Turning the corner

[Paul Lee]

I seem to recall a discussion taking place about this, but can't quite find it at the moment....anyway....

Pitman reaclled that the Titanic changed course at 5.50pm on Sunday April 14th...however, in London, he went further and said that he though that the ship should have turned earlier, at 5.00pm. To his mind, the late course change amounted to an extra 10 miles south.

However, this can't be true, can it? The location of the wrecksite shows that the Titanic was more or less on course....10 extra miles south would indicate that, for the wreck to be found in 44 degrees N, the current must have been to the northward at some point, which I find difficult to believe.

Am I barking up the wrong tree, or was this just a mental lapse of concentration on Pitman's part, or did he give wrong information for a reason?

Cheers

Paul

 

[Dave Gittins]

Paul you are barking up the right tree. Lord Mersey's assessors worked out in 1912 that the turn was not delayed on account of ice. What they didn't spell out was that the 'delay' was due only to the inherent errors in navigation 1912 style.

Pitman, Boxhall and Rowe thought the turn was due at 5-00 p.m, but they can't have been thinking much about it. How did they think Titanic was going to do 126 miles in 5 hours? You can fiddle with clock settings all you like, but Titanic could not reach the 'corner' by 5-00 p.m., however you work it.

The men navigating as they approached the 'corner' were Smith, Wilde and Moody. Smith tried to turn as near as possible to the 'corner', using a longitude sight taken by Wilde and/or Moody, plus some dead reckoning from the noon latitude. He got it pretty right, though the data is not good enough to say precisely what he did.

The supposed delayed turn suited lawyers for White Star. They wanted to show that Smith had taken special care. Actually he did nothing unusual at all.

 

[Samuel Halpern]

Paul, Dave is absolutely correct. There was no delayed turn of the corner. So how did that story come about?

The 5:00 PM arrival at the corner that 3/O Pitman came up with was ridiculous, requiring a speed over ground in excess of 25 knots. And Pitman was careful not to say what the distance from noon to the corner was, and did say that the alter course point was not marked on the chart. Apparently the BOT assessors didn’t pick up on this. They easily could have calculated the distance from noon to the cornar by subtracting the daily runs from the total distance from Daunt Rock to the corner.

The reason for coming up with the delayed turn story goes back to the CQD position of Boxhall. If they changed course at the corner at 5:50 PM, they would have had to be going at speed of about 24.6 knots to reach Boxhall’s CQD position which is 145.7 nautical miles from the corner. They needed a reason to increase the mileage between the corner and Boxhall’s CQD position to get the speed of the ship over ground down to the more reasonable value of 22 knots as assumed by Boxhall. They need 130.5 miles to go from the alter course point, not 145.7. Since they all believed Boxhall’s position was correct, they had to assume the corner was passed much earlier than 5:50 PM, and that they then altered the course at 5:50 PM when the ship was about 15 miles SW of the corner.

Cheers,