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Subject: "RE: How was the deck of the compass platform constructed?" Previous topic | Next topic
BruceSun Mar-11-12 06:56 PM
Member since Apr 11th 2003
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#45394, "RE: How was the deck of the compass platform constructed?"
In response to In response to 36
Mon Mar-12-12 01:52 AMby Bruce

          

I decided to spend a little of the free time I don't have to do some basic research on this to qualify what I wrote in my book and what I stated here.

The compass platform was elevated to keep it away from structural steel that would influence it magnetically.

The Standard compass was the "standard" by which the rest of the compasses were adjusted.

The Standard Compass was amidships because that was the location of least magnetic influence brought on by the natural magnetism of the ship as a whole.


How they do it in 2012 is obviously different. Like I told another guy a few years ago; you can only use today's standards as a research guide when understanding pre-WWI civilian marine practices; Be cautious of late 20th (early 21st) century US practices Vs. turn of the 20th Century British practices; They are not always the same, and by all means do not judge these men based on late 20th Century US practices. The other guy I stated this to didn't listen, and ended up costing a lot of people a lot of money and ruined his credibility in Titanica.


Here are your references. I would advise reading these. They explain the mind set during the age of steamships. They are period and a bit earlier references.

And finally a 1911 article on Olympic stating emphatically why the compass platform was raised. Did they need a clear view for taking azimuths? sure, but the main concern was structural steel. Excuse any spelling or grammar errors, I am in a bit of a rush and this is an OCR - good night.

Bruce




The magnetism of ships, and the deviations of the compass, Volume 2, 1869- By United States. Navy Dept. Bureau of Navigation, Sir George Biddell Airy, Frederick John Evans, Benjamin Franklin Greene, Siméon-Denis Poisson, Archibald Smith, Liverpool Compass Committee, United States. Hydrographic Office


Shipyard practice as applied to warship construction, 1911- By Neil J. McDermaid

Proceedings of the Royal Society of London, Volume 14, 1905

Extracted from the Queen's Regulations and the Admiralty Instructions for the government of Her Majesty's Naval Service.

"No iron of any kind is to be placed nor to remain within the distance of seven feet of the binnacle or standard compasses, when it is practicable, according to the size and construction of the vessel, to remove it; and mixed metal or copper is to be substituted for iron in the bolts, keys, and dowels, in the scarphs of beams, coamings, and head-ledges, and also the hoops of the gaffs and booms and belaying-pins which come within the distance of seven feet of the compasses.

"The spindle and knees of the steering-wheels which come within the distance of seven feet of the compasses are also to be of mixed metal.

"Iron tillers, which work forward from the rudder-head, are not to range within seven feet of the compasses; and in vessels which have iron tillers working abaft the rudder-head, the binnacles are to be placed as far forward from the wheel as may be convenient for the helmsman to steer by.

"The boats' iron davits are to be placed as far as may be practicable and convenient from the compasses.

"All vertical iron stanchions, such as those for the support of the deck, or for the awnings, &c., and likewise the arm-stands, are to be kept beyond the distance of fourteen feet from the compasses in use, so far as the size of the vessel will admit.

"The binnacles for the steering-compasses are to be constructed upon a given plan, with tops made to take off; and in order to prevent improper materials from being deposited therein, they are not to be fitted with doors.

"For the better preservation of the compasses, in every ship a closet is to be constructed in a dry place, sufficiently large for the reception of the ship's establishment of compasses, and it is to be appropriated to that purpose exclusively, the key being kept by the Masters; and in order that the spare compass-cards may never be kept with poles of the same name nearest to each other, cases are supplied which will prevent the possibility of their being packed improperly.

"All ships are to be swung before sailing from the port where they fit out, and subsequently once in each year, for the purpose of ascertaining the errors of the compasses, also immediately on their arrival on a Foreign Station; or if there has been any great change in the ship's geographical position since the errors were observed."


Appendix II.

Suggested Rules relating to the Compasses of Iron Merchant Ships.

"1. It is deemed a necessary equipment for every iron ship to be fitted with a Standard or navigating compass, in addition to one or more compasses for the use of the helmsman.


"2. That so far as the requirements of the ship will permit, special arrangements be made in the course of construction for preparing a place for this compass.

"3. That the Steering-Compasses being subordinate in importance to the Standard Compass, less strict precautions are required for their position but it would in all cases be desirable that these compasses (and of necessity the steering-wheel) should not be placed within half the breadth of the ship from the stern-post, rudder-head, and screw-well.

"4. The Standard Compass to be placed at such a height from the deck (not less in any case than five feet) as to command a clear view of the horizon above the bulwarks, and to be out of the way of the sails, booms, etc.

"5. In ships built with their heads near the north, the Standard Compass to be placed as far forward as the requirements of the ship will permit. In ships built with their heads near the south, this compass to be placed as near the stern as convenient, subject to the condition that it should not be within half the breadth of the ship from the rudder-head, stern-post, or screw-well.

"In ships built near east and west, this compass should not be placed near either extreme of the ship.

Most of the steamers built by Harland and Wolff were constructed with their bows facing S/E which would mean the sweat spot was near the middle. The centerline amidships of 400-01-33 etc. was the “sweet spot” for the Standard Compass. Read the references above if you don’t believe me.

"6. The Standard Compass to be as far as possible, and not less than ten feet, from the end of any elongated mass of iron, especially if vertical, such as iron stanchions, capstan-spindles, steam- and stove-funnels, ventilating-shafts, etc.; and no iron, subject to occasional removal, should be placed within fifteen feet of the Standard Compass, either on the same deck or below it.


"7. The Standard Compass to be placed as far as possible from transverse iron bulkheads.


"8. It would be an extremely desirable arrangement for the deck immediately below the Standard Compass not to be of iron, but to be filled up with wood for a space which may be called the compass platform. This space should not be of less width than a hatchway (4 to 6 feet), and of as great length fore and aft as convenient, but the length not to be less than the width. No transverse iron dock beams to be under the platform, but if necessary fore-and-aft iron stringers, on which the transverse beams outside the wooden surface may abut.

"9. It would be a desirable arrangement, as far as could be carried out, that no masses of iron, such as boilers, tanks, bulkheads, should be placed immediately below the compass, or within 55° of the vertical line through the center (the angle being drawn from the compass as center to the center of the mass).

"10. -Where the Standard Compass is placed on a bridge, the foregoing requirements should be, as far as possible, complied with, the bridge should be of wood, and should not have iron stanchions, or rails (especially if covered with brass) within 10 feet."


The following Rules are applicable to Steering-Compasses.

"1. Not to be within half the width of the ship from the stern-post, rudder-head, or screw-well.

"2. The spindle of the steering-wheel and the forward support in which it works, not to be of iron.

"3. Iron tillers working forward from the rudder-head not to range within six to seven feet of the steering-compass.

"4. Not to be near the upper (or lower) end of elongated masses of iron, especially if vertical, such as steam- and stove-funnels, capstan spindles, etc., and to be as far as possible from any transverse iron bulkhead."

Special Points for the consideration of the Naval Architect.

"1. When arrangements are made for the compasses to be placed in the after part of the ship, building the vessel head north would ensure exaggerated errors both when upright and heeling.

"-With building-slips in a meridional direction, and with the above arrangements, it would be desirable to build the ship head to the south.

"2. Every iron ship after launching, and during the process of first equipment, should as much as possible be kept in a position opposite to that she occupied on the building-slip."







  

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How was the deck of the compass platform constructed? [View all] , Art Braunschweiger, Wed Mar-07-12 05:39 AM
  RE: How was the deck of the compass platform constructed?, Jonathan, Mar 07th 2012, #1
RE: How was the deck of the compass platform constructed?, Art Braunschweiger, Mar 07th 2012, #2
      RE: How was the deck of the compass platform constructed?, bpread, Mar 07th 2012, #3
           RE: How was the deck of the compass platform constructed?, sharktrainer, Mar 08th 2012, #4
                RE: How was the deck of the compass platform constructed?, Art Braunschweiger, Mar 08th 2012, #5
                     RE: How was the deck of the compass platform constructed?, bpread, Mar 08th 2012, #6
                     RE: How was the deck of the compass platform constructed?, Art Braunschweiger, Mar 08th 2012, #7
                     RE: How was the deck of the compass platform constructed?, sharktrainer, Mar 08th 2012, #8
                          RE: How was the deck of the compass platform constructed?, bpread, Mar 08th 2012, #9
                          RE: How was the deck of the compass platform constructed?, Art Braunschweiger, Mar 08th 2012, #10
                               RE: How was the deck of the compass platform constructed?, sharktrainer, Mar 09th 2012, #11
                                    RE: How was the deck of the compass platform constructed?, Art Braunschweiger, Mar 09th 2012, #12
                                    RE: How was the deck of the compass platform constructed?, sharktrainer, Mar 09th 2012, #13
                                         Here's the real deal, bpread, Mar 09th 2012, #14
                                              RE: Here's the real deal, sharktrainer, Mar 09th 2012, #15
                                              RE: Here's the real deal, Scott Andrews, Mar 09th 2012, #20
                                              RE: Here's the real deal, sharktrainer, Mar 09th 2012, #16
                                                   RE: Here's the real deal, jds88, Mar 09th 2012, #17
                                                   RE: Here's the real deal, Art Braunschweiger, Mar 09th 2012, #18
                                                        RE: Here's the real deal, Jonathan, Mar 09th 2012, #19
                                                             RE: Here's the real deal, sharktrainer, Mar 10th 2012, #21
                                                                  RE: Here's the real deal, Art Braunschweiger, Mar 10th 2012, #22
                                                                       RE: Here's the real deal, sharktrainer, Mar 10th 2012, #23
                                                                            RE: Here's the real deal, Art Braunschweiger, Mar 10th 2012, #24
                                                                                 RE: Here's the real deal, sharktrainer, Mar 10th 2012, #26
                                                                                 RE: Here's the real deal, bpread, Mar 10th 2012, #27
                                    RE: How was the deck of the compass platform constructed?, Bruce, Mar 10th 2012, #25
                                         RE: How was the deck of the compass platform constructed?, Art Braunschweiger, Mar 10th 2012, #28
                                              RE: How was the deck of the compass platform constructed?, bpread, Mar 11th 2012, #29
                                              RE: How was the deck of the compass platform constructed?, Art Braunschweiger, Mar 11th 2012, #30
                                              RE: How was the deck of the compass platform constructed?, Bruce, Mar 11th 2012, #31
                                              RE: How was the deck of the compass platform constructed?, sharktrainer, Mar 11th 2012, #32
                                                   RE: How was the deck of the compass platform constructed?, sharktrainer, Mar 11th 2012, #33
                                                        nm, Bruce, Mar 11th 2012, #35
                                                             nm, sharktrainer, Mar 11th 2012, #36
                                                                  RE: How was the deck of the compass platform constructed?, Bruce, Mar 11th 2012 #37
                                              RE: How was the deck of the compass platform constructed?, sharktrainer, Mar 11th 2012, #34
                                                   RE: How was the deck of the compass platform constructed?, Jonathan, Mar 12th 2012, #38
                                                        RE: How was the deck of the compass platform constructed?, c riley, Mar 12th 2012, #39

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