458 THE YERMAK ICE BREAKER. 



felt at once that the fore propeller had to be removed, whioli was done 

 on my returning to Newcastle. No forward propeller could stand the 

 charges of the ice breaker into the polar ice; and if it does so, it stops 

 the progress of the ship. Of course, the YerinaJi' is meant for double 

 service; for the Baltic the forward propeller is useful, and for the 

 Arctic it is objectionable. We have either to sacrifice one or the 

 other; but if a special ice breaker has to be built for the Arctic it 

 ought to be without forward propeller. 



With regard to the strength of the ship, it is not a question of the 

 weight of material; it is a question of knowledge and experience, and 

 I believe that Messrs. Armstrong, Whitworth & Co. have learned very 

 much since our lust trial in the polar ice. One can not make a mis- 

 take in building a ship too strong. The Yeniud- had to be improved 

 in that respect after the first trial, and we have to do something more 

 now. Had it not ])een for this I would not have returned without 

 penetrating farther on, in order to study that unknown region a little 

 more. 



The angle of the stem, 70^ from the vertical line, proved to be a 

 good one; 20'-' for the sides of the ship is also not bad, but it should 

 run a bit higher than on board the Yennak^ because the ship receives 

 with her sides tremendous blows; 25^ would })e still more profital)le. 

 With such a shape of ship one would expect that the ship would roll 

 heavily at sea. T did not dare to give to the Yermak any bilge keel, 

 but T think it would do no harm to the ice-breaking qualities if the 

 ship was supplied with two short bilge keels on the last third of the 

 length of the ship; it would improve, somehow, her rolling quality; 

 also a l)ig rolling chamber would be useful. 



The proportion of the Yenucik is 1 to \\\ it is such because the ship 

 has to enter the port of St. Petersburg. For the polar ice breaker 

 finer lines would be better, but finer lines increase the weight of the 

 ship. I believe 1 to 5 would be a good proportion. 



The size of the ship depends very much on the power required and 

 the quantity of coal supply. The bigger the ship the more powerful 

 will be the engines and the greater the supply of coals. During our 

 work in the Arctic we seldom used our full power; the ship progressed 

 fairly well with the engines working slow. However, sometimes it 

 happened, during the pressure of the ice, that full power was required. 

 In such a case a ship with weak engines has to wait, but it should not 

 be more than a few hours. The progress of the ice breaker with 

 smaller engines will not be so quick; anyhow, it will be progress. I 

 may say, the less power j^ou have the more patience you want in 

 going through the polar ices. The Fram had 200 horsepower; it was 

 not enough for a good ice breaker; but I believe 2,500 horsepower will 

 be suflicient for fairly good progress through the ice. 



