56 Book of Engineering 



and in a couple of hours, or even less, the 

 ship within is high and dry, ready for 

 overhaul or repair. As every ship must 

 be dry-docked at least annually, you can 

 imagine that a floating dock is kept well 

 employed. 



The demands made upon it set an inventor 

 to work, and he produced a plan by which 

 a single dock could lift several ships a day 

 clear from their element, but it was neces- 

 sary to have somewhere for them to be 

 deposited. This is the depositing dock, and 

 it works in connection with what are called 

 grids. 



Imagine several steel sections, shaped like 

 the letter " L," placed in series at the river 

 side, with a little space left between each of 

 the sections. A dozen or more sections 

 make one grid. The sections of a grid are 

 all connected, and are held in position at 

 the back. The floating dock itself is an 

 opposite series of sections, like the letter 

 " L ' reversed, thus J. This type of 

 floating dock has no ends, nor has it a left- 

 hand side. The ship is warped on to the 



