Bow to that

[happy daze john in oz]

We were watching a movie on TV the other night.
A true story which involved a ship, but this was in the 1960's so a ship of that vintage would not be available so a more modern one was used.

The film maker had attempted to keep it all in the theme of the times, but the ship had a very large bulbous bow.

I do not recall seeing such in the 60's, so when were the first ships with such bows built?

We get a lot of Royal Navy ships in Port here in Melbourne, but have never seen one with such a bow, do any of them have such?

[John Arton]

Apparently they were a development of the naval ramming bow and first appeared on merchant ships in the 1930's.
Rgds
J.A.

[happy daze john in oz]

Interesting that as I do not ever recall seeing one much before about 1980.
But as you say there were there.

[j.sabourn]

Your not getting mixed up with bowels and bows are you Victoria.? To distinguish between the two just think of buttons and bows, and Howls and Bowels . JS

[j.sabourn]

I suggest it would come more accurate from someone who has really studied ship design with reference to stability cubic capacity’s true motion through sea conditions etc. in fact someone more closer to a ship designer and architect. The main reason I would assume is with reference to the savings on fuel consumption due to the lessening of friction through the water. To me a bulbous bow always appears to me to look like a weak point on a ship, but this is probably a fallacy. It definetly must give a ship more reserve buoyancy due to the extra cubic. You would have to get others viewpoints to point out the good points to the various bad points of having such. Ships today are built the most suitable as to what trade they are hopefully going on. If they last 30 years the owner is lucky , specialised shipping in other particular job positions are usually out of date in 10 years , there are high gains but also high losses in shipping. Myself I think all shipping merchant that is ,should be nationalised the same as the armed forces .But once that ugly word is mentioned people go into a paralasyis of shock. JS

[John Arton]

The answer to why ships have bulbous bows is that when going ahead the bulb creates a low pressure area ahead of the vessel that allows the main body of the vessel to move through the water with less pressure on its hull resulting in lower fuel consumption. Nothing to do with reserve bouyancy though the small cubics of the bulb is always included in the calculation of reserve bouyancy when assigning freeboard. If you had ever had to crawl into the bulbto do an inspection for load line or construction survey you will know that a slim,trim and small person is the ideal candidate for the job as the floors and framing inside the bulb are not designed to allow easy access to any overweight person as they are robustly constructed, hitting a jetty or another vessel at low speed usually results in just a dent in the plating.
Rgds
J.A.

[happy daze john in oz]

WE were told at a captains Q&A on one cruise that as well as making movement through the water easier it also assisted in reducing pitching!!

[Graham Shaw]

Well the Canberra had a bulbous bow . Bulbous bows started to appear on merchant ships as far back as the 1930's

Yes,and another trivia fact:- After builders trials on completion in 1961 , it was found her bows lifted excessively at speed,and her bow was given extra ballast in the form of concrete,to compensate for the aft-bias of her machinery.

SS Canberra.jpg
One result,operationally,of this was that her 36 foot draft,in later years when downgraded to cruising was that she became restricted or excluded in visiting many smaller ports.That is no problem today as nearly all the larger cruise ships anchor off the port anyway in those smaller ports.

[Graham Shaw]

Did she have the funnels altered as well, seem to remember something about that because of the soot dropping into the pool.Attachment 33803 it may just be camera angle but the attached photo looks as if the funnels are taller.

Yes; 21.06.1962: Work undertaken to alleviate high fuel consumption, reduce soot deposits by extending her funnel uptakes by 1.5m (5ft), and cover the first class stadium turning it into a theatre. Her gross tonnage was now 45,733 grt.
Full Article re Canberra HERE

[Des Taff Jenkins]

And there was me thinking it was for Captains to stand thereupon to have their pictures taken.
Des