REFUELING WARSHIPS AT SEA. 175 



The British Admiralty installed the first marine cableway upon the collier 

 Muriel for experimental purposes. 



The publicity given to this experiment started several English engineers upon 

 the same problem. The Admiralty was overwhelmed with many coaling-at-sea in- 

 ventions. The promoters promised greater capacity, lower first cost, less weight and 

 less complication. One of the most promising of these was an apparatus invented by 

 Engineer Commander Metcalfe. For seve-al years the Admiralty experimented with 

 various coaling-at-sea apparatus of Metcalfe's design. It is understood that these 

 were manufactured in government dockyards. His apparatus was not adopted. 



The Metcalfe apparatus comprised a continuously moving endless rope for 

 supporting and transporting bags of coal from collier to warship. This endless 

 rope was propelled by a winch. A movable pulley was introduced to form a bight in 

 the endless rope which, in connection with a steam piston or ram, was intended to 

 maintain a uniform tension in the endless rope and to act as a take-up and pay-out 

 device to compensate for the motions of the ships. The play of the piston was neces- 

 sarily limited. Should the ships approach one another the head of the piston might 

 crash up against the head of the steam cylinder. And again, should the tow-line 

 slip or part the piston might collide with the opposite end of the cylinder with dis- 

 astrous results. 



Up to the present time the only successful compensator introduced for the pur- 

 pose of maintaining a uniform tension in the cableway or ropeway has been in the 

 form of a winding apparatus. 



The automatic tension engine, heretofore described, represents one such device, 

 and the tensioning winch of Adam, which is an essential part of the apparatus 

 adopted by Germany, is another. 



A vast sum of money was expended in Germany by the backers of Engineer 

 Leue, who had a corresponding apparatus with the piston compensator used in con- 

 nection with a block and fall, but the friction of this block and fall introduced dif- 

 ficulties which made it impossible to maintain a uniform tension. 



In a heavy sea, where the tension is not uniform, the lashing of the loaded 

 strand of the endless rope in the Leue apparatus served to dislodge the bags in 

 transit between collier and warship. 



Even though a piston compensator would give an adequate amount of compen- 

 sation, which, in the author's opinion, should be not less than 200 feet, nevertheless 

 it is clear that any movable pulley in a bight of the endless rope could not have a 

 travel of 200 feet on board any ship of war ; or, at any rate, such a range of compen- 

 sation would be impracticable. 



A counterweight as a compensator failed utterly when tested on the U. S. 

 collier Abaranda. 



COALING A CRUISER AT A SPEED OF 12 KNOTS IN A SEAWAY. 



Figure 14, Plate 67, shows the Italian cruiser Liguria towing the Italian collier 

 Sterope at a speed of 12 knots in a sea rough enough for the screws of the cruiser 



