Freedom From Checking Deviation

A Ship of the Line, the dreadnought of former days.Freedom From Checking DeviationEach time a com­pass is com­pen­sa­ted it is nec­es­sary to check the com­pen­sa­tion by check­ing the dev­i­a­tion on var­ious head­ings. This may be done by the use of de­flec­tor mag­nets. A more exact method is to swing the ship in a circle while bear­ings are taken of a known object on land and the dev­i­a­tion noted on var­ious head­ings. The sun is often taken as a ref­er­ence point for this pur­pose.It is never nec­es­sary to swing ship or to cor­rect the Gyro-Com­pass for eith­er var­i­a­tion or dev­i­a­tion of any kind. Where a Gyro-Com­pass and a mag­netic com­pass are both used on a ship, the ship may be swung to cor­rect the mag­net­ic com­pass—the Gy­ro-Com­pass fur­nish­ing true head­ings. The time re­quired is thereby ma­ter­i­ally short­ened.Influences Due to Magnetism of the ShipWhen a steel ship is build­ing a sub­per­ma­nent mag­ne­tism is in­duced in its keel, hull, and plates. It causes a com­pass dev­i­a­tion classed as “semi­cir­cu­lar.” This dev­i­a­tion must be com­pen­sat­ed for.As a ship moves through the earth’s mag­ne­tic fields in its vary­ing quan­ti­ties and dir­ec­tions, a tem­por­ary and varying mag­ne­tism is in­duced in the soft iron of the ship. The re­sul­tant dev­i­a­tion is classed as “quad­ran­tal,” and must be com­pen­sat­ed for.The Sper­ry is not a Mag­ne­tic Com­pass. Ham­mer­ing, riv­e­ting, and mov­ing through mag­netic fields may in­duce mag­ne­tism in the ship, but will have no ef­fect upon the Sper­ry Gyro-Com­pass.There is no con­di­tion of the ship or cargo for which the Gyro-Com­pass must be cor­rec­ted.

A Ship of the Line, the dreadnought of former days.

A Ship of the Line, the dreadnought of former days.

Freedom From Checking DeviationEach time a com­pass is com­pen­sa­ted it is nec­es­sary to check the com­pen­sa­tion by check­ing the dev­i­a­tion on var­ious head­ings. This may be done by the use of de­flec­tor mag­nets. A more exact method is to swing the ship in a circle while bear­ings are taken of a known object on land and the dev­i­a­tion noted on var­ious head­ings. The sun is often taken as a ref­er­ence point for this pur­pose.It is never nec­es­sary to swing ship or to cor­rect the Gyro-Com­pass for eith­er var­i­a­tion or dev­i­a­tion of any kind. Where a Gyro-Com­pass and a mag­netic com­pass are both used on a ship, the ship may be swung to cor­rect the mag­net­ic com­pass—the Gy­ro-Com­pass fur­nish­ing true head­ings. The time re­quired is thereby ma­ter­i­ally short­ened.

Each time a com­pass is com­pen­sa­ted it is nec­es­sary to check the com­pen­sa­tion by check­ing the dev­i­a­tion on var­ious head­ings. This may be done by the use of de­flec­tor mag­nets. A more exact method is to swing the ship in a circle while bear­ings are taken of a known object on land and the dev­i­a­tion noted on var­ious head­ings. The sun is often taken as a ref­er­ence point for this pur­pose.It is never nec­es­sary to swing ship or to cor­rect the Gyro-Com­pass for eith­er var­i­a­tion or dev­i­a­tion of any kind. Where a Gyro-Com­pass and a mag­netic com­pass are both used on a ship, the ship may be swung to cor­rect the mag­net­ic com­pass—the Gy­ro-Com­pass fur­nish­ing true head­ings. The time re­quired is thereby ma­ter­i­ally short­ened.

Each time a com­pass is com­pen­sa­ted it is nec­es­sary to check the com­pen­sa­tion by check­ing the dev­i­a­tion on var­ious head­ings. This may be done by the use of de­flec­tor mag­nets. A more exact method is to swing the ship in a circle while bear­ings are taken of a known object on land and the dev­i­a­tion noted on var­ious head­ings. The sun is often taken as a ref­er­ence point for this pur­pose.It is never nec­es­sary to swing ship or to cor­rect the Gyro-Com­pass for eith­er var­i­a­tion or dev­i­a­tion of any kind. Where a Gyro-Com­pass and a mag­netic com­pass are both used on a ship, the ship may be swung to cor­rect the mag­net­ic com­pass—the Gy­ro-Com­pass fur­nish­ing true head­ings. The time re­quired is thereby ma­ter­i­ally short­ened.

Each time a com­pass is com­pen­sa­ted it is nec­es­sary to check the com­pen­sa­tion by check­ing the dev­i­a­tion on var­ious head­ings. This may be done by the use of de­flec­tor mag­nets. A more exact method is to swing the ship in a circle while bear­ings are taken of a known object on land and the dev­i­a­tion noted on var­ious head­ings. The sun is often taken as a ref­er­ence point for this pur­pose.

Each time a com­pass is com­pen­sa­ted it is nec­es­sary to check the com­pen­sa­tion by check­ing the dev­i­a­tion on var­ious head­ings. This may be done by the use of de­flec­tor mag­nets. A more exact method is to swing the ship in a circle while bear­ings are taken of a known object on land and the dev­i­a­tion noted on var­ious head­ings. The sun is often taken as a ref­er­ence point for this pur­pose.

It is never nec­es­sary to swing ship or to cor­rect the Gyro-Com­pass for eith­er var­i­a­tion or dev­i­a­tion of any kind. Where a Gyro-Com­pass and a mag­netic com­pass are both used on a ship, the ship may be swung to cor­rect the mag­net­ic com­pass—the Gy­ro-Com­pass fur­nish­ing true head­ings. The time re­quired is thereby ma­ter­i­ally short­ened.

It is never nec­es­sary to swing ship or to cor­rect the Gyro-Com­pass for eith­er var­i­a­tion or dev­i­a­tion of any kind. Where a Gyro-Com­pass and a mag­netic com­pass are both used on a ship, the ship may be swung to cor­rect the mag­net­ic com­pass—the Gy­ro-Com­pass fur­nish­ing true head­ings. The time re­quired is thereby ma­ter­i­ally short­ened.

Influences Due to Magnetism of the ShipWhen a steel ship is build­ing a sub­per­ma­nent mag­ne­tism is in­duced in its keel, hull, and plates. It causes a com­pass dev­i­a­tion classed as “semi­cir­cu­lar.” This dev­i­a­tion must be com­pen­sat­ed for.As a ship moves through the earth’s mag­ne­tic fields in its vary­ing quan­ti­ties and dir­ec­tions, a tem­por­ary and varying mag­ne­tism is in­duced in the soft iron of the ship. The re­sul­tant dev­i­a­tion is classed as “quad­ran­tal,” and must be com­pen­sat­ed for.The Sper­ry is not a Mag­ne­tic Com­pass. Ham­mer­ing, riv­e­ting, and mov­ing through mag­netic fields may in­duce mag­ne­tism in the ship, but will have no ef­fect upon the Sper­ry Gyro-Com­pass.There is no con­di­tion of the ship or cargo for which the Gyro-Com­pass must be cor­rec­ted.

When a steel ship is build­ing a sub­per­ma­nent mag­ne­tism is in­duced in its keel, hull, and plates. It causes a com­pass dev­i­a­tion classed as “semi­cir­cu­lar.” This dev­i­a­tion must be com­pen­sat­ed for.As a ship moves through the earth’s mag­ne­tic fields in its vary­ing quan­ti­ties and dir­ec­tions, a tem­por­ary and varying mag­ne­tism is in­duced in the soft iron of the ship. The re­sul­tant dev­i­a­tion is classed as “quad­ran­tal,” and must be com­pen­sat­ed for.The Sper­ry is not a Mag­ne­tic Com­pass. Ham­mer­ing, riv­e­ting, and mov­ing through mag­netic fields may in­duce mag­ne­tism in the ship, but will have no ef­fect upon the Sper­ry Gyro-Com­pass.There is no con­di­tion of the ship or cargo for which the Gyro-Com­pass must be cor­rec­ted.

When a steel ship is build­ing a sub­per­ma­nent mag­ne­tism is in­duced in its keel, hull, and plates. It causes a com­pass dev­i­a­tion classed as “semi­cir­cu­lar.” This dev­i­a­tion must be com­pen­sat­ed for.As a ship moves through the earth’s mag­ne­tic fields in its vary­ing quan­ti­ties and dir­ec­tions, a tem­por­ary and varying mag­ne­tism is in­duced in the soft iron of the ship. The re­sul­tant dev­i­a­tion is classed as “quad­ran­tal,” and must be com­pen­sat­ed for.The Sper­ry is not a Mag­ne­tic Com­pass. Ham­mer­ing, riv­e­ting, and mov­ing through mag­netic fields may in­duce mag­ne­tism in the ship, but will have no ef­fect upon the Sper­ry Gyro-Com­pass.There is no con­di­tion of the ship or cargo for which the Gyro-Com­pass must be cor­rec­ted.

When a steel ship is build­ing a sub­per­ma­nent mag­ne­tism is in­duced in its keel, hull, and plates. It causes a com­pass dev­i­a­tion classed as “semi­cir­cu­lar.” This dev­i­a­tion must be com­pen­sat­ed for.As a ship moves through the earth’s mag­ne­tic fields in its vary­ing quan­ti­ties and dir­ec­tions, a tem­por­ary and varying mag­ne­tism is in­duced in the soft iron of the ship. The re­sul­tant dev­i­a­tion is classed as “quad­ran­tal,” and must be com­pen­sat­ed for.

When a steel ship is build­ing a sub­per­ma­nent mag­ne­tism is in­duced in its keel, hull, and plates. It causes a com­pass dev­i­a­tion classed as “semi­cir­cu­lar.” This dev­i­a­tion must be com­pen­sat­ed for.

As a ship moves through the earth’s mag­ne­tic fields in its vary­ing quan­ti­ties and dir­ec­tions, a tem­por­ary and varying mag­ne­tism is in­duced in the soft iron of the ship. The re­sul­tant dev­i­a­tion is classed as “quad­ran­tal,” and must be com­pen­sat­ed for.

The Sper­ry is not a Mag­ne­tic Com­pass. Ham­mer­ing, riv­e­ting, and mov­ing through mag­netic fields may in­duce mag­ne­tism in the ship, but will have no ef­fect upon the Sper­ry Gyro-Com­pass.There is no con­di­tion of the ship or cargo for which the Gyro-Com­pass must be cor­rec­ted.

The Sper­ry is not a Mag­ne­tic Com­pass. Ham­mer­ing, riv­e­ting, and mov­ing through mag­netic fields may in­duce mag­ne­tism in the ship, but will have no ef­fect upon the Sper­ry Gyro-Com­pass.

There is no con­di­tion of the ship or cargo for which the Gyro-Com­pass must be cor­rec­ted.

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