Two points I would like to put up for discussion within this thread:
Firstly, What is the correct course of the southerly route between the corner and Nantucket lightship?
Secondly, what course did
Titanic steer after she turned at the corner? 265° or 266°?
1. The southerly route:
4th Officer Boxhall said in the British inquiry:
15666. We have all noticed there is a point on the course, as marked on the chart, where a westbound ship turns, what you call the corner, is that what you refer to as 42 N. 47 W.? - That is so.
15667. And then your view is that the ship, when she turned on her new course at 5.50 had run beyond that corner? - Yes.
15668. And, therefore, was to the south of it? - Yes, to the south and to the westward of it.
15669. Then when she is put on her new course, her new course you tell me was S. 86 W.? - S. 86. W.
15670. Though your impression is that as it is marked on the chart the course there marked is S. 86 W.? - I think it is about S. 84 3/4 W. as a matter of fact.
An upto date chart [2670, Cape Breton to Delaware Bay] indicates the position 40°30'N 69°26 W.
The track for Westbound vessels is marked at 40°34' N. (chart attached)
Based on historical information we find:
Keeping Track of a Maiden Voyage
Following the Olympic’s second voyage of 1911, we will take this point to be about 2 miles south of the Nantucket Shoals light vessel. The light vessel itself was listed in the US Coast Pilot Part III for 1912 at 40° 37’ 05’’ N, 69° 36’ 33’’ W.
40°35' N comes close to the course recommended in chart 2670.
Course from Corner to 69°37' W, 40°35' N: South 85.23 West (decimal), this is 85 1/4.
Boxhall said: I think it is about S. 84 3/4 W. as a matter of fact.
The appropriate position of the Nantucket lightship would be 40°26' N 69°37 W, nine miles to south.
Practically the course to be steered would be 85° (265°), as no helmsman will be able to steer quarters of a degree.
In that case the latitude would change 3.9 minutes of arc to south per one degree longitude at latitude 42° N.
Based on historical and up to date information the course would be 85 1/4, but Boxhall explicitly declared that the course was 84 3/4, a quarter below 85.
Any ideas how Boxhall arrived at 84 3/4?
2. Titanic's course after the Corner.
Senator FLETCHER. How many degrees did you change ? - Mr. PITMAN. I can not remember.
If I had a chart here I could tell you in a minute. South 84 or 86 west would be the true course we were making after 5.50; south 84 or 86, I am not quite certain which, was the true course.
Lightoller said in British enquiry:
13498. Can you tell us what was the course of the ship when she was handed over to you at 6? - I cannot remember the compass course. I know from calculations made afterwards that we were making S. 86 true.
13499. S. 86 W.? - Yes.
13500. That is within four degrees of due w. true? - Yes.
Boxhall comes up with the late turn at the corner:
15659. You would have to take the speed and of course you would have to take the course? - Yes.
15660. Which you have told us was S. 86 W.? - Yes.
15661. Am I right in thinking that the course as marked on the chart is S. 85 W. when you take your turn. I believe it is about S. 85 W.? - Yes.
15662. So that as I follow, the "Titanic" had run on, you say for 50 minutes longer than she otherwise would? - Did I say that?
15663. I thought you said 5.50? - I have not said that so far, but I wish to say it now. I wish to explain it. The night order book was written out and there was an order for the course to be altered at 5.50.
15664. You saw that in the order book? - Yes, I saw it and I remarked to the Chief Officer between 4 o'clock and 6 o'clock that I considered the course ought to have been altered some considerable time before 5.50 - that is, if it was meant to be altered at the corner, 42 N., 47 W. Whether we spoke to the Captain about it or not I do not know. I just remarked that to the Chief Officer, and the course was altered at 5.50. I consider that the ship was away to the southward and to the westward of that 42 N. 47 W. position when the course was altered.
15665. Perhaps you will take the chart in your hand. I want to ask you a question or two about it? - Yes.
(The chart was handed to the witness.)
15666. We have all noticed there is a point on the course, as marked on the chart, where a westbound ship turns, what you call the corner,
is that what you refer to as 42 N. 47 W.? - That is so.
15667. And then your view is that the ship, when she turned on her new course at 5.50 had run beyond that corner? - Yes.
15668. And, therefore, was to the south of it? - Yes, to the south and to the westward of it.
15669. Then when she is put on her new course, her new course you tell me was S. 86 W.? - S. 86. W.
15670. Though your impression is that as it is marked on the chart the course there marked is S. 86 W.? - I think it is about S. 84 3/4 W. as a matter of fact.
15671. The effect would be she would have run a little bit further on the old course and then on the new course she is gradually making back to the line? - That is my impression of the idea which Captain Smith had in altering that course and setting it to that time.
From Boxhall we learn that the proper course would have been 85° (265°), but to compensate the late turn they steered 86° (266°) instead.
From Pitman in USA we learn that no late turn has taken place at all:
Mr. PITMAN. We just took a set of them at sunset, or just as it was getting dusk, when the stars were visible. It was about 6 or 8 o'clock that we took them.
Senator SMITH. Do you know how these observations located the ship?
Mr. PITMAN. Do I know what?
Senator SMITH. Do you know how these observations located the ship?
Mr. PITMAN. Yes; right on the track.
...
Senator SMITH. Were you going straight away on a straight course when you took these observations?
Mr. PITMAN. Yes, sir; exactly.
Senator SMITH. Or did you have a course of speed that took you in a curved direction?
Mr. PITMAN. No; we were proceeding on the track laid down for the company.
...
Senator FLETCHER. And then you changed to this northerly course?
Mr. PITMAN. No. We stuck to the track we were supposed to follow from the 14th of January to the 14th of August, just as agreed upon by the big steamship companies.
Conclusion drawn from statements summarized above:
It was intended to go at 85° (265°) after the corner. Pitman's testimony in US confirms they were on the official track, and the course for that would be 85° (265°), or even a bit less, 84 3/4.
Lightoller said: "I know from calculations made afterwards that we were making S. 86 true".
This question may be asked, afterwards what?
After taking the 7-30 star position and compass checks during Sunday night, of after end of the US enquiry while travelling back to England?
Again Mr. Boxhall:
15671. The effect would be she would have run a little bit further on the old course and then on the new course she is gradually making back to the line? - That is my impression of the idea which Captain Smith had in altering that course and setting it to that time.
But we will se that 86° is not sufficient, they should have much rather changed to 88° (268°):
Pitman in British enquiry:
15174. And, so far as you know, was the steamer's course deflected at all from the course that had been marked out at noon; did it vary to the south, or in any way from the course which had been marked out at noon? - Yes, I considered we went at least 10 miles further south than was necessary.
15175. Do I understand you rightly that in marking the course at noon, the course was marked 10 miles further south than you considered necessary? - No. We had a certain distance to run to a corner, from noon to certain time, and we did not alter the course so early as I anticipated. Therefore we must have gone much further south.
....
15182. But you say he gave instructions to alter the course of the ship? - The course was altered at 5.50. They were the Commander's orders.
15183. Ten miles further south. Was any record made of that at the time? - No, and I thought that the Course should have been altered at 5 p.m.
We take this literally. 50 minutes, 22 knots, 18.3 miles at course 260° beyond the corner will end up 9 miles to south and 15.9 miles - 21 minutes of arc to west of the corner.
The hypothetical turning point derived from Pitman's statement would be 41°51 N, 47°21' W.
The course from there to arrive at Boxhall's CQD position would be 87.78 degrees, 88° or 268°.
The course 86° does not even make sense if really a late turn would have taken them to south as Pitman and Boxhall claimed.
The CQD positions as calculated by Captain Smith an Boxhall are just one respectivly two miles south of the track:
Points of the track and CQD positions relating to track:
42-00 N 47-00 W;
41-56 N 48-00 W;
41-52 N 49-00 W;
41-48 N 50-00 W;
41-47 N 50-15 W; <-- 41-46 N 50-14 W; Boxhall, 1 mile to south
41-46 N 50-30 W; <-- 41-44 N 50-24 W; Smith, 2 miles to south
41-44 N 51-00 W;
Considering all this I come to the conclusion that course 86° was neither steered nor used for any calculations.
When they turned the corner they intended to go on the track at 85° (265°).
The 7-30 stellar position probably was found 1 or 2 miles to the south of the track. This finding is not sufficient to reason that the true course was 86° (266°) instead of 85° (265°).
The 86° figure is part of that fictional late turn story. Attempts to reconstruct the 7-30 position should be made by working backward from the CQD positions with course 85° (265°).