mr. L. V. Hamel, Solicitor to the Board of Trade ; 

 Captain Henderson, Secretary to the British Shipmasters' and Officers' 

 Protection Society, and Mr. Roche, their, solicitor ; Alderman Peckett, 

 of Sunderland ; Captain Mail, manager for Mr. Westall, the owner, and 

 others. 



The ship was run out to sea three or four miles so as to be out of the 

 way of passing vessels. The Tabor is a screw steamer of 520 tons 

 register. Her length between perpendiculars is 208 feet ; breadth, 27'8 

 feet ; depth, 14' 8 feet. She is propelled by two engines of 90-horse power 

 combined, and at the time of the trial had in about 200 tons of water 

 ballast. Her draught of water forward was 6 feet 6 inches, and aft 10 

 feet 4 inches, she being nearly in the same trim as she was at the time 

 the collision happened. Her screw is right-handed, and four blades ;. 

 diameter, 12 feet ; pitch, 17 feet. The top of the blade was about 2 feet 

 out of the water when the blade was parallel with the sternpost. The 

 direction of the wind was S. by W. ^ W. ; force 4 to 5. The sea was 

 perfectly smooth. The weather being a little hazy, and the marks upon 

 the land indistinct, a dumb card could not be used to measure the angles 

 made by the ship's head, but the bridge compass, being in excellent con- 

 dition and not sluggish, was used for this purpose. Mr. Tate and Mr. 

 Hamel noted the time, the change in the ship's head was observed by Mr. 

 Gillie, who also took down the notes, and Mr. Roche noted the time it took 

 to stop and reverse the engines. The ship's head previous to commenc- 

 ing the whole of the trials was steadied at W.S.W., and the engines were 

 kept going full speed ahead, the ship making 8 knots an hour as shown 

 by the patent log. The fore and main trysails were set during trials 

 1 and 2 ; there was no canvas set during trials 3, 4, and 5. 



Trial No. 1 (helm hard a-starboard). — At 3.43 p.m., while the ship 

 was going full speed ahead, the order was given to stop and reverse the 

 engines to full speed astern, at the same time the helm was put hard to 



