BATTLESHIPS. EXPERIENCE GAINED ON THE JUPITER. 197 



has been no change in either of these clearances up to date. Before getting 

 under way the holding-down bolts of the turbine are gone over to see if they are 

 tight, the slip rings on the rotor of the generator are examined to see if they are 

 clean and all insulators are also examined for cleanliness, all connections are 

 generally gone over to make sure they are tight, the oil switch boxes are examined 

 to see if they have the proper amount of oil, and the governor control-valve 

 springs are tested to see if they have the proper tension. After starting the turbine, 

 the emergency trip is tested. In port the oil pump is run once a week to force oil 

 through the turbine bearings and the motor shafts are jacked daily. Due to the fact 

 that the main condenser is used a great deal (the auxiliary condenser being too 

 small to handle the coaling winches), the small pump for draining the turbine 

 casing is run for a few minutes each day when in port to make sure that no water 

 may be allowed to accumulate in the turbine. 



In operation the Jupiter's engines have been highly satisfactory. There has 

 been only one time that anything has happened during the handling of the engines 

 and that was the tripping out of an exciter. The lighting set was immediately put 

 on for exciting and the engines were ready to use again in about one and one-half 

 minutes. If such an accident were to happen again it would take even less time as 

 the men are more familiar with the installation. At the time the incident occurred 

 the ship had just left the navy-yard for the first time. 



The handiness of the engines has been proved more than once ; the ship has been 

 handled a great deal in narrow waters and around docks. She steers very badly at 

 times and the quick response of the engines has more than once helped in getting 

 out of difficulties. The engines have been used to swing ship for compass deviation 

 without putting any way on the ship at all, the total space used for swinging being 

 little more than the ship's length. 



The ability of the turbine to stand severe abuse from water has been demon- 

 strated several times. There is no separator on the main steam line, and several 

 times the boilers have primed and carried considerable water over into the turbine. 

 This was particularly noticeable during dock trials when it was impossible to prop- 

 erly handle the boilers. The only indication the turbine gave was an increase in 

 the first stage pressure and a rattle in the casing as the water was hurled through 

 at a high rate of speed, but the turbine blading showed no signs of bad effects from 

 this. 



The backing qualities of the engines have proved to be all that could be desired ; 

 if the ship is cruising with the resistances in, the time taken for reversing is practi- 

 cally nothing at all; if the resistances are out, it takes a few seconds — not more 

 than three. 



When under way the engine-room is very cool, due to the fact that the gene- 

 rator is fitted with air impellers at each end which take their suction from the 

 engine-room, thus ensuring a good circulation of air. 



After all, the greatest test of the satisfactory working of any machinery is 

 whether or not the men who are actually handling it and caring for it are pleased 



