On the average tramp depending on which part of Ozzie you were bound , one used to assume 6 weeks or thereabouts. JS
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On the average tramp depending on which part of Ozzie you were bound , one used to assume 6 weeks or thereabouts. JS
Some distances via Panama Liverpool to Sydney 12263 n.m. to Wellington 11061,
Via Suez. Adelaide 10570, Albany 9732,Auckland 12564,Fremantle , 9529,Via Cape " " 11642 " " 10760, " " 13256, " " 10987
JS
So as not to confuse young Robert, I assume you are referring to the Chief Officer and not the Chief Engineer, as if the latter that would be normal!Quote:
Originally Posted by happy daze john in oz
But then again John, a nice story, but the Chief Off, (as well as the other navigators) if the ship had been idle for two days would have been calculating every watch, wind, drift, tides, soundings and would have had a good idea where they were. They may even have woken up the Radio Operator and taken D/F bearings.;);)
#33 Could of told him what error was for converting the bearing to make his job easier. Half Delong x cosine latitude. Some things one doesn’t forget , only ships names JS
Ivan my thoughts exactly about DF but while were drifting around while you lot tried to get us going again the R/O would be keeping normal watches or at least I did, Den
I know you would Den, I was only joking, we were all jealous of your time off in port :cripes:Quote:
Originally Posted by Denis O'Shea
D/f bearings as far as I can remember were a last resort and only in the final result as good as the person taken them . Sometimes before the North Sea was full of oil rigs was very easy to get lost in fog and were ones last chance. Approaching Japan one time from the east and no sights for 3 days the Indian R/0 took some and when the fog lifted we were 200 miles out of where they put us. Relying on such was always hit and miss as far as I was concerned. Would rather rely on a line of soundings. JS
Yesterday was not like today where pin point navigation is expected due to computerisation .celestial navigation if you got a cocked hat of four or five bearings and the area of the cocked hat was 2 miles then you were doing well. A sun sight was only a running fix and as good as you’d estimated of your speed from initial sight and your noon latitude. As all navigators know. For non navigators precision was only close when you got on the coast and really knew where you were. A good landfall near enough your ETA was to be cheered. Today most ships you only have to look at a screen to see where you are at any minute of the day. Today we have people at sea who don’t know any different. Crossing the Indian Ocean and making for the Horn of Africa set of a 100 miles to the north or south overnight was to be expected due to current unpredictability , today this would be adjusted all the time by just adjusting your course as your personal tv screen told you. Anyone wanting to know how we navigated 60
Years ago , it was the same as Nelson did all those century’s ago. And was different as of today. JS
Around the uk the big aid to navigation was the Decca navigator. On one trip down the meddy when showing the flag in Italy however the Decca ran out halfway across the bay of Biscay I had to resort to the sextant. Think I was the only one who could work out a sun position line.Even one of the Navy lieutenants who had supposedly taught navigation at Dartmouth asked to come on bridge and keep his hand in .When he didn’t have the RN sight form to fill in , he chucked his hand in. I said we don’t use forms to to work sights out, we use the Haversine formulae or Longitude by chronometer, I strongly suspect he didn’t know what I was talking about. And this was in 1980 . JS......
After a spate of collisions about 3 - 4 years ago involving USA navy craft which wiped out their electronics, the USNavy re-introduced the use of the sextant and celestial navigation, I bet that introduced more than a few puckers. In the USNavy it is possible to become a ship Commander although never having served in any deck or bridge capacity, I wonder if they changed that policy also, speaking to a serving USNavy man some years ago we were discussing this and even he thought it was crazy.
The laymans view of Navigation as per Readers Digest of circa 2002.
" Electronic systems can plot the position of a seaborne vessel or aeroplane to within a few metres , using reflections of radio waves bounced against fixed beacons or satellites. Before this technology became available , Ocean Voyagers had to rely on wind direction , astronomical observations or dead reckoning to calculate their position and direction".
There you have it Ocean Voyagers straight from the horses mouth now we can all go to sea knowing we are all safe and sound. In 1960 i can remember asking the company for an almanac called Star reduction tables put out by the USA for their air navigators during the war. They wouldnt pay the coppers, for this manual which would cut down the average time of 80 minutes of working out 5 stars by 50%. How times have changed. Maybe we were all born too soon . JS