100 LAUNCHING DATA FOR A BATTLESHIP. 



Coefficient of friction and resistance, minimum, about 0.004 



Coefficient of friction and resistance, average after 250 feet 



run, about 0.06 



MISCELLANEOUS. 



The recorded weights at time of launch were subsequently confirmed by the 



observed displacement. 



Method of release — hydraulic triggers. 



Pressure used for triggers — Started with 250 lbs. per sq. in., and was gradually in- 

 creased as blocks were removed to a maximum of 1,600 lbs. per sq. in. just 

 before dog shores were dropped. 



Temperatures on day of launch and on preceding days : — 



Date. Maximum. Minimum. Mean. 



March 20 33° F- 22° F. 28° F. 



March 21 34° F- 19° F. 26° F. 



March 22 38° F. 14° F. 31° F. 



March 23 45° F. 26° F. 36° F. 



March 23 (noon). Temperature on building slip. ... 31° F. 



Lubricant on ground ways, under fore poppets applied several weeks before 

 launching — First a thin coat of stearine, next a 9/16-inch thick coat half tal- 

 low, half stearine. 



On remainder of ground ways under sliding ways, applied two to three weeks be- 

 fore launching — First a thin coat of stearine, next a mixture of three parts 

 tallow to one part stearine. 



Remainder of ground ways to a point 36 feet beyond low-water mark, applied by 

 means of cofferdams three to four days before the launch, and touched up the 

 day before on account of damage from ice — Tallow mixed with lard oil. 



Lubricant on sliding ways, applied two to three weeks before launching — For- 

 ward 80 feet thin coat of stearine, whole length with launching grease smeared 

 on lightly. 



Lubricant on pivoting surface under fore poppets — A mixture of half stearine and 

 half tallow applied 9/1 6- inch thick. 



Removing blocks, etc. — Some of the blocks at ends of vessel and most of the shores 

 were removed the day before the launch. 



Wedges were set by mauls and alternate keel blocks removed, starting at 7.30 

 a. m., on day of launch. Rallies on the wedges, using rams, were made at 10.00, 

 10. 1 1, 10.22 and 10.32 a. m., the last block was out at 12.10 p. m., dog shores 

 dropped at 12.13 ^-^^ ship released at 12.15 P- ^^■ 



About 280 men were employed below the ship; some 40 of these afterward went 

 on board, making about 120 men on the ship at time of launch. 



Vessel was launched just as tide was turning ebb; there was a moderate breeze 

 from the southwest. 



