Negative slip
A recent conversation with an ex naval man brought to mind a time when our twin screw vessel left Auckland for Melbourne and after rounding North Cape we took a course well westward before heading down to our Australian landfall at Wilson’s promontory. For most of the three day run down the Tasman sea the distance traveled equaled or exceeded the theoretical distance due to the pitch of the screws, i.e. three days at neutral or negative slip.
The second mate was an avid navigator, living and sleeping the subject and on asking about this event he claimed to have steamed westward to pick up a seasonal ocean current that gave us this ‘free ride.’
I can appreciate this happening in enclosed waters such as a flowing river or a with a strong tide flow in a narrow strait but my companion is very skeptical about this happening over such a distance.
It happened 50 years ago and the second mate may have been pulling my leg so I would be pleased if some of you Navigational experts could comment..
Bob
A recent conversation with an ex naval man brought to mind a time when our twin screw vessel left Auckland for Melbourne and after rounding North Cape we took a course well westward before heading down to our Australian landfall at Wilson’s promontory. For most of the three day run down the Tasman sea the distance traveled equaled or exceeded the theoretical distance due to the pitch of the screws, i.e. three days at neutral or negative slip.
The second mate was an avid navigator, living and sleeping the subject and on asking about this event he claimed to have steamed westward to pick up a seasonal ocean current that gave us this ‘free ride.’
I can appreciate this happening in enclosed waters such as a flowing river or a with a strong tide flow in a narrow strait but my companion is very skeptical about this happening over such a distance.
It happened 50 years ago and the second mate may have been pulling my leg so I would be pleased if some of you Navigational experts could comment..
Bob