STERN TUBE 4:73 with a cock on it to enable the engineer to draw water from the stern tube, so that its temperature may be tested to ascertain if the bearings are working cool. A strong massive nut G screwed on to the end o* the shaft prevents the propeller from working oft. Fig. 74 —Twm Screws. Refer to the profile of Caledonian Monarch and note the stern tube and the spare tail shaft stowed in the recess at the after end of the tunnel. To unship a propeller hi drydock the nut must be unscrewed and the propeller slung by tackles hooked on to eyebolts for the purpose on each side of the ship's stern. Tne gland is unscrewed and the tail shaft uncoupled from its adjoining length of shafting, and which has M/D3Hlf> BULKHEAD Fig. 75 —Stern Tube for Side Screw. also to be removed to allow of the tail shaft being drawn straight forward, leaving the propeller suspended by the tackles. Repairs and rebushing of the tail shaft can then be executed. The other lengths of shafting pass through bearings supported on widely spaced stools, the forward length being coupled to the thrust shaft