How Far South did the Titanic Reach?

Mar 12, 2011
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I want to go back to Markus's post from the 23rd re : the course made good after turning the corner. I've done the figures myself and I think I broadly agree with him, the course made good was 265, not 266. Thanks to Sam, by the way, for helping me understand how these calculations are made.

Starting from a noon position of 43°02'N 44°31 (126 NM from The Corner @ 60.5°T), 5h50m of steaming at 22 knots at 240.5°T gets us to an actual turning point of
41°59′N, 47°03′W, an overshoot of 2.33 miles. From there, I assume a travel time of an additional 5h50m to get us to 11:40pm. On a course of 266°T at 22 knots, that gets us to
41°50′N 49°52′W. 22.5 knots gets us to 41°49N 49°56′W. Both longitudes are fairly close to the longitude of the wreck sight, but the latitude doesn't work out. A course of 265°T for 5h50m at 22 knots gets us to 41°47.6'N 49°51.7'W, while 22.5 knots gets us to 41°47.3'N 49°55.6'W, which is very close in both latitude and longitude. Of course, the math works out differently if you assume Titanic overshot the corner by a greater or lesser distance, or if you believe a clock setback had taken place before the collision (I remain unconvinced, personally).
 
Mar 22, 2003
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Chicago, IL, USA
Boxhall determined the ship's heading after taking stellar bearings to check the compass deviation. That was after he had calculated the 7:30pm fix.
"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. That is what kept me in the chart room most of the time. I was making computations most of the time."

Lightoller also mentions that the course S86W (266T) was given to him later on:
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.
 
Mar 22, 2003
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Better than any log reading would have been a longitude by chronometer, which ideally would have been taken close to 5:30pm when the sun was on the prime vertical in the west. Unfortunately, nothing of that was ever mentioned, so we have way of knowing if they did that or not.

A lot of suppositions in post #131 above. For me the major problem is the assumption that the log averaged 41.9 miles every two hours from noon to 5:50pm yet averaged 45 miles in two hours from 8 to 10pm all the while running at an average of 75 revolutions per minute.
 

Jim Currie

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Apr 16, 2008
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Funchal. Madeira
David, you wrote: "The ways of 1912 navigation were not those of 1962 or even 2002. The people of Titanic's time were just figuring out how to organize the timekeeping systems we think of as "natural."
Sorry David but that's simply not true. The same systems were in use right up until 1980 and beyond. I used them.
Celtic 2.jpg


The above layout is that of a WSL Scrap Log. When it was filled-in, Celtic was an AMC...an Armed Merchant Cruiser... the same as two of my old ships which were AMCs during WW2. We used exactly the same layout up to 1980.
The personnel would all be WSL employees 99% of whom would be ex RN or serving RNR ratings and officers. The crew was supplemented by weapons operators from the regular Navy. However the important part of the above is the way the Log Book was filled-in. Except for military manoeuvres, it was filled-in in exactly the same way as it was during peace-time. In the same way as I and every other Cadet and Apprentice was taught before 1939 and up until at least 1980.
Note the times of compass checks... i.e. when a compass deviation was calculated...every 4 hours by the sun during daylight hours. At dusk when evening sights were taken and by star or planet at regular intervals thereafter as conditions permitted.
I think you misinterpret the WSL Rules, David regarding compass checks. In my day, there were two types of check. The first was a cursary one whereby the OOW checked the quality of the steering. As all of us knew, even the best helmsman was not above being distracted by thoughts of home or even briefly 'nodding-off'. Consequently, every so often through the Watch, the OOW would lean in front of the helmsman and make sure he was right on course. If he did not do so at regular intervals, the ship could wander off course for quite a while before corrective action could be taken. Half an hour would be just about right. A proper Compass Check like the one you desctibe would only be necessary after the exact compass error was determined. It would only be effective after that time. It was done by establishing the deviation using the pelorus and the Standard Compass. At that moment, since magnetic Variation would be known, the total error of the standard compass was established. Thereafter comparisons would be made with the steering compass. Not long after Titanic, the standard and steering compasses were one and the same.

As for when the clocks were adjusted; the method was to note the entire change on the last line of the first half of the Navigation Day. The method of sharing would be determined by the manning of the bridge, i.e., 3 mate or Multi-Mate.
As with Titanic. the above page simply records all that happened during the 14th day of a specific month. It is the two haves of two stories: (1): How the ship was navigated for the second half of the previous Navigation
day and (2) How it was navigated for the first half of the current Navigation Day. It tells us that there was a plan to adjust the clock by 9 minutes between Navigation Day Noon 14 and Navigation Day Noon 15. However it does not explain the method, if any, as to how that change would be shared between the night Watches. The above page deals with sailing west and therefore retarding the clock. The next page shows how Celtic dealt with clock changes sailing east. Note that when notations were made about a clock change, they were made on the last line of the Calendar day.

Celtic 3.jpg