Optimal speed to avoid collision

[William Oakes]

If this has been asked before, please forgive my question.
I have seen many computer models that calculate flooding and sinking, and break-up.
Has anyone ever done a computer simulation/model to calculate the top speed Titanic could travel at, and still have time once the berg was sited, to make the hard to starboard turn and completely miss the iceberg?
We have Carpathia comining in at 15-18 knots, depending upon which account/testimony that you believe.
But an Olympic class ship like Titanic is much larger and faster.
So how fast can Titanic travel and still navigate around the iceberg?
I would be interested in knowing this.

 

[Michael H. Standart]

There were probably tank tests done to see which hull form would work out best but I'm not aware of any first hand evidence to back it up. The know how to do that had been around for at least half a century although I don't know how often it was used for commercial designs.

The Olympic class was designed to provide a reliable weekly service with three ships, and in order for that to work, they had to be at least 21 knot ships, which in fact they were.

If memory serves, at one point in her career, aided by currents and a following sea, the Olympic briefly achieved something in the range of 26 knots. Mark Chirnside found that information so if he's hanging around, I'll be interested in his insights on this question.

 

[Thomas Krom]

Good day to you gentlemen,



The Olympic had a maximum speed in 1911 of 23.01 knots, while the average serving speed as Mr. Standart mentioned was 21 knots. If you believe that the Titanic had a three bladed centre propeller, which I personally do, the maximum speed of the Titanic was extended by 0.38 knots, making her maximum speed 23.39 knots.


The speed of the Titanic at the time of the collision is believed to have been between an estimated 22.3 to 22 and a half knots, with the triple expansion reciprocating engines producing revolutions of 77 RPM.

 

[Mike Spooner]

Optimal speed to avoid collision! Stop at night time as the Californian did so!​

 

[William Oakes]

Optimal speed to avoid collision! Stop at night time as the Californian did so!​

Stopped isn't a speed.With all due respect, that is not an answer to the question that I asked.
The question is, what maximum moving speed could she travel at, and still navigate around the icebergs?

 

[Incony]

the unknown, i understand,is the exact distance of the iceberg from the Titanic at the time it went hard a starboard at 22 knots.. which is about 38ft a second... and that is because two thirds of the berg is under water - so its submersed size/ diameter could be much bigger than what sits above the water.. if one calculate the time from the call "iceberg right ahead.." to the point of impact, one gets an idea of the distance, and given the Titanic's turning circle of 3860 feet one can plot how far way from the berg the titanic would have to be to avoid something easily as wide and probably wider than itself... i have read this -and it says the berg was about 500 yards away, when sighted.. and as a guide and i cannot certify its accuracy, i just share this.. The Turning Characteristics of the SS Titanic by Samuel Halpern - ppt video online download - so.. 1500 feet wasnt enough to avoid the iceberg, not even its above water part, since ice fell onto the deck.. it took about 37 seconds or perhaps one or two seconds more, to cover that distance, and reach the hidden part of the berg.. Another 25 seconds or 300 yards might have saved it from contact.. as an estimate then i suggest 800 yards at @22 knots.. ie about half a mile would be needed - it is the hidden size of the berg that isnt known, i.e its shape under water.. The speed doesnt alter the turning circle so even the engines full astern or stopped doesnt.. i.e the turning circle was near the same at 11 knots..

 

[William Oakes]

the unknown, i understand,is the exact distance of the iceberg from the Titanic at the time it went hard a starboard at 22 knots.. which is about 38ft a second... and that is because two thirds of the berg is under water - so its submersed size/ diameter could be much bigger than what sits above the water.. if one calculate the time from the call "iceberg right ahead.." to the point of impact, one gets an idea of the distance, and given the Titanic's turning circle of 3860 feet one can plot how far way from the berg the titanic would have to be to avoid something easily as wide and probably wider than itself... i have read this -and it says the berg was about 500 yards away, when sighted.. and as a guide and i cannot certify its accuracy, i just share this.. The Turning Characteristics of the SS Titanic by Samuel Halpern - ppt video online download - so.. 1500 feet wasnt enough to avoid the iceberg, not even its above water part, since ice fell onto the deck.. it took about 37 seconds or perhaps one or two seconds more, to cover that distance, and reach the hidden part of the berg.. Another 25 seconds or 300 yards might have saved it from contact.. as an estimate then i suggest 800 yards at @22 knots.. ie about half a mile would be needed - it is the hidden size of the berg that isnt known, i.e its shape under water..

Thank You!
Great Info!!!!

 

[Samuel Halpern]

The question is, what maximum moving speed could she travel at, and still navigate around the icebergs?

As stated above, speed doesn't alter the turning circle very much with all three engines working. The key parameter is distance to the object when the order to turn is first given. You may be interested in one of my more recent look at this issue here: http://www.titanicology.com/Titanica/NarrowShave.pdf.

In this relatively new article we look closely at the timing of the order to turn Titanic away from the object sighted ahead after the lookouts sounded their 3-bell warning. We show that to completely avoid striking the iceberg without further action, the hard-astarboard helm order would have had to come about the same time as those 3 bells, offering the 1st officer on the bridge almost no time to assess the unfolding situation. With only seconds to assess a difficult situation, it became clear to the 1st officer that the ship was just too close to avoid striking the object that loomed ahead. He had little choice but to take action that would minimize the potential damage to the ship, an action that was in keeping with guidelines that appear in modern day textbooks.

 

[Arun Vajpey]

In this relatively new article we look closely at the timing of the order to turn Titanic away from the object sighted ahead after the lookouts sounded their 3-bell warning. We show that to completely avoid striking the iceberg without further action, the hard-astarboard helm order would have had to come about the same time as those 3 bells, offering the 1st officer on the bridge almost no time to assess the unfolding situation. With only seconds to assess a difficult situation, it became clear to the 1st officer that the ship was just too close to avoid striking the object that loomed ahead. He had little choice but to take action that would minimize the potential damage to the ship, an action that was in keeping with guidelines that appear in modern day textbooks.

Thanks for that Sam. With reference to the highlighted part above, can I ask how much time do you think elapsed between Fleet seeing something in the horizon (call it a 'haze' or whatever you like; but given the conditions, it could not have been anything but the iceberg) and deciding that it was a solid object in the ships path and so ringing the 3 bells? Reading Fleet's testimony, I get the feeling that there was a time lag, perhaps as much as 30 seconds, before he saw what he later described as a haze in the horizon and actually rang the bells.

Putting the question another way, could Fleet have rang those bells earlier? If so, that would also have alerted Murdoch that much earlier and everything else that followed would be similarly affected.

 

[William Oakes]

As stated above, speed doesn't alter the turning circle very much with all three engines working. The key parameter is distance to the object when the order to turn is first given. You may be interested in one of my more recent look at this issue here: http://www.titanicology.com/Titanica/NarrowShave.pdf.

In this relatively new article we look closely at the timing of the order to turn Titanic away from the object sighted ahead after the lookouts sounded their 3-bell warning. We show that to completely avoid striking the iceberg without further action, the hard-astarboard helm order would have had to come about the same time as those 3 bells, offering the 1st officer on the bridge almost no time to assess the unfolding situation. With only seconds to assess a difficult situation, it became clear to the 1st officer that the ship was just too close to avoid striking the object that loomed ahead. He had little choice but to take action that would minimize the potential damage to the ship, an action that was in keeping with guidelines that appear in modern day textbooks.

Thank You so much.
Honestly, this is what I suspected.
At 450 -500 yards, and with the turning points that you describe, there simply wasn't enough time to successfully avoid the iceberg.
And that is a sad conclusion.
Thank You for your well thought out insights.

 

[Jim Currie]

Thank You so much.
Honestly, this is what I suspected.
At 450 -500 yards, and with the turning points that you describe, there simply wasn't enough time to successfully avoid the iceberg.
And that is a sad conclusion.
Thank You for your well thought out insights.

As a point of interest: the berg was first seen high out of the water as a dark shape on a dark night from a point 90+ feet above the water. Since it was not much more than 70 feet high, it had to have been very close indeed to have been described in such a way. The timing between helm order and impact part of the evidence of the Quartermaster on the wheel at the time seems to corroborate this

 

[Steven Christian]

I would think the optimal speed for avoiding collision would be zero. As in stopping for the night like the Californian did. Cheers.

 

[Jim Currie]

I would think the optimal speed for avoiding collision would be zero. As in stopping for the night like the Californian did. Cheers.

Bravo!

 

[Mike Spooner]

22.5 knots was clearly not the safety optimal speed, more like 5-6 knots as the safety optimal speed.

 

[Arun Vajpey]

I am not saying for one moment that there was any similarity between the situations of Endurance and Titanic but didn't Ernest Shakleton comment something about reducng a ship's speed to about 4 knots when there was ice around?