Olympics's Speed

Mark Chirnside

Mark Chirnside

Member
Markus and George;

More regarding the fastest crossing, just after this thread had nearly sunk out of view.

No stop at Plymouth. A chain of thought…;

Olympic once crossed in 5 days 13 hours 6 minutes from Ambrose to Cherbourg at 22.53 knots.

Therefore: 133.1 hours…22.53 knots…2,999 miles.
Therefore: 132.6 hours…22.61 knots…2,999 miles; or

It could be: 132.6 hours…22.70 knots…3,010 miles;
It could be: 132.6 hours…22.81 knots…3,025 miles;
It could be: 132.6 hours…23.00 knots…3,050 miles;
It could be: 132.6 hours…23.19 knots…3,075 miles;
It could be: 132.6 hours…23.33 knots…3,095 miles;
It could be: 132.6 hours…23.37 knots…3,100 miles;
It could be: 132.6 hours…23.75 knots…3,150 miles;
It could be: 132.6 hours…24.13 knots…3,200 miles.

Now then… The lowest mileage is about 2,999 miles; lowest speed 22.61 knots.
But at the other end: the highest is over 3,200 miles; highest speed 24.13 knots.

Assuming a mileage of between 3,025 and 3,095 miles (the latter accurate for the August 1929 crossing); then the speed will be between 22.81 knots and 23.33 knots… I should think this is roughly accurate…

A final note about Olympic's horsepower:
46,000 total according to contemp. publicity and newspapers...
50,000 registered horsepower...
'at least 55,000 horsepower' developed according to Edward Wilding...
59,000 horsepower according to report of Hawke collision, which seems to be accurate in other respects...

Best regards,

Mark.
 
David G. Brown

David G. Brown

RIP
Mark -- thanks for the data. I'm enjoying a bit of a "mind game" regarding Titanic's intended speed on Monday, April 15. Your numbers "dovetail" nicely with my assumptions. And, I am assuming that Titanic would have exhibited similar performance to Olympic once it was on its regular schedule.

Does anyone know the actual pitch of Titanic's two outboard propellers? Not the "design pitch" as published, but what was actually installed for the maiden voyage? That's the one specific detail that I am lacking.

-- David G. Brown
 
Mark Chirnside

Mark Chirnside

Member
David,

The only pitch figure I have for the two outboard propellers is 34'6" and I do not know if this is the 'design pitch' or then actual pitch on the maiden voyage, but I mention it in case it is the maiden voyage pitch.

It's my belief that with all twenty-nine boilers on full steam pressure, assuming the perfect conditions and bearing in mind that the ship had used up many supplies, etc., the speed may have been as high as 23.5 knots. We all know that 23.25 knots was got between Belfast and Southampton when the ship was lightly-loaded and without all boilers lit... I'm not that technically-minded, but it's my opinion... I recall that it was expected that the Titanic would do about a quarter of a knot better...

Personally, I have not come across any information about the different propellers. I do know, however, that Olympic's propellers were definately changed in her 1920 refit, and possibly modified in 1913; but judging from the photographs, they are identical to the originals, certainly not very different. There was also oil-firing, but that did not effect the revolutions significantly, or so I believe... Ismay may have said that the engines delivered up to eighty revolutions per minute, but I know that at least eighty-one was acheived earlier during her career without all boilers alight.

But back to 1911/1912... When researching the Hawke collision for my work I recall that a figure of '22.5 to 23 knots' was stated to be the full speed of the Olympic at sea in the report. I have not got my notes with me at present, but if I remember rightly Captain Smith said in his testimony a maximum a little over 22.5 knots. I definately know that 22.75 knots was attained at one point during her first year, but whether that was fully-loaded or quite empty I do not know. It was a pity that I had less time to look at the enquiry, but I was doing other research about Britannic...

Enough of this waffle...

Best regards,

Mark.

P.S. David, I am looking forward to reading your book. Everybody I know who has read it enjoyed it and I am eagerly awaiting my birthday...
 
David G. Brown

David G. Brown

RIP
Mark -- Thanks for the help. As I say, what I am doing now is a "mind game" mostly to occupy my time on long drives. However, I am convincing myself that Ismay had quite a clever plot in mind for Monday. If I am right...and, if he had succeeded (except for a minor iceberg incident)... he would have scored a real public relations success. I hate to hold onto my thoughts so closely, but there is a very good chance that I am totally wrong in my current hypothesis. If that's the case, I'd rather embarass myself in private.

Thanks again for your help. Hope you enjoy the book.

-- David G. Brown
 
M

Markus Philipp

Member
Mileages on Southern Route, Eastbound and Westbound, before and after 1912

Hi all, nice to see you still being interested in mileages. I have calculated some mileages on the southern route with different destinations and corners.

Assumptions:
- Great circuit between Fastnet Rock and Corner
- Two miles are added because great circuit is approximated by three rhomb lines
- Rhomb line between Corner and New York Ambrose

The positions about the various "Corners" I got from The Titanic Reference Map, ISBN 1-885508-27-1.

Putting the Corner 30 miles to south will lengthen the whole journey by 13 miles.
The mileages to Cherbourg were counted until light house Ft de l'Ouest. I have read some captains of the North German Lloyd counted from Cap de la Hague, others from lighthouse Ft de l'Ouest. The difference is about 24 miles. What the commanders of the Olympic did I don't know.

Enjoy my tables.

Markus


a) Table with total mileages:

From:, To:, Miles, Corner at:, 47° W
Queenstown / Daunt Rock, New York / Ambrose, 2889 miles, Westbound 1901 - 1912, 42°00' N
Queenstown / Daunt Rock, New York / Ambrose, 2903 miles, Westbound 1913, 41°30' N
New York / Ambrose, Plymouth / Eddystone, 3077 miles, Eastbound 1901 - 1912, 41°00' N
New York / Ambrose, Plymouth / Eddystone, 3090 miles, Eastbound 1913, 40°30' N
New York / Ambrose, Cherbourg / Ft de l'Ouest, 3186 miles,Eastbound 1901 - 1912, 41°00' N
New York / Ambrose, Cherbourg / Ft de l'Ouest, 3199 miles,Eastbound 1913, 40°30' N

b) Tables with mileages in detail:

Queenstown / Daunt Rock 51°43' N 8°17' W-
Old Head of Kinsale 51°35' N 8°31' W 11.8 NM
Fastnet Rock 51°21' N 9°36' W 42.8 NM
Corner Westbound 1901 42°00' N 47°00' W 1619.8 NM
New York Ambrose 40°27' N 73°50' W 1214.4 NM
Total:- - 2888.8 NM

Queenstown / Daunt Rock 51°43' N 8°17' W-
Old Head of Kinsale 51°35' N 8°31' W 11.8 NM
Fastnet Rock 51°21' N 9°36' W 42.8 NM
Corner Westbound 1913 41°30' N 47°00' W 1636.4 NM
New York Ambrose 40°27' N 73°50' W 1212.3 NM
Total:- - 2903.3 NM

New York Ambrose 40°27' N 73°50' W-
Corner Eastbound 1901 41°00' N 47°00' W 1220.6 NM
Scilly Isles / Bishop Rocks 49°53' N 6°24' W 1768 NM
Lizard Point / 10 miles south 49°47' N 5°12' W 46.8 NM
Plymouth / Eddystone 50°08' N 4°16' W 41.7 NM
Total:- - 3077.1 NM

New York Ambrose 40°27' N 73°50' W-
Corner Eastbound 1913 40°30' N 47°00' W 1217.1 NM
Scilly Isles / Bishop Rocks 49°53' N 6°24' W 1784 NM
Lizard Point / 10 miles south 49°47' N 5°12' W 46.8 NM
Plymouth / Eddystone 50°08' N 4°16' W 41.7 NM
Total:- - 3089.6 NM

New York Ambrose 40°27' N 73°50' W-
Corner Eastbound 1901 41°00' N 47°00' W 1220.6 NM
Scilly Isles / Bishop Rocks 49°53' N 6°24' W 1768 NM
Cherbourg / Cap de la Hague 49°45' N 1°56' W 173.1 NM
Cherbourg / Ft de l'Ouest 49°41' N 1°19' W 24.3 NM
Total:- - 3186.0 NM

New York Ambrose 40°27' N 73°50' W-
Corner Eastbound 1913 40°30' N 47°00' W 1217.1 NM
Scilly Isles / Bishop Rocks 49°53' N 6°24' W 1784 NM
Cherbourg / Cap de la Hague 49°45' N 1°56' W 173.1 NM
Cherbourg / Ft de l'Ouest 49°41' N 1°19' W 24.3 NM
Total:- - 3198.5 NM
 
M

Markus Philipp

Member
Sorry, something went wrong with Table a). To late to find out this night.

Markus
 
M

Markus Philipp

Member
Another attempt to post that table. Hopefully it works this time:

a) Table with total mileages on southern routes:


From: To: Miles Corner at: 47° W
Queenstown / Daunt Rock New York / Ambrose 2889 miles Westbound 1901 - 1912 42°00' N
Queenstown / Daunt Rock New York / Ambrose 2903 miles Westbound 1913 41°30' N
New York / Ambrose Plymouth / Eddystone 3077 miles Eastbound 1901 - 1912 41°00' N
New York / Ambrose Plymouth / Eddystone 3090 miles Eastbound 1913 40°30' N
New York / Ambrose Cherbourg/Ft de l'Ouest3186 milesEastbound 1901 - 1912 41°00' N
New York / Ambrose Cherbourg/Ft de l'Ouest3199 milesEastbound 1913 40°30' N
 
Mark Chirnside

Mark Chirnside

Member
As another piece of ‘comfirmationary’ information, the White Star Line’s Majestic (formerly HAPAG’s Bismarck) made her second fastest crossing under Captain Hayes — who commanded Olympic when she made her fastest crossing — during 1923. Between New York and Cherbourg (on the same route as Olympic in 1923) she crossed in 5 days 5 hours 21 minutes (125.33 hours roughly) at 24.75 knots.

This puts the crossing mileage at 3,102 miles; it is reasonable to assume that Hayes used a similar route that he did when he commanded Olympic, if not the same.

If Olympic’s 132.6 hour fastest crossing was on the same route, 3,102 miles, then Olympic would have averaged 23.39 knots. Her speed has already been narrowed to between 22.6 and 24.13 knots.

Majestic’s fastest crossing in 1925 under Hayes’ command was exactly five days at 25 knots, or exactly 3,000 miles. However, I think it may have been a bit over this, I cannot get the exact figures. It may even have been a bit more than five days. If Olympic’s best crossing had been on this route, which again is quite possible, it would be the lowest possible speed of 22.62 knots.

Majestic once made 27 knots for a few hours — not loaded fully, more excessive than recommended turbine revolutions, I presume — some two knots more than her fastest crossing.

Even a vessel’s fastest crossing may not be near her full speed: Mauretania’s 26.06 knot record in 1909 was set, but her speed even with her original propellers in 1907 had been 27.36 and 27.75 knots. She was given better props by 1909. Mauretania did 687 miles one day in 192?, when she was trying to regain the Blue Ribband from the Bremen, a speed of 27.78 knots Westbound (24.73 hour day) or 28.95 knots Eastbound (23.73 hour day). This was with slight engine modifications. Reciprocators could also be modified to give extra power; Baltic’s engines were modified in 1904 to give more power for better maintenance of her schedule, so could Olympic’s if she was really that slow.

Olympic was still fast, if not a record-breaker. (Check out the postings about Aquitania’s and Berengaria/Imperator’s average speeds in ‘Technical/Construction/Design/Layout: Ismay intended 26 knots’ during the same period after oil conversion.)

Just a few more thoughts…

Best regards,

Mark.
 
Mark Chirnside

Mark Chirnside

Member
As a further note, Olympic's outer propellers' pitch was 36' in 1913. (Original 34'6") Many changes had been made to her reflecting Titanic, such as the Café Parisian, and if Titanic's propellers really had been 'improved' these could be it.

Another point: I think the 22.5 to 22.75 knot speed figure is for all 24 main boilers, not the five single-end auxiliaries. Auxiliaries as well would be equivilent to 26.5 main boilers in rough terms of furnace numbers, or about 23.5 knots I guess. (That's *only* a rough estimate.)
 
David G. Brown

David G. Brown

RIP
Using the 36' pitch, I was able to "ballpark" a speed estimate of 22.95 knots at 75 rpm. This tallies well with the actual performances recorded by Olympic. So, I decided to extend my estimate to 85 rpm. An interesting result occurred.

36' x 85 rev = 3,060 ft/min forward movement

less 15% slip = 2,601 ft/min actual forward

2601 x 156,060 ft/hr actual forward motion

156,060 / 6,000 ft/naut mile = 26.01 knots theoretical forward speed of ship

So, based on this estimate, it was possible to obtain a 26 knot speed in an Olympic vessel. However, this estimate is not scientifically based and cannot be used as solid proof of anything. It does not reflect increasing losses to surface friction and wake factor, both of which go up geometrically with the speed of the vessel. Still...the numbers are tantalizing.

Titanic had a narrow beam-to-length ratio and extremely fine ends compared to modern cruise ships. An Olympic-class hull was designed to move quickly and efficiently from Europe to America. Today, the need is to move a floating resort quietly through paradise. So, our current ships are much wider and with blunt ends. Form follows function. Because of its fine shape, an Olympic vessel would have been easier to drive than a modern ship, given equal horsepower.

Even with the best design and engineering, a ship is seldom able to obtain even 65% efficiency from its drivetrain. More likely, nearly half of the energy produced by the engines is lost to a variety of factors such as propeller slip and drag created by the hull. That's why Titanic had so much space dedicated to boiler rooms and engines. It took an enormous amount of power to move the ship at even 22 knots.

--David G. Brown
 
Michael H. Standart

Michael H. Standart

Member
David, is there anyway you can account for such variables as the drag induced by the rivets and the fact that the shell plating was done in overlapping strakes rather then that of a smooth welded hull?

I'm no mathmatician, but I think I'm safe in assuming that this would toss a monkey wrench in any chance of achieving 26kt with these hulls.

Cordially,
Michael H. Standart
 
S

Steve Kiger

Guest
The idea of Ismay pushing for a 26 knot run for PR's sake is a fascinating one--it tends to explain why they were racing through the known ice hazards at night full ahead. I agree that it's not necessarily an achievable goal, but I can see where Ismay would find it appealing. Even if he could just say "Well, we were turning 85 revolutions for an hour, and so we were running at 26 knots" would enable him to brag his new class of ships as the equals of the speed-oriented Mauretania class. He just wanted that chance to tout his ships as other than luxurious and safety-conscious. He could achieve the PR version of the best of both worlds--speed and comfort.

PS: Just read "Last Log of the Titanic," and found it an excellent read. Nice to see a writer familiar with his subject rather than just another hack assembling someone else's facts and theories.
 
David G. Brown

David G. Brown

RIP
Michael -- Funny you should mention the b*** seams. I've been reading about them today. It turns out that the proper way to lap plates is with the overlap forward, which is counter-intuitive. However, a forward lap actually creates less drag than lapping toward the stern. This is because the forward lap causes fewer energy-robbing eddies. One book in my library says that placing the laps in this manner will actually cause an increase in speed.

Steve -- thanks for the kind words about my book. Like most people familiar with ships, I have difficulty imagining Titanic at 26 knots. However, keep in mind that Ismay did not have to achieve that breath-taking speed in reality. He only needed to make an appearance of 26 knots for the public. A favorable head current would have reduced the ship's actual speed made good, but caused a greater distance reading on the taffrail log. Dividing the logged distance by the time of the run would yield an artificially high speed for the advertisements.

Figures don't lie...but liars have been known to figure.

-- David G. Brown
 
S

Steve Kiger

Guest
Exactly. The idea was PR driven--the reality of achieving it was less important than the attempt. Even if he couldn't really back it up--the try would be justification enough to plaster it all over advertisements for his ships.
 
P

Pat Cook

Member
I know I've posted this before but thought it worth mentioning here again. I have a set of Aquaprints heralding the size, speed and luxury of 3 White Star liners - Homeric, Majestic and Olympic, circa late 20's - early 30's. In this brochure, obviously a PR pamphlet, it states the Olympic capable of speeds of 23 knots. And this is a PR advert.

For what this is worth.

Best regards,
Cook
 
Top