Mike Spooner
Member
Bob: As any new class ship propeller changes wasn't new. So I don't blame them trying out a three bladed as to a four blades. But at the end of the day more blades smoother the performance.
Propeller Blades
- Thread starter Jessie M.
- Start date
Charley Smith
Member
For anyone interested in Titanic modeling, I found the answer to my prayers! Finely detailed propellers for the Minicraft 1/350 kit AND you have your choice of a 3 or 4 bladed center propeller. These are available for other scales too and there are various other replacement parts - bollards, capstans etc.
www.shapeways.com
ND's Titanic Bits by endaredesign - Shapeways Shops
Scale Models<br /> Update Jan 2022: I receive many messages from store visitors requesting alternative scales and additional parts. Unfortunately due to personal reasons I will not be generating any new work in the coming year, but I hope to get back to things after that. Thanks for visiting -...
Mike Spooner
Member
I would agree as you know a one blade is more efficiency, that if you can put up with the vibration. You would of thought two blade was the answer! But really never took off with large ships. Horses for Courses!
Samuel Halpern
Member
A comparison of the propellers used on Olympic and Titanic.
Notice that the total area and pitch for the center props were the same despite one being 4-bladed and the other three bladed. Titanic's 3-bladed prop was slightly larger in diameter by 3%. For the area tobe the same, the blade widths on Titanic's 3-bladed prop had to be about 29% greater than the blade widths of Olympic's 4-bladed prop. It probably looked something like this:
Notice that the total area and pitch for the center props were the same despite one being 4-bladed and the other three bladed. Titanic's 3-bladed prop was slightly larger in diameter by 3%. For the area tobe the same, the blade widths on Titanic's 3-bladed prop had to be about 29% greater than the blade widths of Olympic's 4-bladed prop. It probably looked something like this:
Mike Spooner
Member
Its hard to believe that extra 6 inches on diameter can make up the same sqft from a four blades to a three blades.
Whilst on the subject centre propellers. I have notice on Olympic the mark numbers in feet are not there behind the propeller. Looks like a wear plates had been added!
Whilst on the subject centre propellers. I have notice on Olympic the mark numbers in feet are not there behind the propeller. Looks like a wear plates had been added!
Charley Smith
Member
I think the blades had to be wider also, not just larger diameter. As you say - 6 more inches wouldn't have done it.
Charley Smith
Member
Here's some interesting changes made to the Olympic Class wing propellers:
On the starboard side is an original Olympic propeller - notice the very slender, conical hub. Now, notice the port propeller with the man climbing on it. Is this the one borrowed from the unfinished Titanic? Notice the hub.
Here's another shot of the thrown port blade before repair. You can clearly see the mounting bolts are ripped - again notice the slender central hub of this propeller.
Here's a later photo - notice the hub is beefier much more rounded. This is not the same.
And lastly - Titanics starboard propeller on the wreck. This is not the same as early Olympic photos.
On the starboard side is an original Olympic propeller - notice the very slender, conical hub. Now, notice the port propeller with the man climbing on it. Is this the one borrowed from the unfinished Titanic? Notice the hub.
Here's another shot of the thrown port blade before repair. You can clearly see the mounting bolts are ripped - again notice the slender central hub of this propeller.
Here's a later photo - notice the hub is beefier much more rounded. This is not the same.
And lastly - Titanics starboard propeller on the wreck. This is not the same as early Olympic photos.
Mike Spooner
Member
Hi Charley,
Do known what year and month the first photo was taken? As I see the centre propeller has been removed.
Do known what year and month the first photo was taken? As I see the centre propeller has been removed.
Charley Smith
Member
No sorry - this is what would be interesting to know, hopefully someone else on here might chime in with more info and ideas.....
In the first photo, it looks like a lot of general work is being done - obviously painting and the center propeller is removed. I wouldn't expect that from an emergency repair due to a damaged propeller. They'd want her back in service making money and not ruining the schedule. Still, I never noticed the hub differences before.
I believe the Hawke collision damage was confined to the starboard shaft & tunnel (aside from the major hull punctures further forward). So this starboard propeller may be original and the port one a whole propeller replacement from another incident - like a thrown blade perhaps.
From the photos, I would also question whether the blades could be interchangeable between the two seemingly different designs. The mounting base of each blade looks much 'flatter' on the slender hubs compared to the others where the base seems to be thicker and more rounded to fit the contour.
Mike Spooner
Member
I did think the first photo may of been first time in dry dock April 1911. But those added on wear plates and partly covering up the feet numbers on the rudder post came at a later date. They certainly look very clean and never seen sea water at that stage.
Good sample were health and safety didn't mean much in those days, as that man hanging on to the propeller with no safety harness!
Matter of interested were did you find the photos?
Good sample were health and safety didn't mean much in those days, as that man hanging on to the propeller with no safety harness!
Matter of interested were did you find the photos?
Charley Smith
Member
Just googling Titanic propellers or Olympic propellers turns up lots of them. Some I've seen and some I haven't.
Kodos the Executioner
Member
Hey folks,
I have been going over the information about the various pitches and ogival configurations on the propellers of the Olympic-class. You guys are awesome.
The picture of Olympic having her screws worked on (Charley’s first pic) raises a couple of interesting questions, however.
How would the ‘cylindrical’ hub affect the ships’ performance as opposed to the ‘rounded’ one? A different range of pitches, perhaps? Less weight for the crankshaft to turn? The cone covers fitted to each appear to be identical, regardless of which one was used.
Would different propeller hub configurations on opposite sides of the ship create problems (balance, vibration, etc.)? It seems it didn’t take much to throw off the smooth operation/turning of the screws, and make your ship “happy-tailed”.
Thanks!
Kodos the Executioner //
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“Mr. Lowe! Take a bosun’s party and a Master-at-Arms, and get those children off of the foc’sle railing at once!”
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