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Why Was SOS Position 20 Miles From Wreck?

Discussion in 'Collision / Sinking Theories' started by Doug Criner, Aug 20, 2010.

  1. Doug Criner

    Doug Criner Member

    Sam Halpern and Jim Currie have been discussing Californian's navigation here: https://www.encyclopedia-titanica.org/discus/messages/5666/206491.html?1282264325

    There are a few miles' inconsistency or uncertainty in Capt. Lord's reported positions, many of which are by dead reckoning. I have been told that expecting additional star shots by Californian is a bit unrealistic for a "tramp steamer" with limited number of officers, etc. - unlike a big ocean liner that could afford the luxury of more frequent and precise fixes.

    OK, forget Californian. How then do we explain Titanic's SOS position being 20 miles or so from the wreck site? Probably this has been discussed before, so maybe just refer me to that thread.

    Thanks. Doug
     
  2. Hello Doug,

    You may want to start HERE then part-2 HERE.
     
  3. Doug Criner

    Doug Criner Member

    OK, Sam, that article was very helpful. I'll want to reread it again.

    A couple of thoughts. It seems Titanic may have made more mistakes in navigation on Sunday, even with a round of evening star shots and a slew of officers, than did Californian with possibly just a single shot of Polaris.

    My experience with celestial navigation is far from fresh - and was in the navy, not merchant ships. I noted several things in your article where Titanic's practices differed from my memory of my own experience.

    Titanic's star shots were taken by the senior officer on deck, and then the data passed off to some "Junior George" officer to work out the fix. Then if the junior officer didn't complete working out the sights before going off watch, he'd palm off the job to the oncoming watch. I think this approach could easily lead to mistakes.

    On my first ship, there was one officer designated as navigator. He stood no watches since he was busy at various hours of the day and night taking sights, working out fixes, laying out courses, etc. He had a quartermaster assigned to him who served as his regular assistant.

    The navigator personally took all the star sights. The quartermaster would record the star names and the times at the "mark." The navigator
    (not the quartermaster) would then read the sextant's altitude and the quartermaster would record it.

    I may be wrong here, but my recollection is that the quartermaster would synchronize the stop watch with the ship's chronometer, including corrections, before the sights were taken (not after as on Titanic).

    The navigator personally worked up the star sights while his quartermaster would perhaps keep up logs, compute DR positions, and maintain the plot. So navigation was the responsibility of the same two men. Maybe this was all overkill 50 years ago, with radar, etc. But Titanic's practices in 1912 (which I assume were typical) would have scared the he!! out of me - with no radar and only primitive radio communications.

    It's surprising to me that Capt. Smith would personally work up a DR position (possibly in error) as his ship was sinking. OK, seemingly no officer was designated as navigator, but I'd think the captain, distracted as he must have been, would have directed a trusted officer to work up the DR for the SOS. Certainly he knew how to do it, but would Capt. Smith have routinely worked up DR positions? (The captain of my little 2100-ton destroyer certainly didn't.)

    But, if your article is correct, the first error was made in the evening star shots (upon which the SOS DR was based). So, even if Capt. Smith, in haste, hadn't compounded the problem with another error of his own, his DR would have been mistaken.

    So, given your article's description of Titanic's procedures, Yes I can well visualize mistakes being made.

    Doug
     
  4. Doug,

    The procedure used on Titanic was described in detail by Boxhall. As far as Smith working up the first CQD position, that does not surprise me. Rostron said it was he who worked out the course to the SOS position when he was informed about it. And Capt. Moore of the Mount temple said essentially the same. I guess some things a Capt. just won't delegate especially if it was not just routine. Even Stewart of the Californian said it was Capt. Lord who worked up their stopped DR.
     
  5. >>I guess some things a Capt. just won't delegate especially if it was not just routine.<<

    For whatever it may be worth...and that may be "Not Much"...I suspect that Captain Smith was trying to at least get a quick and dirty ballpark figure so that rescue ships would have some idea of where to go. It didn't have to be accurate down to the very last micromillimetre. It just had to be close enough to get everybody going in the right direction.
     
  6. It must be pointed out that Titanic did not send just ONE distress position.

    The ship sent TWO positions.

    Any discussion of the "wrongness" of Titanic's distress "position" in the singular is simply historic tomfoolery. To understand what was happening on the ship's bridge it is necessary to determine why the two positions were sent and their relationships to each other as well as the rest of the navigational data.

    Based on simple time-speed-distance dead reckoning the first position given by Captain Smith to the Marconi operators was the ship's predicted midnight location.

    (Remember, "midnight" does not mean April 14th, but rather the meridian on which ships date/time April 15th would begin.)

    Why would Captain Smith choose the ship's predicted midnight position? You'll have to ask him. However, lacking his answer the logical assumption (with all the dangers of an assumption) is that the midnight coordinates were "to hand." And, on the clock he checked it was about midnight.

    Smith obviously realized one truth which escapes many armchair navigators. In a distress situation it is best to get ships heading in your general direction as early as possible. Dead-nuts accuracy is far less important than having potential rescue vessels within visual contact. No rescuer steams blindly to a set of coordinates when he can see the sinking ship.

    So, Smith did the most seamanlike thing he could do at the moment -- send a reasonably close position to get potential rescue ships heading toward Titanic.

    What about the second set of CQD coordinates? Once again, simple time-speed-distance yields the obvious. Boxhall did not gin up a new set of coordinates because he was a nice guy. He would only have done so on orders from Captain Smith. If Smith told him that the initial CQD position was for "midnight;" and to "back up" the position to 11:30, what would Boxhall have done?

    (Note: here is where the "mistake" took place. The Captain and Boxhall did not fully communicate what was needed. Boxhall had just returned from two visits into the damaged bow, so was not situationally aware. Smith should have been more specific, even "talking down" to Boxhall to make sure everything was understood. However, that may have been impossible because steam had just begun roaring out of funnel #1 and speech was at best difficult.)

    The answer is easy. He would have gone 20 minutes on the ship's reciprocal course to develop a dead reckoning position for 11:40. Unfortunately, however, that would not have been 11:40 p.m. based on noon, April 14th. Rather it would have been 11:40 p.m. based on the next day's predicted noon, April 15th.

    And, if you measure, the Smith's original CQD coordinates are within 1912 navigation precision exactly 20 minutes of steaming at 22 knots (the speed Boxhall said he used) away from Boxhall's more famous coordinates.

    One more thing -- the course between Smith and Bohall is 075/255 with 155 representing the direction toward North America. Why would Boxhall have used a 075/255 line to move his "corrected" position 20 minutes from Smith's initial CQD?

    Again, we have to make assumptions based on the usual and customary practice of navigation. Two positions at which a ship claimed to be located are diagnostic of a line of position. In this case, a line of position that would also represent the ship's course -- or, at least the course Boxhall believed it was steering: 255.

    We know the ship should have been steering within reason a course of 266. Subtracting 255 from 266 yields 11 degres, which is as close as could be steered to one compas point difference. (Titanic's compass could only be read accurately to 1/2 a degree. A compass "point" is 1/32nd of 360 degrees or 11 1/4 deg.) So, it would appear that Boxhall believed that Titanic had turned left (requiring starboard helm in 1912 parlance) one compass point from its 266 course.

    If Boxhall's navigation shows a course change to the left, when would it have been made?

    When Boxhall's 075 reciprocal line is extended back in time, and if the ship's 266 course line is extended forward from "The Corner," something curious happens. The two lines cross at 11 hours 30 minutes past noon, April 14th.

    When two lines of position that also happen to be course lines cross, it is a pretty safe bet that crossing indicates a course change. So, it is quite reasonable to impute that at 11:30 p.m. April 14th time Titanic changed course and began to steam south of its intended track.

    Why would Captain Smith have changed course at 11:30 p.m. April 14th? (No other human being on the planet had the authority to change Titanic's course, so we know Smith ordered it.)

    The answer has to be that Smith believed the safety of his ship demanded a change from the 266 course. And, in mid-ocean, what would have prompted that change of course?

    Ice.

    So, from the two (not one) CQD positions we are able to deduce that the story of Titanic steaming blindly into the night and crashing headlong into an iceberg is little more than balderdash.

    Hard navigational evidence in the form of lat/lon coordinates sent from Titanic indicate Captain Smith not only knew about the ice that night, but took action at 11:30 p.m. April 14th 1912 to avoid it.

    -- David G. Brown
     
  7. Hello David, nice to see you have joined the discussion. It's been a while.

    Some people believe the first set of coordinates were transmission errors that were corrected 10 minutes after. I don't. Like you, I believe it was worked up by Capt. Smith and given to Phillips. Bride even mentioned that it was the Captain who gave them the ship's position. But where I disagree with you is where you believe Smith told Boxhall to back his coordinates by 20 minutes of steaming. Smith could have done that in his head, he didn't need a J/O to do that for him.

    >>Hard navigational evidence in the form of lat/lon coordinates sent from Titanic indicate Captain Smith not only knew about the ice that night, but took action at 11:30 p.m. April 14th 1912 to avoid it.<<

    Yes, Smith knew about ice that night, but why wait to 11:30 if he wanted to avoid it? The only thing "hard" about the evidence of the two sets of coordinates transmitted were that both were transmitted as distress coordinates from the ship. They were worked up by two different individuals, and you are trying to infer some unsupported course change by drawing a line between them. There is ZERO evidence for the assumption that you are making that a course change was made at 11:30. The evidence available is that the course being steered had not change after the ship "turned the corner" at 5:50. The course by steering compass was given as N71W, the same course handed over to Olliver at 8 and to Hichens at 10.

    But we've been through all of this before.
     
  8. >>Hello David, nice to see you have joined the discussion. <<

    I'll second that. Beyond that, since I am in no sense a navigator, I'll sit back and watch in the hope that I might learn something.
     
  9. Doug Criner

    Doug Criner Member

    "I suspect that Captain Smith was trying to at least get a quick and dirty ballpark figure so that rescue ships would have some idea of where to go. It didn't have to be accurate down to the very last micromillimetre."

    They were off by about 20 miles (an hour's worth of steaming). "Quick and dirty" doesn't, in my opinion, fall within that error. I think there must be other explanations.
     
  10. >>They were off by about 20 miles (an hour's worth of steaming). "Quick and dirty" doesn't, in my opinion, fall within that error.<<

    They didn't know this with certainty at the time and the ship was sinking. It wasn't perfect but at least it gave anybody within radio range...who was listening...a general idea of where they were. When you're in trouble, that counts for a lot. That they refined the figure does tell that the possibility of error at least occured to them.

    >>I think there must be other explanations.<<

    I think Occam's Razor (Least hypothosis) applies here. A misjudged figure, a slip of a decimal point...trivial errors can add up to a lot. I'm sure you've seen that happen and at times when your own ship was not in extremis.
     
  11. Hello everybody

    "They didn't know this with certainty at the time and the ship was sinking. It wasn't perfect but at least it gave anybody within radio range...who was listening...a general idea of where they were. When you're in trouble, that counts for a lot."

    Even when you have a general idea of where a sinking liner is, it might be quite difficult to spot its actual position. Besides, I am pretty sure that Captain Smith wanted to make clear where the Titanic was, since he already knew about the extent of the damage and the lack of lifeboats.
     
  12. >>Even when you have a general idea of where a sinking liner is, it might be quite difficult to spot its actual position. <<

    Hence the reason for the revised position. It was still off but by good fortune, was good enough to get the Carpathia where she needed to be.
     
  13. Quick and dirty would be fine as long as it doesn't send someone off searching in the wrong direction, where they later find out that they have to turn around and go in the other direction. 10 minutes off in the wrong direction puts you 20 minutes further away from reaching your target. Folks, backing a position by 20 minutes steaming at 22 knots is something Smith could easily do in his head especially since the ship was heading almost due west to begin with.
     
    Robert T. Paige likes this.
  14. Jim Currie

    Jim Currie Member

    Navigators! Answer this question:

    Smith worked his DR. As Sam says, he could work 20 minutes in his head. He could have made a mistake even then. However the main point is that a mistake was made.

    Now, to work a DR (Dead Reckoning) position as all navigators know, you need a starting point.
    If the maths was correct then by elimination, the starting point must have been wrong.

    There's four basic kinds of 'starting point':

    1. An earlier DR plotted on a chart.

    2. An earlier DR in the form of written down co-ordinates

    3. An earlier Fix plotted on a chart from
    a.celestial observation
    or
    b.by reference to points on the chart.

    4. An earlier fix in the form of written down co-ordinates resulting from a and or b.in the previous method.

    Where did Smith start from?

    Incidentally a 20 mile too far error in terms of difference in longitude at latitude 42 degrees north is 27 minutes of longitude too far west.

    Doug et al:

    Smith gave 50-25W as his CQD longitude. Subtract 27 minutes from this and you get a longitude of 49 degrees,58 minutes west. The longitude of the wreck site is so close to this that since Smith was working a DR, the difference is of no consequence.
     
  15. I follow with some interest the discussion here on navigation aboard Titanic. My expertise is as a USN ships navigator in the 1960's- some 50 years after the disaster. Celestial navigation has progressed but the basics are the same. Granted, the tools provided enable a rational, scientific approach to determining position. In my opinion however, the process is as much art as science. As with many situations the Devil is in the details.
    All along the process there is potential for error. Once a great circle route has been laid out, the navigator has, subject to cloud cover, three sightings every 24 hours to compare his determined position with that which has been estimated and plotted on the master chart. Two are celestial- the first 1/2 hour before sunrise and a second 15 minutes after sunset- maximizing star brightness with a visible horizon. The third siting, taken at local apparent noon, provides for latitude only. Each of these sightings contain potential errors. Misreadings due to weather conditions-heavy seas or partial cloud cover, misidentification of stars selected for measure, providing wrong times between individual recordings, not properly conveying ships chronometer time to the navigators stop watch and just plain carelessness. I would suggest that stating a position as "exact" at any given time during this process should be labeled as conditional. Most mistakes can be corrected by subsequent sightings. This caveat was recognized by all commanding officers that I had contact with. Their main concern was "are we ahead or behind -and by how much" Their need for this information became more critical as we approached our destination. The mantra became "Mr. Gwinn, course and speed to station!"
    In 1960 I headed a department that consisted of two very professional quartermaster Petty Officers and two seaman. We were very good at what we did but had no illusions about any individual positioning report. The knowledge that we started every siting from a dead reckoning position that may have been faulty to begin with and also, that our current evaluation could contain mistakes kept us very humble. A siting that resulted in a bulls-eye triangulation on our charts rated it being tacked up on the chart house bulletin board! It didn't happen every time. The saving grace was that we had another chance the next time out.
    I can only imagine about what Titanic's officers thought about when reporting to Smith on these interim positioning evaluations. Could they have reacted the same way I did? I could correct any mistake within the next few hours. The unfortunate fact for these men was that what they thought was an interim report was their final report and it was critical that they had it right. I find it remarkable that the Carpathia did as well as it did in their rescue attempt.
     
  16. What could possibly have occurred to motivate Capt. Smith out of his lethargy to order a course change at 11:30 pm (April 14)? There would've been one thing only that could've stopped Smith's mad dash to New York that night--

    Phillips---sometime before 11:30---must've finally got around to delivering the vital Mesaba ice warning---if anything could galvanize Smith into action that night, well, that would've been it!

    Yet none of this explains the good points Doug raised earlier: a 20 mile discrepancy? . . . all right, most of us could accept an error of a half-mile, or 1 or 2 miles . . . however, when we get to 5, or 10, or 15, or more miles---there is something very seriously wrong . . .

    And, as Jim Currie points out (and especially with his wonderful maps and charts), why was the Californian south of the Boston track, and getting even more souther?

    Why would these two ships be so close? The New York and Boston tracks were separated by at least 30 miles . . . ?

    And why was Smith himself heading directly into an ice zone? Okay, perhaps the message arrived and as David figured out he did finally alter course, in a late attempt to avoid what he already knew to be there . . . ?

    Most intriguing all this . . . yes, most intriguing . . . both ships had the same owner . . .
     
  17. >>Most intriguing all this . . . yes, most intriguing . . . both ships had the same owner . . .<<

    Why would this be of any consequence whatsoever? IMM was much like a lot of the other trusts of the day in that it tried to gobble up as many shipping lines as it could. They were hardly the only ones playing this game but they are...today...the most notorious.

    Take a look at modern business practices and you'll see that very little has changed.
     
  18. IMM did not control the Leyland Line. A number of shares were owned outside of IMM. The Leyland Line has its own general manager and its own board of directors. And they had their own set of regulation which differed somewhat from what other IMM shipping companies used.
     
  19. >>Most intriguing all this . . . yes, most intriguing . . . both ships had the same owner . . .<<

    Sounds somehow like the Gardiner fiction!
     
  20. Georges G.

    Georges G. Member

    «Why Was SOS Position 20 Miles From Wreck

    But the time on the chronometer is really 11:06:52, not 11:07:52. A mistake that is very easily made if one is not being very careful. The result of such an error is an advancement in GMT time by exactly 1 minute. A result that would shift the lines of position for all star sights by 15 minutes-of-arc to the west.

    From the work presented in this article, we see how a simple 1 minute error in reading the time difference between a hack watch and the time on a chronometer can offset a set of star sights by 15 minutes-of-arc. This type of systematic error would tend to go unnoticed since all sights would be affected exactly the same way.»


    The problem I have with the theory is if a mistake was done while reading the chronometer, that error would not go so unnoticed, even if all sights or celestial coordinates (GHAϒ, SHA¤, & Declination) would be affected exactly the same way, because the stars GP Position would not then correspond to the erroneous time. Thence, the LOP (Lines of Positions) linked to their own Azimuth would form an evident and apparent Cocked Hat. Wright or wrong?

    lops10.png