# Curta Mechanical Calculators



## John Campbell (Aug 30, 2005)

A young teenage relation, doing a project for her school, interviewed me the other day. She wanted to know how we did our business at sea, navigating and cargo work, before pocket calculators and computers came along.

I went up to the loft and dug out my CURTA mechanical calculator- this was a great find for the teenager who thought it "very cool" and when we looked up its value on e-bay it costs realize £1000.

I was always an admirer of this device and I could work out a multi grade cargo of white oil in minutes compared to using logs etc.
Any one else used a CURTA.? and still have one.
JC


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## slick (Mar 31, 2006)

Hello John,
If what you are describing looks like a minature cash register and had a rotating handle to the right and weighed a ton (tonne?). They were in regular use in the RFA and when I joined the RFA Orangeleaf Robin Gardner the Chief Officer was a Dab hand at using it and tutored me, by the time I returned to tankers it lay in the locker in the Mates Office unused.
Most people thought it was an aberration on the way to electronic calculators.

Yours aye,

slick


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## John Campbell (Aug 30, 2005)

slick said:


> Hello John,
> If what you are describing looks like a minature cash register and had a rotating handle to the right and weighed a ton (tonne?). They were in regular use in the RFA and when I joined the RFA Orangeleaf Robin Gardner the Chief Officer was a Dab hand at using it and tutored me, by the time I returned to tankers it lay in the locker in the Mates Office unused.
> Most people thought it was an aberration on the way to electronic calculators.
> 
> ...


Hello Slick,
the type of calculator you describe was well known and it was common on nearly all Caltex Tankers and was useful but not so good as the CURTA which was a palm held device. Look it up on
wikipedia.org/wiki/Curta_calculator - 39k 
JC


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## John Crossland (May 11, 2007)

http://en.wikipedia.org/wiki/Curta_calculator


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## R798780 (Oct 27, 2004)

New tanker Luminetta in 1972 had a 'Facit'. Hand cranked and rang a bell, but had push button input and a readout in a window. Next trip I joined the oldest tanker which had a hand cranked device, but the input numbers had to be input by sliding them round on the barrel of the thing. Then crank away the appropriate number of turns. The result was much the same, but a shade slower than the push button job. Promoted to C/o on Lumen next trip I had to use the Facit in anger for calculating cargo and trim. The following trip on Lumiere in 1975 we called at Singapore and I bought an electric brick, a very early Casio calculator. A year later the Facits were all relegated to the cupboard and just gathered dust - except when the new-fangled electronic calculators failed or ran out of batteries, and with LED displays they ate batteries. Then there was a wailing an gnashing of teeth. 'how do you work these things?'.
Happy days


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## Geoff_E (Nov 24, 2006)

"Facit" was the one which sprang to my mind too. They were a BP favourite through until the early '80s. Like Hugh I shelled out on an electronic calculator at the first opportunity.
Never saw or heard of the "Curta" before this thread though!


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## billyboy (Jul 6, 2005)

One chief I sailed with had a calculator which was like two tubes that you rotated. I think he called it a "Blackwall rotary calculator" or something like. Never seen one before or since. Anyone seen one?


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## eriskay (Mar 26, 2006)

Fascinating thread, had not heard of the Curta Calculator until now, Curt Herzstark must have been a very clever man, it seems an ingenious piece of engineering.

Whilst performing contractual Reliability and Performance Tests on large thermal Desalination Plants in the Middle East, in late 60s / early 70s, all the daily noon calcs were done using a slide rule, which gave good accuracy up to two or three decimal places. The consultant representing the Client was difficult to please/convince and invariably I was always having to defend my figures and claim 'foul'. To say the least, it used to get quite heated and my opinion of the relative usefulness or necessaity of highly-paid Consultants diminished with the passage of time. 

The it happened! Early 1970. A new commissioning engineer arrived out on site from the Head Office. This lad was a pure enigma. To say he was not of 'engineer material' would be an understatement. Good lad, but born with a silver spoon, of rich land-owning people, public school, etc, etc. Very posh, airs and graces, but likeable. The memorable bit was when it came to the watchkeeping chores such as logs, calcs, chemistry, etc, his paperwork was immacualte ... and extremely accurate when I covertly checked on it ... but I thought he was taking the Mick when I started to see results expressed to the 4th or 5th decimal place! When I challenged him on his apparent skills with the slide rule, he produced this 'gizmo' and told me it was how he did the calcs. It was a calculator - the first I had ever seen! Texas Instruments manufacture. Very basic model, brick-size, costing at that time around £80 or so. So, with his agreement, I set up the irritating doubting-Thomas of a Consultant one day, having beforehand produced all the results to the 6th decimal place, which he quickly claimed was impossible and that I was simply being facetious. Produced the calculator and that was the last time we got any grief from Mr. Overpaid Consultant !

This is a little off-topic but quasi-related : Don't ask me now where I got it, but in amongst my various artefacts collected over many years I have a clever-looking device called an Admiral Jean Cras Plotter, invented for and used by the French Navy and Air Forces for plotting bearings and courses on a chart. It is manufactured by the French company Topoplastic S.A. of Paris and in French is called a 'Regle-Rapporteur'. Anyone come across this navigation device?


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## Billieboy (May 18, 2009)

Eriskay, did you do any work on the Doha desalination plant in Qatar in about 1975? Wiers Carhcart were the main Contractors.


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## GEORDIE LAD (Sep 6, 2005)

During my days of Rallying in the 60's,the Curta calculator was invaluable.Landlubber version.Cheers....Doug


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## eriskay (Mar 26, 2006)

*Billieboy - Weir Westgarth Desalination Plants*

No - I was over in Abu Dhabi at that time, where we had put in six Plants. The Ras Abu Fontas units in Qatar was one of the few major projects that I was not personally involved with, although I knew the Plants well and was involved in the engineering and contract management side back home. A very good friend and colleague was the Site Manager on the Fontas project.

I was involved a few years later in the Desalination Plant installed at the Qatar Fertiliser Company (QAFCO) at Umm Said, on behalf of Norsk-Hambro.


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## Billieboy (May 18, 2009)

Site manager for Weir was a big Scot, nice bloke, Mac something I think, can't remember his name, too long ago. I was there for two nights I think, got in late and crashed in the compound, had a look around the next day and a couple of meetings, flew out early. It was June I think, dusty, glad to get home.


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