82 A TREATISE ON DREDGES AND DRKlx ;i\< I 



to the elasticity of the upper portion of the ladder, many breaks 

 are certainly spared to the dredging machines. 



All the winches are moved by independent double cylinder 

 engines; the winch controlling the ladder is provided with friction 

 clutches of Minoto's system and also with a friction brake applied 

 by means of a lever arm. The lowering or raising of the ladder is 

 done by means of lever arms controlling the drums of the winch 

 around which the chains holding the lower end of the ladder are 

 played in or out. 



A steam crane is ocated at the bow of the steamer for lifting 

 the rocks too large to be taken up by the buckets; while a second 

 steam crane is mounted on deck for the raising or lowering of 

 the ladder. Both cranes are provided with friction clutches of 

 Minoto's system. 



The motive power, as indicated above, is provided by two inde- 

 pendent engines. These are so arranged that each one of them may 

 act either on the propelling or dredging apparatus. The advantage 

 of such an arrangement is that in case one of the engines breaks down 

 the work will continue without interruption. Besides, these two 

 engines can be easily coupled so as to act directly on the dredging 

 apparatus when working in hard material. On the dredge there 

 are two propellers, four bladed, with their shafts in continuation of 

 the revolving shafts operated by the engine. The great advantage 

 of two propellers is that the vessel may turn in a small radius 

 when the two propellers are revolving in opposite directions. 

 A simple movement allows the power to be changed from dredging 

 to the propellers. 



On account of the heavy seas prevailing in the locality the dredge 

 was made a real steamer. Sailing under her own steam she went 

 alone from Marseilles to Boulogne and on such a long voyage she 

 proved her seaworthy qualities. The hull is entirely of steel divided 

 in various compartments separated by watertight bulkheads to 

 insure its floating even in case one of the compartments wen; 

 injured. 



The dredge is equipped with every device ordinarily found on a 

 modern steamer. 



The messroom and quarters for the officers mid crew and the 

 cabins of the engineers and captain are well heated and ventilated 

 and are lighted by electricity. Powerful arc light lamps mounted 

 on deck furnish light for work at night. 



