Object on the Floating Crane Barge

[Samuel Halpern]

What is that object that can be seen on the floating-crane barge in a photograph of Titanic being fitted out in the Thompson dry-dock at the H&W shipyard in February 1912? Was it a propeller waiting to be fitted onto the center-propeller shaft of Titanic? How many propeller blades does it appear to really have? Using 3D CAD imaging, some of these questions can now be answered.
Check out my latest article "The Object on the Barge" at: http://www.titanicology.com/Titanica/ObjectOnTheBarge.pdf

 

[Steven Christian]

What is that object that can be seen on the floating-crane barge in a photograph of Titanic being fitted out in the Thompson dry-dock at the H&W shipyard in February 1912? Was it a propeller waiting to be fitted onto the center-propeller shaft of Titanic? How many propeller blades does it appear to really have? Using 3D CAD imaging, some of these questions can now be answered.
Check out my latest article "The Object on the Barge" at: http://www.titanicology.com/Titanica/ObjectOnTheBarge.pdf

I read your paper. Enjoyed it. Thanks. A couple of observations...1. At first glance it certainly looks like a propeller. I would bet money on it being so. But it looks kind of small to me comparing it some of the other items in the picture. It doesn't look like its 17 or 16 1/2 feet across. Also the hub looks off center in the pic if that's the hub that I'm seeing. But that could just be my eye or or something to do with optics of the camera. Logic can sometimes be a tricky thing. Logically a barge next to Titanic with the crane there one would conclude that its for Titanic. But H&W was building other ships there at the time so how does one know for sure that prop is for Titanic? Glad to be corrected on anything I observed/stated. Anyway enjoyed the article. Thanks again.

 

[Tim Aldrich]

Great paper Mr. Halpern. I enjoyed reading it.

 

[Mark Chirnside]

Logically a barge next to Titanic with the crane there one would conclude that its for Titanic. But H&W was building other ships there at the time so how does one know for sure that prop is for Titanic?

This is the key point.

There isn't any evidence it was intended for Titanic.

A key problem is that people have both asserted that it was a 4-bladed propeller AND that it could ONLY be intended for Titanic. There is no evidence to support these assertions.

It links back to familiarity bias in that humans have a natural tendency to interpret information to support what they already believe. In this case, it means ignoring the H&W documentation of Titanic's propeller configuration (the 3-bladed centre propeller) in favour of speculation (stated as fact) as to what the photo in question shows. That speculation involves two sets of assertions, each of which is questionable to say the least.

Best wishes


Mark.

 

[Jim Currie]

Just like Lusitania's?

This is the key point.

There isn't any evidence it was intended for Titanic.

A key problem is that people have both asserted that it was a 4-bladed propeller AND that it could ONLY be intended for Titanic. There is no evidence to support these assertions.

It links back to familiarity bias in that humans have a natural tendency to interpret information to support what they already believe. In this case, it means ignoring the H&W documentation of Titanic's propeller configuration (the 3-bladed centre propeller) in favour of speculation (stated as fact) as to what the photo in question shows. That speculation involves two sets of assertions, each of which is questionable to say the least.

Best wishes


Mark.

Absolutely! and we have no idea how many blades were on the center prop that was fitted. All we know is that two separate propeller configurations were considered for Olympic and Titanic.

 

[Steven Christian]

This is the key point.

There isn't any evidence it was intended for Titanic.

A key problem is that people have both asserted that it was a 4-bladed propeller AND that it could ONLY be intended for Titanic. There is no evidence to support these assertions.

It links back to familiarity bias in that humans have a natural tendency to interpret information to support what they already believe. In this case, it means ignoring the H&W documentation of Titanic's propeller configuration (the 3-bladed centre propeller) in favour of speculation (stated as fact) as to what the photo in question shows. That speculation involves two sets of assertions, each of which is questionable to say the least.

Best wishes


Mark.

That's a good point. I have friends who are machinist's and if I showed them that picture I'm pretty certain they would say pump impeller. That would be their bias because of what they worked on most of the time. But to me it defiantly looks like a prop. The article was a good read and the math was fairly easy to follow. Maybe someday someone can move a little mud around and see whats buried like Mr. Halpern alluded to in his article. Seems that it wouldn't take much to move to settle the question. Only a couple of feet of mud to expose the underside of the hub. Cheers.

 

[Manon Caillard]

We have no idea how many blades were on the center prop that was fitted. All we know is that two separate propeller configurations were considered for Olympic and Titanic.

Yes we do. It had 3 blades. Go read Mark Chirnside and Samuel Halpern's work !

 

[Manon Caillard]

What is that object that can be seen on the floating-crane barge in a photograph of Titanic being fitted out in the Thompson dry-dock at the H&W shipyard in February 1912? Was it a propeller waiting to be fitted onto the center-propeller shaft of Titanic? How many propeller blades does it appear to really have? Using 3D CAD imaging, some of these questions can now be answered.
Check out my latest article "The Object on the Barge" at: http://www.titanicology.com/Titanica/ObjectOnTheBarge.pdf

Great article by the way ! It was a pleasure reading it.

I remember a couple of months ago I saw this picture and, zooming-in, wondered : "mmm, who said this was four-bladed ? It doesn't seem that obvious..." But I sadly said to myself that I guess we would never know, I had absolutely no idea of how someone could determine and prove the number of blades the propeller had.
And wow ! This idea of a 3D model you got is just excellent. Well done.

Cheers,
Manon

 

[Samuel Halpern]

All we know is that two separate propeller configurations were considered for Olympic and Titanic.

More than that. The propeller configurations installed on a number of WSL vessels was documented in a H&W engineering notebook that Mark uncovered in 2008.

The mystery of Titanic's central propeller

A unique engineering notebook helps unravel an enduring Titanic mystery

www.encyclopedia-titanica.org

 

[Mark Chirnside]

Maybe someday someone can move a little mud around and see whats buried like Mr. Halpern alluded to in his article. Seems that it wouldn't take much to move to settle the question. Only a couple of feet of mud to expose the underside of the hub. Cheers.

It's more complicated than that, unfortunately. Bill Sauder addresses it here:



While it would be nice to have evidence from the wreck available to us, it isn't. Therefore we have to accept the Harland & Wolff records of what Titanic was fitted with.

Best wishes

 

[Tim Aldrich]

Mr. Halpern, as you are the OP of this thread, and I'm not a bloke to hijack threads, I am requesting your permission to make a post regarding some (minor) experimentation I have done. What I have is a modern representation of what you have already shared and might be more relevant to our modern world.

 

[Jim Currie]

More than that. The propeller configurations installed on a number of WSL vessels was documented in a H&W engineering notebook that Mark uncovered in 2008.

The mystery of Titanic's central propeller

A unique engineering notebook helps unravel an enduring Titanic mystery

www.encyclopedia-titanica.org

If you are considering these particular records as proof-positive of a 3 blade central propeller, Sam,- which they certainly seem to be - then I am curious as to why so much time and effort has been spent in proving the obvious?
By the way, I enjoyed your offering.
Might I suggest a visit to https://grabcad.com/library/3-blade-ship-propeller-?
There you will be able to bring up a standard 3 blade prop and play around with the attitudes. If you do, you will find that a standard 3 blade prop lying face down would show the location of each blade root clear of each other on the hub. Something like this:

 

[Mark Chirnside]

If you are considering these particular records as proof-positive of a 3 blade central propeller, Sam,- which they certainly seem to be - then I am curious as to why so much time and effort has been spent in proving the obvious?

Sam's focus was the 'object on the floating crane'. The issue is that several people have misrepresented this image, claiming BOTH: 1) that it was a four-bladed unit AND 2) that it was therefore going to be fitted on Titanic.

These are two assumptions loaded on top of each other and used as a pretext to deliberately ignore the H&W evidence that Titanic was completed with a 3-bladed centre propeller (and, incidentally, an increased pitch on her port and starboard propeller blades compared to Olympic in 1911-12).

The object in the photograph is, in reality, a different question to what Titanic's propeller configuration was.

Best wishes

 

[Jim Currie]

Sam's focus was the 'object on the floating crane'. The issue is that several people have misrepresented this image, claiming BOTH: 1) that it was a four-bladed unit AND 2) that it was therefore going to be fitted on Titanic.

These are two assumptions loaded on top of each other and used as a pretext to deliberately ignore the H&W evidence that Titanic was completed with a 3-bladed centre propeller (and, incidentally, an increased pitch on her port and starboard propeller blades compared to Olympic in 1911-12).

The object in the photograph is, in reality, a different question to what Titanic's propeller configuration was.

Best wishes

Hello Mark.
Surely Sam's intention in writing that article was an attempt to cross the tees and dot the eyes? i.e. to identify the object on the barge and by doing so, show that it was a 3 blade propeller and therefore, that the assertion that Titanic was fitted with a 4 blade version was incorrect?

You were already convinced, since you wrote:
"used as a pretext to deliberately ignore the H&W evidence that Titanic was completed with a 3-bladed centre propeller."
That tells me that you assume the Yard Note evidence is 100% proof that a 3 blade prop was indeed, fitted.
I am aware of your deductions regarding Titanic having a 3 blade and the following year, Olympic having her 4 blade replaced by a 3 blade. Note that blade numbers govern thrust and also affect levels of vibration. Thus, a 3 blade will give better performance but a 4 blade, less vibration. I suggest to you that was why Olympic reverted to a 4 blade center prop. It is also a pointer to a 3 blade experiment on Titanic which, had she survived, would have been replaced as with the Olympic.
Having so pontificated: I prefer to believe that unless we have a photograph of the actual situation or an "As-Built" engineering declaration documentation, we can never be 100% sure.
By the way - I can't clearly see the object on the barge and while it looks like a type of propeller - if you can see three horizontal extremities it is a 4 blade and 2 if it is a three blade.
In the latter, the horizontal extremities creating the "disc" are set 120 degrees apart.

Stay Safe.

 

[Mark Chirnside]

Surely Sam's intention in writing that article was an attempt to cross the tees and dot the eyes? i.e. to identify the object on the barge and by doing so, show that it was a 3 blade propeller and therefore, that the assertion that Titanic was fitted with a 4 blade version was incorrect?

What Sam did was address the false claims a number of people have made about that photo. Whatever speculation people offer, that photo is not evidence of what was fitted to Titanic.

The evidence of what was fitted to Titanic is in H&W's own engineering records.

Best wishes


Mark.