Propeller Blades

[Mike Spooner]

Seeing that believing is better evident that a piece of paper!
Can you be 100% sure what was fitted to the Titanic?

 

[Ioannis Georgiou]

In case of the centre prop yes. We know from Olympic that they did change it too during the years and do a test what is better. The documentation as far as I know match with the photographs. H&W own records would not have something which was not added on the ship. It is not a "report" or "article" in a magazine which can be inaccurate.

 

[Mike Spooner]

What I have read a change of a propeller blade from a new type of ship was quite common. So IF Titanic centre propeller was change to a three bladed. I would of thought that's a good idea to compare two identical ships for performance in there early days of sailing.

 

[Charley Smith]

My opinion of the 3 vs 4 blade controversy is the same as Ioannis'. The documentation found at H&W in recent years is about as 'slam dunk - case closed' as you can get. There's no other known definitive photos or records to disprove it. The H&W document clearly states the size, number of blades and the blade angle of each ships propellers. Changes were meticulously recorded for the surviving Olympic as different blade angles were tried and the center prop went from 4 to 3 and back to 4 blades. I think this one source along with photos that survive provides good evidence to deduce that:

1. The Olympic class was designed with a 4 bladed center propeller.
2. Titanic introduced a 3 bladed center propeller but the testing results were lost.
3. Olympic was then switched to a 3 bladed center propeller but later switched back.
4. Britannic was finally built with a 4 blade center propeller.
5. There was some reason the 3 blade design wasn't desirable.

I would really like a photo to turn up or get to actually see the propeller just for the 'AHA!' value, but for now... We found 'the Bible' from the people who built the propellers. I want an accurate scale 3 blade for my Minicraft!

 

[Bob Read]

Here’s any article I wrote analyzing how Titanic probably ended up being the first of the Olympic class to have a three bladed center propeller: http://www.titanic-cad-plans.com/wp-content/uploads/2010/06/Titanic-center-propeller-article.pdf

 

[Charley Smith]

<Here’s any article I wrote analyzing how Titanic probably ended up being the first of the Olympic class to have a three bladed center propeller: http://www.titanic-cad-plans.com/wp-content/uploads/2010/06/Titanic-center-propeller-article.pdf>

Excellent article. Thanks for sharing!

 

[Charley Smith]

Perhaps someone on this board knows the answer to this:

Was there speculation or any idea that the Titanic may have had a three bladed propeller BEFORE the H&W records were found or did it just broadside everyone?

 

[Seumas]

The great thing about Mark Chirnside's discovery about the three bladed central propeller is that it gives us hope that somewhere there are still some more secrets and surprises regarding RMS Titanic lurking in a dusty box or cob webbed file cabinet waiting for someone to find them.

 

[Bob Read]

Charley: I know of no speculation about Titanic having a three bladed center propeller before Mark made his discovery. Like a lot of things on Titanic, there was no written documentation or photos so we just had to extrapolate on the basis of early Olympic knowledge. Mark’s discovery is the only evidence we currently have about Titanic’s center propeller.

 

[Mike Spooner]

The Olympic well may have an three bladed centre propeller in the wars years and changed back to a four bladed propeller after the war years.
The is mention of increase vibration using the three blades over four blades. Yet I didn't see any comments made by Titanic of the centre propellers vibration. Another factor on Olympic. Do we know if there was any different in fuel computation between a three or four bladed propeller!
Yes it will be a great discovery if the sea bed is removed from Titanic centre propeller and put to bed of any further discussion on the matter.

 

[Bob Read]

Olympic received her 3 bladed propeller in March 1913. The Olympic experiment most likely was short because we have film of a new Britannic in dry dock with a four bladed center propeller.

 

[Charley Smith]

Probably vibrated everybody's fillings out yet became the least of their worries on the Titanic....

 

[Bob Read]

There was probably some increased vibration but another factor may have been that the propeller just didn’t provide much increased performance.

 

[Mike Spooner]

Just another angle on Olympic. If is to use an three bladed propeller and Britannic is used a four bladed propeller. It still gives them an opportunity to compare the performance between the two ships.

 

[Bob Read]

Mike: They already knew how a four bladed propeller performed on Olympic during her first 18 months of service. Since Britannic had a four bladed propeller, Olympic probably had a 3 bladed propeller les than two years at most.