Boxhall's CQD position


Where did I ever suggest such nonsense? I showed that she was set to the southeast.
You said: "A1: The Calculated distance to run from Daunt Rock departure to The Corner is exactly 1673 nautical miles. The distance is made-up of 55 miles from Daunt Rock to 1 mile south of the Fastnet Rock, then 1618 nautical miles on a Great Circle course to The Corner. According to 3rd Officer Pitman, Titanic had covered a total of 1549 miles since FaoP...Full away on Passage...at Daunt. That left 124 miles, not 126 miles left to run at Noon, April 14."

It would only leave 124 miles if the ship had followed the GC track perfectly, which I take it you agree she did not do. Therefore, the remaining distance to the corner had be more than 124 miles, and that is my point.
 

Jim Currie

Member
Well here's mine:

Boxhall only needed a DR for 5-50 pm. Unless he made allowances for drift and leeway, to obtain it, he would assume that the ship passed through The Corner turning point. Only after 7-30 pm sights were worked out, would Boxhall have known that his 5-50 pm DR was way-out or spot-on.
in fact he very clearly tells you what his thoughts were (not his reason for thinking them) in his evidence:
5667. And then your view is that the ship, when she turned on her new course at 5.50 had run beyond that corner? A: - Yes.
15668. And, therefore, was to the south of it? A: - Yes, to the south and to the westward of it."

Earlier he said:
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."

If the ship did not follow the track but was ahead of and the south and west of where she was supposed to turn, How do you suppose Boxhall figured that out?

If Boxhall knew the distance from Noon to the turning point was 126 miles, and he used a speed of 22 knots, that means he thought the ship overshot the mark by 2.33 nautical miles.
If, on the other hand, he knew the distance to the turning point was 124 nautical miles, then the ship overshot the mark by 4.33 nautical miles.
Now you tell me and everyone else: what overshoot would you consider to be "considerable"?
 
Now you tell me and everyone else: what overshoot would you consider to be "considerable"?
About 10 miles, or thereabouts.
You also asked,
If the ship did not follow the track but was ahead of and the south and west of where she was supposed to turn, How do you suppose Boxhall figured that out?
The same way that made Pitman say over month after the events took place: "Yes, I considered we went at least 10 miles further south than was necessary....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....I thought that the course should have been altered at 5 p.m....Judging from the distance run from noon."
 

Jim Currie

Member
Keep digging, Sam.

Boxhall said that he used a course of 266 True to work his CQD position. To do that, he had to have an origin sometime before 7-30 pm sights. the only such origin would be the DR for 5-50 pm.
If you use the course line of 266 True-086 True as a position line and run it back from his distress impact position until it crosses an extension of the 240.5 True course line at a point 128. 33 miles from Noon that day, you will find that they cross at a position 4.3 miles (not 10 miles) from The Corner - at 41-58'North, 47-05.1'West.
Boxhall must have used that position for his DR turn position at 5-50 pm and believed that the ship had 124 miles, not 126 miles to run until 5-50 pm.
 

Jim Currie

Member
Here's another "trauma" for you, Sam

In your article " They Were Gradually Working Her Up". you observe:
"Taking an average between 75 and 76 rpm from 12 noon up until 11:40 p.m., we get an average speed of 22.3 knots through the water, a result which happens to match very well with the taffrail log reading of 260 nautical miles through the water observed by QM George Rowe at the time the accident happened.

Let's use that same taffrail log again.

First: As you know, I believe that Boxhalls's distress position error was simply one of using too much runtime and combining it with the wrong speed. But how did he calculate the runtime? Here's what I think.

When he entered the chartroom, he saw the notation..."11-46...struck iceberg...All stop." He knew that a clock change was due at midnight. However, since Moody and Pitman were on the boat deck he would not know if the partial or full one had been allowed for in the 11-46 time recorded. My contention is that Boxhall made the mistake of assuming the time recorded was either fully retarded or unaltered time when in fact, it was partially retarded time. He therefore either duplicated an allowance already made for a partial clock change or allowed for a full clock change and converted that time to what he thought was the equivalent GMT then applies the result to the GMT for 7-30 pm sights. I use GMT throughout.
Time of Stop/impact...11-46 pm....3-31 am GMT
Time of sights..............................10-36 pm GMT
Runtime ...................................... 4rs - 55 minutes.
4 hours 55 minutes at 22 knots = distance steamed 108.2 miles.
Now we use the Patent Log.

When at 49-56 West, the patent Log read 260 miles. If Titanic had reached 50-13 west, it would have read 272.6 miles. This means that at 10-58 pm GMT. (8 pm ship time), 4 hours 33 minutes earlier, it should, according to Boxhall, have been reading 272.6 minus 100.1 miles run = 172.5 miles. But what was it reading at 8 pm?
Titanic was making 22.5 knots during that period, so she would have covered a distance of 102,4 miles since 8 pm...2.1 miles more. So instead of 172.5 miles; it follows that at 8 pm the log would have been reading 170.1 miles.
170.1 subtracted from the Impact time patent log reading of 260 miles suggests that at 8 pm, Titanic had another 89.9 miles left to run until impact. At 22.5 knots this would take her almost exactly 4 hours...until the unaltered clock read 12 o'clock Midnight.
What was it Colonel Gracies said?
" I was awakened in my stateroom at 12 o'clock. The time, 12 o'clock, was noted on my watch, which was on my dresser, which I looked at promptly when I got up. At the same time, almost instantly, I heard the blowing off of steam, and the ship's machinery seemed to stop."
We can test this. by runnin back from the true impact positon for 4 hours at 22.5 knots.

Then there is the effort made by Captain Smith. Let's use the same thought process.

If the Patent Log read 170.1 at 8 pm and Smith's DR for 8 pm was 20 miles too far ahead, the Patent Log reading for 20 miles ahead would have been 190.1 miles
If the Patent log read 260 miles at 49-56'W at impact, then at 50-24'W it would have read 280.9. This would Give Smith a distance run of 90.8 miles between his 8 pm DR and the place where he reckoned Titanic had stopped.
He would have made allowance for westward drift, so let's say he used full speed distance of 90 miles. If he did then if he used a runtime of 3 hours 40 minutes as you believe he did, then Titanic would have made 24.6 knots. However, if he used a 4 hour run time, then she would have averaged exactly 22.5 knots.

In rest my case.

 
Boxhall said that he used a course of 266 True to work his CQD position.
He also said he determined that by taking stellar sights to determine compass deviation. That was after he worked the 7:30pm position. It had nothing to do with any DR position taken beforehand. You asked me what I would consider to be a significant overshoot of the corner. I said about 10 miles. I wouldn't consider 4 miles 'significant'. And that overshoot, if Boxhall is to be believed (which is another story), put the vessel not just south of the corner, but south and to the west of the corner. That is what he said. Pitman said essentially the same thing, only he quantified it all by stating the vessel should have turned about 5 o'clock. Of course, that was not the story that was told weeks earlier at the American inquiry. It's all tied to that erroneous SOS position that Boxhall worked out. They got the position wrong and they got the time wrong.
 

Jim Currie

Member
Read the evidence again, Sam. Boxhall used his 7-38 pm fix position and the same course for azimuth observations (compass error) after he had reported the 7-38 pm position to the captain and that was some time after 9 pm. probably nearer to 10 pm.
The Course Board showed 264.5 True but Boxhall used 266 True. He said he assumed that the Captain had made a course allowance to the right to bring the ship back onto the prescribed course line after the turn.
The only way he could have assumed that and known it's effectiveness was by measuring the course being made good was between the 2 known positions...at 5-50 pm and at 7-38 pm.
Not only that, but if the ship had been more than 4 miles to the south and west of The Corner, the course compensation to the right would have been proportionately greater... 268 True or even more.
 
The Course Board showed 264.5 True
The course board showed the standard compass course and the steering compass course.
The only way he could have assumed that and known it's effectiveness was by measuring the course being made good was between the 2 known positions.
The course made good is obtained between two fixes. You cannot use a DR and a fix. Navigation 101. Perhaps Boxhall needed to go back to nav school if he did such a thing.
Perhaps you should also take your own advise and go back to the evidence. Boxall said, "I was taking star bearings for compass error for myself, and was working those out." That was after he worked up the 7:30 position. He wanted to check on the deviation. The standard compass course is what they went by. The variation was known if he had his position, which he had from the 7:30 fix. To find the ship's true course he needed to know the deviation error accurately. That's why he was checking the deviation error by taking star bearings at the standard compass. He knew what the course was called for. He knew the variation for the location they were at. Once an accurate measure of deviation was obtained, or confirmed, he would know the exact magnetic course being steered, and then subtracting the variation, he would get the true course, which he later got and which indicated that they making S86W true, 266°T.
 

Jim Currie

Member
You are being too pedantic, Sam.

When crossing the Atlantic or any other vast stretch of ocean (which I have done many times), you had to keep up your DRs because quite often you might only get the opportunity for sights 2 or three times during the entire trip across.
Apart from any other reason, it was therefore essential that you had a very good idea of the True Course you were making good. Because that was the only course which would give you a fairly accurate DR and a fairly accurate position to which potential rescuers would come to if needed. That meant that you either used the True Course chalked on the Course Board, the calculated course between a Fix and a DR or between the last DR and a Fix or between 2 DRs. In the last case, it was essential that you allowed for influence due to the elements...mainly Leeway and Drift.
The information chalked on the Course Board was not for the exclusive use of the Helmsman. In fact, it was for use of the OOW. I can show you a pic of one of mine if you wish?
Anyway, how do you know what was chalked on Titanic's board?

You obviously do not know very much about Azimuths.

Titanic was swung for Deviation before she left Belfast. At that time, the Compass Adjuster would swing her through the 32 points of the compass, noting the deviation error each time and moving the magnets in the binnacle and the quadrantal spheres to smooth them out as far as was possible.
During that time, the Adjuster would create a Deviation Card. This would be retained on board and used by the Navigators.
In fact, with Titanic (or any other vessel) on a constant heading, the Magnetic Deviation for that heading would not change until the heading was changed appreciably. Only the Magnetic Variation would decrease as the ship progressed westward.
When bearings of a celestial body or objects in line were taken, the True bearing was calculated and compared with the bearing according to the compass used. The result was the error of that compass. The Local Magnetic Variation would be applied to that error to check the Deviation. This was then checked with the Deviation Card. No big deal and in fact, a waste of time in most cases. In the case of Titanic, the Magnetic Variation was changing by about half a degree every 6 hours or so.

Boxhall did not leave the chatroom much before 10 pm and said so:
" I was inside the chart room working up stellar observations from 8 o'clock.
I finished before 10 o'clock, because I gave Mr. Lightoller the results when I finished..After I had worked these observations of Mr. Lightoller's I was taking star bearings for compass error for myself, and was working those out..
I had used that same position two or three times after giving it to the Captain, and that same course I used two or three times after giving it to the Captain as well, between 10 o'clock and the time of the collision, for the purpose of working up stellar deviations."

How long do you think it would have taken for Boxhall to work 4 or probably 5 sextant observations? How long do you think it took to calculate even a single observation? I can tell you now, without fear of contradiction: he would not have left that chartroom until he was ready to, present his findings to the Senior Officer of The Watch and that would not have been before 9-30 pm.

But blowing your smoke away and returning to the problem on hand. Please explain why it is that the "numbers" I drew your attention to do not illustrate very clearly where Boxhall went wrong?

Incidentally. if I am correct, Titanic made good a True course of S 85.45 West between 7-30 pm sights and when she hit the iceberg.
 
Anyway, how do you know what was chalked on Titanic's board?
Lightoller: "The standard course is on a board and the steering compass course is also on a board. Therefore, the quartermaster uses the board that is there for the steering compass. The senior officer of the watch looks to the standard compass board and passes that course along."
 

Jim Currie

Member
Lightoller: "The standard course is on a board and the steering compass course is also on a board. Therefore, the quartermaster uses the board that is there for the steering compass. The senior officer of the watch looks to the standard compass board and passes that course along."
What else do you think was on that board, Sam?

While you think of an answer to that, why don't you address the subject of this thread?
 

Jim Currie

Member
Lightoller: "The standard course is on a board and the steering compass course is also on a board. Therefore, the quartermaster uses the board that is there for the steering compass. The senior officer of the watch looks to the standard compass board and passes that course along."
Let's play your game of se(a)m-antics, Sam.

Lightoller was talking about two boards. The board that was used by The Quartermaster which had the "Course to Steer" on it and the board used by The Senior OOW. which had the Standard Compass Course on it. What else do you think that second board might have had on it?

While you mull over the above, why don't you respond to the theme of the thread?
 
I am intrigue and fascinating how come the cream of the crop officers could of made that 20 mile mistake in the navigation position. After all to those officers this must only another run of the mill crossing which they have done many times before. Not been an navigator myself I properly make mistakes where I put forward another theory!
First I look what do you need for navigation equipment? Compass, Sextant, Chromometer clock, RPM meter of the prop shafts speed.
I see there is four compass are mention! Not to sure why so many? Never less they are all manmade. Any thing manufacture is never 100% accurate. In manufacturing world you must have a tolerance limit + & -.
First the accuracies of the compasses. The worse enemy is iron and has adjusted to compensate for that. I guest the compass accurate is again from the Olympic. Now if not mistaken the deck compass above the lounge has been raised by a further 3 feet in height. Then the deck changes made between the two ships are quite a few. I am now thinking all this changes will have impact on the compasses reading.
Sextant. How do we know the accuracy of this instrument? I see its stored in sturdy wooden box indicating they may be delicate and handle with care. However should the sextant take a knock or dropped. What is used to check the accuracy of the instrument and is the tool to check the sextant accurate too?
Chromometer (Clock). How do we know the accuracy? It may been OK when leaving the factory, but it may have to taken a knock when placed in the ship. Again what is it check against?
The propeller speed is taken of a meter! How do we known the accuracy of the reading?
You might think I am been a bit pedantic here. In my working career I have work with calibration instruments for many years and only know to well what you may think is accuracy, until check against a master gauge can throw up a few surprises!
I also considered is it important this instruments have to synchronise with each other?
I another problem the ship delivery date is delayed due to the Olympic accident with HMS Hawke, then the propeller blade repair were the shuffle of the two ships take place in the Thompson dry dock Belfast in March, this can only add more loss time to complete ship. Are they coming under pressure to get the Titanic up and sailing before any further delays, and cutting corners?
Just my thoughts of the day.
 
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