Skip to main content

How many stern tube bearing are there and how are they connected with stern tube?Material of bearing and why white metal does not rotate with shaft?

  • Stern tube bearings generally consists of two ( fwd and aft ) bearings which are pressed in and secured to the stern tube the bearing sleeves are made of high strength ductile iron and centrifugally lined with high tin base babbitt. 
  • The bearing bore is normally finish machined to fit the propeller shaft and outside diameter is semi finished for final machining in shipyard.
Two procedures are commonly used for fitting stern tubes 
  • The stern frame is finish machined.The stern tube is pressed in and secured by bolting or welding .The stern tube is bored and bearings are then pressed into stern tube 
  •  In the second procedure, the stern tube is bored in the shop and fitted with its bearings then the entire assembly is pressed into the stern frame at shipyard. Boring of stern tube to provide an interference fit

Comments

  1. I wanted to thank you for this great Information and knowledge, I definitely loved every little bit of it. I have you bookmarked your web site to check out the latest stuff you post. Your blog is eye-catching. I get pleasure from it. Thanks for sharing this beautiful piece of writing with me, get more information at ASTM A53 Grade B for more Ashtapad Overseas related information and knowledge.

    ReplyDelete

Post a Comment

If you have any doubts.Please let me know

Popular posts from this blog

Why is a man hole door elliptical in shape?

Any opening in a pressure vessel is kept to a minimum and for a man entry an elliptical hole  is lesser in size than the corresponding circular hole. More over it is prime concern to have a  smoothed generous radius at the corners to eliminate stress concentration. Hence other  geometrical shapes like rectangle and square are ruled out.  To compensate for the loss of material in the shell due to opening, a doubler ring has to be  provided around the opening. The thickness of the ring depends on the axis length along the  dirrection in which the stresses are maximum and the thickness of the shell. It is important to  align the minor axis along the length of the vessel, as the stress in this direction is  maximum. Longitudinal stress: Pd/2t where P= pressure inside the vessel, d= diameter of the arc, t=  thickness of the shell plating  Circumferential stress: Pd/4t  More over a considerable material and weight saving is achieved as minor is along the  direction of maximum stress.

Shell Expansion Plan

It is a two dimensional drawing of a three dimensional surface of the ship’s hull form. This plan is very useful for the following information:It is used for marking the location of a hull Damage on this plan by identifying the strake number , letter and frame number so that the exact location of the damage and also suggested repairs are marked in a localised copy. The shell expansion can be used for finding areas of painting surfaces such as topside, boot topping and bottom areas by applying Simpsons rules directly.  In the shell expansion the vertical scale used is different from the horizontal scale and a suitable adjustment has to be made when calculating areas. This becomes useful in solving disputes concerning areas of preparation and painting. It gives information on the thickness of the original strake which is indicated by the number in the circle shown in the strake.  The quality of steel used is also shown by letters A,B,D E and AH, BH,DH, EH.