Practical Motor-Boating 



II. — The proper location of the power plant and 

 mechanical attachments, and their care and operation 



By George M. Petersen 



THE amateur boatman should thor- 

 oughly understand the names and 

 location of the various parts of his 

 craft, in order to take good care of it. 

 The principal ones are as follows: stem, 

 keel, stern-post, dead wood, shaft-log, keel- 

 son, bilge keelson, deck beams, stringers, 

 knee, shear-brake, ribs, bulkheads and car- 

 lines. The planking of the hull is really 

 the skin or shell. It covers the ribs and 

 frame of the boat and may be applied in 

 several different ways. The edge nail 

 construction is probably the most durable 

 for a boat which is subject to severe 

 pounding through seas or heavy engine 

 vibration, as the planks are narrow and 

 are secured through both the edge and the 

 face. 



The shape of the stern of the motor- 

 boat is also of vital importance, since it 

 affects speed as well as seaworthiness and 

 ability to run with the sea. For instance, 

 the V-shaped stern shown at points A 

 and B on page 277 may give the longest 

 water line on a given overall length as 

 well as the most protection to the rudder, 

 but it is not a good design for backing or 

 running with an overtaking sea. The 

 "square transom" and the "rounded tran- 

 som" are fairly satisfactory types, al- 

 though the rounded is more expensive to 

 construct. A "compromise stern," D, 

 is seaworthy and dry when running before 

 a storm, but it is never used on a craft 

 where the maximum of accommodation is 

 desired because of the large amount of 



deck-room which is sacrificed to its use. 

 The old style "fan-tail" is shown at E. 

 This is now almost obsolete, for the reason 

 that it is almost impossible to back a 

 small boat against a heavy sea because of 

 the resistance offered to the hull by the 

 waves. This type is inclined to be un- 

 wieldly when running with a sea, as the 

 waves will lift the stern. A type of stern 

 which is still popular is shown in the 

 illustration above. It is known as the 

 "torpedo." This type is adapted to shallow 

 waters where a minimum draft is desired, 

 but has a tendency to squat when the boat 

 is under way, thereby greatly decreasing 

 her speed. It is a good "heavy weather" 

 type, however. 



Strictly speaking, the power plant con- 

 sists of the engine only, but it is customary 

 among small motor-boat operators to in- 

 clude everything that is connected with 

 the actual operation of the craft. For 

 instance, the engine classification includes 

 the following: the crank-case, or base of 

 the engine; the cylinder, including the 

 water jacket, or top of the engine; the 

 crank-shaft upon which is mounted the fly- 

 wheel at the forward end while the shaft 

 connects with the rear end ; the connecting 

 rod which connects the piston with the 

 crank-shaft, being attached to the form 

 by means of a "wrist pin"; the carburetor, 

 by means of which the proper amount of 

 air is admitted with the gasoline to the 

 compression chamber; the spark coil and 

 battery which generate the spark which is 



275 



