THE PROPELLING MACHINERY OF THE U. S. S. LEVIATHAN. 225 



and the buckets and sections are notched out to fit over these projections (Fig. ii, 

 Plate 99). 



To allow for fitting, at one place on the rotor rim the notches are cut out and 

 the buckets and sections entered at this point and driven round. The tips of all the 

 rotor buckets are thinned and no shroud strip is fitted, vi^hich is somewhat unusual. 



In the case of the high-pressure astern impulse-wheel buckets, the first and sec- 

 ond rows are entirely unsupported, but the third row has a round wire threaded 

 through each bucket and silver soldered; the widths of the buckets are about i 

 inch, the lengths varying from 2]/^ inches to 3^4 inches. 



The mid-pressure rotor has four rows of buckets on the impulse wheel, the 

 first row is entirely unsupported, the second and third rows have one round wire 

 threaded through each bucket and the last row has two round binding wires. The 

 lengths of the buckets vary from 4 inches to 7^ inches and are about i^% inches 

 in width. 



Water-Gauge Glasses on Turbine Casings. — On the lower half of each turbine 

 casing, at the steam inlet belt and at the exhaust belt, a water-gauge glass column 

 is fitted so that the engineers can see when there is water lying in the bottom of 

 the casings. 



Turbine-Lifting Gear. — The gear for lifting the upper half casings and the 

 rotors is operated by electric motor, one motor being arranged to do the work of 

 lifting the parts of the two turbines of each line of shafting. The motors, counter 

 shafts, worms and worm wheels are all secured to brackets in the roof girders of 

 the engine-rooms. 



Each casing has four large, square, thread-screwed columns, one of which is 

 fitted at each corner of the turbine; the lower end of each column is let into a recess 

 in the cast-iron pedestal and has ball-bearing surfaces. 



The threaded columns are each fitted with a composition nut which is arranged 

 to fit into lifting pads cast on the top half of the casing. The upper end of the 

 columns have flanges which are bolted to the gear from the rotor. The threaded 

 columns revolve, and in this way the top casing is lifted evenly and always remains 

 parallel to the joint. 



The rotors are lifted in the same way except that a cast-steel girder is fitted 

 between the two columns at each end of the turbine, and to carry the rotor a strap 

 is fitted under the rotor shaft and bolted to the girder. The girder is made to fit 

 over the composition nuts, and the rotor is then raised right up into the top half- 

 casing. 



Shaft-Turning Gear. — Each line of shafting is fitted with electric motor turn- 

 ing gear, which is arranged on the aft bulkheads in the turbine engine-rooms. 



The Maneuvering Gear. — The entire maneuvering of the turbine engines is 

 carried out from the working platform of the forward engine-room, the regulator 

 valves being all arranged at the forward bulkhead. 



To give protection from the heat radiated off these large high-pressure steam 

 fittings, a vertical steel plate screen has been erected in front of the valves, about 



