370 ANNUAL KEPORT SMITHSONIAN INSTITUTION, 1913. 



vide that there yhall not be any stress on the bolts, and yet prevent 

 the buckets getting loose. 



Bearings. — The turbine shaft, which is of Siemens Martin steel, 

 is supported by two ring-lubricated bearings of 380 millimetei*s diam- 

 eter, and its diameter is increased to 470 and 480 millimeters where the 

 runner wheels are mounted. A forged-on flange coupling transmits 

 the whole power of the turbine to the generator shaft. In addition to 

 lubricating rings, each bearing is provided with a separate pump for 

 the circulation of the oil, and this pump is driven by the turbine 

 shaft. It draws the warm oil from the bearings, passes it through a 

 coil situated in the discharge pit of the turbine, and then pumps the 

 oil through a filter to the main shaft again. This device greatly in- 

 creases the safe running. The bearings have to withstand the weight 

 of the shaft and runners, and also the thrust due to the water jets. 

 They are supported by a strong frame, which is grouted into the 

 foundations and held fast by anchor bolts. 



Casing. — On the same side as the distributing pipe there is a 

 strong frontal iron plate, to which the inlet bend and distributing 

 piping are fastened. The upper half of the casing is made of wrought 

 iron 10 millimeters thick, in two parts bolted to the foundation 

 frame and to the frontal plate at the center line. AVhen the run- 

 ner wheel has to be taken out for repairs the upper part of the 

 casing is lifted off. At the side of the casing where the shaft comes 

 through it, deflector rings and water-splash guards prevent any 

 Avater escaping from the casing. For the purpose of inspecting the 

 buckets and nozzles a pit is provided in the foundations by means 

 of which it is possible to descend into the turbine chamber for that 

 purpose. 



The turbine-chamber walls are covered with iron plates from the 

 foundation frame up to the ceiling of the tailrace, with a view to 

 protect them from erosion as well as to prevent an^^ leakages in 

 the air ducts between the turbines. 



Nozzles. — The largest diameter of the water jet when the nozzle 

 is fully opened is about 1.50 millimeters. In order to reduce the regu- 

 lating power the needle rod is provided with a balancing piston 

 acting in opposite direction to two buffer springs. The latter have, 

 the tendency to close the needle. The power resulting from the 

 closing energ3^ of the needle and springs and the opening energy of 

 the piston is so calculated that the needle is always balanced, no 

 matter what the opening is. The turbine is regulated by simulta- 

 neously adjusting the four nozzles, which are connected to each other 

 by means of rods and levers. A rod and lever connects the regu- 

 lating shaft to the main shaft of the universal oil-pressure governor. 



Guarantee.'^. — For the speed governor and pressure regulator, as 

 well as for the efficiency of the turbines, the following guarantees 



