# Traverse Tables



## Stephen J. Card

I have been reading various the TITANIC inquests... back from 1912 and also recent by MAIB.

Whenever one of the surviving navigators, Lightoller 2/O, 
Boxhall 4/O and Lowe 5/O mention that they were working out a DR position for:

a. course alteration 
b. for working out star sights
c. for sending out CQD (SOS) 

In every case they work out a DR using Traverse Tables.

Of course the tables are useful, but for always? Why not simply dividers and a five second bit of chartwork?

Personally, I'd rather check, check, check and check again... if you were going to work a position for a SOS on chartwork. To check again using Traverse Tables it would take another hour!

It seems navigation back then was 'difficult'. I'm not talking GPS... just simple Nories, chronometer and sextant. It seems on the White Star ships they always used 'noon at noon' and then during the morning and evening watches applied ship's time for longitude.... not our simply "Clocks will be retarded one hour at 0200".

Bridge watches were split into Dog watches.... some mates on 4 on 8and junior mates on 2 watches.... and watch changed at 2200 instead of 2400 etc.

During star sights it was practice for the senior mate to take a set of sights. He would then bugger off watch and then wait for a junior to come on watch to work out the sights. 

Seems like the chart may have been locked away in the chart drawer and perhaps the key for the radar was keeps around the Captain's neck!

Oh... please remember. All of the mates on board that ship were all Master's or Extra Master's. 

Thanks.

Stephen


----------



## Split

Can't remember anything quite like that. When I kept the 4-8 I did my own sights. In fact, it helped pass the time, with an apprentice watching for traffic Most of the sight was calculated from the DR position, beforehand, anyway.

When I was last year apprentice, the mate taught me how to take them. I remember when a sample of the new nautical almanack was put on board, in 1951. I was relieved because I hated that HATS formula, The new hour angle of Aries I found much easier and I would be using the new one for my exams.


----------



## Pilot mac

Stephen, 
there were still some 'old men' around in the early 70's that had 'noon at noon', what a pain.

regards
Dave


----------



## Stephen J. Card

Split said:


> Can't remember anything quite like that. When I kept the 4-8 I did my own sights. In fact, it helped pass the time, with an apprentice watching for traffic Most of the sight was calculated from the DR position, beforehand, anyway.
> 
> When I was last year apprentice, the mate taught me how to take them. I remember when a sample of the new nautical almanack was put on board, in 1951. I was relieved because I hated that HATS formula, The new hour angle of Aries I found much easier and I would be using the new one for my exams.



Thanks Split.

Good info.

I must try to find a copy of an almanac from 1912. 

Sun was OK... but stars? Ahhhhh! A joy. 

Stephen


----------



## Stephen J. Card

Pilot mac said:


> Stephen,
> there were still some 'old men' around in the early 70's that had 'noon at noon', what a pain.
> 
> regards
> Dave



Just one ship.. with Shaw Savill. The OM standing in the chartroom at the moment of noon waiting for HIM to plot the noon position.... then demand the speed. Thing is I always did it in seconds....he knew I was doing it fast for all of the info... position, speed, general average, distance to go and etc. Never told him that I had one of those 'box of tricks'.... a Tamaya NC77. He never told it what did.

Stephen


----------



## Duncan112

Stephen J. Card said:


> Bridge watches were split into Dog watches.... some mates on 4 on 8and junior mates on 2 watches.... and watch changed at 2200 instead of 2400 etc.


Stephen, I remember reading somewhere (possibly in Geoffrey Marcus' "The Maiden Voyage") that the reason the watches were split so (Senior on 8 - 12, 12-4, 4-8 and junior on 10-2, 2-6, 6-10 was that White Star believed that this would ensure that there was always a pair of eyes not more than two hours old on the bridge and also there was no possibility of both watchkeepers being unaccustomed to the lighting conditions simultainiously.

The use of traverse tables is interesting though - being an Engineer and not knowing much about the inticracies of navigation is there a possibility that they were using a small scale chart rather than the plotting sheet that I recall being used for ocean navigation and would this have made a difference to the speed of working out a position?


----------



## Binnacle

Pilot mac said:


> Stephen,
> there were still some 'old men' around in the early 70's that had 'noon at noon', what a pain.
> 
> I sailed around the world with one 'old man' who liked noon at noon. One passage, London/Wellington , about 42 days, he wanted steaming time to be 24 hours +/- change of longitude. I had to keep track of the difference between clock change and longitude change and apply that correction at EOP Wellington when making up the voyage abstract, plus of course the difference between Equation of time sailing London and arriving NZ. The chief engineer complained (understandably). I think The OM took his copy of Lecky's "Wrinkles in Practical Navigation" to bed with him. Happy days.


----------



## Stephen J. Card

Duncan, Thanks.

Thanks for the Geoff Marcus. Must admit I've not seen it on the shelf for thirty years!!! I agree that the split watch sounds like a good idea. No good with a good mate on at the end of watch for a few ales at midnight! No, probably not such a good idea.

Re charts for scales.... For the passage there should always have the correct up on the table... and especially a good large scale to use. Not seven or days.... but on N. Atlantic can be well done on just two sheets. This would be quite adequate and good enough to be able for solving short distances. Traverse Tables for distance of 600. 
I never used traverse for long distance using Mercator Sailing... using Meridioal Parts for the Spheroid. Plotting sheet is great for sights .... but not for for plotting a fix.... even on large scale.

One story... about 1978... large tanker on voyage from US Gulf to Rotterdam on Great Circle. The whole voyage was plotted on several large plotting sheets. They did everything right... courses, waypoints.... sun sights, stars, DR positions etc etc.. the whole nine yards. Sadly passing through Lat 32 15 N and 64 40W... they saw something that looked odd. Before not long their ship with 180,000 tonnes of crude where sitting on the reefs. Mercifully she sat on a sandy patch and the ship was salvage. Remember... if you are plotting.... put the positions of a real nav charts and look for lights and islands!

Stephen


----------



## Stephen J. Card

Binnacle,

I was 2nd Mate had one master who started calling me "Pilot!" Every thing was Pilot this or Pilot that. An hour or two later I heard the master chatting with Lecky on the bridge wing, "I'm reading a great book name...Rendezvous - South Atlantic ...... by DOUGLAS REEMAN"

No further comment required... unless you have not read it!

Stephen


----------



## ninabaker

HMS Dauntless was visiting Glasgow the other day and I was fortunate enough to be invited for an evening look around.

The bridge of course is full of all the very latest electronic satnav stuff, electronic charts and various radars etc. As all of this seemed to be dependent on GPS, I asked the ship's Exec Officer what they did in case of the enemy putting the satelites out of action.

Apparently the electronic systems can continue to calculate current position based on last known position. Everyone else on the visit (none of them ex seafarers) seemed happy with that. I then asked - do you mean you rely entirely on dead reckoning then? Oh yes, the 2-ringer says, we can carry on like that pretty accurately for up to 5 hours.......

If you dont know these new destroyers, take a look a pic of one - the windage is collossal. he captain told me it is something like a ration of 1:10, which is staggering and I would have thought that DR would be highly unreliable, not least if all the ships in a convoy were in the same GPS-less situation and with highly variable drifts.

Apparently all deck officers do a few sextant sights at Dartmouth and each ship's Navigator would usually practice a bit when out on exercise. The ship does carry actual paper charts and a sextant (glad to hear it), but it is my experience that taking sights is a highly "perishable" skill. Not at all like riding a bike. I think you need loads of practice to remain accurate.

I find it all a bit worrying as I would think that the satellites would be the first thing for the ECM crowd to have a go at.

nina


----------



## Duncan112

I suspect that there will also be some form of Inertial Navigation System on board somewhere - they might not want to talk about it but the aircraft ones are accurate to a couple of meters on a trans Atlantic crossing


----------



## ninabaker

Duncan112 said:


> I suspect that there will also be some form of Inertial Navigation System on board somewhere - they might not want to talk about it but the aircraft ones are accurate to a couple of meters on a trans Atlantic crossing


The officer might very well have been referring indirectly to an INS. However, my understanding of these systems is that they are just sophisticated DR under another name and can be out by half a mile within an hour's sailing. Without an external input, from sextant sights or GPS, these systems cannot tell actual position or speed over the ground, only speed through the water.

These are obviously far more sophisticated than anything I saw in my career, even on the cable ship I finished up on.

nina


----------



## Cisco

I spent the last year of my cadetship on a passo boat. With 5 of you taking morning sights and noon you wouldn't have been able to get near the chart table....
Chart on table was of such a scale as to be not much use anyway.
We had to do everything involved in our sight books right up to and including the noon position. Involved both traverse and ABC tables...
Then each had to fill in both a morning and a noon chit and give them to the senior second mate who in turn would give them to the old man who would decide where we were....or at least had been just a short time before.
First time I saw those green plotting sheets was when I went foreign flag after getting second mates..


----------



## borderreiver

Cisco said:


> I spent the last year of my cadetship on a passo boat. With 5 of you taking morning sights and noon you wouldn't have been able to get near the chart table....
> Chart on table was of such a scale as to be not much use anyway.
> We had to do everything involved in our sight books right up to and including the noon position. Involved both traverse and ABC tables...
> Then each had to fill in both a morning and a noon chit and give them to the senior second mate who in turn would give them to the old man who would decide where we were....or at least had been just a short time before.
> First time I say those green plotting sheets was when I went foreign flag after getting second mates..


At long last proper navigation. Many thanks. you have warmed my hart.
As day work mate. Had to go back to watchkeeping for a short period doing it your way was faster then the 2 nd mate with his fancy box of tricks


----------



## sidsal

First post mentions radar !! Not in my ships until 1945 - then with armed guard on it in port. 
One master I sailed with used to describe the slide rule I used as my "guess stick".


----------



## Stephen J. Card

How many for prefrences for Marc St Hilaire or Long By Chron?

Mostly stuck with Long by Chron for morning sights and noon lat... easy as no ploting was required.... and they say limited and should with P/L running close to north-south. On a long voyage (s) round the Cape to Gulf etc... the second mate 'suggested' that we should use the same method... easy for us to check our working. Eight months later I was convinced! 

By the time I was a 'star' navigator... and was use my NC77.... so never used them for reduction tables..... but cheated to find seven stars!

Stephen


----------



## vasco

I used my trusted HP41C for my calcs, far outdid the Tamaya as it had alphanumeric display and a built in almanac, as well as being fully programmable to keep up with the old mans eccentricities. Had one guy who wanted ETAs every quarter of a knot from 10 to 14, ship was eco cruising at 10.5 and was six weeks away from the next port. When he saw how easy it was for me he just asked for 10, 10.5 & 11kts.
And the amount of times I had to prove that my calculator was as accurate as the almanac well...... Mind you, a couple of old men did buy their own.
For the Ten years prior to that it was Nories all the way using marc St Hilaire.
For cadet training,(I work on the coast), it is still nice to take the odd sight and I can still go to Nories and open up to the right tables without looking. That's 30 yrs after I stopped using them.


----------



## slick

All,
HP41C how modern some of us had the steam driven HP35...
Myerscough and Hamilton Tables of choice when Tables were called for...

Yours aye,

slick


----------



## Stephen J. Card

slick said:


> All,
> HP41C how modern some of us had the steam driven HP35...
> Myerscough and Hamilton Tables of choice when Tables were called for...
> 
> Yours aye,
> 
> slick



Never saw the HP. I remember hearing that the calculations could be done, but with NC77 was good because the almanac was 'included'.

Unfortunately the calculator almanac finished after end on the day of the century! There was a correction for another or a year but the finish. Otherwise still works and almost in daily use as a calculator... 37 years old.

Stephen


----------



## Split

Stephen J. Card said:


> Thanks Split.
> 
> Good info.
> 
> I must try to find a copy of an almanac from 1912.
> 
> Sun was OK... but stars? Ahhhhh! A joy.
> 
> Stephen


Sorry! Almanac! I've been ashore 52 years. 

How I identified and worked out the altitudes and direction of stars before twilight? That mate had, which I lost no time in buying for myself on my next leave--they were war surplus goods-- , a circular set of star identifiers issued by the US government to the aircrew navigators. It was great and, providing there were no clouds, I found them with the sextant every time. I, still, have that, along with my sextant. I wonder if it is worth anything?


----------



## James_C

Split said:


> Sorry! Almanac! I've been ashore 52 years.
> 
> How I identified and worked out the altitudes and direction of stars before twilight? That mate had, which I lost no time in buying for myself on my next leave--they were war surplus goods-- , a circular set of star identifiers issued by the US government to the aircrew navigators. It was great and, providing there were no clouds, I found them with the sextant every time. I, still, have that, along with my sextant. I wonder if it is worth anything?


The star identifier is still published by the Admiralty, a series of plastic plates with azimuth overlays for a number of different latitudes - all you need is a DR and LHA of Aries. Of course such things are being superseded by electronic versions.


----------



## Stephen J. Card

Split said:


> Sorry! Almanac! I've been ashore 52 years.
> 
> I wonder if it is worth anything?






Split,

Worth a lot when the whole GPSsystem fails! Just think... as a 'navigator' you would be worth a half million for a year's work!

Heck, no more charts.... or even corrections! 

The term 'navigator' hardly even means the same any more... I think just call them 'Watchkeepers'!

Stephen


----------



## Aberdonian

*Rude Star Identifier*



James_C said:


> The star identifier is still published by the Admiralty, a series of plastic plates with azimuth overlays for a number of different latitudes - all you need is a DR and LHA of Aries. Of course such things are being superseded by electronic versions.


For old time's sake....

Keith


----------



## Stephen J. Card

Aberdonian said:


> For old time's sake....
> 
> Keith





All all I ask is a tall ship
and a star to steer her by......


----------



## China hand

They were good bits of gear; still have mine.


----------



## vasco

Stephen J. Card said:


> Never saw the HP. I remember hearing that the calculations could be done, but with NC77 was good because the almanac was 'included'.
> 
> Unfortunately the calculator almanac finished after end on the day of the century! There was a correction for another or a year but the finish. Otherwise still works and almost in daily use as a calculator... 37 years old.
> 
> Stephen


 My HP41 still calculates the almanac and I say with all modesty was envied by NC77 owners.

One old man was forever trying to out do it, he would say can mine do something his calculator did, like distance off vertical angle, for me to say no.not yet. Then into programming mode and yes it could. He bought the Hp in the end.

Mr Card, out of curiosity, what is your definition of a watchkeeper. I am proud to say I have been a watchkeeper and navigator for 40yrs.


----------



## Stephen J. Card

Vasco...

I have some news.... not so sure if good or bad!

Just say on EBAY for a HP41. One 'pack' available... all the gear laid out for inspection. Good news is that it is available for 500 pounds!

The bad news. Under EBAY it is called as 'Vintage Electronics'. Cheeky sods.


In my NC-77 is all BAD news! There is one available in perfect condition... even the wooden box looks perfect. Mine is available for $1.04!!!!!!! And the bad worse part... NC77 is called EBAY is under 'OLD Vintage Electronics'!

As for my 'watchkeeper'..... I think IMO would rather everyone did no navigation at all and spend the rest of time watching on what electronic gadget is up and what box on the paper form to tick or an X. 

I wonder what of the new lads... or ladies coming in what they are coming to. How many of the youngsters can even get close up to seeing a ship never mind get a chance to get on board one. 

Good a lot of sea miles under your keel! That HP was well a good investment.

Stephen


----------



## vasco

All very interesting, my HP is worth more than my sextant!


----------



## 8575

Having watched folk when I was a cadet using the back of cancelled charts to construct their own plotting chart I thought this was what everybody did! However, after a while I figured out that there is no need to (a) make your own or (b) buy purpose made ones as all you really need is any suitable large scale chart that covers the same latitude as you. Admittedly you might have to plot over land but all so much easier to do. Did get a few quizzical looks from the OM occasionally! 

Stars - I remember the American circular identifiers and also the UK version which, if memory serves, wasn't circular but square but essentially did the same thing but the real gem for saving time were Air Sight Reduction Tables (AP3720 (?)) - 7 stars and effortless identification - loved the enormous intercepts too!


----------



## Aberdonian

*USN Star Identifier*



Waighty said:


> Stars - I remember the American circular identifiers


Got mine by post in the 50's from Charles Frank in Glasgow.
A name to conjure with.

Keith


----------



## slick

All,
A useful item, once again from US sources a plastic CHART CORRECTION TEMPLATE DMA Stock No. WOXZP9998.
I still have it... just no charts these days...


Yours aye,

slick


----------



## Chris Isaac

Aberdonian said:


> Got mine by post in the 50's from Charles Frank in Glasgow.
> A name to conjure with.
> 
> Keith


NO, Abracadabra, now that is a name to conjure with!


----------



## Aberdonian

Magic! (Jester)

Keith


----------



## Uricanejack

Stephen J. Card said:


> How many for prefrences for Marc St Hilaire or Long By Chron?
> 
> Mostly stuck with Long by Chron for morning sights and noon lat... easy as no ploting was required.... and they say limited and should with P/L running close to north-south. On a long voyage (s) round the Cape to Gulf etc... the second mate 'suggested' that we should use the same method... easy for us to check our working. Eight months later I was convinced!
> 
> By the time I was a 'star' navigator... and was use my NC77.... so never used them for reduction tables..... but cheated to find seven stars!
> 
> Stephen


My personal preference was Marc St Hillarie.
I used Long by chrom as a cadet from time to time so I was familiar with it when I went for my exams.

A few month s ago I posted an old template for long by chrom on a sailing website. 

I never bothered with the purpose built calculators.
Initially I used Norries and traverse tables. Changing to a scientific calculator in the mid 80’s and traverse tables. 
I found I was just as quick with traverse tables.
One 2nd mate I sailed with had a Casio programmable calculator. I wanted one but bought a Casio PB 1000 and wrote my own navigational programs.

I quite deep sea voyaging about 25 years ago. In those days I used a sextant daily for our noon position and took stars when the opportunity arose on my watch or on evening meal relief.

On every ship I sailed on noon was at noon. Not apparent noon. It only took a few more minutes to calculate using traverse tables.
I did write a program for my PB 1000 which would do a Mercator sailing. But I rarely used it. 16K expanded to 32K memory was just not enough to store them all and I would just use the sight reduction program I wrote. Then use traverse tables for my run to noon. Never used plotting sheets except for stars as said a chart from the right latitude with its compass rose worked just fine.


----------



## Uricanejack

Stephen J. Card said:


> I have been reading various the TITANIC inquests... back from 1912 and also recent by MAIB.
> 
> Whenever one of the surviving navigators, Lightoller 2/O,
> Boxhall 4/O and Lowe 5/O mention that they were working out a DR position for:
> 
> a. course alteration
> b. for working out star sights
> c. for sending out CQD (SOS)
> 
> In every case they work out a DR using Traverse Tables.
> 
> Of course the tables are useful, but for always? Why not simply dividers and a five second bit of chartwork?
> 
> Personally, I'd rather check, check, check and check again... if you were going to work a position for a SOS on chartwork. To check again using Traverse Tables it would take another hour!
> 
> It seems navigation back then was 'difficult'. I'm not talking GPS... just simple Nories, chronometer and sextant. It seems on the White Star ships they always used 'noon at noon' and then during the morning and evening watches applied ship's time for longitude.... not our simply "Clocks will be retarded one hour at 0200".
> 
> Bridge watches were split into Dog watches.... some mates on 4 on 8and junior mates on 2 watches.... and watch changed at 2200 instead of 2400 etc.
> 
> During star sights it was practice for the senior mate to take a set of sights. He would then bugger off watch and then wait for a junior to come on watch to work out the sights.
> 
> Seems like the chart may have been locked away in the chart drawer and perhaps the key for the radar was keeps around the Captain's neck!
> 
> Oh... please remember. All of the mates on board that ship were all Master's or Extra Master's.
> 
> Thanks.
> 
> Stephen


plotting on a small scale chart of the Atlantic would be quite inaccurate. Compared to calculating using travers tables. Which would only take a few minutes certainly less than 5 minutes.
And I would not be surprised if they could do it in less than one minute.


----------



## Uricanejack

I quite deep sea about 25 years ago.
The old transit satellite system was still in use. And to my mind relatively new only a few years before I had been on ships as 3rd mate where we had no satellite navigation system or loran C. For some strange reason I was on one which had an Omega (about as much use as **** o a bull). 

I took observed positions using sextant daily. When offshore. Provided I could see both the sun and the horizon. 

I was surprised a few years ago chatting with a young navigational officer from Princess Cruises who was quite proud of having used a sextant once on a repositioning trip across the Atlantic. She had to ask the captain specially because the sextants were kept in his safe. She was quite proud of knowing how though felt it wasn’t really practical nowadays.

Other youngsters I have met tell similar tales regarding it as an archaic practice which they have to learn for exams but never use for real.
Others who I know had only worked coastal but persevered through the astro navigation to get a deep sea certificate and went for a while to get some time. Showed great pride in having learned how to and used occasionally.

Times Change.


----------



## 8575

Since this thread is about Traverse Tables and since I've just been browsing through my old Burton's Tables I found this little gem written in by hand:

Using Traverse Tables to convert Feet into Metres and Pounds into Kilogrammes:

Course 18 degrees, "Dist" = Feet, "Dep" = Metres

Course 27 degrees, "Dist" = Pounds, "Dep" = Kilograms

I have no idea where I got this snippet but it works, roughly. I wonder who spent their boring watch thumbing through the tables until they got what they wanted! (EEK)


----------



## Stephen J. Card

Uricanejack said:


> plotting on a small scale chart of the Atlantic would be quite inaccurate. Compared to calculating using travers tables. Which would only take a few minutes certainly less than 5 minutes.
> And I would not be surprised if they could do it in less than one minute.



I have to assume that in 1912 they would have the same or similar chart of Admiralty Cataloge No. 4404.... Gulf of maine to Strait of Bell Island including Giuf of St Lawrence. 

The region of Grand Banks etc... they would have that largest scale chart in use. Would have been adequate for DR position and sending a CQD/SOS. Right also that Traverse Tables would give same information. I would want to have the chart as if you were thinking about plotting rescue ships... or should have been in the earlier day so they could a plot of ice warnings. 

At some point there was a mistake as the the DR was quite a difference compared to the place they found the CARPATHIA and eventually found her at bottom of the sea.

102 years since the sinking.. 14th April.

Stephen


----------



## slick

Hello Waighty,
Thank you for that gem it is now in my Burtons (2B Pencil please), indeed one wonders how it was arrived at, a flash of light on the 12-4 or deductions with a pipe of twist ?....

Yours aye,

slick


----------



## 8575

Glad to help Slick; I wrote mine in biro! Maybe I was worried it would fade with time! Actually I can't think of a time I used the conversions in anger so to speak - maybe one day.

Nice to know others use Burtons; I was much scorned by colleagues in my deep sea days on the basis that only the righteous use Nories, which as we both know is b*****ks, Burtons is by far the better set! The reality is that one tends to stick with what one starts with and Warsash used Burtons.

Yours aye,

Waighty


----------



## Mikey Hall

Burtons were my choice. Never could get the hang of Nories.
Anyone remember Capt Ogura's tables in Nories? What was all that about?
Mike


----------



## Stephen J. Card

Never made a 'choice'. Only NORIE'S on J&J Denholm vessels and only saw NORIE'S at Glasgow College. Of course knew about Burtons. I think I saw a set in a bookshop once... the layout of logs were very different.... perhaps a bit clearer to read. In those days I didn't need glasses!


----------



## borderreiver

used both. Took Nories in for exams as it has lot of help in the front which the exam ones had cut out and borrowed the exam room burtons which had better ABC.
Do you still remember putting the c correction on to your noon postions


----------



## Stephen J. Card

borderreiver said:


> .
> Do you still remember putting the c correction on to your noon postions


Yes. I was used to 'long by chron'.... then to 4-8 in Marc St Hilarious!


Re.... Captain Ogura's method is in the old editions from the 60s. I have a couple of spare from 1983 and Ogura's method is deleted.

For Navigation text books..... I always like Nicholl's Concise Guide.... perhaps a good place to buy Brown Son & Fergusson. I see they sell now the new edition of 80 quid!!! A GPS is cheaper!


----------



## China hand

When you think about the race to get the pos worked out, as if it was life or death, as we plodded across the Pacific at around 13 knots, it puts the "now" generation into a whole new world.(Hippy)


----------



## Robert Hilton

I have somewhere a Nories dated 1888. It contains a complete treatise on navigation, but no Marc St. Hilaire. It gives Admiral Sumner's New Method for sight reduction, which I'm told Marc St. Hilaire realised could be shortened by cutting out a section of the working. 

It has two traverse tables, one in quarter points and the other in "the new degrees."


----------



## Farmer John

I was always fascinated by the "Bar 10" bit of many of the... numbers ( I think they were logarithms, but that may just be my logorrhea) . I know it was used to protect us simple people from having to use negative characteristics while still having the mantissa just fine and dandy (this explanation may be a little technical for some on the site, but trust me, I don't understand it myself).

Seriously, I was amazed by spherical trigonometry, so many of the absolutes of plane trigonometry just went, no boring internal angles adding up to to 180°, no more and no less, and such other heresies. This may have led me to set off on my first trip with a book on Relativity and another on non-Euclidian geometry. I did enjoy them, but never really had time to read them. I wish I could return to that kind of optimism, but I have to say that some kind of loss of this feeling has saved me from spending too much on books on quantum physics, though I have enjoyed fractals and fuzzy logic (much my favourite).


----------



## Stephen J. Card

Just yesterday on SN re Noon Sights I noticed that one example was in logs using BAR method the other used the DECIMAL method.

I still have my old school using the BAR method... still in good condition! On first ship I was given Norie's and had to learn all a new decimal method. Well, not to learn exactly science, I was just told to get on with it.

My crunch came until 1980. I sat Masters in Glasgow... no problem. Just for writtens... could not sea time to do orals. At the same time I had a thought to take another ticket.... a Liberian Certificate. For their requirements I had time for their ticket. So... just about a month I sat in Glasgow I flew to Reston VA to the Liberian Exam Centre.

How many of you have actually see the Liberian examinations... quite impressive. 

The allocated time is your own....a day or ten weeks. The examiner gives the candidate with a 'pile' of papers... about 150 papers. Some questions had one or two questions, some had others... half a dozen questions.... some written and some orals... orals are 'short written' or multiple choice. The stack of papers are random. One may paper on nav... next stability... or The Rules then law. You could not see all of the papers. The pile sit on the examiners desk. When you are ready you pick up the first sheet... sit down and work on the questions... written or calculations etc. Sometimes like Stability there may be a calculation to show then a written answer to show method. When you finish the paper... pass it to the examiner and then pick up the next sheet from the pile. If you want to break... you cannot start another paper until you have finished one... then go to teh machine... ccoffee etc OR.... if you think you have enough time for lunch... take a break. If you think you want a longer break... OK... or come next day! I did not have the luxury of time and I had flights back to Bermuda so I had a hotel and did the exam in three days.... no breaks.... just right through the whole day. 

My problem with the exam.... the Liberian Exam is all in IMPERIAL... not SI!!!!! I did not a clue! The first stability paper I had to take all weights, length etc... change everything to metric.... work out my answers in metric then change to Imperial. I was up the creek! the examiner saw me doing what i was up against... he simple gave me small book with all the imperial formulae and get on with it. I spoke to teh examinaer and also found that law paper was a problem.... they gave me a book on Liberian law. They gave me to read the booklet during the evening to study. 

Anyhow, I passed and was gone. Perhaps it is easier than in DOT... a good idea in the volume of work that you must remember... not just wait for DOT to hope that the right questions come up on this exam. Had I not just Glasgow college and sat for DOT writtens there is not a chance to pass the Liberian exam. Either way... study and work. 

Here is the best part. My Liberian Cert has a Written Exam number on it. In the Liberian office they have no copy of my UK ticket. If by some chance I had a 'mishap' and lost my UK ticket... the Liberian Cert would be still 'clean'.

Back to traverse.....


----------



## Split

slick said:


> All,
> A useful item, once again from US sources a plastic CHART CORRECTION TEMPLATE DMA Stock No. WOXZP9998.
> I still have it... just no charts these days...
> 
> 
> Yours aye,
> 
> slick


No charts? As one Ancient Mariner to a younger Mariner.

Whatchagot and how do you do it?


----------



## Split

Uricanejack said:


> I quite deep sea about 25 years ago.
> The old transit satellite system was still in use. And to my mind relatively new only a few years before I had been on ships as 3rd mate where we had no satellite navigation system or loran C. For some strange reason I was on one which had an Omega (about as much use as **** o a bull).
> 
> I took observed positions using sextant daily. When offshore. Provided I could see both the sun and the horizon.
> 
> I was surprised a few years ago chatting with a young navigational officer from Princess Cruises who was quite proud of having used a sextant once on a repositioning trip across the Atlantic. She had to ask the captain specially because the sextants were kept in his safe. She was quite proud of knowing how though felt it wasn’t really practical nowadays.
> 
> Other youngsters I have met tell similar tales regarding it as an archaic practice which they have to learn for exams but never use for real.
> Others who I know had only worked coastal but persevered through the astro navigation to get a deep sea certificate and went for a while to get some time. Showed great pride in having learned how to and used occasionally.
> 
> Times Change.


Of course! All that is archaic, in much that same way as srting handles on cars. We must all move on.

Having to learn things "for the examiner" is another thread to be started, I suspect, and that cuts through all generations of ship's officers.


----------



## 8575

Stephen J. Card said:


> Just yesterday on SN re Noon Sights I noticed that one example was in logs using BAR method the other used the DECIMAL method.
> 
> I still have my old school using the BAR method... still in good condition! On first ship I was given Norie's and had to learn all a new decimal method. Well, not to learn exactly science, I was just told to get on with it.
> 
> My crunch came until 1980. I sat Masters in Glasgow... no problem. Just for writtens... could not sea time to do orals. At the same time I had a thought to take another ticket.... a Liberian Certificate. For their requirements I had time for their ticket. So... just about a month I sat in Glasgow I flew to Reston VA to the Liberian Exam Centre.
> 
> How many of you have actually see the Liberian examinations... quite impressive.
> 
> The allocated time is your own....a day or ten weeks. The examiner gives the candidate with a 'pile' of papers... about 150 papers. Some questions had one or two questions, some had others... half a dozen questions.... some written and some orals... orals are 'short written' or multiple choice. The stack of papers are random. One may paper on nav... next stability... or The Rules then law. You could not see all of the papers. The pile sit on the examiners desk. When you are ready you pick up the first sheet... sit down and work on the questions... written or calculations etc. Sometimes like Stability there may be a calculation to show then a written answer to show method. When you finish the paper... pass it to the examiner and then pick up the next sheet from the pile. If you want to break... you cannot start another paper until you have finished one... then go to teh machine... ccoffee etc OR.... if you think you have enough time for lunch... take a break. If you think you want a longer break... OK... or come next day! I did not have the luxury of time and I had flights back to Bermuda so I had a hotel and did the exam in three days.... no breaks.... just right through the whole day.
> 
> My problem with the exam.... the Liberian Exam is all in IMPERIAL... not SI!!!!! I did not a clue! The first stability paper I had to take all weights, length etc... change everything to metric.... work out my answers in metric then change to Imperial. I was up the creek! the examiner saw me doing what i was up against... he simple gave me small book with all the imperial formulae and get on with it. I spoke to teh examinaer and also found that law paper was a problem.... they gave me a book on Liberian law. They gave me to read the booklet during the evening to study.
> 
> Anyhow, I passed and was gone. Perhaps it is easier than in DOT... a good idea in the volume of work that you must remember... not just wait for DOT to hope that the right questions come up on this exam. Had I not just Glasgow college and sat for DOT writtens there is not a chance to pass the Liberian exam. Either way... study and work.
> 
> Here is the best part. My Liberian Cert has a Written Exam number on it. In the Liberian office they have no copy of my UK ticket. If by some chance I had a 'mishap' and lost my UK ticket... the Liberian Cert would be still 'clean'.
> 
> Back to traverse.....


When I was up for masters in Bristol (in the days when the college was still there) one of our number was told by his Liberian flag employers that the master's job was his whatever ticket he got. So while still studying for the UK one he sat the Liberian one. He had to go to Lloyd's Register office in the city and spent three days sitting the all-paper master's exam. 15 papers in all, including rule of the road. He passed by the way and also passed the UK ticket as well.


----------



## 8575

borderreiver said:


> used both. Took Nories in for exams as it has lot of help in the front which the exam ones had cut out and borrowed the exam room burtons which had better ABC.
> Do you still remember putting the c correction on to your noon postions


Take a look at the Noon Position thread re C correction.


----------



## vasco

Waighty said:


> Since this thread is about Traverse Tables and since I've just been browsing through my old Burton's Tables I found this little gem written in by hand:
> 
> Using Traverse Tables to convert Feet into Metres and Pounds into Kilogrammes:
> 
> Course 18 degrees, "Dist" = Feet, "Dep" = Metres
> 
> Course 27 degrees, "Dist" = Pounds, "Dep" = Kilograms
> 
> I have no idea where I got this snippet but it works, roughly. I wonder who spent their boring watch thumbing through the tables until they got what they wanted! (EEK)



I am surmising that as the traverse tables are really solving right angle triangles a bit of trig was used to find the angle.

In the case of the distance, the hypotenuse is 1 (foot) multiply this by the sine of 18 gives you the opposite (dep), 0.3090. Which is roughly the coversion factor (0.3048).

The constant is the angle, which for more accurate should be 17.75 deg.

Well, i think it works, what do you think?.

In latter days using the p-r function was an easy traverse solve on a calculator.


----------



## Stephen J. Card

Waighty said:


> When I was up for masters in Bristol (in the days when the college was still there) one of our number was told by his Liberian flag employers that the master's job was his whatever ticket he got. So while still studying for the UK one he sat the Liberian one. He had to go to Lloyd's Register office in the city and spent three days sitting the all-paper master's exam. 15 papers in all, including rule of the road. He passed by the way and also passed the UK ticket as well.



OOps! Did I say 150 papers... should have said 15 papers! The 150 papers must have thought I was thinking about Extra Masters! ;-)

I guess if you had gone through the enough study for DOT then you should be doing the Liberian also. I remember thinking that it was not just a walk-in... walk-out ticket.


In1981 I was on a Liberian vessel. As you know, the tickets had to displayed on the board. Anyhow, the master, self as the mate, the second mate and third mate. The second mate had a Mate FG DOT and Liberian Mate. But master, self and the 3/M had a Master Liberian. The OM told me that the 3/M had a full Master FG DOT. Floored by that one. The 3/M was in his late 50s and had never sailed higher that 3/M. Sad case. Just could not do the job at all... on the bridge was fine but on deck could not hack it and always sailed on general cargo vessels. Nice fellow.... not booze... just couldn't 'watch'.

Stephen


----------



## slick

All,
Re Orals and the Sextant, I think it was Captain Diston in Hull who liked presenting candidates with the Sextant with an "off the Arc" reading I fell into the trap and was duly admonished, however the next time round I had the sextant off pat!! including the Principles.

Yours aye,

slick


----------



## Farmer John

slick said:


> All,
> Re Orals and the Sextant, I think it was Captain Diston in Hull who liked presenting candidates with the Sextant with an "off the Arc" reading I fell into the trap and was duly admonished, however the next time round I had the sextant off pat!! including the Principles.
> 
> Yours aye,
> 
> slick


When it's on it's off, when it's off it's on, was that the principle?


----------



## slick

Farmer John,
With a micrometer sextant say you can see that the reading is "off the arc" and it is showing say 28' in fact it is 32'... is that right?

Yours aye,

slick


----------



## Farmer John

slick said:


> Farmer John,
> With a micrometer sextant say you can see that the reading is "off the arc" and it is showing say 28' in fact it is 32'... is that right?
> 
> Yours aye,
> 
> slick


At the end of a very long look back, I can definitely say I no longer have a clue. I do have some notes somewhere!


----------



## Stephen J. Card

"When it's on it's off, when it's off it's on, was that the principle?"


28 might 32 confuse for sure!


I guess the principle would "If it is on the arc, remove (less) the error and if it is off the arc, add the error." 

If the value on the micrometer says EXACTLY 28' if it is off the arc then the value should be CORRECTED value should be 32'.... and ADD 32'. Or we just getting a difficult thing to explain!!! ;-)


----------



## Cisco

If your index error is 4' off the arc then it will be 28' + 4' = 32'..........


----------



## Stephen J. Card

I think we are thinking wind the micrometer the direction BACKWARDS.... 

if you wind back to a setting of say 32' then you would be wanting a volume of 28' MINUS.


Byt as you said....endex error.... if off the arc, then add and on the arc then take it off.


----------



## Farmer John

Stephen J. Card said:


> I think we are thinking wind the micrometer the direction BACKWARDS....
> 
> if you wind back to a setting of say 32' then you would be wanting a volume of 28' MINUS.
> 
> 
> Byt as you said....endex error.... if off the arc, then add and on the arc then take it off.


When it's on it's off, when it's off it's on.

I may have no idea what it applies to, but I was well told the rule.


----------



## vasco

it's on it's off said:


> If it is off the arc it is reading less so add it (put it on)
> 
> If it is on the arc it is reading more so subtract it (take it off)
> 
> As for the minus 60 bit I don't remember that, never had an error more than 5 minutes so just counted the divisions.


----------



## 8575

vasco said:


> I am surmising that as the traverse tables are really solving right angle triangles a bit of trig was used to find the angle.
> 
> In the case of the distance, the hypotenuse is 1 (foot) multiply this by the sine of 18 gives you the opposite (dep), 0.3090. Which is roughly the coversion factor (0.3048).
> 
> The constant is the angle, which for more accurate should be 17.75 deg.
> 
> Well, i think it works, what do you think?.
> 
> In latter days using the p-r function was an easy traverse solve on a calculator.


Err! You might be right. In fact you are, it's just that my grey matter is cranking up to take in all the information, digest it and then follow your reasoning. But all is well... ... now if I could remember what Traverse Tables were really for... ...!! (Cloud)


----------



## vasco

That's why I like these little gems, keeps the old brain ticking looking for answers


----------



## 8575

Stability provides many "little gems" for the brain, although I don't think I'll revisit side bilging or Tcherbicheff's Rules (not sure about the spelling of the name)!


----------



## vasco

Waighty said:


> Stability provides many "little gems" for the brain, although I don't think I'll revisit side bilging or Tcherbicheff's Rules (not sure about the spelling of the name)!


That's the thing, it's nice to be able to pick the little gems


----------

