Top speed

[Eugene_Manstein]

If I remember correctly, in 'Titanic & other ships' Lightoller wrote that after a couple of years of operation the Titanic could develop a much more rapid speed than the one with which they were going at night of 14/15 April...
But how much more rapid, is it possible to suppose (theoretically)?

Some sources claim that her maximum speed was supposed to be 24-25 knots (around 78 RPM)...

Does anybody know what was the Oly's maximum speed (for comparison)??

Would be thankful for any help!
Eugene (Russia).

 

[Dave Gittins]

Titanic was probably good for around 23 knots "through the water". The speed of liners was often exaggerated by quoting speed achieved with the aid of current. Between New York and Britain some remarkable speeds were quoted, thanks to the Gulf Stream and sailors like to brag.

 

[Eugene_Manstein]

I see, thank you for the comment, Dave!

I read somewhere that the maximum speed achieved by the Titanic was just over 23 knots, yes (during the Belfast trip, if I'm not wrong!).

And the Oly's abs. record was 24 (83 RPM) - during her sea trials!

 

[Adam Went]

Faster speeds could always be achieved if they were willing to divert power, but yes, as it was Titanic topped out at around 24 knots.
Pretty brisk back in the day!


Cheers,
Adam.

 

[Michael H. Standart]

>>Faster speeds could always be achieved if they were willing to divert power,<<

To a point. Limiting factors are hull form and power, with the former being a surprisingly critical factor. You get to a point on a ship where even if you double the power, you'll get only one knot more speed out of her because of the resistance of the hull.

 

[Dave Gittins]

It's actually very hard to determine top speed. Offshore there are currents and inshore there are tidal streams. Then there is the wind, which can have quite an effect on a ship the size of a liner. There's also the sailor's love of a good story.

I recently tested my own small yacht under power after a repair. In a channel about one mile long she did 5 knots at the inner end, where tide is negligible, and 6.2 knots at the other end. Going the other way, she did 4 knots at the start and 5 at the end. Conclusion: she's good for about 5 knots in still water.

Some ports might still have measured miles marked out for testing logs. Ours disappeared years ago. On our course, you had to make runs in both directions because of the tide.

I mistrust tales of high speeds on the open sea. I once made 7 knots dead to windward, while making about 5 knots through the water. I'd picked the right time to use a tidal steam.

 

[Eugene_Manstein]

Many thanks for sharing your thoughts and comments here, Dave, Adam and Michael!

Interesting to read! Despite the fact that, as we all know, the Olympic-class liners were not specially designed for speed, their rapidity of 23-24 knots looks quite impressive, really! It's only 2 or 3 knots below the Mauritania’s record!
Although it is not very fast by today's standards, of course. For example, our pleasure-boats (called Meteors) on the Neva river usually go at a speed of 30 knots – it is their abs. normal & constant speed.

 

[Michael H. Standart]

>>Although it is not very fast by today's standards, of course.<<

Actually, for the vast majority of cruise ships, that's pretty much the norm. Speed has it's uses, but high speed is damned expensive. So much so that attempts to build record breakers were extremely rare.

 

[Adam Went]

I dunno, Michael, the Carpathia was chugging along pretty quickly when she had to come to Titanic's aid after they diverted the power! ;-)

Of course the battle in the Edwardian era was for the Blue Riband so everybody was trying to make faster ships, whereas Olympic and Titanic were sacrificing some of that for size and luxury.

Cheers,
Adam.

 

[Michael H. Standart]

>>I dunno, Michael, the Carpathia was chugging along pretty quickly when she had to come to Titanic's aid after they diverted the power! ;-)
<<

Not really. Realistically, they got perhaps 13 knots out of her. The whole 17 knot myth died forever when the location of the wreck established that the Titanic's position was off by almost 13 miles. (IOW, they were closer to the Carpathia then they realized.)

Also, tank testing using engineers models of the Carpathia established past any point of real debate that the hull really wasn't good for much more beyond that even when new.

 

[Adam Went]

Michael:

The location of the wreck means nothing, it's already been more or less proven that the Titanic zig-zagged down to the bottom, she didn't just drop like a stone from the very position she was sinking at. The journey to the bottom might well have thrown her off a couple of miles, as well as movement of the lifeboats after the sinking, etc.

Cheers,
Adam.

 

[Dan Johnson]

Michael:

The location of the wreck means nothing, it's already been more or less proven that the Titanic zig-zagged down to the bottom, she didn't just drop like a stone from the very position she was sinking at. The journey to the bottom might well have thrown her off a couple of miles, as well as movement of the lifeboats after the sinking, etc.

Cheers,
Adam.

The boilers did drop like a stone and are right in the middle of the debris field.

 

[Michael H. Standart]

>>The location of the wreck means nothing, it's already been more or less proven that the Titanic zig-zagged down to the bottom, she didn't just drop like a stone from the very position she was sinking at. The journey to the bottom might well have thrown her off a couple of miles, as well as movement of the lifeboats after the sinking, etc.<<

Actually, the location of the wreck means everything, particularly as Dan noted, the location of the boilers which would have plunged straight down like a stone.

The zig zagging you refer to was not side to side but a seesaw motion of the bow as it would plunge, tip up, stall, then plunge again. (Lather, rinse, repeat until the bow ploughs into the bottom.) Another point: The difference was not a couple of miles, the difference was thirteen miles. Seesaw wobbling up and down doesn't get you a variance like that.

There's also the matter of the Carpathia's hull form which wasn't even remotely capable of 17 knots even with all the power maxed out to the red lines.

 

[Oliver K]

I understand that 24 kt was the top speed, but that was the top speed for carrying passengers and other duties, if the ships engines ran at full throttle, wouldn't she of been capable of going faster then 24 kts?

 

[Michael H. Standart]

That WAS full throttle.

The top speed you can get out of a ship depends on the power of the engines as well as the hull form. There are other factors, like if the hull is clean instead of fouled and if you can get a helping hand from any local currents as well as the weather, bit power and hull form are the two biggies and what it boils down to is resistance going through the water. The narrower the hull, the less resistance and the more speed you can get for a given amount of power. The beamier the hull, the greater the resistance.You get to a point where the resistance builds up so much that if you double the power, you only gain a knot more speed.

The Olympics were designed to be 21 knot ships in service. In practice, as shown with the Olympic on several occasions, they could get more. 24 would be about the ship's very best speed. I've seen around 26 mooted in a remarkable set of circumstances of perfect weather and local currents.