Sequence of placing correctors, precautions during swinging

Sequence of placing correctors, precautions during swinging

Bi – D – E – HE – Bp – Cp
(1)
If -Bi, place flinder bar forward.
If +Bi, place flinder bar aft.
If superstructure abaft the compass, flinders bar on forward part. If superstructure forward of the compass, flinders bar on after part.
(2)
If +D, place quadrantal spheres athwartship.
If -D, place quadrantal spheres F&A.
(3)
Place quadrantal spheres diagonally.
(4)
Vertical force instrument (VFI) when vessel upright.
(5)
If +Bp, place parmanent red pole forward.
If -Bp, place parmanent red pole aft.
(6)
If +Cp, place parmanent red pole stbd.
If -Cp, place parmanent red pole port.
In short,
Soft iron – flinder bar, quadrantal spheres
Parmanent magnet – Heeling error, Horizontal magnet

Precautions before swinging:
Vessel upright.
Secure Cargo gear.
Moveable steel at a safe distance.
Flinder bar and quadrantal spheres to be corrected before swinging.
No bubble.
Correct azimuth.
Free movement of gimbal arrangement.

Precautions during swinging:
No ship within 3 cable.
Keep heading steady for at least 2 minutes on each heading.
Swing should not be less than 45 minutes.
Record on deviation book.