204 LAUNCHING OF SHIPS IN RESTRICTED WATERS. 



ment being used on both sides of the vessel. To assist in stopping the vessel a 

 mask was also fitted on the stern, i6 feet wide by 1 1 feet high, the lower edge being 

 8 feet above the keel line. As a further precaution, a 11,000-pound anchor was se- 

 cured on the port side of the ship at frame 112, with a lo-inch hawser stopped up 

 at intervals and carried to the stern bitts. This anchor was to be dropped upon sig- 

 nal given from the forecastle should the brakes fail to act, and was intended to turn 

 the stern down stream. A 6,000-pound anchor was housed in the port hawse pipe 

 and was to be dropped if it became necessary to hold the bow." 



The results of the launching, as far as they concern the launching brake, were 

 as follows: — 



Launching weight 4,ioo tons. 



Maximum velocity 16 feet per second. 



Velocity when ship floats 13 feet per second. 



Total distance friction ropes were drawn through 



brakes before ship was stopped 341 feet. 



The same brakes and arrangements were used in launching the Maumee, a sis- 

 ter ship to the Kanawha. The results in the case of the Maumee were as follows : — 



Launching weight 4,370 tons. 



Maximum velocity 17-25 feet per sec. 



Velocity when ship floats 14 feet per sec. 



Distance cables were drawn through brakes before 



ship stopped 329 feet. 



The same brakes, but without the stern mask, were used in launching the 

 Cuyama, a sister ship to the Kanawha and Maumee. The results in the case of 

 the .Cuyama were as follows : — 



Launching weight 4.056 tons. 



Maximum velocity 16.7 feet per sec. 



Velocity when ship floats i4-5 feet per sec. 



Distance cables were drawn through brakes before 



ship stopped 444 feet. 



By comparing the foregoing data the effect of the stern mask may be estimated 

 as the Cuyama, without the mask and with a slightly greater velocity (when afloat) 

 traveled 125 feet farther than the Maumee. 



The action of the wire rope cables under pressure between the upper and lower 

 cast steel brake blocks bears a very important part in the successful operation of 

 this type of brake. There were no reliable data on the coefficient of friction under 

 the actual working condition, and no guide as to what type of wire rope was best 



