How Far South did the Titanic Reach?

Nov 26, 2016
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No Markus. Current does not significantly effect the Patent Log.
Jim, I do not think I said that.
You said, If we use 126 miles Noon to the Corner, we get a minimum distance between fixed points of 257.7 miles. The patent Log read 260 miles. Looks to me that the Log was pretty accurate.
I said, if the log registrates 260 miles from noon to collision, and the distance assessed by two fix points is nearly the same, the conclusion must be there was no current.

About the 162 miles: By the way, it has been suggested that 5th officer Lowe's distance of 162 miles from Noon to The Corner was a typing error. Perhaps Lowe was remembering the calculated distance run indicated by the patent Log at sights? i.e. 162 miles. That would give an average speed from Noon of 21.6 knots. A coincidence?

I do not feel comfortable about this. From Lowes testimony about the 8 pm DR Position we can take that the log reading at 6 pm was 126 miles in 6 hours. The thereof deduced distance from noon to 8 pm would be 168 miles. At 7.30 the reading would have been 157.5 miles.
To carry this point to extremes, supposed the log readings were 126 at 6 pm. and 162 at 7.30, the difference would be 36 miles in 1.5 hours, corresponding speed 24 knots.
From my side, I prefer the 162 miles to be regarded as typing error.
 

Jim Currie

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I have no idea, Marcus. I only know that back in the old days, that was the value used in all teaching establishments. the idea then, was to make the GC curve as smooth as possible and to ensure that the Traverse Table values of 600 minutes of D Long were not exceeded.
 
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The iron on the bottom does not lie. It speaks to where Titanic foundered. In particularly, the single-ended boilers which would have drifted very little in sub-surface currents after they broke free during the breakup. Undoubtedly, the intact wreck did move with the surface currents prior to the breakup, so the exact spot of where the ship stopped for the last time was close to, but not exactly the lat/lon of the boilers.

Both sets of distress signal lat/lons are too far off from where the boiler field to be acceptable under 1912 standards for accurate navigation. This discrepancy alone discounts them from being "accurate" or "exactly where the ship struck the iceberg." In 1912 given the weather conditions it would have been expected to fix the ship's position within a 3-mile or less circle. That's a radius of 1.5 miles or less -- too far to accommodate the differences between the wreck site and both sets of distress coordinates. No matter how they were created, those wireless lat/lons were wrong.

The ship did not steam long enough or fast enough after impact on the iceberg to greatly affect any forensic reconstruction of events. We do not know the exact time or RPMs for the re-start. But, assume Olliver was correct about "half speed," and the ship steamed for 6 minutes or 1/10th of an hour. That would mean it made 0.1 x 11 knots which = 1.1 nautical miles from the impact. That distance still puts the ship within the circle of acceptable navigation using 1912 methods. Restarting the engines was not a good idea, but it didn't significantly complicate the computation of the ship's CQD location. So, the error in the lat/lons contained in the distress messages remains unquestioned.

We can learn how the first distress lat/lon was created by simply predicting the longitude the ship would have been crossing 12 hours 47 minutes after noon on Sunday, April 14th. This would have been 00:00 o'clock -- 'midnight" -- marking the start of April 15th. That longitude using 1912 practices would have been 50 24 W, or exactly the longitude of Titanic's first distress call. Circumstantial evidence is that Captain Smith gave the predicted location of Titanic at 00:00 o'clock April 15th to the wireless for the ship's first CQD messages. Boxhall was off the bridge at the time, so could not have done it while the Captain is known to have passed through the wireless office at the appropriate time.

Boxhall's so-called "corrected" CQD lat/lon is nothing more than backing up the ship's track by 20 minutes on the reciprocal of 255, or 075 degrees. The distance is too precise to conclude otherwise. It is exactly 20 minutes of steaming at 22 knots "up track" from the ship's predicted midnight location. No matter how he says he got his CQD position, Boxhall did nothing more than calculate Titanic's predicted location 20 minutes prior to midnight using April 15th time. So, his lat/lon was not for the accident, but for minus 11:40 o'clock, Monday, April 15th -- which was a date and time that never existed for Titanic.

The line of 255/075 if taken back to the ship's intended track of 266 from "The Corner" crosses at the ship's dead reckoning position for 11 hours 30 minutes after noon, April 14th. This is a significant time because it coincides perfectly with IMM/White Star regulations and the best practices of 1912 navigators to check their steering compasses against their standard compasses every half hour. The full detail of men necessary to make a course change (quartermaster and officer on the standard compass platform; quartermaster and officer in wheelhouse) would have been in position for this compass check. They were also the men needed to make a course change. The efficiency of making a course change at the same time of a compass check is obvious enough not to need further discussion.

Titanic's own CQD lat/lons coupled with the know course and speed from "The Corner" combine to prove the ship made a one-point (11 degree) turn to port at 11 hours 30 minutes after noon, April 14th.

The ship was heading 255 immediately prior to the accident. Using 22 knots and that heading, the most probable position for impact on the iceberg would have been 41 48 N; 50 04 W. This impact lat/lon lies north and west of the wreck site as defined by the boiler field, producing a current/windage set (navigator speak for direction of a current) of southeast. The distance of under 7 miles must be divided by the time since the last fix which in this case should be Lightoller's 7:30 stars. That fix was not recovered in testimony, so we are forced to go back to the turning of "The Corner" a bit more than 6 hours earlier. This yields a drift (speed) of a not or less. The combined set and drift are quite believable for the weather encountered that day and the area of the accident.

We have evidence that the bridge crew expected to see ice sometime after 11 p.m. that evening. Given that the bridge routine was governed by unaltered April 14th hours, we can reasonably assume they anticipated ice after the 11 p.m. compass check and before the 11:30 compass evolution. Nobody noted the exact time when the lookouts saw that "haze" across the ship's track. There being no meteorological haze that night, Fleet and Lee must have deliberately used the word "haze" to obfuscate reality. What they saw was the ice field.. All of this circumstantial evidence gives motivation for the hard evidence that Titanic turned south by one compass point (11 degrees) at 11:30 in April 14th time. Captain Smith was attempting to avoid the ice he knew lay across the ship's path from wireless reports and which could now be seen visually.

-- David G. Brown
 
Nov 26, 2016
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about wind and speed
Olympic run data february 1912, day 2,3,4
feb 10, 536 miles, 21,57 knots, fresh WNW wind to fresh N'ly gale, high swell
feb 11, 545 miles, 22,02 knots, mod. N to light var. to mod. WNW wind
feb 12, 563 miles, 22,70 knots, mod. N to mod. NE gale, rough NNE sea

Beesley wrote about the weather on Sunday April 14:
There is not much to tell after leaving Queenstown from Thursday to Sunday. The sea was calm, in fact as calm that only a few passengers omitted their meals.The wind blowing from west or south west, "fresh" as the daily weather chart indicated ...

About Sunday: ... when we went on deck after lunch we noticed a change of temperature of that kind, that not many preferred to expose themselves to the cold wind - an artificial wind which mainly if not completely was caused by the fast run of the ship. ... I am sure there was no wind wawing at this time. I noticed the same strength of wind arriving at Queenstown, which died off when we stopped, and revived immediately when we left the Harbour ...

It seems there is no wind available to explain a slow down from 22 to 21 knots sunday afternoon.
 

Jim Currie

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Let's not confuse what is said by someone in evidence as fact. In my list in post #360, I listed No. 1, 2 and 3 as facts. Perhaps I should have said that they are believed to be true, not fact, for the following reasons:

I like to keep things simple and to the point; the point being that you reject the idea that Titanic slowed down between Noon April 14 and 8 pm that evening.

You caution "Let's not confuse what is said by someone in evidence as fact."

No one is doing that , Sam. Obviously the "someone" you have in mind is 5th officer Lowe.
However, by the same token, evidence should not be rejected out of hand without detailed consideration of all relevant, available evidence followed by full and final acceptance or rejection of said evidence. You have not done so. I will attemp to do so. I'll try and abbreviate.

I'm not sure what all that bit about Patent Logs and engine rpm is meant to convey but I can assure you it does not happen like that in practice. The words sea bottom bring shivers to the timbers of all practical navigators.

Historic performance by Titanic or any other vessel is interesting but is just that. It has no bearing on the debate.

As I see it, there are burning questions:

1. Why did 5th Officer Lowe say that he used a speed of 21 knots to calculate the 8 pm DR if he did not do so?

A: Because he did, and he derived that speed by dividing the Patent Log reading at 6 pm by 6 when he cam on duty at 6 pm on the evening of April 14. That was the way it was always done if the speed by engine revolutions was not used.
Your argument about Patent Log readings and speed by rpm between 8 pm and 10 pm does not hold water. You are not comparing like-for-like. The improvement in rpm speed was because of minimum slip of Titanic's propellers due to fair weather. That same fair weather would have little influence on the Patent Log reading.

2. When Lowe took over from 5th Officer Moody at 6 pm that evening, the latter would have given him the very latest speed and course. If Titanic had been making 22.06 or any speed other than 21 knots, Moody would have said so and Lowe would have remembered it. So why on earth would Lowe say the speed was 21 knots and not 22.06 knots?
A: Because 21 knots was in fact her speed.

3. At 8 pm,3rd Officer Pitman handed over the Watch to 4th Officer Boxhall The former believed Titanic was making 21.5 knots and said so. Why would he say so? Why would he not have told Boxhall that the speed was 22.06 Knots?
A: Because although he knew for sure, the speed at Noon, he did not assume continuity and reverted to an assumed speed of 21.5 knots based on engine rpm. He would have passed that intelligence on to his relief, Joseph Boxhall, at 8 pm.

3. If, as would be the normal course of events, Pitman had told Boxhall Titanic's course and speed at 8 pm and had stated at that time that the ship had been making 22 + knots since Noon. Boxhall would not have made any connection between ship speed and propeller slip. After all, she had made that same speed before Noon that day and the weather during that period was vastly different. So why did he use a slower speed from 7-30 pm to work his distress position?
A: At 8 pm, Boxhall had little interest in ship's speed, from then on he was engrossed in working sights.

3. At 10 pm, Boxhall's boss, Lightoller handed over to 1st Officer Murdoch. Like Pitman, Lightoller also stated that he thought Titanic was making 21.5 knots. Why? He must have already known the ship's average speed from Noon to 7-30 pm. he would get that from the results of his 7-30pm sights worked by Boxhall.
a: Lightoller already knew the results of his 7-30 pm celestial observations and knew speed made good since Noon that day. If it had been 22 + knots, he would have said so instead, he still used 21.5 knots.

The time difference between ship and GMT was 2 hours 58 minutes at Noon, April 14. The fact that both Boxhall and Lightholler did not allude to that 2 hour 58 minute difference when asked, should tell us all something. Specially if it came from Lightoller since he was off Watch at the time of impact with the iceberg. By the same token, if there had been no clock alteration, why would Boxhall allude to one?
Pitman refered to a watch to get his 2-20 pm sinking time. Since Stewardess Annie Robinson had fully adjusted time of sinking as 1-40 pm there is little doubt that he had unaltered time on his watch

Conclusion:

Since Pitman and Lightoller only mention a speed of 21.5 knots up to 10 pm, and the latter had the results of the 7-30 pm sights at that time, then the ship's speed up to 7-30 pm could not have been more that 21.5 knots.
Boxhall completed the 7-30 pm sights by about 9-30 pm therefore, at that time, he knew the ship's average speed between Noon and 7-30 pm. That speed must have been less than 22 knots. Otherwise, why would he declare "taking into consideration that it was smooth water and that there ought to have been a minimum of slip, I allowed 22 knots."

How much more proof of a slow down does anyone need?
 

Jim Currie

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I

The real problem I have with your statement is that you don't quantify what "well above" means, and expect people to just accept what you are saying.

Sam, If you have a problem, then it's not with anything to do with the definition of "well above". If you read the meat of my post, you will see that I'm concerned with the reference point of the horizon.
You're the one that arranged for Californian to be 16 miles away from the sinking Titanic. I wrote "For Californian to have been 16 miles or less from Titanic;s position at that time," and you simply jumped in to defend your arrangement. I pointing out that if these men on Californian were seeing rockets on the horizon, they were seeing them at extreme range. The 16 mile bit was bait.;)

The distance between two object at sea... one with a height of eye of 500 feet and the other with a height of eye of 45 feet is exactly 33.4 nautical miles. Don't take my word for it. I don't have Bowditch, I have Burtons. They are now almost 70 years old but I'm sure you can still read them:



As you can also see from the above table,if someone with a height of eye of 45 feet sees something right on the horizon and his radar tell him it's 16 miles away, then that object has a height of 55 feet above sea level.
Burton's distances 001.jpg





Clearly, for all practical purposes, rocket bursts from 16 miles away would be seen close to where the horizon would be, which itself was NOT visible that night.

Really? Then how do you explain the following from captain Lord of the Californian :

"I told them it was a very strange night; it was hard to define where the sky ended and the water commenced. There was what you call a soft horizon. I was sometimes mistaking the stars low down on the horizon for steamer's lights."

Of course the horizon was vi
sible...just not hard enough to be used as an exact reference point. For your information, Sam. When you look at the horizon through binoculars on such an night as it was then, you can't see a hard line. However, your eyes automatically focus on your personal horizon. The best reference are the setting or rising stars. That's what captain Lord was talking about. he did in fact see a horizon of sorts.

In any case, the rockets we are discussing were seen at 3-30am on the morning of April, 15. Californian had not moved from where she had originally stopped. If these rockets were from Carpathia, then she was about 7 miles away from Boxhall. Right? If your claim that Californian was 16 miles away from the sinking Titanic was true, then at 3-30am, Carpathia was 16 + 7 = 23 miles away from Californian. Right? Now have another look at Burtons. From it you will find that if an observer with a height of eye of 45 feet will just see a rocket flash right on the horizon if that rocket only rises to a height of 180 feet. Are you telling us that was the maximum altitude of Carpathia's distress rockets?


By the way Alex, this is the type of verification of evidence that Sam was referring to in his post #16 above.
 
Mar 22, 2003
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As for your zero evidence of Captain Smith seeing the log at 4 pm: are you serious?
What I said is that there is zero evidence of Capt. Smith seeing a 4pm log reading of 84 miles or expecting to see 86.4 miles. For all you or anyone else knows, the 4pm log reading could easily have been almost 90 miles, consistent with an average of 22.3 miles of advance per hour.
You still avoid the most important question. You still have not addressed the question as to what speed Boxhall thought she was doing before he determined she was making 22 knots.
The reason is quite simple, Boxhall assumed the ship was still carrying 75 rpms, the same since Saturday noon. Since the vessel ran about 22 knots from noon Sat to noon Sun, and since conditions certainly were not any worse than what was encountered during that interval, he simple assumed the ship would do as well then and she had done previous. You are trying to read at lot more into what he said.
 
Nov 26, 2016
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I've done some of my own math working at this problem myself, and I realized my methodology is flawed because I've been using flattened sphere calculations rather than the round sphere calculations that everyone else is using. I will have to do some more work and post my results later.
I think the differences between flattened and round sphere calculations can be neglected.
The earth's radius is 6357 Kilometers near the pole and 6378 kilometers at the equator. Travelling by 1' of longitude with one or the other radius would make either 1849 or 1855 meters. The official definiton of 1 nautical mile is 1852 meters. The error would be just 0,16%, even less as we are travelling between 40 and 50 degrees latitude. Another formula for Bessel ellipsoid says:

1' = 1852 - 9,3 * cos (2 * degree latitude)
This makes 1853,6 meters at 50° and 1850,4 meters at 40° latitude.
1,6 meters of 1852 meters, percentage 0,086%.
Supposed the log is calibrated to register "1852 meter" miles, the indication would be 132,11 instead of 132 miles.

The accuracy of stellar fixes is about one mile, so the error caused by not accounting for the flattened sphere is neglectable related to the normal inaccuracy of stellar navigation.
 
Nov 26, 2016
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about speed, current and log, Lowe 21 knots

For my calculations I assume as point where Titanic stopped 41-46 N and 49-56 W, 132 miles behind the corner.
From noon to corner we have 258 miles to travel. Of course we are not sure whether the turn was made at the corner.
Jim proposed in the skatch he posted a turning point ESE of the corner, 41-57 N and 46-52 W.
The distances will be: noon-corner: 123 miles; corner-stop: 137 miles; Both add on to 260 miles.
The log indicated 260 miles from noon to collision.

The chart which i have on hand shows north atlantic current, 0.4 .. 0.8 knots east of the corner, heading to ENE.
Between corner an longitude 50 it shows a "slope water current", about 0.5 knots, heading to east.
From the chart I should judge we have to estimate a current of 0.5 knots from noon to stop position.
Supposed the log would be able to indicate exact miles through the water it should count 6 miles more, 264...266 miles.
That means a lack of 2...3 percent.

Find attached an excel file which calcaulates speed and courses between noon, point of turn, 7-30 position and stop position.
The green fields allow to fill in coordinates for turning point, stop point and noon position.
The 7-30 position is derived from stop position and elapsed time with or without retardation.

There are two cases at question:

a) No clock retardation:
avarage speed 22 knots
close to speed the day before
turn point 2 miles west of corner, 3 miles south of 42 N
in agreement with Rowe's 45 miles in two hours

b) Clock retardation 24 minutes:
average speed 21.36 knots
21 knots from noon to 7.30 position, 22 knots from 7.30 til stop position
turn point 6 miles east of corner, 3 miles south of 42 N
in agreement with Lowe's 21 knots
not in agreement with revolutions unchanged

-> Hard to say what is more likely.
If we choose case a) no clock retardation
then 1h 33 minutes do not make sense anymore.
Instead we have to use "about two hours", be it 1.57 of 2.02.
This will put the first CQD on 12.25 unaltered time.
But Bride's testimony put's it nearer to 12 than to 12.25
.... To say nothing about rockets seen and fired.
 

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Mar 22, 2003
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From my side, I prefer the 162 miles to be regarded as typing error.
A simple transposition of the last two digits. 162 -> 126. And to be correct, Lowe never stated that the log read 126 at 6pm. What he did say was that he took the distance to the corner and divided it by the time to the corner to get the speed he used. The distance to the corner was known at noon; a distance that fits in very nicely with what Olympic did on the three separate trips the year before over the exact same route of travel. The time to the corner turn that Sunday was set by Capt. Smith. Lowe however took that distance and divided it by 6 hours to get the speed that he told Sen. Smith. In my opinion, Lowe was trying to downplay how fast Titanic was actually making that day. He only mentions the log when Sen. Smith challenged him as to the accuracy of his speed calculation.

What we know about the log is that it measured 260 miles from noon to the time of collision, and it advanced about 45 miles in the two hour interval between 8 and 10pm. Those are the hard facts that are in the historical record. We were also told by multiple sources that ship was averaging 75 to 76 rpm since noontime Saturday, and making 75 rpm as late as 11pm Sunday night. As stated elsewhere, unless the revolutions were changed, the log will not significantly jump up or down in two hours from a longer term average. And we also know that the log, which depends only on how fast the ship is running through the water, is not affected by current. If the ship did 260 miles in 11 hours and 40 minutes, then we can expect her to make an average of 44.6 miles in two hours. If the she did 260 miles in 12 hours and 4 minutes, then we can expect her to make an average of 43.1 miles in two hours. But, we were told she made 45 miles in two hours, consistent with the 44.6 mile average that we get using the 11 hour 40 minute time duration from noon. For me that says it all.
 

George Jacub

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Jim, the launch times in their Table 2 are pretty much wrong from start to finish, except for Lifeboats 16, 14 and 12.
 
Mar 12, 2011
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Markus
You're absolutely right. I was doubting my figures because I was coming up with positions slightly different from Sam Halpern and other expert navigators here (which I am not) but the differences are so small that it doesn't make much difference in the scheme of things. I'm teaching myself the math as I go along, they don't make network engineers take math quite this complex these days!
 

Jim Currie

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Hello Aaron. You wrote:

"The crew on the Californian did not pay much attention to the other ship and the fact that their ship was swinging around all night means their estimate bearings were of course not going to be accurate."

I'm afraid that just isn't true.

If you read the entire evidence of the Officers of Californian, you will find that they received specific orders from their captain. I can assure you, these orders would have been followed to the letter.


There are two kinds of bearings taken from the bridge of a ship...relative to the bow and by sighting across a compass, the error of which is known. I presume you mean the first one-relative bearings...i.e. 'so many points on the bow or quarter.? If so, I can assure you that when a bridge officer refers to so many ' points' on the bow, you can be sure that he will be accurate to withing a few degrees either side. On her following ship, I have moved 'ahead to one side to give you an idea. In fact, on the ship in the picture, one point on each bow was in line with the foremast sampson posts.

upload_2016-10-17_21-20-26.png


Stone of the Californian said the pyrotechnics he was seeing went as high as the other ship's masthead light. The reason for that was that he was watching her through binoculars. He could use the position of the white masthead light relative to the other ship's deck lights as a guage.

" The Titanic was facing the Californian almost head on, so when the bow of the Titanic moved closer to the water the rockets would burst at a lower altitude and possibly appeared closer to her decks lights further aft which glowed to them as a cluster of bright light, and when her stern rose and her bow dropped, the rockets would appear closer to the bright light."

No Aaron. If Titanic was heading straight for Californian then those on the latter would have seen Titanic's red and green sidelights
and her white masthead light all the time she was sinking. Additionally, her accommodation lights except her bridge front cabin lights would have been shut out to an observer right ahead of her.

The Mount Temple evidence is suspect, to say the least. if we believe her captain, then she was heading northward when Californian passed her going south. If we plot in revers the evidence of Captain Rostron vis a vis Californian's movements between 8 pm and 8 30 pm then work back at 13 .5 knots, reversing Californian's course to the time she met with Mount Temple, we find that the latter was much farther north than his evidence suggested.


 
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The key sentence in Lowe's testimony: Senator SMITH. What speed did you use in getting the 8 p. m. position?
Mr. LOWE. I used the speed for the position at 8 o'clock, and got it by dividing the distance from noon to the corner by the time that had elapsed from noon until the time we were at time Corner.
Later on he made the calculation, dividing 125,7 miles by 6 hours and found 21 knots.
The time to turn at the Corner was calculated out of estimated speed 21,5 knots. Time to reach the Corner: 5.52 pm, round to 5.50 pm.
If really we can assess Lowe's statement as misleading simplification without having bad conscience then I would be inclined to say, based on the discussion about speed there was no clock set back between noon and collision.

If we do so, then the inevitable necessary conclusion must be, that both Boxhall and Lightoller are wrong with the 1h 33 minutes conversion as they stated in the US enquiry.

I found this Statement from Lightoller in TIP | United States Senate Inquiry | Day 5 | Testimony of Charles H. Lightoller, cont.
Mr. LIGHTOLLER. I think it was Mr. Boxhall.
...
Senator SMITH. Was he on watch Sunday night, or at his post of duty?
Mr. LIGHTOLLER. At his post of duty.
Senator SMITH. On Sunday night?
Mr. LIGHTOLLER. Undoubtedly.
Senator SMITH. What time; do you know?
Mr. LIGHTOLLER. I believe he was on the 8 to 12 watch.
Senator SMITH. That would take him two hours beyond your watch?
Mr. LIGHTOLLER. More than two hours, considering what the clock went back.
Senator SMITH. The clock went back some at that time?
Mr. LIGHTOLLER. Yes.

So Lightoller was bearing in mind there was a clock set back intended at midnight (12.23 back to 12?)
If asked, how to convert the time of sinking 2.20 into GMT, he might have thought erronously, this was after the clock change, so the conversion must be 1 h 33 minutes. Lightoller was not on duty from 10 to 12. When he came on the bridge after the collison he could not know what had happened with the clocks.

But he was present while Pitman made his statement pointing out the clocks were not set back and that he got ship's time of Saturday! midnight and that his watch was correct. Despite hearing all this Lightoller said: 5.47 - 2.20 - 5.47 Greenwich mean time: 2.20 apparent time of ship.
I have to say I am a bit stumped. How to get out of this?
 

Jim Currie

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Don't think l I'm explaining my point properly, Marcus. Mia culpa!

Start again, James. (My Sunday name).

If the Patent Log was accurate, and I believe we are in agreement that it was, and if Titanic was making the same average speed after Noon April 14 as she was before Noon April, 14, then at 6 pm when the reading was received on the bridge, it would have shown that Titanic had covered a total of 132.6 nautical miles during the previous 6 hours. By simple arithmetic, the average speed would then have been 22.1 Knots.
Since, in my opinion, the distance from the Noon April 14 position to The Corner was 124 nautical miles, Titanic would have over-run her planned turning point by 6.6 nautical miles
If, on the other hand, the weather was on the beam with a moderate sea and swell and the Patent Log read 125.7 at 6 pm then she had lost 6.8 nautical miles somewhere. In the absence of reduced engine rpm and/or a fierce head wind, the only other cause had to have been current; a head current of 6.8 divided by 6 = 1.13 knots.

The reading of 125.7 for 6 pm is derived from the evidence of 5th Officer Lowe. I remind you:

"If you take the average speed from 12 to 6 - that is giving her a run of six hours - she will not jump up in two hours, from 12 to 6 o'clock, from that average speed. You have six hours in there to take a mean on.
Q: And you are able to say that the speed at that time was 21 knots?
A: Twenty-one knots or under; it was really 20.95, about. If the speed had been increased or reduced during the interval when I was off duty, I would have been informed of it."

Bottom line, Marcus: if Titanic was making 22.1 knots up until Noon at a given number of rpm and nothing had changed after Noon regarding engine rpm or weather then the only possible cause for her to slow down by the amount she did was a 1.1 knot (rounded down)head current.

However, to address your concern re distances to the 7-30 pm celestial observations:

The problem you are encountering is because you assume that Titanic passed thought the position of The Corner. In fact. she could not have done so, if we believe 5th Officer Lowe's evidence which suggests she only covered 122.2 miles from Noon until 5-50 pm. This being the case, then she must have turned before The Corner...6.8 miles short of it to be exact.

Perhaps the following little sketch (not to scale) will better explain my thoughts.
Lowe's evidence.jpg
 

Rob Lawes

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A problem I have with your theory David is that QM's Oliver and Hitchens, Boxhall and the lookouts Fleet and Lee would all have known of this course correction and said nothing about it at either inquiry.

Which sounds better to any investigation "we became aware of a haze sir, fearing it may have been ice the Captain ordered the ship to come around to port to open the distance. It was jjust bad luck it extended further south than any one knew"

Or

"We saw a haze, did nothing then at the last minute spotted the berg and had no time to svoid it"

Why hide a course change designed to increase the safety of the ship. The fact it didn't doesn't mean the bridgr team didn't try.

To omit the information just makes them look less competent.